Resist composition, laminate, and pattern formation method

Abstract

Provided is a non-chemically amplified resist composition that is excellent in sensitivity and limit resolution in photolithography using high-energy rays, particularly in electron beam (EB) lithography and EUV lithography. 【Solution means】A resist composition characterized by containing at least one hypervalent iodine compound, a carboxy group-containing compound, and a solvent selected from the following formulas (1), (2), and (3). TIFF2026122764000327.tif33108 (In the formula, n1 is 0 to 2, n2 is 0 to 1, and n3 is 0 to 3. R 11 ~R 13 is a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms. X 1 ~X 3 is *-O-X A1 -, or *-X A2 (-R 14 )-C(=O)-. X A1 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms. X A2 is nitrogen or sulfur. R 14 is a hydrogen atom, a halogen atom, or a hydrocarbyl group having 1 to 20 carbon atoms.)

Description

[Technical Field]

[0001] The present invention relates to a resist composition, a laminate, and a pattern forming method using the resist composition. [Background technology]

[0002] With the expansion of the IoT market, there is an increasing demand for higher integration, higher speed, and lower power consumption in LSIs, leading to rapid miniaturization of pattern rules. Logic devices, in particular, are driving this miniaturization. As cutting-edge miniaturization technology, mass production of 10nm node devices is underway using double, triple, and quadruple patterning in ArF immersion lithography, and further research is progressing on 7nm node devices using next-generation 13.5nm extreme ultraviolet (EUV) lithography.

[0003] As miniaturization progresses, image blurring due to acid diffusion has become a problem (Non-Patent Literature 1). To ensure resolution in fine patterns with processing dimensions of 45 nm or more, it has been suggested that controlling acid diffusion is important, in addition to improving the dissolution contrast as has been conventionally proposed (Non-Patent Literature 2). However, since chemically amplified resist compositions increase sensitivity and contrast through acid diffusion, if acid diffusion is suppressed to the extreme by lowering the post-exposure bake (PEB) temperature or shortening the PEB time, sensitivity and contrast decrease significantly.

[0004] Adding an acid generator that produces bulky acids to suppress acid diffusion is effective. Therefore, copolymerizing an onium salt acid generator with a polymerizable olefin into a polymer has been proposed. However, for pattern formation of resist films with processing dimensions of 16 nm or more, chemically amplified resist compositions are considered insufficient from the standpoint of acid diffusion, and the development of non-chemically amplified resist compositions is desired.

[0005] Polymethyl methacrylate (PMMA) is an example of a material for non-chemically amplified resist compositions. PMMA is a positive-type resist material in which the main chain is cleaved by EUV irradiation, reducing its molecular weight and improving its solubility in organic solvents and developers.

[0006] Hydrogen silsesquioxane (HSQ) is a negative-type resist material that becomes insoluble in alkaline developers due to crosslinking caused by the condensation reaction of silanols induced by EUV irradiation. Chlorine-substituted calixarenes also function as negative-type resist materials. These negative-type resist materials have small molecular sizes before crosslinking and do not blur due to acid diffusion, resulting in low edge roughness and very high resolution. They are used as pattern transfer materials to demonstrate the resolution limit of exposure equipment. However, these materials have insufficient sensitivity and require further improvement.

[0007] One factor that makes material development for EUV lithography difficult is the low number of photons in EUV exposure. The energy of EUV is far higher than that of ArF excimer laser light, and the number of photons in EUV exposure is 1 / 14th of that of ArF exposure. Furthermore, the dimensions of patterns formed by EUV exposure are less than half those of ArF exposure. For this reason, EUV exposure is susceptible to variations in the number of photons. Variations in the number of photons in the ultrashort wavelength synchrotron radiation region are a physical phenomenon called shot noise, and this effect cannot be eliminated. For this reason, so-called stochastics is attracting attention. Although the effect of shot noise cannot be eliminated, how to reduce this effect is being discussed. In addition to increasing dimensional uniformity (CDU) and line width roughness (LWR) due to the effect of shot noise, a phenomenon of hole blockage has been observed with a probability of one in several million. When holes are blocked, it results in poor electrical conductivity and the transistor does not operate, so it negatively affects the overall performance of the device. When considering practical sensitivity, resist compositions primarily composed of PMMA or HSQ are significantly affected by stochastics and have not been able to achieve the desired resolution performance.

[0008] As a method to reduce the effects of shot noise on the resist side, the introduction of elements that strongly absorb EUV light has attracted attention. Patent Document 1 proposes a chemically amplified resist composition containing iodine atoms that strongly absorb EUV light. However, as mentioned above, chemically amplified resist compositions cannot achieve excellent resolution performance in EUV lithography, where processing dimensions will become increasingly miniaturized in the future. In particular, in line-and-space patterns, as the pattern dimensions become smaller, pattern distortion and breaks increase significantly, so reducing these will lead to an improvement in critical resolution.

[0009] Patent Document 2 proposes a negative-type resist composition using a tin compound. Because it mainly consists of tin, which has high absorption of EUV light, it improves stochastics and enables high sensitivity and high resolution. However, so-called metal resists of this type have many problems, such as insufficient solubility in resist solvents, storage stability, and defects due to etching residue. Furthermore, since metal resists are negative-type resists that are insoluble in developer solutions mainly because the exposed areas become metal oxides, an inversion process is required when applied to patterning contact holes, which raises concerns in terms of cost. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2018-5224 [Patent Document 2] Special Publication No. 2021-503482 [Non-patent literature]

[0011] [Non-Patent Document 1] SPIE Vol. 5039 p1 (2003) [Non-Patent Document 2] SPIE Vol. 6520 p65203L-1 (2007) [Overview of the project]

Problems to be Solved by the Invention

[0012] The present invention has been made in view of the above circumstances, and an object thereof is to provide a non-chemically amplified resist composition excellent in sensitivity and limit resolution in photolithography using high-energy rays, particularly EUV lithography, and a laminate and a patterning method using the resist composition.

Means for Solving the Problems

[0013] In order to solve the above problems, in the present invention, A resist composition containing at least one hypervalent iodine compound, a carboxy group-containing compound, and a solvent selected from the following formulas (1), (2), and (3) is provided.

Chemical Formula

[0013] , 3 , 14 , , 13 , , A1 , , , A1 , , 14 , A1 , , 1 , , , 11 , 14 , , A2 , ~R 13 are each independently a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms which may contain a hetero atom. X 1 ~X 3 are each independently *-O-X A1 -, or *-X A2 (-R 14 )-C(=O)-. X 3 may be *-S-X A1 -. X A1 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms which may contain a hetero atom. X A2 is nitrogen or sulfur, and in the case of nitrogen, R 14 may be present. R 14R is a hydrocarbyl group or ester having 1 to 20 carbon atoms, which may contain hydrogen atoms, halogen atoms, or heteroatoms. * represents a bond with the iodine atom in the formula. *1, *2, *3, *4, *5, and *6 represent bonds with the carbon atoms or heteroatoms of the heterocycle in the formula. However, *1, *2, *3, *4, *5, and *6 are bonded to adjacent carbon atoms or heteroatoms of the heterocycle. 21 ~R 24 Each of these is independently a halogen atom, a C1-C40 hydrocarbyl group which may contain heteroatoms, -NH2, -NO2, -SF5, -N(CH3)2, -N(C2H5)2, -OH, or -CN. 22 may be a hydrogen atom. When n1 is 2 or more, each R 21 These may be the same or different from each other, and there may be multiple R 21 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. When n3 is 2 or more, each R 24 These may be the same or different from each other, and there may be multiple R 24 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. 2 R 22 When bonded to a nitrogen atom, R 22 X 2 (That is the case.)

[0014] Such a resist composition would be a non-chemically amplified resist composition with excellent sensitivity and limiting resolution in photolithography using high-energy beams, particularly electron beam (EB) lithography and EUV lithography.

[0015] Furthermore, it is preferable that the carboxyl group-containing compound is either or both a polymer containing repeating units represented by the following formula (4) and a compound represented by the following formula (5). [ka] (In the formula, R AX is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. A This refers to a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A3 - is X A3 is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 20 carbon atoms, and the saturated hydrocarbylene group may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * represents a bond with a carbon atom of the main chain. p is 1, 2, 3, or 4. R 31 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 31 This may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, or a sulfonyl group. Furthermore, some or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group may be substituted with a group containing a heteroatom, and some of the -CH2- of the p-valent hydrocarbon group may be substituted with a group containing a heteroatom. 32 is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They may be the same or they may be different.

