Resist composition and patterning process

Abstract

The present invention aims to provide a non-chemical amplification resist composition having excellent sensitivity and limiting resolution in photolithography using high-energy rays, and a pattern forming method using the resist composition. A resist composition comprising at least one ultra-autogenous iodine compound represented by any one of the following formulas (1) to (4), a carboxylic acid derivative compound, and a solvent, wherein the carboxylic acid derivative compound is a polymer comprising a carboxylic acid derivative compound represented by the following formula (5) or a carboxylic acid derivative repeating unit represented by the following formula (6).

Description

Technology Field

[0001] The present invention relates to a resist composition 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 of LSIs, leading to rapid miniaturization of pattern rules. In particular, logic devices are driving this miniaturization. As a cutting-edge miniaturization technology, mass production of 10 nm node devices is being carried out using double patterning, triple patterning, and quadro patterning of ArF immersion lithography, and furthermore, the development of 7 nm node devices using next-generation extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm is underway.

[0003] With the progress of miniaturization, blurring of the image due to acid diffusion is becoming a problem (Non-patent Literature 1). It has been suggested that in order to secure resolution in fine patterns with processing dimensions of 45 nm or more, control of acid diffusion is important in addition to the improvement of dissolution contrast proposed in the past (Non-patent Literature 2). However, since chemical amplification resist compositions increase sensitivity and contrast through acid diffusion, if one attempts to suppress acid diffusion to the extreme by lowering the post-exposure bake (PEB) temperature or shortening the PEB time, the sensitivity and contrast are significantly reduced.

[0004] It is effective to suppress acid diffusion by adding an acid-generating agent that generates bulky acid. Therefore, copolymerizing an acid-generating agent of an onium salt having a polymerizable olefin in a polymer has been proposed. However, regarding the pattern formation of resist films with processing dimensions of 16 nm or more, it is thought that pattern formation cannot be achieved with chemically amplified resist compositions from the perspective of acid diffusion, so the development of non-chemically amplified resist compositions is required.

[0005] Polymethyl methacrylate (PMMA) can be cited as a material for non-chemical amplification resist compositions. PMMA is a positive-type resist material in which solubility in organic solvent developers is improved as the main chain is cleaved and the molecular weight is reduced by EUV irradiation.

[0006] Hydrogensilsesquioxane (HSQ) is a negative-type resist material that becomes insoluble in alkaline developers due to crosslinking caused by the condensation reaction of silanols generated by EUV irradiation. Additionally, chlorine-substituted calixalene also functions as a negative-type resist material. Because these negative-type resist materials have small molecular sizes prior to crosslinking and do not experience blurring due to acid diffusion, they exhibit low edge roughness and very high resolution, making them suitable for use as pattern transfer materials to indicate the resolution limits of exposure devices. However, these materials have insufficient sensitivity, requiring further improvement.

[0007] One factor that makes the development of materials for EUV lithography difficult is the low number of photons in EUV exposure. The energy of EUV is much higher than that of ArF excimer laser light, and the number of photons in EUV exposure is one-fourteenth of that in ArF exposure. Furthermore, the dimensions of patterns formed by EUV exposure are less than half of those formed by ArF exposure. For this reason, EUV exposure is susceptible to variations in the number of photons. Variations in the number of photons in the extreme wavelength synchrotron region constitute shot noise as a physical phenomenon, and this effect cannot be eliminated. For this reason, so-called stochastics is attracting attention. Although the effect of shot noise cannot be eliminated, discussions are underway on how to reduce it. Due to the influence of shot noise, not only are dimensional uniformity (CDU) and line with roughness (LWR) increased, but a phenomenon in which holes become occluded with a probability of one in a million is also observed. If holes are blocked, it results in a failure of current conduction and prevents the transistor from operating, which negatively affects the overall performance of the device. When considering practical sensitivity, resist compositions with PMMA or HSQ as the main components are significantly affected by stochastics, making it impossible to obtain the desired resolution performance.

[0008] As a method to reduce the impact of shot noise on the resist side, the introduction of elements with high absorption of EUV light is attracting attention. Patent Document 1 proposes a chemical amplification resist composition containing iodine atoms with high absorption of EUV light. However, as mentioned above, excellent resolution performance cannot be realized in EUV lithography, where processing dimensions are becoming increasingly finer in the future, with chemical amplification resist compositions. In particular, for line and space patterns, as the pattern dimensions decrease, pattern collapse and breakage increase significantly, so reducing these leads to an improvement in limiting resolution.

[0009] Patent Document 2 proposes a negative-type resist composition using a tin compound. Since this composition is composed mainly of a tin element that absorbs EUV light, its stochastics are improved, enabling high sensitivity and high resolution. However, this so-called metal resist faces many challenges, such as insufficient solubility in resist solvents, storage stability, and defects caused by residue after etching. Furthermore, since the metal resist is a negative type in which the exposed portion becomes a metal oxide and is insoluble in the developer, when applied to patterning contact holes, an additional inversion process is required, raising concerns regarding cost. Prior art literature

[0010] Japanese Patent Publication No. 2018-5224 and Japanese Patent Publication No. 2021-503482

[0011] SPIE Vol. 5039 p1(2003)SPIE Vol. 6520p65203L-1(2007) The problem to be solved

[0012] The present invention, made in consideration of the above circumstances, aims to provide a non-chemical amplification resist composition having excellent sensitivity and limiting resolution in photolithography using high-energy rays, particularly electron beam (EB) lithography and EUV lithography, and a pattern forming method using the resist composition. means of solving the problem

[0013] As a result of repeated careful consideration to achieve the above objective, the inventors discovered that a resist composition having a predetermined ultra-autogenous iodine compound and a carboxylic acid derivative compound as main components provides a resist film with low roughness and high resolution, which is highly effective for precise micro-processing, and thus came to make the present invention.

[0014] That is, the present invention provides the following resist composition and pattern forming method.

[0015] 1. A resist composition comprising at least one ultra-autogenous iodine compound represented by any one of the following formulas (1) to (4), a carboxylic acid derivative compound, and a solvent, wherein

[0016] A resist composition in which the above carboxylic acid derivative compound is a polymer comprising a carboxylic acid derivative compound represented by the following formula (5) or a carboxylic acid derivative repeating unit represented by the following formula (6).

[0017]

[0018] (In the equation, m1 is 0, 1, or 2. When m1 is 0, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, or 5, and 1 ≤ n1 + n2 ≤ 6. When m1 is 1, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, or 7, and 1 ≤ n1 + n2 ≤ 8. When m1 is 2, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9, and 1 ≤ n1 + n2 ≤ 10. n3 is 1 or 2. n4 is 0, 1, 2, 3, or 4, provided that 1 ≤ n3 + n4 ≤ 5. n5 is 1 or 2. n7 is 0, 1, 2, 3 or 4, provided that 1 ≤ n5 + n6 ≤ 5. n7 is 0, 1, 2, 3 or 4. n8 is 1, 2, 3 or 4.

