Resist composition, laminate, and pattern formation method

Abstract

The present invention provides a resist composition capable of achieving high sensitivity and high resolution in a pattern formation method, a laminate comprising a resist film obtained from the resist composition, and a pattern formation method using the resist composition. [Solution] A resist composition characterized by comprising a hypervalent iodine compound of a specific structure and a solvent.

Description

[Technical Field]

[0001] The present invention relates to a resist composition, a laminate, and a pattern forming method. [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 the conventionally proposed improvement of dissolution contrast (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 smaller in the future.

[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, its stochastics are improved, enabling 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.

[0010] In contrast, Patent Document 3 proposes a positive-type resist composition using a hypervalent iodine compound. Because it contains iodine elements that have high absorption of EUV light, it improves stochastics similar to metal resists, enabling high sensitivity and high resolution. Furthermore, since it is composed only of organic molecules, it can improve upon the problems of metal resists, such as developer solubility and defects caused by residue. However, its performance as a resist material is still not satisfactory, and there is a need to develop resist materials that are useful for forming even finer patterns. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2018-005224 [Patent Document 2] Special Publication No. 2021-503482 [Patent Document 3] Japanese Patent Publication No. 2023-167368 [Non-patent literature]

[0012] [Non-Patent Document 1] SPIE Vol.5039 p1 (2003) [Non-Patent Document 2] SPIE Vol.6520 p65203L-1 (2007) [Overview of the project] [Problems that the invention aims to solve]

[0013] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that can achieve high sensitivity and high resolution in a pattern formation method, a laminate comprising a resist film obtained from the resist composition, and a pattern formation method using the resist composition. [Means for solving the problem]

[0014] To solve the above problems, the present invention provides a resist composition comprising a hypervalent iodine compound represented by the following general formula (1) and a solvent. [ka] (In the formula, m is an integer between 0 and 2, n is an integer between 1 and 40, and k is an integer between 0 and (2m+4). Each m and each k may be the same or different.) R 11 This is a carbonyl group or a hydroxylene group having 1 to 40 carbon atoms, which may contain a heteroatom. 11 They may be the same as or different from each other. R 12 This is a carbonyl group or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. 12 They may be the same as or different from each other. R 13 This is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a halogen atom or a heteroatom. Each R 13 They may be the same or different from each other.

[0015] The resist composition of the present invention has iodine atoms with high absorption capacity for EUV light. Furthermore, the resist composition used in the present invention contains a hypervalent iodine compound represented by the above general formula (1) and a solvent, and does not necessarily contain the carboxylic acid compound that is essential in Patent Document 3. As a result, the resist composition of the present invention can form a resist film with a uniform material distribution and high density, and the LWR and resolution performance are further improved compared to conventional non-chemically amplified resists. In other words, due to these characteristics, the resist composition of the present invention can achieve high sensitivity, high resolution, and low LWR in pattern formation methods.

[0016] Furthermore, in the present invention, the laminate comprises a substrate and A resist film obtained from the resist composition described above on the substrate and The present invention provides a laminate that is equipped with the following features.

[0017] In the laminate of the present invention, which comprises a resist film obtained from the resist composition of the present invention, the resist film exhibits high sensitivity and excellent limiting resolution, making it effective for precise microfabrication. Furthermore, it can be applied to the formation of both positive and negative patterns. Therefore, the laminate of the present invention has a wide range of applications and is highly useful in resist process technology.

[0018] In this case, the laminate may further include a resist underlayer film between the substrate and the resist film.

[0019] If a resist underlayer is required for pattern formation, the resist underlayer can be appropriately placed between the substrate and the resist film.

[0020] Furthermore, the present invention provides a pattern forming method, A step of forming a resist film on a substrate, or on the resist underlayer of a substrate having a resist underlayer laminated thereon, using the resist composition described above, The process involves exposing the resist film with high-energy rays, The process involves developing the exposed resist film using a developer solution. The present invention provides a pattern formation method that includes [specific details].

[0021] With this pattern formation method of the present invention, high sensitivity, high resolution, and low LWR can be achieved because the resist composition of the present invention is used.

[0022] Furthermore, in the present invention, i-rays, KrF excimer laser light, ArF excimer laser light, electron beams, or extreme ultraviolet light can be used as the high-energy rays.

[0023] Various types of high-energy rays can be used, as described above.

[0024] Furthermore, in the present invention, a developing solution that dissolves the exposed areas but not the unexposed areas can be used.

[0025] Alternatively, the developing solution used may be one that dissolves the unexposed areas but not the exposed areas.

[0026] Thus, the pattern forming method of the present invention can be applied to the formation of both positive and negative patterns. [Effects of the Invention]

[0027] As described above, the resist composition of the present invention can achieve both high sensitivity and high resolution in pattern formation methods, such as photolithography using high-energy beams, particularly electron beam (EB) lithography and extreme ultraviolet (EUV) lithography. Therefore, the resist composition of the present invention is extremely useful for forming fine patterns.

[0028] Furthermore, the laminate of the present invention can be applied to the formation of both positive and negative patterns, has a wide range of applications, and is highly useful in resist process technology.

[0029] Furthermore, the pattern forming method of the present invention can achieve both high sensitivity and high resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the laminate of the present invention. MODES FOR CARRYING OUT THE INVENTION

[0031] As described above, there has been a demand for the development of a resist composition capable of achieving both high sensitivity and high resolution in a pattern forming method.