[0016] As carboxyl group-containing compounds, those such as the above are particularly suitable for use.

[0017] Furthermore, in this invention, The present invention provides a laminate comprising a substrate and a resist film which is a film formed from the above-mentioned resist composition on the substrate.

[0018] Such a laminate would be a laminate using a non-chemically amplified resist composition that exhibits excellent sensitivity and limiting resolution in photolithography using high-energy beams, particularly electron beam (EB) lithography and EUV lithography.

[0019] Furthermore, the laminate of the present invention may also include a resist underlayer film between the substrate and the resist film.

[0020] The resist composition of the present invention can also be made in this manner if necessary.

[0021] Furthermore, it is preferable that the resist film contains ligand exchange reaction products between the hypervalent iodine compound and the carboxyl group-containing compound.

[0022] Such a resist film offers excellent sensitivity and critical resolution, and can form both positive and negative patterns.

[0023] Furthermore, in this invention, The present invention provides a pattern formation method comprising the steps of: forming a resist film on a substrate or on a resist underlayer of a substrate having a resist underlayer laminated on it using the above-mentioned resist composition; exposing the resist film with high-energy rays; and developing the exposed resist film using a developer.

[0024] Such a pattern formation method provides excellent sensitivity and critical resolution in photolithography using high-energy beams, particularly electron beam (EB) lithography and EUV lithography.

[0025] Furthermore, it is preferable to use i-rays, KrF excimer laser light, ArF excimer laser light, electron beams, or extreme ultraviolet light as the high-energy beam.

[0026] In the pattern formation method of the present invention, these high-energy rays can be used particularly suitably.

[0027] In the pattern formation method of the present invention, it is possible to use a developing solution that dissolves the exposed areas but not the unexposed areas.

[0028] Alternatively, it is possible to use a developing solution that dissolves the unexposed areas but not the exposed areas.

[0029] The resist composition of the present invention can form either positive or negative patterns. [Effects of the Invention]

[0030] The resist composition of the present invention is extremely useful for forming fine patterns, particularly in photolithography using i-line, KrF excimer laser light, ArF excimer laser light, EB, or EUV, as it achieves both high sensitivity and high resolution. [Modes for carrying out the invention]

[0031] As described above, in photolithography using high-energy rays, particularly EUV lithography, there has been a need for the development of non-chemically amplified resist compositions that are excellent in sensitivity and critical resolution, as well as for the development of laminates and pattern formation methods using such resist compositions.

[0032] As a result of diligent research to achieve the above objective, the inventors of the present invention have found that a resist composition mainly composed of a predetermined hypervalent iodine compound and a carboxyl group-containing compound (polymer or monomolecule compound) provides a resist film exhibiting excellent resolution and is extremely effective for precise microfabrication, leading to the present invention.

[0033] In other words, the present invention is a resist composition comprising at least one hypervalent iodine compound selected from the following formulas (1), (2), and (3), a carboxyl group-containing compound, and a solvent. [ka] (In the formula, n1 is 0, 1, or 2, n2 is 0, 1, or 2, and n3 is 0, 1, 2, or 3. R 11 ~R 13 Each of these is independently a C1-C10 hydrocarbyl group which may contain a halogen atom or a heteroatom.1 ~X 3 Each of them is independently, *-OX A1 -, or *-X A2 (-R 14 )-C(=O)-. X 3 is *-SX A1 - It's fine. X A1 This is a carbonyl group, or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. A2 It is nitrogen or sulfur, and in the case of nitrogen, R 14 It may have R 14 R is a hydrocarbyl group or ester having 1 to 20 carbon atoms, which may contain hydrogen atoms, halogen atoms, or heteroatoms. * represents a bond with the iodine atom in the formula. *1, *2, *3, *4, *5, and *6 represent bonds with the carbon atoms or heteroatoms of the heterocycle in the formula. However, *1, *2, *3, *4, *5, and *6 are bonded to adjacent carbon atoms or heteroatoms of the heterocycle. 21 ~R 24 Each of these is independently a halogen atom, a C1-C40 hydrocarbyl group which may contain heteroatoms, -NH2, -NO2, -SF5, -N(CH3)2, -N(C2H5)2, -OH, or -CN. 22 may be a hydrogen atom. When n1 is 2 or more, each R 21 These may be the same or different from each other, and there may be multiple R 21 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. When n3 is 2 or more, each R 24 These may be the same or different from each other, and there may be multiple R 24 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. 2 R 22 When bonded to a nitrogen atom, R 22 X 2 (That is the case.)

[0034] The present invention will be described in detail below, but is not limited thereto. In this specification, when a numerical range is described using endpoints, it includes all values ​​within that range (for example, "0 to 3" includes 0, 1, 2, and 3).

[0035] [Resist composition] The resist composition of the present invention comprises a predetermined hypervalent iodine compound, a carboxyl group-containing compound, and a solvent as its main components.

[0036] [Hypervalent iodine compounds] Hypervalent iodine compounds are a general term for iodine compounds that formally have valence electrons exceeding the octet rule, and include three-coordinate iodine compounds (iodine(III) compounds) with an oxidation state of +3 and five-coordinate iodine compounds (iodine(V) compounds) with an oxidation state of +5.

[0037] The hypervalent iodine compound used as the main component of the resist composition in the present invention is at least one three-coordinate hypervalent iodine compound selected from the following formulas (1), (2), and (3). [ka] (In the formula, n1 is 0, 1, or 2, n2 is 0, 1, or 2, and n3 is 0, 1, 2, or 3. R 11 ~R 13 Each of these is independently a C1-C10 hydrocarbyl group which may contain a halogen atom or a heteroatom. 1 ~X 3 Each of them is independently, *-OX A1 -, or *-X A2 (-R 14 )-C(=O)-. X 3 is *-SX A1 - It's fine. X A1 This is a carbonyl group, or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. A2 It is nitrogen or sulfur, and in the case of nitrogen, R 14 It may have R 14R is a hydrocarbyl group or ester having 1 to 20 carbon atoms, which may contain hydrogen atoms, halogen atoms, or heteroatoms. * represents a bond with the iodine atom in the formula. *1, *2, *3, *4, *5, and *6 represent bonds with the carbon atoms or heteroatoms of the heterocycle in the formula. However, *1, *2, *3, *4, *5, and *6 are bonded to adjacent carbon atoms or heteroatoms of the heterocycle. 21 ~R 24 Each of these is independently a halogen atom, a C1-C40 hydrocarbyl group which may contain heteroatoms, -NH2, -NO2, -SF5, -N(CH3)2, -N(C2H5)2, -OH, or -CN. 22 may be a hydrogen atom. When n1 is 2 or more, each R 21 These may be the same or different from each other, and there may be multiple R 21 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. When n3 is 2 or more, each R 24 These may be the same or different from each other, and there may be multiple R 24 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. 2 R 22 When bonded to a nitrogen atom, R 22 X 2 (That is the case.)

[0038] In the formula, n1 is 0, 1, or 2, n2 is 0, 1, or 2, and n3 is 0, 1, 2, or 3.

[0039] R 11 ~R 13 Each of these is independently a C1-C10 hydrocarbyl group which may contain a halogen atom or a heteroatom.

[0040] R 11 ~R 13 Examples of halogen atoms represented by R include fluorine, chlorine, bromine, and iodine atoms. 11 ~R 13The hydrocarbyl group having 1 to 10 carbon atoms represented by may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 10 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, tert-pentyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, etc.; cyclic saturated hydrocarbyl groups having 3 to 10 carbon atoms such as cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, norbornyl group, tricyclo[5.2.1.0 2,6 decanyl group, adamantyl group, etc.; alkenyl groups such as vinyl group, allyl group, etc.; aryl groups having 6 to 10 carbon atoms such as phenyl group, naphthyl group, etc.; groups obtained by combining these, and the like. Further, some or all of the hydrogen atoms of the hydrocarbyl group may 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 some of -CH2- of the hydrocarbyl group may be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc. As a result, it may contain a hydroxy group, a cyano group, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-O-C(=O)-), etc. R 11 ~R 13 is preferably a hydrocarbyl group having 1 to 4 carbon atoms.

[0041] X 1 ~X 3 are each independently, *-O-X A1 -, or *-X A2 (-R 14 )-C(=O)-. X 3 may be *-S-X A1 -. X A1 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms which may contain a hetero atom. X A2It is nitrogen or sulfur, and in the case of nitrogen, R 14 It may have R 14 This is a hydrocarbyl group or ester having 1 to 20 carbon atoms, which may contain a hydrogen atom, a halogen atom, or a heteroatom. * represents a bond with the iodine atom in the formula.