[0019] m2 is 0, 1, or 2. When m2 is 0, n9 is 0, 1, 2, 3, or 4. When m2 is 1, n9 is 0, 1, 2, 3, 4, 5, or 6.

[0020] R 1 ~R 8 is a hydrocarbyl group having 1 to 10 carbon atoms, which may each independently contain a halogen atom or a heteroatom. Also, R 1 and R2 , R 3 and R 4 , R 5 and R 6 , or R 7 and R 8 These may combine with each other to form a ring together with the carbon atoms they bond to and the atoms between these carbon atoms.

[0021] R 11 ~R 14 is a hydrocarbyl group having 1 to 40 carbon atoms, which may each independently contain a halogen atom or a heteroatom. When n2 is 2 or greater, each R 11 They may be identical or different from each other, and multiple R 11 These may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n4 is 2 or greater, each R 12 They may be identical or different from each other, and multiple R 12 They may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n6 is 2 or greater, each R 13 They may be identical or different from each other, and multiple R 13 These may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n7 is 2 or greater, each R 14 They may be identical or different from each other, and multiple R 14 They may combine with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0022] R 15 When (n8) having 1 to 40 carbon atoms is a hydrocarbon group or (n8) having 2 to 40 carbon atoms is a heterocyclic group, and n8 is 2, R 25may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, a sulfonyl group, or a thioketone bond. Additionally, the above (n8) may be substituted with a hydrocarbon group or a group in which part or all of the hydrogen atoms of the heterocyclic group of (n8) are substituted with a group containing a heteroatom, and the above (n8) may be substituted with a group containing a heteroatom for part of the -CH2- of the hydrocarbon group, and R 14 and R 15 They may combine with each other to form a ring together with the carbon atoms they bond to and the atoms between these carbon atoms.

[0023] R 16 It is a hydrocarbyl group having 1 to 10 carbon atoms that may contain a halogen atom or a heteroatom.

[0024] R 17 It is a hydrocarbyl group having 1 to 40 carbon atoms that may contain a halogen atom or a heteroatom. When n9 is 2 or greater, each R 22 They may be identical or different. Also, multiple R 22 They may combine with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0025] R 18 It is a carbonyl group, or a hydrocarbylene group having 1 to 10 carbon atoms that may contain a heteroatom.

[0026] *1 and *2 represent bond losses with carbon atoms of the aromatic ring in the formula. Note that *1 and *2 are bonded to adjacent carbon atoms of the aromatic ring.)

[0027]

[0028] (In the formula, p is 1, 2, 3, or 4.

[0029] R 21When p with 1 to 40 carbon atoms is a hydrocarbon group or p with 2 to 40 carbon atoms is a heterocyclic group and p is 2, R6 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. Additionally, some or all of the hydrogen atoms of the hydrocarbon group or the heterocyclic group may be substituted with a group containing a heteroatom, and some of the -CH2- of the hydrocarbon group may be substituted with a group containing a heteroatom.

[0030] R 22 is a single bond or a hydrocarbylene group having 1 to 10 carbon atoms, and some or all of the hydrogen atoms of this hydrocarbylene group may be substituted with a group containing a heteroatom, or some of the -CH2- of this hydrocarbylene group may be substituted with a group containing a heteroatom. When p is 2, 3, or 4, each R 22 They may be identical or different.

[0031] R 23 ~R 26 is a hydrocarbyl group having 1 to 40 carbon atoms, which may each independently contain a halogen atom or a heteroatom. Also, R 23 and R 24 They may bond with each other to form a ring together with the carbon and oxygen atoms to which they bond, and R 25 and R 26 These may combine with each other to form a ring together with the carbon and oxygen atoms they bond to.

[0032] R A is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group.

[0033] X A is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A1 -is. X A1is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and this saturated hydrocarbylene group may include a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * indicates a bond loss with a carbon atom of the main chain.)

[0034] 2. A resist composition of 1 in which the polymer containing the above-mentioned carboxylic acid derivative repeating unit does not contain repeating units containing acid instability groups other than the repeating unit represented by formula (6).

[0035] 3. A laminate comprising a substrate and a resist film obtained from one or two resist compositions on the substrate.

[0036] 4. A laminate of 3 having a resist lower layer between the substrate and the resist film.

[0037] 5. A laminate of 3 or 4 in which the above resist film is formed by the ligand exchange of the iodine compound and the carboxyl group-containing compound.

[0038] 6. A pattern forming method comprising: a process of forming a resist film on a substrate or on a lower layer of a substrate having a lower layer laminated thereon using a resist composition of 1 or 2; a process of exposing the resist film to i-line, a KrF excimer laser, an ArF excimer laser, EB, or EUV; and a process of developing the exposed resist film using a developer. Effects of the invention

[0039] The resist composition of the present invention is particularly useful for forming fine patterns by achieving both excellent roughness and high resolution in i-line, KrF excimer laser, ArF excimer laser, EB lithography, and EUV lithography. Specific details for implementing the invention

[0040] [Resist composition]

[0041] The resist composition of the present invention comprises a predetermined ultra-autogenous iodine compound and a carboxylic acid derivative compound as a main component.

[0042] [Superalkaline iodine compounds]

[0043] The above-mentioned ultra-advanced iodine compound is at least one tripordination ultra-advanced iodine compound represented by any one of the following formulas (1) to (4).

[0044]

[0045] In equations (1) to (4), m1 is 0, 1, or 2. When m1 is 0, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, or 5, and 1 ≤ n1 + n2 ≤ 6. When m1 is 1, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, or 7, and 1 ≤ n1 + n2 ≤ 8. When m1 is 2, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9, and 1 ≤ n1 + n2 ≤ 10. n3 is 1 or 2. n4 is 0, 1, 2, 3, or 4. Provided that 1 ≤ n3 + n4 ≤ 5. n5 is 1 or 2. n6 is 0, 1, 2, 3 or 4. Provided that 1 ≤ n5 + n6 ≤ 5. n7 is 0, 1, 2, 3 or 4. n8 is 1, 2, 3 or 4. m2 is 0, 1 or 2. When m2 is 0, n9 is 0, 1, 2, 3 or 4. When m2 is 1, n9 is 0, 1, 2, 3, 4, 5 or 6.

[0046] Among formulas (1) to (3), R 1 ~R 8 is a hydrocarbyl group having 1 to 10 carbon atoms, which may each independently contain a halogen atom or a heteroatom. Also, R 1 and R 2 , R 3 and R 4 , R 5 and R 6 , or R7 and R 8 These may combine with each other to form a ring together with the carbon atoms they bond to and the atoms between these carbon atoms.

[0047] R 1 ~R 8 Examples of halogen atoms represented by R include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. 1 ~R 8 The hydrocarbyl group having 1 to 10 carbon atoms represented by may be saturated or unsaturated, and may be straight, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 10 carbon atoms 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 2,6 Examples include cyclic saturated hydrocarbyl groups having 3 to 10 carbon atoms, such as decyl groups and adamantyl groups; alkenyl groups, 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. Additionally, some or all of the hydrogen atoms of the above hydrocarbyl 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 above hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may include hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, carbamate bonds, lactone rings, sulfone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc. R 1 ~R 8As such, a hydrocarbyl group having 1 to 4 carbon atoms is preferred.