[0032] As a result of intensive studies on the above problems, the present inventors have found that a resist composition containing a predetermined hypervalent iodine compound as a main component provides a resist film having extremely high sensitivity and excellent resolving power, and is extremely effective for precise microfabrication, which has led to the completion of the present invention.

[0033] That is, the present invention provides a resist composition containing a hypervalent iodine compound represented by the following general formula (1) and a solvent. Chemical formula (In the formula, m is an integer of 0 to 2, n is an integer of 1 to 40, and k is an integer of 0 to (2m+4). Each m and each k may be the same as or different from each other. R 11 is a carbonyl group or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a hetero atom. Each R 11 may be the same as or different from each other. R 12 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms which may contain a hetero atom. Each R 12 may be the same as or different from each other. R 13This is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a halogen atom or a heteroatom. Each R 13 They may be the same or different from each other.

[0034] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0035] [Resist composition] The resist composition of the present invention mainly comprises a hypervalent iodine compound represented by the following general formula (1) and a solvent. [ka] (In the formula, m is an integer between 0 and 2, n is an integer between 1 and 40, and k is an integer between 0 and (2m+4). Each m and each k may be the same or different.) R 11 This is a carbonyl group or a hydroxylene group having 1 to 40 carbon atoms, which may contain a heteroatom. 11 They may be the same as or different from each other. R 12 This is a carbonyl group or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. 12 They may be the same as or different from each other. R 13 This is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a halogen atom or a heteroatom. Each R 13 They may be the same or different from each other.

[0036] As described above, the resist composition of the present invention mainly contains a hypervalent iodine compound represented by the general formula (1) above. On the other hand, the resist composition of the present invention does not necessarily have to contain polymers or photoacid generators as contained in conventional chemically amplified resist compositions. However, the resist composition of the present invention can form a positive or negative pattern, particularly through EB or EUV exposure, due to a difference in solubility between the exposed and unexposed areas. The mechanism is not fully clear, and we do not wish to be bound by theory, but it can be inferred, for example, as follows.

[0037] The hypervalent iodine compound represented by the above general formula (1) is a cyclic oligomer consisting of a three-coordinate hypervalent iodine atom compound. Because such hypervalent iodine compounds have a relatively large molecular size, a homogeneous resist film can be formed on a substrate even without containing the carboxylic acid compound that is considered essential in Patent Document 3 as a resist composition.

[0038] The resist film of the present invention, formed on a substrate, changes polarity when its main component, a hypervalent iodine compound, is decomposed by light, and a pattern is formed during the development process. By appropriately selecting the developer, either a positive or negative pattern can be formed.

[0039] 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, the hypervalent iodine compound represented by the above general formula (1) is decomposed by light, becoming a monovalent iodine compound, and at the same time, the oligomer structure 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.

[0040] On the other hand, in the case of a negative pattern, the hypervalent iodine compound represented by the above general formula (1) is decomposed by light, causing crosslinking or re-bonding, which leads to an increase in molecular weight and a change in polarity. As a result, it is presumed that a negative pattern is formed in which the unexposed areas are removed by the alkaline aqueous solution.

[0041] From the above inference, it can be said that the resist composition of the present invention is a non-chemically amplified resist composition. Since the resist composition of the present invention does not require an acid-unstable group-containing base polymer or a photoacid generator like conventional chemically amplified resist compositions, adverse effects due to acid diffusion (e.g., image blurring) do not occur, and fine patterns can be resolved.

[0042] The resist composition of the present invention is particularly effective in EUV lithography. This is because the resist composition of the present invention has iodine atoms with high absorption capacity for EUV light, and does not require the carboxylic acid compounds that are essential in Patent Document 3. As a result, it is possible to form a resist film with a uniform material distribution and high density, and it has the characteristic of further improving LWR and resolution performance compared to conventional non-chemically amplified resists. In other words, due to these characteristics, the resist composition of the present invention can achieve high sensitivity, high resolution, and low LWR in pattern formation methods.

[0043] 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.

[0044] Japanese Patent Publication No. 2015-180928 and Japanese Patent Publication No. 2018-095853 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, these patent documents only state that the resist compositions can improve line edge roughness as a characteristic of the resist compositions, and do not mention 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. Furthermore, while Patent Document 3 proposes a positive-type resist composition using a hypervalent iodine compound, it does not describe the hypervalent iodine compound represented by the above general formula (1) of the present invention. It does not mention the effect that by using an oligomer of a hypervalent iodine compound, as in the present invention, it is not necessary to include the carboxylic acid compound that is essential in Patent Document 3, and a uniform material distribution and high-density resist film can be formed, resulting in further improvements in LWR and resolution performance compared to conventional non-chemically amplified resists. Therefore, it is thought that these patent documents do not lead to the idea of ​​a non-chemically amplified resist composition that is extremely sensitive, exhibits excellent resolution, and is extremely effective for precise microfabrication, as in the present invention. In other words, the present invention clearly provides a novel resist composition and pattern formation method.

[0045] The components of the resist composition of the present invention will be described below.