[0042] *1, *2, *3, *4, *5, and *6 represent carbon atoms of the heterocycle or bonds with heteroatoms in the formula. However, *1, *2, *3, *4, *5, and *6 are bonded to adjacent carbon atoms or heteroatoms of the heterocycle.

[0043] X A1 This is a carbonyl group or a C1-C10 hydrocarbylene group which may contain a heteroatom. The C1-C10 hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkylene groups with 1 to 10 carbon atoms, such as methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-1,3-diyl group, propane-2,2-diyl group, butane-2,3-diyl group, butane-1,4-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, etc.; cyclopentanediyl group, cyclohexanediyl group, norbornanediyl group, adamantanediyl group, tricyclo[5.2.1.0 2,6Examples include cyclic saturated hydrocarbylene groups having 3 to 10 carbon atoms, such as decanediyl groups; alkenylene groups having 2 to 10 carbon atoms, such as vinylene groups and propynylene groups; arylene groups having 6 to 10 carbon atoms, such as phenylene groups, methylphenylene groups, ethylphenylene groups, n-propylphenylene groups, isopropylphenylene groups, n-butylphenylene groups, and naphthylene groups; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, and as a result, it may contain a hydroxyl group, a cyano group, an alkyl halide, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), etc. A1 Preferred members include carbonyl groups, C1-C4 hydrocarbylene groups, or C1-C4 fluorinated hydrocarbylene groups.

[0044] X A2 is nitrogen or sulfur, and in the case of nitrogen, R 14 It may have R 14 R is a hydrocarbyl group or ester having 1 to 20 carbon atoms, which may contain hydrogen atoms, halogen atoms, or heteroatoms. 14 Specific examples of halogen atoms and hydrocarbyl groups represented by R are, respectively. 11 ~R 13 Examples of halogen atoms and hydrocarbyl groups represented by the same symbols as those exemplified are also included.

[0045] R 21 ~R 24 Each of these is independently a halogen atom, a C1-C40 hydrocarbyl group which may contain heteroatoms, -NH2, -NO2, -SF5, -N(CH3)2, -N(C2H5)2, -OH, or -CN. 22 may be a hydrogen atom. When n1 is 2 or more, each R21 These may be the same or different from each other, and there may be multiple R 21 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. When n3 is 2 or more, each R 24 These may be the same or different from each other, and there may be multiple R 24 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded.

[0046] R 21 ~R 24 Examples of halogen atoms represented by R include fluorine, chlorine, bromine, and iodine atoms. 21 ~R 24 The C1-C40 hydrocarbyl group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include C1-C40 alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6Examples include cyclic saturated hydrocarbyl groups having 3 to 40 carbon atoms, such as decanyl groups, adamantyl groups, and adamantylmethyl groups; and aryl groups having 6 to 40 carbon atoms, such as phenyl groups, naphthyl groups, and anthracenyl groups. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, it may contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, carbamate bonds, amide bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc. 21 ~R 24 X can be used to substitute any position in the aromatic ring in the above formula. 2 R 22 When bonded to a nitrogen atom, R 22 X 2 That is the case.

[0047] Specific examples of hypervalent iodine compounds represented by formula (1) are listed below, but are not limited to these. In the following formulas, *1 and *2 are the same as described above.

[0048] [ka]

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[0108] Specific examples of hypervalent iodine compounds represented by formula (2) are listed below, but are not limited to these. In the following formulas, *3 and *4 are the same as described above.

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[0232] Specific examples of hypervalent iodine compounds represented by formula (3) are listed below, but are not limited to these. In the following formulas, *5 and *6 are the same as described above.

[0233] [ka]

[0234] [ka]

[0235] [ka]

[0236] [ka]

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[0239] [ka]

[0240] [ka]

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[0310] [ka]

[0311] [Carboxylate-containing compounds] The carboxyl group-containing compound is preferably a polymer containing repeating units represented by the following formula (4) (carboxyl group-containing polymer) or a compound represented by the following formula (5) (monomolecular compound).

[0312] [ka] (In the formula, R A X is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. A This refers to a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A3 - is X A3 is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 20 carbon atoms, and the saturated hydrocarbylene group may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * represents a bond with a carbon atom of the main chain. p is 1, 2, 3, or 4. R 31 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 31This may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, or a sulfonyl group. Furthermore, some or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group may be substituted with a group containing a heteroatom, and some of the -CH2- of the p-valent hydrocarbon group may be substituted with a group containing a heteroatom. 32 is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They may be the same or they may be different.

[0313] In formula (4), R A X is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. A This refers to a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A3 - is X A3 This is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and the saturated hydrocarbylene group may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * represents a bond with a carbon atom of the main chain.

[0314] In equation (5), p is 1, 2, 3, or 4.

[0315] In formula (5), R 31 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 31 This may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, or a sulfonyl group. Furthermore, some or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group may be substituted with a group containing a heteroatom, and some of the -CH2- of the p-valent hydrocarbon group may be substituted with a group containing a heteroatom.

[0316] In formula (5), R 32 is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They may be the same as or different from each other.

[0317] R 31 The p-valent hydrocarbon group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. The p-valent hydrocarbon group is obtained by removing p hydrogen atoms from a hydrocarbon. Examples of the hydrocarbon include alkanes with 1 to 40 carbon atoms, alkenes with 2 to 40 carbon atoms, alkynes with 2 to 40 carbon atoms, cyclic saturated hydrocarbons with 3 to 40 carbon atoms, cyclic unsaturated hydrocarbons with 3 to 40 carbon atoms, and aromatic hydrocarbons with 6 to 40 carbon atoms.

[0318] Examples of alkanes having 1 to 40 carbon atoms include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and their structural isomers.

[0319] Examples of alkenes having 2 to 40 carbon atoms include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, and their structural isomers.

[0320] Examples of alkynes having 2 to 40 carbon atoms include acetylene, propyne, butyn, pentyn, hexyn, heptyn, octin, nonine, decine, and their structural isomers.

[0321] Examples of the cyclic saturated hydrocarbons having 3 to 40 carbon atoms include cyclopropane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, adamantane, norbornane, and the like.

[0322] Examples of cyclic unsaturated hydrocarbons having 3 to 40 carbon atoms include cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, and norbornene.

[0323] Examples of aromatic hydrocarbons having 6 to 40 carbon atoms include benzene, naphthalene, and biphenyl.

[0324] R 31 The p-valent heterocyclic group represented by is a group obtained by the elimination of p hydrogen atoms from a heterocyclic compound. Examples of such heterocyclic compounds include furan, pyridine, pyrazole, and thiazolidine.

[0325] The p-valent hydrocarbon group or p-valent heterocyclic group may have some or all of its hydrogen atoms substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and as a result may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Furthermore, the p-valent hydrocarbon group may have some of its constituent -CH2- substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result may contain a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), etc.

[0326] R 32The hydrocarbylene group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, and dodecane-1,1 Examples include alkanediyl groups with 1 to 20 carbon atoms, such as 2-diyl groups; cyclic saturated hydrocarbylene groups with 3 to 20 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl groups; unsaturated aliphatic hydrocarbylene groups with 2 to 20 carbon atoms, such as vinylene and propene-1,3-diyl groups; arylene groups with 6 to 20 carbon atoms, such as phenylene and naphthylene groups; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups constituting the hydrocarbylene group may be substituted with a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms, and as a result, the material may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, carbamate bonds, lactone rings, sultone rings, carboxylic acid anhydrides, and the like.

[0327] Among the carboxylic acid compounds represented by formula (5), those in which p is 2, 3, or 4 are preferred. In this case, when mixed with a hypervalent iodine compound, a strong high molecular weight resist film is easily formed, which is preferable from the viewpoint of etching resistance and developer resistance.

[0328] Specific examples of carboxyl group-containing repeating units represented by formula (4) are, but are not limited to, those listed below. Note that in the following formula, R A This is the same as described above.

[0329] [ka]

[0330] [ka]

[0331] Examples of carboxylic acid compounds represented by formula (5) are listed below, but are not limited to these. The carboxylic acid compounds may be commercially available or synthesized.