[0048] Among formulas (1) to (3), R 11 ~R 14 is a hydrocarbyl group having 1 to 40 carbon atoms that may contain a halogen atom or a heteroatom. When n2 is 2 or greater, each R 11 They may be identical or different from each other, and multiple R 11 These may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n4 is 2 or greater, each R 12 They may be identical or different from each other, and multiple R 12 They may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n6 is 2 or greater, each R 13 They may be identical or different from each other, and multiple R 13 These may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n7 is 2 or greater, each R 14 They may be identical or different from each other, and multiple R 14 They may combine with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0049] R 11 ~R 14 Examples of halogen atoms represented by R include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. 11 ~R 14The hydrocarbyl group having 1 to 40 carbon atoms represented by may be saturated or unsaturated, and may be in a straight chain, branched chain, or cyclic form. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms 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 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 decyl groups, adamantyl groups, and adamantylmethyl groups; and aryl groups having 6 to 40 carbon atoms, such as phenyl groups, naphthyl groups, and anthracenyl groups. Additionally, some or all of the hydrogen atoms of the hydrocarbyl 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 hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may include hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, carbamate bonds, lactone rings, sulfone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc.

[0050] In Equation (3), R 15 When (n8) having 1 to 40 carbon atoms is a hydrocarbon group or (n8) having 2 to 40 carbon atoms is a heterocyclic group, and (n8) is 2, R 15may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, a sulfonyl group, or a thioketone bond. Additionally, the above (n8) may be substituted with a hydrocarbon group or a group in which part or all of the hydrogen atoms of the heterocyclic group of (n8) are substituted with a group containing a heteroatom, and the above (n8) may be substituted with a group containing a heteroatom for part of the -CH2- of the hydrocarbon group, and R 14 and R 15 They may combine with each other to form a ring together with the carbon atoms they bond to and the atoms between these carbon atoms.

[0051] R 15 The (n8) hydrocarbon group represented by may be saturated or unsaturated, and may be a straight chain, branched, or cyclic. The (n8) hydrocarbon group is a group obtained by removing (n8) hydrogen atoms from a hydrocarbon. Examples of the hydrocarbons include alkanes having 1 to 40 carbon atoms, alkenes having 2 to 40 carbon atoms, alkynes having 2 to 40 carbon atoms, cyclic saturated hydrocarbons having 3 to 40 carbon atoms, cyclic unsaturated hydrocarbons having 3 to 40 carbon atoms, and aromatic hydrocarbons having 6 to 40 carbon atoms.

[0052] Specific examples of the above-mentioned alkanes having 1 to 40 carbon atoms include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and structural isomers thereof.

[0053] Specific examples of the above-mentioned alkenes having 2 to 40 carbon atoms include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, and structural isomers thereof.

[0054] Specific examples of the above alkynes having 2 to 40 carbon atoms include acetylene, propine, butyne, pentine, hexine, heptine, octine, nonine, decine, and structural isomers thereof.

[0055] Specific examples of the above-mentioned cyclic saturated hydrocarbons having 3 to 40 carbon atoms include cyclopropane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, adamantane, norbornane.

[0056] Specific examples of the above-mentioned cyclic unsaturated hydrocarbons having 3 to 40 carbon atoms include cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, norbornene.

[0057] Specific examples of the above aromatic hydrocarbons having 6 to 40 carbon atoms include benzene, naphthalene, biphenyl, etc.

[0058] R 15 The (n8) heterocyclic group represented by is a group obtained by removing (n8) hydrogen atoms from a heterocyclic compound. Examples of the above heterocyclic compounds include furan, pyridine, pyrazol, thiazolidine, etc.

[0059] R 15 The hydrocarbon group (n8) represented by (n8) or the heterocyclic group (n8) may have some or all of its hydrogen atoms substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and as a result, may include a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Additionally, the hydrocarbon group (n8) may have some of its constituent -CH2- substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., and as a result, may include 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 sulfone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), etc.

[0060] In Equation (4), R 16 It is a hydrocarbyl group having 1 to 10 carbon atoms that may contain a halogen atom or a heteroatom. 16Specific examples of the halogen atom and hydrocarbyl group represented by are, respectively, R 1 ~R 8 Examples of the same as those exemplified as halogen atoms and hydrocarbyl groups represented by can be given.

[0061] In Equation (4), R 17 It is a hydrocarbyl group having 1 to 40 carbon atoms that may contain a halogen atom or a heteroatom. When n9 is 2 or greater, each R 17 They may be identical or different. Also, multiple R 17 These may combine with each other to form a ring together with the carbon atom of the aromatic ring to which they are bonded. R 17 Specific examples of the halogen atom and hydrocarbyl group represented by are, respectively, R 11 ~R 14 Examples of the same as those exemplified as halogen atoms and hydrocarbyl groups represented by can be given.

[0062] In Equation (4), R 18 The carbonyl group is a hydrocarbylene group having 1 to 10 carbon atoms, which may contain a carbonyl group or a heteroatom. The hydrocarbylene group having 1 to 10 carbon atoms may be saturated or unsaturated, and may be straight, branched, or cyclic. Specific examples thereof include alkylene groups having 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; 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 decandyl 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. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms, and as a result, may include a hydroxyl group, a cyano group, an alkyl halide 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 sulfone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), etc. R 18 As for, a carbonyl group, a hydrocarbylene group having 1 to 4 carbon atoms, or a fluorinated hydrocarbylene group having 1 to 4 carbon atoms is preferred.

[0063] In Equation (4), *1 and *2 represent bonding losses with carbon atoms of the aromatic ring in the equation. However, *1 and *2 are bonded to adjacent carbon atoms of the aromatic ring. The combinations of *1, *2 and m2 can be conceived in seven patterns as shown below.

[0064]

[0065] (in the food, n9, R 17 and R 18 It is the same as above. The dashed line is R 16 -Represents bond loss with C(=O)-O-.)

[0066] Specific examples of the ultra-autogenous iodine compound represented by formula (1) include those shown below, but are not limited thereto.

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] Specific examples of the ultra-autogenous iodine compound represented by formula (2) include those shown below, but are not limited to these.

[0080]

[0081]

[0082]

[0083]

[0084] Specific examples of the ultra-autogenous iodine compound represented by formula (3) include those shown below, but are not limited to these.

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091] Specific examples of the ultra-electron iodine compound represented by formula (4) include those shown below, but are not limited thereto. In addition, in the following formulas, Me is a methyl group.

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148] [Carboxylic acid derivative compounds]

[0149] The above carboxylic acid derivative compound is a polymer comprising a carboxylic acid derivative compound represented by the following formula (5) or a carboxylic acid derivative repeating unit represented by the following formula (6) (hereinafter also referred to as a carboxylic acid derivative-containing polymer).