[0046] [Hypervalent iodine compounds] The hypervalent iodine compound represented by the following general formula (1) is a cyclic oligomer of a three-coordinate hypervalent iodine compound. [ka] (In the formula, m is an integer between 0 and 2, n is an integer between 1 and 40, and k is an integer between 0 and (2m+4). Each m and each k may be the same or different.) R 11This is a carbonyl group or a hydroxylene group having 1 to 40 carbon atoms, which may contain a heteroatom. 11 They may be the same as or different from each other. R 12 This is a carbonyl group or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. 12 They may be the same as or different from each other. R 13 This is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a halogen atom or a heteroatom. Each R 13 They may be the same or different from each other.

[0047] In the above general formula (1), m is an integer between 0 and 2, n is an integer between 1 and 40, and k is an integer between 0 and (2m+4). m is preferably between 0 and 1, and particularly preferably 0. n is preferably between 1 and 10, more preferably between 1 and 4, even more preferably between 1 and 2, and most preferably 1. k is preferably between 0 and 8, more preferably between 0 and 6, even more preferably between 0 and 4, even more preferably between 0 and 2, and most preferably 0 or 1. Each m and each k may be the same as or different from each other.

[0048] In the above general formula (1), R 11This is a carbonyl group or a C1-C40 hydrocarbylene group which may contain a heteroatom. The C1-C40 hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkylene groups with 1 to 40 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 2,6 Examples include cyclic saturated hydrocarbylene groups having 3 to 40 carbon atoms, such as decanediyl groups; alkenylene groups having 2 to 40 carbon atoms, such as vinylene groups and propynylene groups; arylene groups having 6 to 40 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 heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, 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. 11 Preferably, the carbonyl group, the C1-C10 hydrocarbylene group, or the C1-C10 fluorinated hydrocarbylene group are used. 11 They may be the same as or different from each other.

[0049] In the above general formula (1), R 12 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 2,6 Examples 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 heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, 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. 12 Preferably, the carbonyl group, the 1-4 carbon dioxide hydrocarbylene group, or the 1-4 carbon dioxide fluorinated hydrocarbylene group are used. 12They may be the same as or different from each other.

[0050] In the above general formula (1), R 13 This is a C1-C40 hydrocarbyl group which may contain a halogen atom or a heteroatom. Specific examples of the halogen atom include fluorine, chlorine, bromine, and iodine atoms. The C1-C40 hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C40 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl groups; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6 Examples 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, the group may contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, carbamate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc. Each R 13 These may be the same or different from each other. Also, multiple Rs 13 However, they may bond with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0051] Specific examples of hypervalent iodine compounds represented by the general formula (1) above include, but are not limited to, those listed below. In the formula below, Me is a methyl group and Ph is a phenyl group.

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] [ka]

[0063] [ka]

[0064] [Method for producing hypervalent iodine compounds] The hypervalent iodine compounds used in this invention can be obtained by known methods. For example, they can be obtained by preparing a 2-iodobenzamide derivative from a 2-iodobenzoic acid derivative and an amino acid derivative, and then oxidatively cyclizing it with an oxidizing agent such as m-chloroperbenzoic acid. For synthesis methods, see, for example, J.Mater.Chem.C, 2025, vol.13, pp.842-848.

[0065] In the resist composition of the present invention, the hypervalent iodine compound represented by general formula (1) is preferably included in an amount of 0.01 to 50% by mass, more preferably 0.01 to 10% by mass, and particularly preferably 1 to 10% by mass, in the total resist composition including the solvent. The hypervalent iodine compound represented by general formula (1) may be used alone or in a mixture of two or more types.

[0066] [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 represented by the above general formula (1) and other components described later, and can form a resist film when included in the resist composition. 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, and 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.

[0067] 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.

[0068] [Other ingredients] The resist composition of the present invention may further contain a surfactant. A fluorine-based and / or silicone-based surfactant is preferred. Specific 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.

[0069] If the resist composition of the present invention contains the surfactant, its content is preferably 0.0001 to 2% by mass of the total solids. One surfactant may be used alone, or two or more may be used in combination.

[0070] The resist composition of the present invention may further contain at least one selected from radical scavengers, crosslinking agents, carboxyl group-containing compounds, and other hypervalent iodine compounds. This allows for control of the photoreaction during photolithography and adjustment of sensitivity.

[0071] Specific examples of the radical scavengers include hindered phenols, quinones, hindered amines, and thiol compounds. Specific examples of hindered phenols include dibutylhydroxytoluene (BHT) and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). Specific examples of quinones include 4-methoxyphenol (methoquinone) and hydroquinone. Specific examples of hindered amines include 2,2,6,6-tetramethylpiperidine-N-oxy radical. Specific examples of thiols include dodecanethiol and hexadecanethiol.

[0072] If the resist composition of the present invention contains the radical scavenger, its content is preferably 0.01 to 10% by mass of the total solid content. One radical scavenger may be used alone, or two or more may be used in combination.