[0332] [ka]

[0333] [ka]

[0334] [ka]

[0335] [ka]

[0336] [ka]

[0337] [ka]

[0338] A carboxyl group-containing polymer containing repeating units represented by formula (4) may further contain other repeating units (hereinafter also referred to as other repeating units). The other repeating units are not particularly limited, but those that can improve the solubility in solvents of polymers that are poorly soluble with only carboxyl group-containing repeating units are preferred. Preferred other repeating units include repeating units having a rigid skeleton and a cyclic structure that is expected to have high etching resistance, and repeating units containing a styrene skeleton.

[0339] Specific examples of the aforementioned other repeating units include, but are not limited to, those listed below. Note that in the following formula, R A This is the same as above, and X B These are, independently, -CH2- or -O-.

[0340] [ka]

[0341] [ka]

[0342] [ka]

[0343] [ka]

[0344] [ka]

[0345] [ka]

[0346] [ka]

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[0369] [ka]

[0370] In the resist composition of the present invention, the content ratio of the hypervalent iodine compound to the carboxyl group-containing compound (a polymer containing repeating units represented by formula (4) and / or a compound represented by formula (5)) is preferably such that, if the carboxyl group-containing compound is a carboxyl group-containing polymer, it is the content ratio of the hypervalent iodine compound (moles) to the carboxylic acid-containing repeating units (moles) in the polymer; if it is a monomolecule compound represented by formula (5), it is the content ratio of the hypervalent iodine compound (moles) to the monomolecule compound (moles) is preferred in molar ratio, hypervalent 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.

[0371] The hypervalent iodine compound may be used alone or in combination of two or more types. The carboxyl group-containing polymer may be used alone or in combination of two or more types with different composition ratios, weight-average molecular weights (Mw), and / or molecular weight distributions (Mw / Mn). The monomolecule compound may be used alone or in combination of two or more types. The carboxyl group-containing polymer and the monomolecule compound may be used individually or in combination.

[0372] As described later, the hypervalent iodine compound is the main component in the resist composition of the present invention. Therefore, the total amount of the hypervalent iodine compound and the carboxyl group-containing compound is preferably 30 to 100 parts by mass, more preferably 50 to 100 parts by mass, even more preferably 80 to 100 parts by mass, extremely preferably 90 to 100 parts by mass, particularly preferably 95 to 100 parts by mass, and even more preferably 98 to 100 parts by mass, per 100 parts by mass of the total solid content of the resist composition of the present invention.

[0373] In the carboxyl group-containing polymer, the content ratio (molar ratio) of carboxyl group-containing repeating units (repeating units represented by formula (4)) and other repeating units is preferably carboxyl group-containing repeating units:other repeating units = 10:90 to 90:10, more preferably 15:85 to 85:15, and even more preferably 20:80 to 80:20.

[0374] The weight-average molecular weight (Mw) of the carboxyl group-containing polymer is preferably 1,000 to 500,000, more preferably 3,000 to 100,000, and even more preferably 3,000 to 20,000. In this invention, the weight-average molecular weight Mw and the number-average molecular weight Mn are measured values ​​on a standard polystyrene basis by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and the dispersion degree Mw / Mn is the value obtained from these. When measuring GPC, it is usually performed at room temperature around 23 degrees Celsius, but it may also be performed at higher or lower temperatures.

[0375] Furthermore, if the molecular weight distribution (Mw / Mn) of the carboxyl group-containing polymer is broad, low molecular weight and high molecular weight polymers may be present, which may result in the appearance of foreign matter on the pattern or deterioration of the pattern shape after exposure. Therefore, as the pattern rule becomes finer, the influence of Mw and Mw / Mn tends to increase. To obtain a resist composition suitable for fine pattern dimensions, it is preferable that the Mw / Mn of the carboxyl group-containing polymer be narrowly dispersed, between 1.0 and 2.0.

[0376] One method for synthesizing the carboxyl group-containing polymer is to heat a monomer that provides the repeating units mentioned above in an organic solvent with a radical polymerization initiator added, and polymerize it.

[0377] Specific examples of organic solvents used in polymerization reactions 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), and γ-butyrolactone (GBL). Specific examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauroyl peroxide. The amount of polymerization initiator added is preferably 0.01 to 25 mol% of the total amount of 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.

[0378] The polymerization initiator may be added to the monomer solution and supplied to the reaction vessel, or an initiator solution may be prepared separately from the monomer solution and each supplied to the reaction vessel independently. Since the polymerization reaction may proceed and a superpolymer may be formed by radicals generated from the initiator during the waiting time, it is preferable from a quality control viewpoint to prepare the monomer solution and the initiator solution independently and add them dropwise. In addition, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol may be used in combination to adjust the molecular weight. In this case, the amount of the chain transfer agent added is preferably 0.01 to 20 mol% of the total amount of monomers to be polymerized.

[0379] The amount of each monomer in the monomer solution can be appropriately set, for example, to achieve a preferred content ratio of the repeating units described above.

[0380] [solvent] The resist composition of the present invention contains a solvent. The solvent is not particularly limited as long as it can dissolve the hypervalent iodine compound, the carboxyl group-containing compound, and other components, if present, as described later, and form a film.

[0381] Such solvents are preferably organic solvents, and specific examples include ketones such as cyclohexanone, methyl-2-n-pentyl ketone, and methyl isoamyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, 4-methyl-2-pentanol, and methyl 2-hydroxyisobutyrate; propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, Examples include ethers such as 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, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; carboxylic acids such as formic acid, acetic acid, and propionic acid; lactones such as γ-butyrolactone; and mixed solvents thereof.

[0382] In the resist composition of the present invention, the amount of solvent is preferably such that the solid content concentration in the resist composition is 0.1 to 20% by mass, more preferably 0.1 to 15% by mass, and even more preferably 0.1 to 10% by mass. In the present invention, "solid content" refers to all components of the resist composition other than the solvent. The solvent may be used alone or as a mixture of two or more types.

[0383] When the solvent is a combination of two or more types, the combination is not particularly limited, but an aprotic solvent and a protic solvent can be combined. The aprotic solvent can be selected from the above-mentioned ketones, ethers, esters, and lactones, and the protic solvent can be selected from the above-mentioned alcohols and carboxylic acids, with a combination of esters as the aprotic solvent and carboxylic acids as the protic solvent being preferred. When aprotic and protic solvents are combined, the mixing ratio is not particularly limited, but it is preferable that the aprotic solvent accounts for 50 to 90% by mass of the total mass of both, and more preferably 60 to 80% by mass. When the aprotic solvent is within the above range, the balance between the aprotic and protic solvents is favorable, the solubility of the solids in the resist composition is good, the resist composition becomes uniform, and the protic solvent cooperates with the hypervalent iodine compound to improve the resolution of the resist composition.

[0384] [Other ingredients] The resist composition may further contain a surfactant. A fluorine-based and / or silicone-based surfactant is preferred. Examples of such surfactants include those described in paragraph

[0276] of U.S. Patent Application Publication 2008 / 0248425. Furthermore, surfactants other than the fluorine-based and / or silicone-based surfactants described in paragraph

[0280] of U.S. Patent Application Publication 2008 / 0248425 may also be used.

[0385] If the resist composition contains the surfactant, its content is preferably 0.0001 to 2% by mass of the total solids. The surfactant may be used alone or in combination of two or more types.

[0386] The resist composition may further contain a radical scavenger. By adding a radical scavenger, the photoreaction during photolithography can be controlled and the sensitivity adjusted.

[0387] Examples of the radical scavengers include hindered phenols, quinones, hindered amines, and thiol compounds. Specifically, examples of hindered phenols include dibutylhydroxytoluene (BHT) and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). Examples of quinones include 4-methoxyphenol (methoquinone) and hydroquinone. Examples of hindered amines include 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethylpiperidine-N-oxy radical. Examples of thiols include dodecanethiol and hexadecanethiol.

[0388] If the resist composition contains the radical scavenger, its content is preferably 0.01 to 10% by mass of the total solids. The radical scavenger may be used alone or in combination of two or more types.

[0389] The resist composition may further contain a crosslinking agent. Adding a crosslinking agent promotes the crosslinking reaction during photolithography, improving the glass transition temperature of the pattern and resulting in a pattern with excellent resolution at fine lines.