[0150]

[0151] In equation (5), p is 1, 2, 3 or 4.

[0152] In Equation (5), R 21 When p of C1–40 is a hydrocarbon group or p of C2–40 is a heterocyclic group, and p is 2, R 21 It 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. Additionally, some or all of the hydrogen atoms of the hydrocarbon group or the heterocyclic group may be substituted with a group containing a heteroatom, and some of the -CH2- of the hydrocarbon group may be substituted with a group containing a heteroatom.

[0153] R 21The p-value hydrocarbon group represented by may be saturated or unsaturated, and may be a straight chain, a branched chain, or a cyclic chain. The p-value hydrocarbon group is a group obtained by removing p hydrogen atoms from a hydrocarbon. Examples of the hydrocarbons include alkanes having 1 to 40 carbon atoms, alkenes having 2 to 40 carbon atoms, alkynes having 2 to 40 carbon atoms, cyclic saturated hydrocarbons having 3 to 40 carbon atoms, cyclic unsaturated hydrocarbons having 3 to 40 carbon atoms, and aromatic hydrocarbons having 6 to 40 carbon atoms.

[0154] Specific examples of the above-mentioned alkanes having 1 to 40 carbon atoms include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and structural isomers thereof.

[0155] Specific examples of the above-mentioned alkenes having 1 to 40 carbon atoms include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, and structural isomers thereof.

[0156] Specific examples of the above alkynes having 1 to 40 carbon atoms include acetylene, propine, butyne, pentine, hexine, heptine, octine, nonine, decine, and structural isomers thereof.

[0157] Specific examples of the above-mentioned cyclic saturated hydrocarbons having 3 to 40 carbon atoms include cyclopropane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, adamantane, norbornane.

[0158] Specific examples of the above-mentioned cyclic unsaturated hydrocarbons having 3 to 40 carbon atoms include cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, norbornene.

[0159] Specific examples of the above aromatic hydrocarbons having 6 to 40 carbon atoms include benzene, naphthalene, biphenyl, etc.

[0160] R 21The p-relational group represented by is a group obtained by removing p hydrogen atoms from a relational compound. Specific examples of the relational compound include furan, pyridine, pyrazol, thiazolidine, etc.

[0161] The above p-hydrocarbon group or p-heterocyclic group may have some or all of its hydrogen atoms substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and as a result, may include a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Additionally, the above p-hydrocarbon group may have some of its constituent -CH2- substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., and as a result, may include 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 sulfone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), etc.

[0162] In Equation (5), R 22 is a single bond or a hydrocarbylene group having 1 to 10 carbon atoms, and some or all of the hydrogen atoms of this hydrocarbylene group may be substituted with a group containing a heteroatom, or some of the -CH2- of this hydrocarbylene group may be substituted with a group containing a heteroatom. When p is 2, 3, or 4, each R 22 They may be identical or different.

[0163] R 22The hydrocarbylene group represented by may be saturated or unsaturated, and may be in a straight chain, branched chain, or cyclic form. Specific examples thereof include alkanediyl groups having 1 to 20 carbon atoms, such as 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-1,12-diyl group; Examples include cyclic saturated hydrocarbylene groups having 3 to 20 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornandiyl, and adamantandiyl; unsaturated aliphatic hydrocarbylene groups having 2 to 20 carbon atoms, such as vinylene and propene-1,3-diyl; arylene groups having 6 to 20 carbon atoms, such as phenylene and naphthylene; and groups obtained by combining these. In addition, 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, or halogen atoms, and some of the -CH2- constituting the hydrocarbylene group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, or nitrogen atoms, and as a result, may include a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a carbamate bond, a lactone ring, a sulfone ring, a carboxylic acid anhydride, etc.

[0164] In Equation (6), R A is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. X A is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A1 -is. X A1is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and this saturated hydrocarbylene group may include a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * indicates a bond loss with a carbon atom of the main chain.

[0165] Among equations (5) and (6), R 23 ~R 26 Each is a hydrocarbyl group having 1 to 40 carbon atoms, which may independently contain a halogen atom or a heteroatom, and also, R 23 and R 24 They may bond with each other to form a ring together with the carbon and oxygen atoms to which they bond, and R 25 and R 26 These may combine with each other to form a ring together with the carbon and oxygen atoms they bond to.

[0166] R 23 ~R 26 Specific examples of halogen atoms represented by this include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0167] R 23 ~R 26 The hydrocarbyl group having 1 to 40 carbon atoms represented by may be saturated or unsaturated, and may be straight, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms 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. Additionally, some or all of the hydrogen atoms of the hydrocarbyl 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 hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may include hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, carbamate bonds, lactone rings, sulfone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), etc.

[0168] As for the carboxylic acid derivative compound represented by formula (5), it is preferable that p is 2, 3, or 4.

[0169] Specific examples of the carboxylic acid derivative compound represented by formula (5) include those shown below, but are not limited thereto. In addition, among the following formulas, R B is 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, 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 ] It is a decanyl group, adamantyl group, adamantylmethyl group, phenyl group, naphthyl group, anthracenyl group, or a group represented by any one of the following formulas (AL-1) to (AL-9).

[0170]

[0171] (In the formula, * indicates a joining hand.)

[0172]

[0173]

[0174]

[0175]

[0176]

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192]

[0193]

[0194]

[0195]

[0196]

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210]

[0211] Specific examples of repeating units containing a carboxylic acid derivative represented by formula (6) may be those shown below, but are not limited thereto. In addition, among the following formulas, R A and R B It is the same as above.

[0212]

[0213]

[0214]

[0215]

[0216]

[0217]

[0218] The above-mentioned polymer containing the carboxylic acid derivative may further include repeating units other than the repeating unit represented by Formula (6) (hereinafter also referred to as other repeating units). The above-mentioned other repeating units are not particularly limited, but repeating units having a cyclic structure that is rigid and expected to have high etching resistance, or repeating units having a styrene backbone are preferred.

[0219] Specific examples of other repeating units mentioned above may include those shown below, but are not limited thereto. In addition, among the following formulas, R A is the same as above, and X B Each is independently -CH2- or -O-.

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242]

[0243]

[0244]

[0245]

[0246]

[0247]

[0248]

[0249]

[0250] In the above carboxylic acid derivative-containing polymer, the content ratio (molar ratio) of the repeating unit represented by Formula (6) and other repeating units is preferably 10:90 to 90:10, more preferably 15:85 to 85:15, and even more preferably 20:80 to 80:20.