[0073] Specific examples of the crosslinking agent include compounds having carbon-carbon unsaturated bonds as functional groups, such as vinyl groups, (meth)acrylate groups, allyl groups, alkynyl groups, and aromatic rings. Specific examples of compounds having a vinyl group include linear alkenes, branched alkenes, and cyclic alkenes, which may have substituents. Specific examples of compounds having a (meth)acrylate group include acrylic acid, methacrylic acid, acrylic acid esters, and methacrylic acid esters, which may have substituents. Specific examples of compounds having an allyl group include allyl alcohol, allyl ether, allyl ester, allyl amide, allylamine, and allyl group-containing isocyanurates, which may have substituents. Specific examples of compounds having an alkynyl group 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. Specific examples of compounds having the aromatic ring include arenes, heteroarenes, styrene, stilbene, phenylacetylene, acenaphthylene, and chalcone, which may have substituents. The crosslinking agent may have only one of the functional groups, or it may have multiple functional groups. The number of functional groups contained in the crosslinking agent is preferably 1 to 10, and more preferably 2 to 8.

[0074] If the resist composition of the present invention 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.

[0075] The resist composition of the present invention may optionally contain a carboxyl group-containing compound. When the carboxyl group-containing compound is included, it is preferable that the carboxyl group-containing compound is a polymer containing repeating units represented by the following general formula (2), or a compound represented by the following general formula (3). [ka] (In the formula, R A This is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. X A This is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A1 - is X A1 This is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 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. 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. 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 or different from each other.

[0076] In the above general formula (2), R A X is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. A This is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A1 - is X A1This is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 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.

[0077] In the above general formula (3), p is 1, 2, 3, or 4.

[0078] In the above general formula (3), 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.

[0079] In the above general formula (3), R 32 is a single bond or a hydrocarbylene group having 1 to 10 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.

[0080] 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 a group obtained by the removal of 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.

[0081] Examples of the aforementioned alkanes having 1 to 40 carbon atoms include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and their structural isomers.

[0082] Examples of alkenes having 2 to 40 carbon atoms include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, and their structural isomers.

[0083] Examples of alkynes having 2 to 40 carbon atoms include acetylene, propyne, butyne, pentine, hexine, heptine, octin, nonine, decine, and their structural isomers.

[0084] Examples of the cyclic saturated hydrocarbons having 3 to 40 carbon atoms include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, adamantane, norbornane, and the like.

[0085] Examples of the cyclic unsaturated hydrocarbons having 3 to 40 carbon atoms include cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, and norbornene.

[0086] Examples of the aforementioned aromatic hydrocarbons having 6 to 40 carbon atoms include benzene, naphthalene, and biphenyl.

[0087] 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 thiazolidinediones.

[0088] 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.

[0089] 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.

[0090] Of the carboxylic acid compounds represented by the above general formula (3), those in which p is 2, 3, or 4 are preferred. Such carboxylic acid compounds readily form a high molecular weight, robust resist film when mixed with hypervalent iodine compounds, and are preferred from the viewpoint of etching resistance and developer resistance.

[0091] Specific examples of repeating units represented by the general formula (2) above are shown below, but are not limited to these. Note that in the formula below, R A This is the same as described above.

[0092] [ka]

[0093] [ka]

[0094] Examples of carboxylic acid compounds represented by the above general formula (3) include, but are not limited to, those listed below.

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] A polymer containing the repeating unit represented by the above general formula (2) may further contain repeating units other than the repeating unit represented by the above general formula (2) (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 a polymer that is poorly soluble with only the repeating unit represented by the above general formula (2) are preferred. The other repeating units are preferably repeating units having a rigid skeleton and a cyclic structure that is expected to have high etching resistance, or repeating units containing a styrene skeleton.

[0102] 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-.

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109]

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[0110]

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[0116]

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[0117]

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[0119]

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[0121]

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[0131] [ka]

[0132] [ka]

[0133] When the resist composition of the present invention contains a carboxyl group-containing compound as an optional component, the content ratio of the hypervalent iodine compound represented by general formula (1) to the carboxyl group-containing compound (or, if the carboxyl group-containing compound is a carboxyl group-containing polymer, the content ratio of the hypervalent iodine compound represented by general formula (1) to the repeating units having carboxyl groups in the polymer) is preferably, in molar ratio, 100:0 to 50:50, more preferably 100:0 to 60:40, and even more preferably 100:0 to 80:20. The hypervalent iodine compound represented by general formula (1) may be used alone or in combination of two or more types. Similarly, the carboxyl group-containing compound may be used alone or in combination of two or more types. If the carboxyl group-containing compound is a polymer, it may be used alone or in combination of two or more types with different composition ratios, Mw and / or Mw / Mn.

[0134] In the carboxyl group-containing polymer, the content ratio (molar ratio) of repeating units having carboxyl groups and other repeating units is preferably 10:90 to 90:10 for repeating units having carboxyl groups and other repeating units, more preferably 15:85 to 85:15, and even more preferably 20:80 to 80:20.

[0135] The weight-average molecular weight (Mw) of the carboxyl group-containing polymer is preferably 1,000 to 500,000, and more preferably 3,000 to 100,000. In this invention, the weight-average molecular weight Mw and the number-average molecular weight Mn are measured in polystyrene equivalents by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0136] The molecular weight distribution Mw / Mn can be determined from the Mw and Mn thus obtained. Furthermore, if the molecular weight distribution (Mw / Mn) of the carboxyl group-containing polymer is broad, there may be polymers with lower molecular weights or higher molecular weights compared to Mw, which may result in foreign matter being observed on the pattern or deterioration of the pattern shape after exposure. For this reason, as the pattern rule becomes finer, the influence of Mw and Mw / Mn tends to increase. Therefore, in order 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 1.00 and 2.00. It is preferable that Mw / Mn be greater than 1.30, with a lower limit of 1.40, 1.50, or 1.60, and an upper limit of 1.70, 1.80, or 1.90.