[0390] Examples of crosslinking agents include compounds having carbon-carbon unsaturated bonds as functional groups, such as vinyl groups, (meth)acrylate groups, allyl groups, alkynyl groups, and aromatic rings. Specifically, examples of compounds having vinyl groups include linear alkenes, branched alkenes, and cyclic alkenes, which may have substituents. Examples of compounds having (meth)acrylate groups include acrylic acid, methacrylic acid, acrylic acid esters, and methacrylic acid esters, which may have substituents. Examples of compounds having allyl groups include allyl alcohol, allyl ether, allyl ester, allyl amide, allylamine, and allyl group-containing isocyanurates, which may have substituents. Examples of compounds having alkynyl groups include linear alkynes, branched alkynes, cyclic alkynes, alkynyl alcohol, alkynyl ether, alkynyl ester, alkynyl amide, alkynylamine, and alkynyl group-containing isocyanurates, which may have substituents. Compounds having an aromatic ring include arenes, heteroarenes, styrene, stilbene, phenylacetylene, acenaphthylene, and chalcone, which may have substituents. The crosslinking agent may have only one of the above functional groups or may have multiple of them. The number of above functional groups contained in the crosslinking agent is preferably 1 to 10, and more preferably 2 to 8.

[0391] If the resist composition contains the crosslinking agent, its content is preferably 0.01 to 50% by mass of the total solids. The crosslinking agent may be used alone or in combination of two or more types.

[0392] If the resist composition contains the crosslinking agent, it may further contain a photopolymerization initiator (photoradical generator). The photopolymerization initiator can generate radicals by irradiation with high-energy rays, thereby promoting the crosslinking of the crosslinking agent.

[0393] Specific examples of the aforementioned photopolymerization initiators include benzophenone, benzophenone derivatives such as methyl benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, and fluorenone; 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, and 2-methyl-1-[4-(methylthio)phenyl]-2-morphol Acetophenone derivatives such as nopropan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]-phenyl}-2-methylpropan-1-one, and methyl phenylglyoxylate; thioxanthone derivatives such as thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, and diethylthioxanthone; benzyl, benzyldimethylketal, benzyl Benzyl derivatives such as benzoin-β-methoxyethyl acetal; benzoin derivatives such as benzoin, benzoin methyl ether, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; 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, Oxime compounds such as 2-propanedione-2-(O-benzoyl)oxime, 1,3-diphenylpropanetrione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)]ethanone, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime);α-hydroxyketone compounds such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methylpropane; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl) Examples include α-aminoalkylphenone compounds such as butan-1-one; phosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and titanocene compounds such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium.

[0394] If the resist composition contains the photopolymerization initiator, its content 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, based on the total solid content. A content of 0.1% by mass or more is sufficient to obtain the desired blending effect.

[0395] As described above, the resist composition mainly contains hypervalent iodine compounds and carboxyl group-containing compounds, but does not require acid-unstable group-containing polymers or photoacid generators, as is common in conventional chemically amplified resist compositions. However, the resist composition of the present invention can form a positive-type pattern in which the exposed areas are soluble in the developer, or a negative-type pattern in which the exposed areas are insoluble in the developer, particularly by EB or EUV exposure. The mechanism is not fully clear, but it can be inferred, for example, as follows.

[0396] The hypervalent iodine compounds, represented by formulas (1), (2), or (3), are compounds containing a three-coordinate hypervalent iodine with a carboxylate ligand. It is believed that when such a three-coordinate iodine compound is mixed with a carboxyl group-containing compound, an exchange of carboxylate ligands occurs in an equilibrium reaction. If the original carboxylate ligand can be removed by some method, a hypervalent iodine compound with a new ligand is produced. For example, if the hypervalent iodine compound of formula (1') below is mixed with a carboxyl group-containing compound and the resulting low-boiling point acetic acid is removed, the ligand exchange is completed. Here, the carboxyl group-containing compound becomes a polymer bonded to the hypervalent iodine compound.

[0397] [ka]

[0398] Polymers to which hypervalent iodine compounds are bonded are formed during film formation. This is because even if such polymers are synthesized in advance, they are insoluble in most organic solvents, making it impossible to prepare a solution. This is presumed to be because hypervalent iodine compounds, which inherently have low solvent solubility due to their high polarization, become even less soluble when carboxyl group-containing compounds are used as ligands. Therefore, it is desirable to remove the original low-molecular-weight carboxylic acid component during film formation and the subsequent baking process to complete the ligand exchange reaction and form a resist film.

[0399] The resist film obtained from the resist composition of the present invention undergoes a change in polarity when its main component, a hypervalent iodine compound, is decomposed by light, and a pattern is formed during the development process. Although the mechanism is not fully understood, it is speculated to be as follows. By appropriately selecting the developer, either a positive or negative pattern can be formed.

[0400] The resist composition of the present invention can be either positive or negative depending on the selection of its components. In the case of the positive type, it contains a polymer to which a hypervalent iodine compound is bonded during film formation. When this is decomposed by light, it becomes a monovalent iodine compound, and at the same time, the bond between the carboxyl group-containing compound and the hypervalent iodine compound is released, and the molecular weight decreases. As a result, it is presumed that a positive type pattern is formed in which the exposed areas are removed by an organic solvent.

[0401] On the other hand, in the case of the negative type, the polymer contains a hypervalent iodine compound crosslinked with a hypervalent iodine compound generated during film formation. When this is decomposed by light, crosslinking or re-bonding occurs, leading to an increase in molecular weight and a change in polarity. As a result, it is presumed that a negative type pattern is formed in which the unexposed areas are removed by an alkaline aqueous solution.

[0402] The hypervalent iodine compounds represented by formulas (1), (2), or (3) have one of the thiophene, pyrazole, or pyridine skeletons bonded to the iodine atom. Unlike three-coordinate hypervalent iodine compounds with an aryl group and a carboxylate ligand, these compounds are expected to have a smaller molecular weight, superior solubility in developing solutions, and significantly different photoreactivity. Therefore, they can form highly sensitive patterns with excellent resolution and low roughness.

[0403] The hypervalent iodine compounds represented by formulas (1), (2), or (3) can undergo ligand exchange with a carboxyl group-containing compound at one of the two ligands at the apical position of the hypervalent iodine. Therefore, the crosslinking density of the crosslinked structure after ligand exchange with the carboxyl group-containing compound is lower than that of compounds such as diacetoxyiodothiophene, which can undergo ligand exchange with the carboxyl group-containing compound at two locations in the repeating unit. Consequently, the crosslinking cleavage and bond rearrangement reactions can be carried out with less energy by exposure. Therefore, the resist using the hypervalent iodine compound used in the present invention can form patterns with higher sensitivity compared to resist compositions using hypervalent iodine, such as diacetoxyiodothiophene, which can undergo ligand exchange with the carboxyl group-containing compound at two locations in the repeating unit.

[0404] From the above inference, it can be said that the resist composition of the present invention is a non-chemically amplified resist composition. The resist composition of the present invention does not require acid-unstable group-containing polymers or photoacid generators like conventional chemically amplified resist compositions. Therefore, adverse effects due to acid diffusion (e.g., image blurring) do not occur, and fine patterns can be resolved.

[0405] The resist composition of the present invention is particularly effective in EUV lithography. This is due to the presence of iodine atoms with high absorption capacity for EUV light. That is, shot noise is reduced, and higher resolution and lower LWR can be achieved.

[0406] As a resist composition for EUV lithography capable of forming fine patterns, metal resists mainly composed of metallic tin compounds, which have high absorption capacity for EUV light similar to iodine atoms, have been reported (for example, Patent Document 2). However, as mentioned above, such metal resists have many problems, such as insufficient solubility in solvents, storage stability, and defects due to etching residues caused by the presence of metallic elements. On the other hand, the resist composition of the present invention does not use metallic elements, so it is more advantageous than metal resists in terms of defects, and there are no problems with solubility in solvents. Furthermore, the resist composition of the present invention can be applied to both positive and negative type processes, thus having a wide range of applications. For example, in the contact hole formation process, a metal resist developed using negative type development requires an inversion process after pillar pattern formation, but such a process is unnecessary with positive type resists. Therefore, from the viewpoint of process simplicity, the resist composition of the present invention is more useful than metal resists.

[0407] Japanese Patent Publication No. 2015-180928 and Japanese Patent Publication No. 2018-95853 describe resist compositions containing hypervalent iodine compounds as additives, and resist compositions incorporating hypervalent iodine compounds into the polymer backbone of a base polymer. However, the only characteristic of the resist compositions described in these patent documents is that they can improve line edge roughness, and there is no mention of the possibility of photodegradation of hypervalent iodine compounds or their potential to function as materials for non-chemically amplified resist compositions. Furthermore, according to the descriptions of the amounts used and specific examples, hypervalent iodine compounds are not the main components. Therefore, it is thought that these patent documents do not lead to the idea of ​​a material like the present invention, which can reduce shot noise in EUV lithography and form fine patterns as a material for non-chemically amplified resist compositions. In other words, the present invention clearly provides a novel resist composition and pattern formation method.