[0251] The weight average molecular weight (Mw) of the above-mentioned polymer containing the carboxylic acid derivative is preferably 1,000 to 500,000, and more preferably 3,000 to 100,000. In addition, in the present invention, Mw is a polystyrene equivalent measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0252] In addition, when the molecular weight distribution (Mw / Mn) of the above-mentioned carboxylic acid derivative-containing polymer is wide, there is a risk that foreign substances may be visible on the pattern or the shape of the pattern may deteriorate after exposure because low molecular weight or high molecular weight polymers are present. Therefore, as the influence of Mw or Mw / Mn tends to increase as the pattern rule becomes finer, in order to obtain a resist composition suitable for use with fine pattern dimensions, it is preferable that the Mw / Mn of the above-mentioned carboxylic acid derivative-containing polymer be narrowly dispersed in the range of 1.0 to 2.0.

[0253] As a method for synthesizing the above-mentioned polymer containing a carboxylic acid derivative, for example, a method of polymerizing a monomer that provides the aforementioned repeating unit by adding a radical polymerization initiator to an organic solvent and heating it may be used.

[0254] Specific examples of organic solvents used in the polymerization reaction include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, cyclopentanone, cyclohexanone, methyl ethyl ketone (MEK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), γ-butyrolactone (GBL), etc. Specific examples of the polymerization initiator include 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, lauroyl peroxide, etc. The amount of the polymerization initiator added is preferably 0.01 to 25 mol% with respect to 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 perspective of production efficiency.

[0255] The polymerization initiator may be added to the monomer solution and supplied to the reaction port, or the initiator solution may be prepared separately from the monomer solution and supplied to the reaction port independently. Since there is a possibility that the polymerization reaction may proceed due to radicals generated from the initiator during the waiting time and that the superpolymer itself may be formed, it is preferable to prepare the monomer solution and the initiator solution independently and add them dropwise from the perspective of quality control. 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% relative to the total amount of monomers to be polymerized.

[0256] In addition, the amount of each monomer in the above monomer solution may be appropriately set, for example, to a desirable content ratio of the repeating unit described above.

[0257] In the resist composition of the present invention, the content ratio of the ultra-vitamin iodine compound and the carboxylic acid derivative compound (in cases where the carboxylic acid derivative compound is a polymer containing the carboxylic acid derivative, the content ratio of the ultra-vitamin iodine compound to the repeating unit of the carboxylic acid derivative in the polymer) is preferably 10:90 to 90:10 in molar ratio, more preferably 20:80 to 80:20, and even more preferably 30:70 to 70:30. The ultra-vitamin iodine compound may be used as a single type, and the carboxylic acid derivative compound may be used as a single type, or two or more types with different composition ratios, Mw, and / or Mw / Mn may be used in combination.

[0258] [solvent]

[0259] The above resist composition comprises a solvent. The solvent is not particularly limited as long as it is capable of dissolving the above-mentioned ultra-autogenous iodine compound, carboxylic acid derivative compound, and other components described below to form a film. As such a solvent, an organic solvent is preferred, and specific examples thereof 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 2-methyl hydroxyisobutyrate; and ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether. Examples include 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 mono tert-butyl ether acetate; carboxylic acids such as formic acid, acetic acid, and propionic acid; lactones such as γ-butyrolactone; and mixed solvents thereof.

[0260] In the resist composition of the present invention, the content of the solvent is preferably such that the solid content concentration in the resist composition is 0.1 to 20 mass%, more preferably such that it is 0.1 to 15 mass%, and even more preferably such that it is 0.1 to 10 mass%. Furthermore, in the present invention, solid content refers to the general term for all components of the resist composition other than the solvent. The solvent may be used as a single type or as a mixture of two or more types.

[0261] [Other ingredients]

[0262] The resist composition of the present invention may further include a surfactant. Fluorine-based and / or silicone-based surfactants are preferred as said surfactants. Examples of such surfactants include the surfactant described in paragraph

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

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

[0263] When the resist composition of the present invention includes the surfactant, the content thereof is preferably 0.0001 to 2 mass% of the total solid content. The surfactant may be used alone or in combination of two or more types.

[0264] The resist composition of the present invention may further include a radical scavenger. By adding a radical scavenger, the photoreaction during photolithography can be controlled, thereby allowing the sensitivity to be adjusted.

[0265] Examples of the above radical scavengers include hindered phenols, quinones, hindered amines, thiol compounds, etc. 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-oxyradical. Examples of thiols include dodecanethiol and hexadecanethiol.

[0266] When the resist composition of the present invention includes the radical scavenger, the content thereof is preferably 0.01 to 10 mass% of the total solid content. The radical scavenger may be used alone or in combination of two or more types.

[0267] The resist composition of the present invention may further include a crosslinking agent. By adding a crosslinking agent, the crosslinking reaction during photolithography is promoted, thereby improving the glass transition point of the pattern and obtaining a pattern with excellent resolution in fine lines.

[0268] Examples of the above-mentioned 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 chain 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 alcohols, allyl ethers, allyl esters, allyl amides, allylamines, and allyl group-containing isocyanurates, which may have substituents. Examples of compounds having an alkynyl group include chain alkynes, branched alkynes, cyclic alkynes, alkynyl alcohols, alkynyl ethers, alkynyl esters, alkynyl amides, alkynyl amines, and alkynyl group-containing isocyanurates, which may have substituents. Examples of compounds having an aromatic ring include arenes, heteroarenes, styrenes, stilbenes, phenylacetylenes, acenaphtylenes, and chalcones, 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 the above functional groups included in the crosslinking agent is preferably 1 to 10, and more preferably 2 to 8.

[0269] When the resist composition of the present invention includes the crosslinking agent, the content thereof is preferably 0.01 to 50 mass% of the total solid content. The crosslinking agent may be used alone or in combination of two or more types.

[0270] The resist composition of the present invention may further include a photopolymerization initiator when it includes the crosslinking agent. The photopolymerization initiator can generate radicals by irradiating high-energy rays and promote the crosslinking of the crosslinking agent.

[0271] Specific examples of the above photopolymerization initiator include benzophenone derivatives such as benzophenone, 0-benzoylbenzoate methyl, 4-benzoyl-4'-methyldiphenylketone, dibenzylketone, fluorenone, etc.; and acetophenone derivatives such as 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]-phenyl}-2-methylpropan-1-one, phenylglyoxylate methyl, etc. Thioxanthone derivatives such as thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, diethylthioxanthone; benzyl derivatives such as benzyl, benzyldimethylketal, benzyl-β-methoxyethylacetal; benzoin derivatives such as benzoin, benzoin methyl ether, 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-1,2-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, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), etc. Oxime compounds; 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, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methylpropane; α-aminoalkylphenone compounds such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholine-4-yl-phenyl)butan-1-one;Examples include phosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and titanocene compounds such as bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium.

[0272] When the resist composition of the present invention includes the photopolymerization initiator, the content thereof is preferably 0.1 to 10 mass% of the total solid content, more preferably 0.1 to 5 mass%, and most preferably 0.1 to 1 mass%. If it is 0.1 mass% or more, a sufficient blending effect can be obtained.

[0273] As described above, the resist composition of the present invention comprises a superautogenous iodine compound and a carboxylic acid derivative compound as main components, and in particular, by EB or EUV exposure, can form a positive type pattern in which the exposed portion becomes soluble in the developer or a negative type pattern in which the exposed portion becomes insoluble in the developer. Although the mechanism is not entirely clear, it is speculated as, for example, as follows.