[0137] 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.

[0138] 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 radical 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 radical 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.

[0139] The radical 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 supplied to the reaction vessel independently. Since the polymerization reaction may proceed due to radicals generated from the initiator during the waiting time, potentially producing a superpolymer, 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.

[0140] 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.

[0141] The resist composition of the present invention may further contain, as an optional component, other hypervalent iodine compounds other than the hypervalent iodine compound represented by general formula (1) above. By adding other hypervalent iodine compounds, the reactivity to light can be controlled and the sensitivity can be adjusted. As other hypervalent iodine compounds, hypervalent iodine compounds represented by the following general formula (4) or (5) (hereinafter also referred to as other hypervalent iodine compounds) are preferred. [ka] (In the formula, m1 and m2 are integers between 0 and 2.) n1 is an integer between 0 and 4 when m1 is 0, an integer between 0 and 6 when m1 is 1, and an integer between 0 and 8 when m1 is 2. When m2 is 0, n2 is an integer between 1 and 3, and n3 is an integer between 0 and 5, satisfying 1 ≤ (n2 + n3) ≤ 6. When m2 is 1, n2 is an integer between 1 and 3, n3 is an integer between 0 and 7, and 1 ≤ (n2 + n3) ≤ 8. When m2 is 2, n2 is an integer between 1 and 3, n3 is an integer between 0 and 9, and 1 ≤ (n2 + n3) ≤ 10. R 41 This is a hydrocarbyl group having 1 to 10 carbon atoms, which may contain a halogen atom or a heteroatom. R 42 This is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a halogen atom or a heteroatom. When n1 is 2 to 8, each R 42 These may be the same or different from each other. Also, multiple Rs 42 However, they may bond with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded. R 43 This is a carbonyl group or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. *3 and *4 represent the bonds with the carbon atoms of the aromatic ring in the formula. However, *3 and *4 must be bonded to adjacent carbon atoms of the aromatic ring. R 51 and R 52Each of these is independently a C1-C10 hydrocarbyl group which may contain a halogen atom or a heteroatom. 51 and R 52 However, they may bond with each other to form a ring together with the carbon atoms to which they are bonded and the atoms between those carbon atoms. R 53 This is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a halogen atom or a heteroatom. When n3 is 2 to 9, each R 53 These may be the same or different from each other. Also, multiple Rs 53 However, they may bond with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0142] In the above general formula (4), m1 is an integer between 0 and 2. When m1 is 0, n1 is an integer between 0 and 4; when m1 is 1, n1 is an integer between 0 and 6; and when m1 is 2, n1 is an integer between 0 and 8. n1 is preferably 0, 1, 2, 3, or 4; more preferably 0, 1, 2, or 3; even more preferably 0, 1, or 2; and most preferably 0 or 1.

[0143] In the above general formula (4), R 41 This is a C1-C10 hydrocarbyl group which may contain halogen atoms or heteroatoms. Specific examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. The C1-C10 hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C10 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl groups; 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 10 carbon atoms, such as decanyl groups and adamantyl groups; alkenyl groups having 2 to 10 carbon atoms, such as vinyl groups and allyl groups; aryl groups having 6 to 10 carbon atoms, such as phenyl groups and naphthyl groups; and groups obtained by combining these. 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- groups of the hydrocarbyl group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, the group may contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, carbamate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc. 41 Preferably, the group is a hydrocarbyl group having 1 to 4 carbon atoms or a fluorinated hydrocarbyl group having 1 to 4 carbon atoms, and more preferably a hydrocarbyl group having 1 to 4 carbon atoms.

[0144] In the above general formula (4), R 42 This is a C1-C40 hydrocarbyl group which may contain a halogen atom or a heteroatom. Specific examples of the halogen atom include fluorine, chlorine, bromine, and iodine atoms. The C1-C40 hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C40 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl groups; 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, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc. When n1 is 2 to 8, each R 42 These may be the same or different from each other. Also, multiple Rs 42 However, they may bond with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0145] In the above general formula (4), R 43 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 heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- of the hydrocarbylene group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, 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. 43 Preferred members include carbonyl groups, C1-C4 hydrocarbylene groups, or C1-C4 fluorinated hydrocarbylene groups.

[0146] In the general formula (4) above, *3 and *4 represent the bonds with the carbon atoms of the aromatic ring in the formula. However, *3 and *4 are bonded to adjacent carbon atoms of the aromatic ring. There are seven possible combinations of *3, *4, and m1, as shown below. [ka] (In the formula, n1, R 42 , and R 43 This is the same as above. The dashed line is R 41 (This represents a bond between -C(=O)-O-.)

[0147] Specific examples of hypervalent iodine compounds represented by the general formula (4) above include, but are not limited to, those listed below. In the following formulas, Me represents a methyl group.