[0408] [Laminated structure] The present invention provides a laminate characterized by comprising a substrate and a resist film formed on the substrate, which is a film formed from the resist composition described above. Such a laminate comprising a resist film obtained from the non-chemically amplified resist composition of the present invention is extremely effective for precise microfabrication because the resist film, which is a film formed from the resist composition described above, is extremely sensitive and exhibits excellent resolution. Furthermore, it can be applied to the formation of both positive and negative patterns, thus having a wide range of applications and being extremely useful in resist process technology.

[0409] In this case, a resist underlayer film may be provided between the substrate and the resist film as needed.

[0410] Furthermore, it is preferable that the laminate of the present invention contains a resist film which includes a ligand exchange reaction product between the hypervalent iodine compound and the carboxyl group-containing compound. In other words, the laminate is obtained by forming a resist film obtained from the resist composition of the present invention on a substrate, and it is preferable that the resist film is formed by ligand exchange between the hypervalent iodine compound and the carboxyl group-containing compound.

[0411] As described above, by removing the low molecular weight carboxylic acid produced as a by-product during film formation and the subsequent baking process, the hypervalent iodine compound undergoes a ligand exchange reaction with the carboxyl group-containing compound, forming a resist film containing the ligand exchange reaction product (i.e., giving a film-forming material). Upon completion of the ligand exchange, the carboxyl group-containing compound becomes a polymer crosslinked by the hypervalent iodine compound. Thus, it is preferable to complete the ligand exchange reaction and form a resist film.

[0412] [Pattern formation method] When the resist composition of the present invention is used in the manufacture of various integrated circuits, known lithography techniques can be applied. For example, a pattern formation method may include the steps of forming a resist film on a substrate using the resist composition described above, or on the resist underlayer of a substrate on which a resist underlayer film is laminated; exposing the resist film with high-energy rays; and developing the exposed resist film using a developer. Hereinafter, the resist underlayer film will also be simply referred to as the "underlayer film".

[0413] First, the resist composition of the present invention is applied to a substrate for integrated circuit manufacturing, or onto the underlying layer of a substrate with a laminated underlying layer (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.), or to a substrate for mask circuit manufacturing, or onto the underlying layer of a substrate with a laminated underlying layer (Cr, CrO, CrON, MoSi2, SiO2, etc.) using an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating, so that the coating thickness is 0.01 to 2 μm. This is then pre-baked on a hot plate, preferably at 60 to 200°C for 10 seconds to 30 minutes, more preferably at 80 to 180°C for 30 seconds to 20 minutes, to form a resist film. The underlying layer refers to the film formed between the substrate and the resist film in a multilayer resist process, and the underlying layer is not particularly limited; conventionally known films can be used.

[0414] Next, the resist film is exposed using high-energy rays. Examples of high-energy rays include ultraviolet rays (g-rays (436 nm), h-rays (405 nm), i-rays (365 nm), etc.), far ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer laser light (KrF excimer laser light, ArF excimer laser light, etc.), gamma rays, and synchrotron radiation. Preferably, i-rays, KrF excimer laser light, ArF excimer laser light, electron beams, or extreme ultraviolet rays are used as the high-energy rays. When ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. are used as the high-energy rays, the exposure amount is preferably 1 to 300 mJ / cm², either directly or using a mask to form the desired pattern. 2 To the extent, more preferably 10-200 mJ / cm² 2 Irradiate to a degree that results in the desired exposure. When using electroluminescence (EB) as the high-energy beam, the exposure amount is preferably 0.1 to 8000 μC / cm², either directly or using a mask to form the desired pattern. 2 To a degree, more preferably 0.5 to 5000 μC / cm² 2 The pattern is drawn to a certain extent. Furthermore, the resist composition of the present invention is particularly suitable for fine patterning using EB or EUV, among other high-energy rays.

[0415] After exposure, PEB (Photopolymerization) is performed as needed. In this case, it is preferable to perform the PEB on a hot plate or in an oven at 30-200°C for 10 seconds to 30 minutes, more preferably at 60-180°C for 30 seconds to 20 minutes.

[0416] After exposure or PEB, develop the image using a developer and then perform patterning. The developing solution used at this time is an alkaline aqueous solution such as tetramethylammonium hydroxide aqueous solution or tetrabutylammonium hydroxide aqueous solution; 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutylketone, 5-methyl-2-hexanone, methylcyclohexanone, acetophenone, methylacetophenone, isopropyl alcohol, isoamyl alcohol, n-butanol, tert-butyl alcohol, tert-pentyl alcohol, n-pentanol, cyclohexanol, formic acid, acetic acid, propionic acid, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, cyclohexyl acetate, 4-tert-butylcyclohexyl acetate, octyl acetate, isobornyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotate, chloro Ethyl tonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl phenyl acetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate Examples of organic solvents include zyl, 2-phenylethyl acetate, 1-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-trimethylhexyl alcohol, 2,6-dimethyl-4-heptanol, toluene, anisole, and ε-caprolactone. These developers may be used individually or in mixtures of two or more.

[0417] After development, rinsing is performed as needed. A solvent that mixes with the developer but does not dissolve the resist film is preferred as the rinsing solution. Preferred solvents include C3-C10 alcohols, C8-C12 ether compounds, C6-C12 alkanes, alkenes, alkynes, and aromatic solvents.

[0418] Rinsing can reduce the occurrence of deformation and defects in the resist pattern. However, rinsing is not always necessary, and omitting it can reduce the amount of solvent used.

[0419] As described above, the resist composition of the present invention, upon exposure, creates a difference in solubility between the exposed and unexposed areas, allowing for the formation of positive or negative patterns. Therefore, it is possible to use a developer that dissolves the exposed areas but not the unexposed areas, or vice versa. Thus, the pattern formation method of the present invention can be widely applied to the formation of various fine patterns, as it can form positive or negative patterns by appropriately selecting the developer.

[0420] Thus, the present invention relates to a non-chemically amplified resist composition, characterized in that a heterocyclic hypervalent iodine compound is used as the resist material containing the hypervalent iodine compound. This improves solvent solubility, thereby improving sensitivity, and also increases uniformity, resulting in reduced roughness, making it effective for forming fine patterns. [Examples]

[0421] The present invention will be specifically described below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0422] [1] Synthesis of hypervalent iodine compounds [Synthesis Example 1-1] Synthesis of hypervalent iodine compound I-1 [ka]

[0423] To a solution prepared by dissolving 40 g of Oxon® (potassium peroxymonosulfate) in 40 g of water, a solution prepared by dissolving 28.0 g of the starting compound 4-iodo-1-methylpyrazole-5-carboxylic acid in 40 g of acetonitrile was added dropwise at room temperature. After addition, the mixture was stirred for 2 hours to obtain an oily substance. Diisopropyl ether was added to the resulting reaction solution and the supernatant was removed to obtain the intermediate Int.I-1 as an oily substance (yield 23.8 g, yield 80%). Next, 17 g of Int.I-1 and 27 mL of acetic anhydride were mixed, and the mixture was stirred at 140°C for 2 hours. The reaction solution was then allowed to return to room temperature, and diisopropyl ether was added to the resulting reaction solution and the supernatant was removed to obtain the target hypervalent iodine compound I-1 as a solid (yield 8.5 g, yield 43%).

[0424] [Synthesis Examples 1-2~1-3] Synthesis of hypervalent iodine compounds I-2 and I-3 [ka]

[0425] [ka]

[0426] I-2 and I-3 were synthesized in the same manner as I-1, except that the raw materials were changed as shown in the above formula. (I-2: yield 36%, I-3: yield 22%)

[0427] [2] Synthesis of carboxyl group-containing polymers The monomers a-1 to a-3, b-1 to b-3, and c-1 to c-3 used in the synthesis of the carboxyl group-containing polymer are as follows:

[0428] [ka]

[0429] [ka]

[0430] [ka]

[0431] [Synthesis Example 2-1] Synthesis of Polymer P-1 Under a nitrogen atmosphere, monomer a-1 (56g), monomer b-1 (36g), 5.4g of V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 180g of MEK were placed in a flask to prepare a monomer-polymerization initiator solution. In another flask under a nitrogen atmosphere, 55g of MEK was placed and heated to 80°C with stirring, and then the monomer-polymerization initiator solution was added dropwise over 4 hours. After the addition was complete, the polymerization solution was kept at 80°C and stirred for 2 hours, then cooled to room temperature. The obtained polymerization solution was added dropwise to 4000g of hexane that had been vigorously stirred, and the precipitated polymer was filtered off. The obtained polymer was washed twice with hexane (1200g) and then vacuum-dried at 50°C for 20 hours to obtain a white powdery polymer P-1 (yield 90g, yield 98%). The Mw of polymer P-1 was 8000, and the Mw / Mn ratio was 1.42. Note that Mw and Mn are standard polystyrene equivalent values ​​measured by GPC using THF as the solvent. Specifically, the measurements were taken under the following conditions (the same applies below).