[0274] In the aforementioned carboxylic acid derivative compounds, the carboxylic acid derivative portions are thermally decomposed into carboxylic acid during pre-baking after forming the resist film. Additionally, the ultra-autogenous iodine compounds represented by formulas (1), (2), (3), or (4) are triply coordinate compounds having an aryl group and a carboxylate ligand. It is believed that when these triply coordinate iodine compounds are mixed with carboxylic acid compounds, an exchange of carboxylate ligands occurs as an equilibrium reaction. At this time, if the original carboxylate ligands can be removed by any means, an ultra-autogenous iodine compound having new ligands is produced. For example, 1-iodo-naphthylene diacetate as a superadvanous iodine compound and a carboxylic acid derivative compound are mixed, and in a pre-bake process, the carboxylic acid derivative portion is thermally decomposed into carboxylic acid to remove the low-boiling point acetic acid generated by the ligand exchange reaction between the carboxylic acid compound and the superadvanous iodine compound, thereby completing the ligand exchange. Here, the carboxylic acid compound becomes a polymer cross-linked by the superadvanous iodine compound.

[0275] When a resist solution is prepared by directly adding carboxylic acid compounds and ultra-autogenous iodine compounds to a solvent, there is a problem in that the carboxylic acid compounds have low solubility in solvents and do not dissolve in general-purpose solvents; therefore, the solution cannot be dissolved unless a solvent containing carboxyl groups is used. Thus, it is presumed that using carboxylic acid derivative compounds, in which the carboxylic acid compounds are protected by organic groups, enables solubility in general-purpose solvents. Furthermore, it is presumed that using carboxylic acid derivative compounds prevents the aggregation of carboxyl groups within the film compared to the case where carboxylic acid compounds are used directly, thereby improving component uniformity after film formation and reducing roughness during patterning.

[0276] Polymers cross-linked with ultra-electron iodine compounds are formed during film formation. This is because, even if such cross-linked polymers are synthesized in advance, they do not dissolve in most organic solvents, making it impossible to prepare a solution. It is presumed that this is because ultra-electron iodine compounds, which have low solvent solubility due to their high polarization, become even more solubility when carboxylic acid compounds are used as ligands. Therefore, it is desirable to form a resist film by reacting a carboxylic acid derivative compound with a carboxylic acid compound during film formation and the subsequent baking process, thereby removing the original low-molecular-weight carboxylic acid component and completing the ligand exchange reaction.

[0277] When the above carboxylic acid derivative compound is converted into a carboxylic acid compound by heat, the baking temperature can be adjusted according to the type of organic group protecting the carboxylic acid.

[0278] The above resist composition may further include an acid generating agent. As for the acid generating agent, there are those that generate acid by thermal decomposition (thermal acid generating agents) or those that generate acid by light irradiation (photoacid generating agents), and either can be used. Specific examples of the above acid generating agent include those described in paragraphs

[0061] to

[0085] of Japanese Patent Publication No. 2007-199653. The acid generating agent reacts with a carboxylic acid derivative compound by generating acid through heat or light, thereby reacting the carboxylic acid derivative portion with the carboxylic acid. With the presence of the acid generating agent, the reaction to generate carboxylic acid can be completed at a low temperature compared to the case where the reaction with carboxylic acid is carried out by heat alone, thereby achieving a low-temperature effect of the process.

[0279] If the above acid generator is a thermal acid generator, during pre-baking after application of the resist composition, acid is generated from the thermal acid generator to react the carboxylic acid derivative compound with the carboxylic acid.

[0280] When the above acid generator is a photogenerator, after pre-baking following the application of the resist composition, the resist film is fully exposed to light, and an acid is generated from the photogenerator to react the carboxylic acid derivative compound with the carboxylic acid. Additionally, in this case, the process includes baking the resist film after full-front exposure to cause the ultracarriers in the resist film to undergo a ligand exchange reaction between the iodine compound and the carboxylic acid compound.

[0281] When the resist composition of the present invention includes an acid generating agent, the content thereof is preferably 0.05 to 20 parts by mass and more preferably 0.1 to 10 parts by mass per 100 parts by mass of a compound containing a carboxylic acid derivative. The additive acid generating agent may be used alone or in combination of two or more types.

[0282] The resist film obtained from the resist composition of the present invention undergoes a change in polarity as the iodine compound, which is the main component, is decomposed by light, and a pattern is formed by a development process. Although the mechanism is not entirely clear, it is speculated, for example, as follows.

[0283] The resist composition of the present invention may be a positive type or a negative type depending on the selection of components. In the case of the positive type, it includes a polymer in which an iodine compound is bonded to a superatom during film formation. As this is decomposed by light, it becomes a monovalent iodine compound, and at the same time, the bond between the carboxylic acid compound and the superatom iodine compound is released, and the molecular weight is reduced. As a result, it is presumed that a positive type pattern is formed in which the exposed area is removed by an organic solvent.

[0284] On the other hand, the negative type includes a polymer in which the ultra-electrons generated during film formation are cross-linked with an iodine compound. As this is decomposed by light, cross-linking or re-cross-linking of the bonds occurs, leading to an increase in molecular weight or 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.

[0285] It is preferable that the above-mentioned ultra-vital iodine compound has a rigid backbone with a large molecular weight so that it hardly volatilizes even under vacuum conditions during EB or EUV exposure. If ultra-vital iodine with a small molecular weight is used, the compound decomposed by exposure volatilizes under vacuum, causing significant exposure shrinkage of the resist film, contamination of the exposure machine by volatile components, and dimensional changes due to shrinkage of the resist pattern occur. Therefore, the aforementioned problems are resolved by using an ultra-vital iodine compound with a rigid backbone with a large molecular weight so that it hardly volatilizes. In addition, by using an ultra-vital iodine compound with a rigid backbone and a large molecular weight, the glass transition point of the pattern is improved, pattern twisting is prevented to improve resolution, and etching resistance is also improved.

[0286] It is preferable that the above-mentioned ultra-autogenous iodine compound has multiple ultra-autogenous iodine bonds in one molecule. In this case, in both the positive and negative types, the crosslinking density of the pattern is increased, thereby preventing twisting of the pattern and enabling the formation of a pattern with high etching resistance and excellent resolution.

[0287] Based on the aforementioned conjecture, the resist composition of the present invention can be described as a non-chemical amplification resist composition. The resist composition of the present invention comprises a carboxylic acid derivative compound in which a carboxyl group is substituted with an acid unstable group, but the acid unstable group detaches during baking prior to pattern exposure, and no reaction occurs in which the acid unstable group detaches during pattern exposure. On the other hand, since the acid unstable group detaches during pattern exposure and subsequent baking in conventional chemical amplification resist compositions, the resist composition of the present invention does not cause adverse effects (e.g., blurring of the image) due to acid diffusion, and thus can resolve fine patterns.