[0148] [ka]

[0149]

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[0150]

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[0151]

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[0152]

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[0153]

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[0154]

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[0155]

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[0201]

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[0202] [ka]

[0203] [ka]

[0204] In the general formula (5) above, m2 is an integer between 0 and 2. When m2 is 0, n2 is an integer between 1 and 3, n3 is an integer between 0 and 5, and 1 ≤ (n2 + n3) ≤ 6. When m2 is 1, n2 is an integer between 1 and 3, n3 is an integer between 0 and 7, and 1 ≤ (n2 + n3) ≤ 8. When m2 is 2, n2 is an integer between 1 and 3, n3 is an integer between 0 and 9, and 1 ≤ (n2 + n3) ≤ 10.

[0205] In the above general formula (5), R 51 and R 52 Each of these is independently a C1-C10 hydrocarbyl group which may contain a halogen atom or a heteroatom. 51 and R 52 However, they may bond to each other and form a ring with the carbon atoms to which they are bonded and the atoms between the carbon atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The C1-C10 hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C10 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 2,6A cyclic saturated hydrocarbyl group having 3 to 10 carbon atoms such as a decanyl group and an adamantyl group; an alkenyl group such as a vinyl group and an allyl group; an aryl group having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group; and groups obtained by combining these groups. Further, part or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and part of -CH2- in the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom. As a result, the group may contain a hydroxy group, a cyano group, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-O-C(=O)-) and the like. R 51 and R 52 is preferably a hydrocarbyl group having 1 to 4 carbon atoms.

[0206] In the above general formula (5), R 53 is a halogen atom, or a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The hydrocarbyl group having 1 to 40 carbon atoms may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include an alkyl group having 1 to 40 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, an n-hexyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group and an n-decyl group; a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclopentylbutyl group, a cyclohexylmethyl group, a cyclohexylethyl group, a cyclohexylbutyl group, a norbornyl group, a 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, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc. When n3 is 2 to 9, each R 53 These may be the same or different from each other. Also, multiple Rs 53 However, they may bond with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0207] Specific examples of hypervalent iodine compounds represented by the general formula (5) above include, but are not limited to, those listed below.

[0208] [ka]

[0209] [ka]

[0210] [ka]

[0211] [ka]

[0212] If the resist composition of the present invention contains other hypervalent iodine compounds, the other hypervalent iodine compounds may consist solely of the hypervalent iodine compound represented by general formula (4), solely of the hypervalent iodine compound represented by general formula (5), or a combination of the hypervalent iodine compound represented by general formula (4) and the hypervalent iodine compound represented by general formula (5). Furthermore, the hypervalent iodine compound represented by general formula (4) and the hypervalent iodine compound represented by general formula (5) may each be used individually or in combination of two or more different types.

[0213] If the resist composition of the present invention contains other hypervalent iodine compounds as optional components, the other hypervalent iodine compounds are preferably included in a molar ratio of the hypervalent iodine compound represented by the general formula (1) above, such that the ratio of the other hypervalent iodine compound to the hypervalent iodine compound represented by the general formula (1) is 0:100 to 50:50, and more preferably 0:100 to 10:90.

[0214] [Laminated structure] The present invention is a laminate comprising a substrate, A resist film obtained from the resist composition described above on the substrate and It is a laminate that possesses the following characteristics:

[0215] In the laminate of the present invention, which comprises a resist film obtained from the resist composition of the present invention, the resist film exhibits high sensitivity and excellent limiting resolution, making it effective for precise microfabrication. Furthermore, it can be applied to the formation of both positive and negative patterns. Therefore, the laminate of the present invention has a wide range of applications and is highly useful in resist process technology.

[0216] For example, as shown in Figure 1, the laminate may further include a resist underlayer film 2 between the substrate 3 and the resist film 1. That is, the laminate may further include a resist underlayer film between the substrate and the resist film.

[0217] If a resist underlayer is required for pattern formation, the resist underlayer can be appropriately placed between the substrate and the resist film.

[0218] [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 a step of forming a resist film on a substrate using the resist composition described above, a step of exposing the resist film with high-energy rays, and a step of developing the exposed resist film using a developer solution as needed.

[0219] In other words, the present invention is a pattern forming method, A step of forming a resist film on a substrate, or on the resist underlayer of a substrate having a resist underlayer laminated thereon, using the resist composition described above, The process involves exposing the resist film with high-energy rays, The process involves developing the exposed resist film using a developer solution. This is a pattern formation method that includes [something].

[0220] First, the resist composition of the present invention is applied onto a substrate for manufacturing integrated circuits, or onto the resist underlayer film of a substrate obtained by laminating a resist underlayer film (such as Si, SiO₂, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflection film, etc.), or onto a substrate for manufacturing mask circuits, or onto the resist underlayer film of a substrate obtained by laminating a resist underlayer film (such as Cr, CrO, CrON, MoSi₂, SiO₂, etc.) by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., for example, to a coating film thickness of 0.01 to 2 μm. The coating film thus obtained is prebaked, for example, 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, whereby a resist film can be formed. The resist underlayer film means a film formed between a substrate and a resist film in a multilayer resist process, and the resist underlayer film is not particularly limited, and any conventionally known one can be used.