[0432] ·Equipment: HLC-8320GPC • Column: TSK guardcolumn +TSKgel G4000HXL +TSKgel G2000HXL +TSKgel Super H5000 Pump and column constant temperature: 40°C ·Eluent:THF • Detector: RI (Differential Refraction) detector ·Injection volume: 100 μl

[0433] [ka]

[0434] [Synthesis Examples 2-2 to 2-13] Synthesis of Polymers P-2 to P-13 The polymers shown in Table 1 below were synthesized using the same method as in Synthesis Example 2-1, except that the types and mixing ratios of each monomer were changed. Note that polymer P-13 is a polymer that does not have a carboxyl group (-COOH) and therefore does not fall under the category of carboxyl group-containing compounds of the present invention.

[0435] [Table 1]

[0436] [3] Preparation of resist composition [Examples 1-1 to 1-21, Comparative Examples 1-1 to 1-6] Hypervalent iodine compounds and carboxyl group-containing compounds were dissolved in a solvent containing 0.01% by mass of surfactant (PF-636, manufactured by Omnova) with the compositions shown in Table 2 below. The resulting solution was filtered through a 0.2 μm Teflon® filter to prepare the resist compositions of Examples 1-1 to 1-21 (R-01 to R-21) and Comparative Examples 1-1 to 1-4 (CR-01 to CR-04). In addition, polymers, photoacid generators, and sensitivity modifiers were dissolved in a solvent containing 0.01% by mass of surfactant (PF-636, manufactured by Omnova) with the compositions shown in Table 3 below. The resulting solution was filtered through a 0.2 μm Teflon® filter to prepare the resist compositions of Comparative Examples 1-5 to 1-6 (CR-05 to CR-06). The resist composition R-04 of Examples 1-4 combines a pyrazole-type hypervalent iodine compound represented by formula (1) and a thiophene-type hypervalent iodine compound represented by formula (2).

[0437] [Table 2]

[0438] [Table 3]

[0439] In Tables 2 and 3, the hypervalent iodine compounds I-4 and I-5, carboxyl group-containing compounds m-1 to m-6, photoacid generator PAG-1, sensitivity modifiers Q-1 and I-6, and solvent are as follows:

[0440] [ka]

[0441] [ka]

[0442] [ka]

[0443] [ka]

[0444] [ka]

[0445] • Solvent: PGMEA (Propylene glycol monomethyl ether acetate) AcOH (acetic acid) GBL (γ-butyrolactone)

[0446] [4] EUV lithography evaluation (line and space pattern) [Examples 2-1 to 2-21, Comparative Examples 2-1 to 2-6] Each resist composition (R-01 to R-21, CR-01 to CR-06) was spin-coated onto a Si substrate formed with a silicon-containing spin-on hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. to a thickness of 20 nm. A 40 nm thick resist film was then fabricated by post-application baking (PAB) for 60 seconds at the temperature listed in Table 4 using a hot plate. A 36 nm line-and-space (LS) 1:1 pattern was exposed onto the resist film using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9, 90-degree dipole illumination). PEB was then performed on a hot plate for 60 seconds at the temperature listed in Table 4, followed by development for 30 seconds using the developer listed in Table 4 to form an LS pattern with a space width of 18 nm and a pitch of 36 nm.

[0447] The obtained resist patterns were evaluated as follows. The results are shown in Table 4.

[0448] [Sensitivity evaluation] The aforementioned LS pattern was observed using a Hitachi High-Tech SEM (CG-6300) to determine the optimal exposure dose Eop(mJ / cm²) for obtaining an LS pattern with a space width of 18 nm and a pitch of 36 nm. 2 We calculated this value and defined it as the sensitivity.

[0449] [LWR rating] The LS pattern obtained by irradiating with the optimal exposure was measured at 10 points along the longitudinal direction of the space width using a Hitachi High-Tech SEM (CG-6300), and the LWR was calculated as three times the standard deviation (σ) (3σ) from the results. The smaller this value, the less roughness and the more uniform the space width pattern obtained.

[0450] [Evaluation of Limit Resolution] The minimum line width (nm) at which the pattern can be resolved by gradually increasing the exposure from the optimal exposure for forming the aforementioned LS pattern was determined using a Hitachi High-Tech SEM (CG-6300), and this was defined as the limiting resolution (nm). A smaller value indicates superior limiting resolution and the ability to form finer patterns.

[0451] [Table 4]

[0452] Developer: nBA (butyl acetate) TMAH (2.38% by mass tetramethylammonium hydroxide aqueous solution)

[0453] As shown in Table 4, in Examples 2-1 to 2-21, which used the resist composition containing the heterocyclic hypervalent iodine compound of the present invention, it was found that both positive and negative patterns could be formed depending on the developer used. Furthermore, when comparing the resist compositions of Comparative Examples 2-1 and 2-2 with the resist composition of the present invention for positive patterns and negative patterns, it was found that the present invention exhibited superior sensitivity. When comparing the resist compositions of Comparative Examples 2-3 and 2-4 with the resist composition of the present invention, it was found that the present invention exhibited superior sensitivity, resolution, and LWR. It was also found that the present invention exhibited superior sensitivity, resolution, and LWR when compared with Comparative Examples 2-5 and 2-6, which are chemically amplified resist compositions using an acid catalyst reaction. The results of Example 2-4, which used resist composition R-04, show that the combination of heterocyclic hypervalent iodine compounds of the present invention is also effective. Therefore, it was found that the resist composition of the present invention exhibits superior resolution and other properties in LS pattern formation by EUV exposure.

[0454] [5] EUV lithography evaluation (contact hole pattern) [Examples 3-1 to 3-21, Comparative Examples 3-1 to 3-6] Each resist composition (R-01 to R-21, CR-01 to CR-06) was spin-coated onto a Si substrate formed with a silicon-containing spin-on hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. to a thickness of 20 nm. The resist film was then processed using a hot plate at the temperature listed in Table 5 for 60 seconds to produce a resist film with a thickness of 50 nm. Next, the resist film was exposed using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple pole illumination, wafer-mounted dimensions of 64 nm pitch, +20% bias hole pattern mask). The resist film was then processed using a hot plate at the temperature listed in Table 5 for 60 seconds, followed by development using the developer listed in Table 5 for 30 seconds to obtain a hole pattern with dimensions of 32 nm.

[0455] The obtained resist patterns were evaluated as follows. The results are shown in Table 5.

[0456] [Sensitivity evaluation] The aforementioned contact hole pattern was observed using a Hitachi High-Tech SEM (CG-6300) to determine the optimal exposure dose Eop(mJ / cm²) for obtaining a hole pattern with dimensions of 22 nm. 2 We calculated this value and defined it as the sensitivity.

[0457] [CDU Rating] The dimensions of 50 hole patterns obtained by irradiating with the optimal exposure were measured, and the standard deviation (σ) calculated from these results was multiplied by three (3σ) and defined as the CDU. A smaller CDU value indicates a more uniform hole diameter pattern.

[0458] [Evaluation of Limit Resolution] The minimum hole diameter (nm) that can be resolved by gradually decreasing the exposure amount from the optimal exposure amount for forming the aforementioned hole pattern was determined using a Hitachi High-Technologies Corporation length-measuring SEM (CG-6300), and this was defined as the limiting resolution (nm). A smaller value indicates superior limiting resolution and the ability to form patterns with finer hole diameters.