[0288] The resist composition of the present invention is particularly effective in EUV lithography. This is derived from having iodine atoms that have high absorption capacity for EUV light. That is, shot noise is reduced, and higher resolution and low LWR can be achieved.

[0289] As an EUV resist composition capable of forming fine patterns, a metal resist has been reported with a main component of a metallic tin compound that has high absorption capacity for EUV light, similar to iodine atoms (e.g., Patent Document 2). However, as previously mentioned, such metal resists have many problems, such as insufficient solubility in solvents, poor storage stability, and defects caused by residues after etching resulting from the inclusion of metal elements. On the other hand, since the resist composition of the present invention does not use metal elements, it is more advantageous than the metal resist in terms of defects and has no problems regarding solubility in solvents. Furthermore, since the resist composition of the present invention can be applied in both positive and negative types, it has a wide range of applications. For example, in a contact hole formation process, a metal resist that is developed as a negative type requires an inversion process after the filler pattern is formed, whereas such a process is unnecessary for a positive type resist. Therefore, from the perspective of process simplicity, the resist composition of the present invention can be said to be more useful than a metal resist.

[0290] Japanese Patent Publication No. 2015-180928 and Japanese Patent Publication No. 2018-95853 describe a resist composition containing a superautogenous iodine compound as an additive, or a resist composition in which a superautogenous iodine compound is included in the polymer backbone of a base polymer. However, regarding the characteristics of the resist compositions described in these patent documents, the only description is that they can improve line edge roughness, and they do not mention at all the possibility that the superautogenous iodine compound will photodecompose or function as a material for a non-chemical amplification resist composition. Furthermore, according to the descriptions regarding the mixing amount and specific examples, the superautogenous iodine compound is not a main component. Therefore, it is believed that these patent documents do not lead to the conception of a material capable of reducing shot noise in EUV lithography and, moreover, forming fine patterns as a material for a non-chemical amplification resist composition, as in the present invention. In other words, it can be said that the present invention provides a clearly novel resist composition and a pattern forming method.

[0291] [Pattern Formation Method]

[0292] When the resist composition of the present invention is used in the manufacture of various integrated circuits, known lithography techniques may be applied. For example, a pattern formation method may include a process of forming a resist film on a substrate or on a lower layer of a substrate having a lower layer laminated thereon using the aforementioned resist composition, a process of exposing the resist film to high-energy rays, and a process of developing the exposed resist film using a developer solution as needed.

[0293] First, the resist composition of the present invention is applied to a substrate for manufacturing an integrated circuit, or to a substrate for manufacturing an integrated circuit having a laminated lower layer (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.), or to a substrate for manufacturing a mask circuit, or to a substrate for manufacturing a mask circuit having a laminated lower layer (Cr, CrO, CrON, MoSi2, SiO2, etc.), by a suitable application method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating, so that the thickness of the coated film is 0.01 to 2 μm. This is pre-baked on a hot plate, preferably at 60 to 250°C for 10 seconds to 30 minutes, more preferably at 80 to 220°C for 30 seconds to 20 minutes, to form a resist film. In addition, the term "lower layer" refers to a film formed between a substrate and a resist film in a multilayer resist process. As for the above lower layer, it is not particularly limited and conventionally known materials may be used.

[0294] Next, the resist film is exposed using high-energy rays. Examples of the high-energy rays include ultraviolet rays, far-ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. 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 / ㎠ and more preferably 10 to 200 mJ / ㎠ by using a mask for forming the target pattern or directly. When EB is used as the high-energy rays, the exposure amount is preferably 0.1 to 8000 μC / ㎠ and more preferably 0.5 to 5000 μC / ㎠ by using a mask for forming the target pattern or directly. In addition, the resist composition of the present invention is suitable for fine patterning by EB or EUV, particularly among high-energy rays.

[0295] After exposure, PEB is performed as needed. At this time, after exposure, it is preferable to perform the process on a hot plate or in an oven at a temperature of 30 to 200°C for 10 seconds to 30 minutes, more preferably at 60 to 120°C for 30 seconds to 20 minutes.

[0296] After exposure or after PEB, patterning is performed by developing with a developer as needed. The developer used at this time is an alkaline aqueous solution such as an aqueous tetramethylammonium hydroxide solution or an aqueous tetrabutylammonium hydroxide 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 penteneate, methyl crotonicate, ethyl crotonicate, methyl propionate, ethyl propionate, 3-ethyl ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, 2-methyl hydroxyisobutyrate, 2-ethyl hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl phenylacetate, benzyl formate, phenylethyl formate, 3-methyl phenylpropionate, benzyl propionate, 2-phenylethyl acetate, 2-propanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, Examples of organic solvents include 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, ε-caprolactone, etc. These developing solutions may be used as a single type or as a mixture of two or more types.

[0297] After development, rinsing is performed as needed. As for the rinsing solution, a solvent that is mixed with the developer and does not dissolve the resist film is preferred. As such a solvent, alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes, alkenes, alkynes, and aromatic solvents having 6 to 12 carbon atoms are preferably used.

[0298] By rinsing, the breakdown of the resist pattern or the occurrence of defects can be reduced. In addition, rinsing is not strictly necessary, and the amount of solvent used can be reduced by not rinsing.

[0299] Examples

[0300] The present invention will be specifically described below by presenting synthetic examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0301] [1] Synthesis of carboxylic acid derivative compounds

[0302] [Synthesization Example 1-1] Synthesis of Carboxylic Acid Derivative Compound m-1

[0303]

[0304] 4.2 g of 1,3,5-benzenetricarboxylic acid, 7.9 g of triethylamine, and 60 g of methylene chloride were placed in a 200 mL flask and stirred under an ice bath. 9.6 g of 1-chloro-1-methoxy-2-methylpropane was added dropwise, and after stirring at room temperature for 8 hours, 60 mL of water was added. After extracting the organic layer, the organic layer was washed twice with 30 mL of water and concentrated at 40°C to obtain the target compound m-1 in oil form (amount of water 18 g, yield 86%).

[0305] Nuclear magnetic resonance spectrum of compound m-1 ( 1 The results of H-NMR / DMSO-d6) are shown below.

[0306] 1H-NMR (500 MHz, DMSO-d6) δ 0.95 (d, 18H), 3.41 (s, 9H), 4.92 (m, 3H), 5.82 (s, 3H), 8.78 (s, 3H).

[0307] [Synthesization Examples 1-2 to 1-6] Synthesis of Carboxylic Acid Derivative Compounds m-2 to m-6

[0308] Compounds m-2 to m-6 were synthesized using the same method as Synthesis Example 1-1, except that the type of raw material compound was changed.

[0309]

[0310] [2] Synthesis of polymers containing carboxylic acid derivatives

[0311] The monomers used in the synthesis of carboxylic acid derivative-containing polymers P-1 to P-10 are as follows.