[0221] Next, the resist film is exposed using a high-energy ray. Specific examples of the high-energy ray include ultraviolet rays (g-line (436 nm), h-line (405 nm), i-line (365 nm), etc.), deep ultraviolet rays, electron beams (EB), extreme ultraviolet rays (EUV), X-rays, soft X-rays, excimer laser beams (KrF excimer laser beam, ArF excimer laser beam, etc.), γ-rays, synchrotron radiation, and the like. As the high-energy ray, it is preferable to use i-line, KrF excimer laser beam, ArF excimer laser beam, electron beam, or extreme ultraviolet ray. When ultraviolet rays, deep ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser beams, γ-rays, synchrotron radiation or the like are used as the high-energy ray, exposure is performed directly or using a mask for forming a target pattern, with an exposure dose preferably of 1 to 300 mJ / cm 2 , more preferably 10 to 200 mJ / cm 2 for irradiation. When EB is used as the high-energy ray, exposure is performed directly or using a mask for forming a target pattern, with an exposure dose preferably of 0.1 to 2000 μC / cm 2 , more preferably 0.5 to 1500 μC / cm2 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.

[0222] 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 to 200°C for 10 seconds to 30 minutes, more preferably at 60 to 180°C for 30 seconds to 20 minutes.

[0223] After exposure or PEB, develop and pattern the image using a developer as needed. The developers used at this time include alkaline aqueous solutions such as tetramethylammonium hydroxide aqueous solution; 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, isopropyl alcohol, isoamyl alcohol, n-butanol, n-pentanol, cyclohexanol, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, cyclohexyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotate, ethyl crotate, propionic acid Examples of organic solvents include methyl, 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, 2-phenylethyl acetate, 1-propanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, and 4-methyl-2-pentanol. These developers may be used individually or in mixtures of two or more.

[0224] After development, rinsing should be 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. Alternatively, water may be used as the rinsing solution instead of an organic solvent.

[0225] 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.

[0226] The resist composition of the present invention, upon exposure, exhibits a difference in solubility between exposed and unexposed areas, enabling 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 various fine pattern formations, as it allows for the formation of positive or negative patterns by appropriately selecting the developer. [Examples]

[0227] The present invention will be specifically described below using synthesis examples, examples, and comparative examples, but the present invention is not limited to these.

[0228] [1] Synthesis of hypervalent iodine compounds The hypervalent iodine compounds used in the examples are represented by the following formulas (I-1) to (I-2), where Ph is a phenyl group. [ka]

[0229] The hypervalent iodine compound represented by formula (I-1) was synthesized with reference to ChemRxiv, 2024, 10.26434 / chemrxiv-2024-1lj6h. The hypervalent iodine compound represented by formula (I-2) was synthesized with reference to J.Mater.Chem.C, 2025, 13,842.

[0230] [2] Polymer synthesis The monomers used in the comparative example are represented by the following formulas (c-1) to (c-2). [ka]

[0231] Under a nitrogen atmosphere, monomer c-1 (101 g), monomer c-2 (42 g), 5.4 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 180 g of MEK were placed in a flask to prepare a monomer-polymerization initiator solution. In another flask under a nitrogen atmosphere, 55 g 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, and then cooled to room temperature. The obtained polymerization solution was added dropwise to 4000 g of hexane that had been vigorously stirred, and the precipitated polymer was filtered off. Furthermore, the obtained polymer was washed twice with 1200 g of hexane and then vacuum dried at 50°C for 20 hours to obtain a white powdery polymer P-10 (yield 137 g, yield 96%). In polymer P-10, the ratio of repeating units derived from c-1 to those derived from c-2 was 60:40 in molar ratio. The Mw of polymer P-10 was 9800, and the Mw / Mn ratio was 1.82. Note that Mw is a polystyrene-converted value measured by GPC using THF as the solvent.

[0232] [3] Preparation of resist composition [Examples 1-1 to 1-4, Comparative Examples 1-1 to 1-3] Hypervalent iodine compounds and additives were dissolved in a solvent containing 0.01% by mass of surfactant (PF-636, manufactured by Omnova) according to the compositions shown in Table 1 below. The resulting solutions were filtered through a 0.2 μm Teflon® filter to prepare resist compositions (R-01 to R-04) and comparative resist composition (CR-01). 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) according to the compositions shown in Table 2 below. The resulting solutions were filtered through a 0.2 μm Teflon® filter to prepare comparative resist compositions (CR-02 to CR-03).

[0233] [Table 1]

[0234] [Table 2]

[0235] In Tables 1 and 2, the additives O-1, m-1, photoacid generator PAG-1, sensitivity modifier Q-1, and solvent are as follows:

[0236] [ka]

[0237] [ka]

[0238] [ka]

[0239] [ka]

[0240] • Solvent: PGMEA (Propylene glycol monomethyl ether acetate) AcOH (acetic acid) HBM (methyl 2-hydroxyisobutyrate) PA (propionic acid) GBL (γ-butyrolactone)

[0241] [4] EUV lithography evaluation (line and space pattern, positive tone development) [Examples 2-1 to 2-4, Comparative Examples 2-1 to 2-3] Each resist composition (R-01 to R-04, CR-01 to CR-03) 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 temperatures listed in Table 3 using a hot plate. Each fabricated resist film was then exposed to a 36 nm line-and-space (LS) 1:1 pattern 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 temperatures listed in Table 3, followed by development for 30 seconds with the developer listed in Table 3 to form an LS pattern with a space width of 18 nm and a pitch of 36 nm.

[0242] The obtained resist patterns were evaluated as follows. The results are shown in Table 3.