[0459] [Table 5]

[0460] As shown in Table 5, in Examples 3-1 to 3-21, which used the resist composition containing the heterocyclic hypervalent iodine compound of the present invention, it was found that both positive and negative patterns could be formed depending on the developer used. Furthermore, when comparing the resist composition of the present invention with the resist composition of comparative evaluation examples 3-1 and 3-2, it was found to have superior sensitivity. When comparing the resist composition of the present invention with the resist composition of comparative evaluation examples 3-3 and 3-4, it was found to have superior sensitivity and CDU. It was also found to have superior sensitivity, resolution, and CDU when compared with comparative evaluation examples 3-5 and 3-6, which are chemically amplified resists using acid catalyst reactions. From the results of Example 3-4 using resist composition R-04, it was found that the combination of heterocyclic hypervalent iodine compounds of the present invention is also effective. Therefore, it was found that the resist composition of the present invention is excellent in resolution and other properties when forming contact hole patterns by EUV exposure.

[0461] This specification includes the following inventions:

[0462] [1]: A resist composition characterized by comprising at least one hypervalent iodine compound selected from the following formulas (1), (2), and (3), a carboxyl group-containing compound, and a solvent. [ka] (In the formula, n1 is 0, 1, or 2, n2 is 0, 1, or 2, and n3 is 0, 1, 2, or 3. R 11 ~R 13 Each of these is independently a C1-C10 hydrocarbyl group which may contain a halogen atom or a heteroatom. 1 ~X 3 Each of them is independently, *-OX A1 -, or *-X A2 (-R 14 )-C(=O)-. X 3 is *-SXA1 - It's fine. X A1 This is a carbonyl group, or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. A2 It is nitrogen or sulfur, and in the case of nitrogen, R 14 It may have R 14 R is a hydrocarbyl group or ester having 1 to 20 carbon atoms, which may contain hydrogen atoms, halogen atoms, or heteroatoms. * represents a bond with the iodine atom in the formula. *1, *2, *3, *4, *5, and *6 represent bonds with the carbon atoms or heteroatoms of the heterocycle in the formula. However, *1, *2, *3, *4, *5, and *6 are bonded to adjacent carbon atoms or heteroatoms of the heterocycle. 21 ~R 24 Each of these is independently a halogen atom, a C1-C40 hydrocarbyl group which may contain heteroatoms, -NH2, -NO2, -SF5, -N(CH3)2, -N(C2H5)2, -OH, or -CN. 22 may be a hydrogen atom. When n1 is 2 or more, each R 21 These may be the same or different from each other, and there may be multiple R 21 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. When n3 is 2 or more, each R 24 These may be the same or different from each other, and there may be multiple R 24 However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. 2 R 22 When bonded to a nitrogen atom, R 22 X 2 (That is the case.)

[0463] [2]: The resist composition according to [1], characterized in that the carboxyl group-containing compound is either or both a polymer containing repeating units represented by the following formula (4) and a compound represented by the following formula (5). [ka] (In the formula, R AX is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. A This refers to a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A3 - is X A3 is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 20 carbon atoms, and the saturated hydrocarbylene group may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * represents a bond with a carbon atom of the main chain. p is 1, 2, 3, or 4. R 31 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 31 This may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, or a sulfonyl group. Furthermore, some or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group may be substituted with a group containing a heteroatom, and some of the -CH2- of the p-valent hydrocarbon group may be substituted with a group containing a heteroatom. 32 is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They may be the same or they may be different.

[0464] [3]: A laminate characterized by comprising a substrate and a resist film which is a film formed of the resist composition described in [1] or [2] above on the substrate.

[0465] [4]: The laminate according to [3] above, characterized in that it further comprises a resist underlayer film between the substrate and the resist film.

[0466] [5]: The laminate according to [3] or [4] above, characterized in that the resist film contains ligand exchange reaction products of the hypervalent iodine compound and the carboxyl group-containing compound.

[0467] [6]: A pattern forming method comprising the steps of: forming a resist film on a substrate or on a resist underlayer of a substrate having a resist underlayer laminated thereon using the resist composition described in [1] or [2] above; exposing the resist film with a high-energy beam; and developing the exposed resist film using a developer.

[0468] [7]: The pattern formation method according to [6] above, characterized in that the high-energy ray is an i-ray, KrF excimer laser light, ArF excimer laser light, electron beam, or extreme ultraviolet light.

[0469] [8]: The pattern forming method according to [6] or [7] above, characterized in that the developing solution used dissolves the exposed areas but does not dissolve the unexposed areas.

[0470] [9]: The pattern forming method according to [6] or [7] above, characterized in that the developing solution used dissolves the unexposed areas but does not dissolve the exposed areas.

[0471] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. A resist composition characterized by comprising at least one hypervalent iodine compound selected from the following formulas (1), (2), and (3), a carboxyl group-containing compound, and a solvent. 【Chemistry 1】 (wherein, n1 is 0, 1 or 2; n2 is 0, 1 or 2; n3 is 0, 1, 2 or 3. R １１ ~R １３ is each independently a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms which may contain a hetero atom. X １ ~X ３ is each independently *-O-X Ａ１ -, or *-X Ａ２ (-R １４ )-C(=O)-. X ３ is *-S-X Ａ１ -. X Ａ１ is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms which may contain a hetero atom. X Ａ２ is nitrogen or sulfur, and when it is nitrogen, it may have R １４ . R １４ is a hydrogen atom, a halogen atom, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a hetero atom, or an ester. * represents a bond to an iodine atom in the formula. *1, *2, *3, *4, *5 and *6 represent a carbon atom of a heterocyclic ring in the formula or a bond to a hetero atom. However, *1, *2, *3, *4, *5 and *6 are bonded to an adjacent carbon atom of the heterocyclic ring or to a hetero atom. R ２１ ~R ２４ is each independently a halogen atom, a hydrocarbyl group having 1 to 40 carbon atoms which may contain a hetero atom, -NH ２ , -NO ２ , -SF ５ , -N(CH ３ ) ２ , -N(C ２ H ５ ) ２ , -OH, or -CN. R ２２ may be a hydrogen atom. When n1 is 2 or more, each R ２１ may be the same as or different from each other, and a plurality of R ２１ may be bonded to each other to form a ring together with the carbon atom of the heteroaromatic ring to which they are bonded. When n3 is 2 or more, each R ２４ may be the same as or different from each other, and a plurality of R ２４ However, they may bond to each other and form a ring together with the carbon atoms of the heteroaromatic ring to which they are bonded. ２ R ２２ When it bonds with a nitrogen atom to which it is bonded, R ２２ is, X ２ (That is the case.)

2. The resist composition according to claim 1, characterized in that the carboxyl group-containing compound is either or both a polymer containing repeating units represented by the following formula (4) and a compound represented by the following formula (5). 【Chemistry 2】 (In the formula, R Ａ X is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. Ａ This refers to a single bond, a phenylene group, a naphthylene group, or *-C(=O)-O-X Ａ３ - is true. X Ａ３ This is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 20 carbon atoms, and the saturated hydrocarbylene group may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * represents the bond with the carbon atoms of the main chain. p is 1, 2, 3, or 4. R ３１ 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 ３１ This may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, or a sulfonyl group. Furthermore, some or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group may be substituted with a group containing a heteroatom, and the -CH of the p-valent hydrocarbon group ２ - May be partially substituted with a group containing a heteroatom. ３２ This is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom, and the -CH of the hydrocarbylene group ２ - A portion of it may be substituted with a group containing a heteroatom. When p is 2, 3, or 4, each R ３２ They may be the same or different from each other.

3. A laminate characterized by comprising a substrate and a resist film on the substrate which is a film formed from the resist composition described in claim 1 or claim 2.

4. The laminate according to claim 3, characterized in that it further comprises a resist underlayer film between the substrate and the resist film.

5. The laminate according to claim 3, characterized in that the resist film contains a ligand exchange reaction product between the hypervalent iodine compound and the carboxyl group-containing compound.

6. A pattern forming method characterized by comprising the steps of: forming a resist film on a substrate or on a resist underlayer of a substrate having a resist underlayer laminated thereon using the resist composition according to claim 1 or claim 2; exposing the resist film with a high-energy beam; and developing the exposed resist film using a developer.

7. The pattern formation method according to claim 6, characterized in that i-rays, KrF excimer laser light, ArF excimer laser light, electron beams, or extreme ultraviolet light are used as the high-energy rays.

8. The pattern forming method according to claim 6, characterized in that the developing solution used dissolves the exposed areas but not the unexposed areas.

9. The pattern forming method according to claim 7, characterized in that the developing solution used dissolves the exposed areas but does not dissolve the unexposed areas.

10. The pattern forming method according to claim 6, characterized in that the developing solution used dissolves the unexposed areas but not the exposed areas.

11. The pattern forming method according to claim 7, characterized in that the developing solution used dissolves the unexposed areas but not the exposed areas.

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