[0243] [Sensitivity evaluation] The aforementioned LS pattern was observed using a Hitachi High-Tech Corporation measuring SEM (CG-6300), and the optimal exposure dose Eop(mJ / cm²) was determined to obtain 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.

[0244] [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.

[0245] [Evaluation of Limit Resolution] The minimum line width (nm) at which the pattern can be resolved was determined using a Hitachi High-Tech SEM (CG-6300) to gradually increase the exposure from the optimal exposure for forming the aforementioned LS pattern. This was defined as the limiting resolution (nm). A smaller value indicates superior limiting resolution and the ability to form finer patterns.

[0246] [Table 3]

[0247] Developer: nBA (butyl acetate) TMAH (2.38% by mass tetramethylammonium hydroxide aqueous solution)

[0248] [5] EUV lithography evaluation (line and space pattern, negative tone development) [Examples 3-1 to 3-4, Comparative Examples 3-1 to 3-3] Each resist composition (R-01 to R-04, CR-01 to CR-03) 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 temperatures listed in Table 4 using a hot plate. Each fabricated resist film was exposed to a 36 nm line-and-space (LS) 1:1 pattern using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9, 90-degree dipole illumination). After exposure, the film was baked (PEB) on a hot plate for 60 seconds at the temperatures listed in Table 4, and then developed 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.

[0249] The obtained resist patterns were evaluated as follows. The results are shown in Table 4.

[0250] [Sensitivity evaluation] The aforementioned LS pattern was observed using a Hitachi High-Tech Corporation measuring SEM (CG-6300), and the optimal exposure dose Eop(mJ / cm²) was determined to obtain 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.

[0251] [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.

[0252] [Evaluation of Limit Resolution] The minimum line width (nm) at which the pattern can be resolved was determined using a Hitachi High-Tech SEM (CG-6300) to gradually increase the exposure from the optimal exposure for forming the aforementioned LS pattern. This was defined as the limiting resolution (nm). A smaller value indicates superior limiting resolution and the ability to form finer patterns.

[0253] [Table 4]

[0254] The results shown in Tables 3 and 4 indicate that the resist composition of the present invention exhibits excellent sensitivity, LWR, and resolution in line-and-space pattern formation by EUV exposure, regardless of whether positive or negative tone development is performed.

[0255] [6] EUV lithography evaluation (contact hole pattern) [Examples 4-1 to 4-4, Comparative Examples 4-1 to 4-3] Each resist composition (R-01 to R-04, CR-01 to CR-03) 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 50 nm thick resist film was then fabricated by post-application baking (PAB) for 60 seconds at the temperatures listed in Table 5 using a hot plate. 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). A bake (PEB) was performed on a hot plate for 60 seconds at the temperatures listed in Table 5, and development was performed for 30 seconds with the developer listed in Table 5 to obtain a 32 nm hole pattern.

[0256] The obtained resist patterns were evaluated as follows. The results are shown in Table 5.

[0257] [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 32 nm. 2 ) was sought.

[0258] [CD Uniformity (CDU) Evaluation] 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.

[0259] [Evaluation of Limit Resolution] The minimum hole diameter (nm) that can be resolved while gradually decreasing the exposure from the optimal exposure 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.

[0260] [Table 5]

[0261] The results shown in Table 5 indicate that the resist composition of the present invention exhibits excellent sensitivity, CDU, and resolution in contact hole pattern formation by EUV exposure.

[0262] In other words, the above examples demonstrate that the resist composition of the present invention can achieve both high sensitivity and high resolution in pattern formation methods, and is extremely useful for forming fine patterns.

[0263] 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. [Explanation of symbols]

[0264] 1... Resist film, 2... Resist underlayer film, 3... Substrate 10...Laminated structure.

Claims

1. A resist composition characterized by comprising a hypervalent iodine compound represented by the following general formula (1) and a solvent. 【Chemistry 1】 (In the formula, m is an integer between 0 and 2, n is an integer between 1 and 40, and k is an integer between 0 and (2m + 4). Each m and each k may be the same or different.) R １１ This is a carbonyl group or a hydroxylene group having 1 to 40 carbon atoms, which may contain a heteroatom. １１ They may be the same as or different from each other. R １２ This is a carbonyl group or a hydroxylene group having 1 to 10 carbon atoms, which may contain a heteroatom. １２ They may be the same as or different from each other. R １３ This is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a halogen atom or a heteroatom. １３ They may be the same or different from each other.

2. A laminate, comprising a substrate, A resist film obtained from the resist composition according to claim 1 on the substrate and A laminate characterized by having the following features.

3. The laminate according to claim 2, characterized in that the laminate further comprises a resist underlayer film between the substrate and the resist film.

4. A pattern formation method, A step of forming a resist film on a substrate, or on the resist underlayer of a substrate having a resist underlayer laminated thereon, using the resist composition described in claim 1, The process involves exposing the resist film with high-energy rays, The process involves developing the exposed resist film using a developer solution. A pattern forming method characterized by including the following.

5. The pattern formation method according to claim 4, 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.

6. The pattern forming method according to claim 4 or 5, characterized in that the developing solution used dissolves the exposed areas but not the unexposed areas.

7. The pattern forming method according to claim 4 or 5, characterized in that the developing solution used dissolves the unexposed areas but not the exposed areas.

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