[0312]

[0313]

[0314]

[0315] [Synthesization Example 2-1] Synthesis of Polymer P-1

[0316] Under a nitrogen atmosphere, monomer a-1 (70 g), monomer b-1 (11 g), 4.6 g of V-601 (manufactured by Fujifilm Wako Junyaku Co., Ltd.), and 124 g of MEK were placed in a flask to prepare a monomer-polymerization initiator solution. 62 g of MEK was placed in a separate flask under a nitrogen atmosphere and heated to 80°C while stirring, after which the monomer-polymerization initiator solution was added dropwise over 4 hours. After the addition was finished, stirring was continued for 2 hours while maintaining the temperature of the polymerization solution at 80°C, and then cooled to room temperature. The obtained polymerization solution was added dropwise to 4000 g of vigorously stirred hexane, and the precipitated polymer was separated by filtration. The obtained polymer was washed twice with hexane (1200 g) and vacuum dried at 50°C for 20 hours to obtain a white powder-type polymer P-1 (quantity 78 g, yield 98%). The Mw of polymer P-1 was 8000, and the Mw / Mn ratio was 1.44. In addition, Mw is a polystyrene equivalent measurement value by GPC using THF as a solvent.

[0317]

[0318] [Synthesization Examples 2-2 to 2-10] Synthesis of Polymers P-2 to P-10

[0319] The polymer shown in Table 1 below was synthesized using the same method as Synthesis Example 2-1, except that the type and mixing ratio of each monomer were changed.

[0320]

[0321] [3] Preparation of a resist composition

[0322] [Examples 1-1 to 1-20, Comparative Examples 1-1 to 1-4]

[0323] Resist compositions (R-01 to R-20, CR-01 and CR-02) were prepared by dissolving a superautogenous iodine compound, a carboxylic acid derivative or a carboxylic acid compound, and a photogenerator in a solvent containing 0.01 mass% of a surfactant (PF-636, manufactured by Omnova Co.) according to the compositions shown in Table 2 below, and filtering the obtained solution through a 0.2 μm Teflon (registered trademark) filter. In addition, resist compositions (CR-03 and CR-04) were prepared by dissolving a polymer, a photogenerator, and a sensitivity modifier in a solvent containing 0.01 mass% of a surfactant (PF-636, manufactured by Omnova Co.) according to the compositions shown in Table 3 below, and filtering the obtained solution through a 0.2 μm Teflon (registered trademark) filter.

[0324]

[0325]

[0326] In Tables 2 and 3, the ultra-autogenous iodine compounds I-1 to I-3, carboxylic acid compound d-1, thermal acid generators TAG-1 to TAG-3, photo-generating agent PAG-1, sensitivity modifier Q-1, and solvent are as follows.

[0327]

[0328]

[0329]

[0330]

[0331]

[0332] · Solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0333] AcOH (acetic acid)

[0334] GBL (γ-butyrolactone)

[0335] When the carboxylic acid derivative compounds of Examples 1-1 to 1-20 were used, they were soluble only in PGMEA, whereas when the carboxylic acid compounds of Comparative Examples 1-1 and 1-2 were used, they were not soluble without the addition of acetic acid. From this, it was found that by protecting the carboxylic acid and making it a carboxylic acid derivative, it becomes soluble in general-purpose solvents.

[0336] [4] EUV lithography evaluation (line and space pattern)

[0337] [Examples 2-1–2-20, Comparative Examples 2-1–2-4]

[0338] Each resist composition (R-01 to R-20, CR-01 to CR-04) was spin-coated onto a Si substrate having a film thickness of 20 nm formed on a silicon-containing spin-on hard mask SHB-A940 (silicon content of 43 mass%) manufactured by Shin-Etsu Kagaku High School Co., Ltd., and pre-baked (PAB) for 60 seconds at the temperature listed in Table 4 using a hot plate to produce a resist film with a film thickness of 40 nm. With respect to the above resist film, a 36 nm line and space (LS) 1:1 pattern was exposed using an ASML-manufactured EUV scanner NXE3400 (NA 0.33, σ 0.9, 90-degree dipole illumination), and then PEB was performed on a hot plate at the temperature listed in Table 4 for 60 seconds, followed by development with the developer listed in Table 4 for 30 seconds to form an LS pattern with a space width of 18 nm and a pitch of 36 nm.

[0339] The following evaluation was performed on the obtained resist patterns. The results are shown in Table 4.

[0340] [Sensitivity Evaluation]

[0341] The above LS pattern was observed using a measuring SEM (CG-6300) manufactured by Hitachi High-Tech Corporation, and the optimal exposure amount Eop (mJ / cm²) that obtains an LS pattern with a space width of 18 nm and a pitch of 36 nm was determined and used as the sensitivity.

[0342] [LWR Evaluation]

[0343] The LS pattern obtained by irradiating with an optimal exposure amount was measured at 10 points along the length of the space width using a measuring SEM (CG-6300) manufactured by Hitachi High-Tech Corporation, and the value of three times the standard deviation (σ) (3σ) from the result was calculated as LWR. The smaller this value, the less roughness and the more uniform the space width pattern is obtained.

[0344] [Limited Resolution Assessment]

[0345] From the optimal exposure amount at which the above LS pattern is formed, the limit line width (nm) at which the pattern is formed by gradually increasing the exposure amount was determined using a measuring SEM (CG-6300) manufactured by Hitachi High-Tech Corporation, and this was set as the limit resolution (nm). The smaller this value, the better the limit resolution and the finer the pattern can be formed.

[0346]

[0347] Developer: nBA (butyl acetate)

[0348] TMAH (2.38 mass% aqueous solution of tetramethylammonium hydroxide)

[0349] From the results shown in Table 4, when comparing Examples 2-1 to 2-3 and Examples 2-4 to 2-6, it was found that the addition of a thermal acid generator allowed the carboxylic acid derivative compound to be reacted with the carboxylic acid at a low temperature prebaking, thereby enabling the formation of a pattern. Additionally, when comparing Examples 2-17 to 2-20, it was found that the prebaking temperature could be adjusted depending on the type of substituent of the carboxylic acid derivative. Furthermore, when comparing Examples 2-1 to 2-20 and Comparative Examples 2-1 to 2-2, it was found that using a carboxylic acid derivative allowed for the formation of a resist pattern with excellent LWR. Moreover, when compared to Comparative Examples 2-3 and 2-4, which are chemically amplified resist compositions using an acid catalytic reaction, it was found to have excellent sensitivity, resolution, and LWR.

[0350] [5] EUV lithography evaluation (contact hole pattern)

[0351] [Examples 3-1 to 3-20, Comparative Examples 3-1 to 3-4]

[0352] Each resist composition (R-01 to R-20, CR-01 to CR-04) was spin-coated onto a Si substrate having a film thickness of 20 nm formed on a silicon-containing spin-on hard mask SHB-A940 (silicon content of 43 mass%) manufactured by Shin-Etsu Kagaku High School Co., Ltd., and PAB was performed for 60 seconds at the temperature listed in Table 5 using a hot plate to produce a resist film with a film thickness of 50 nm. Next, the resist film was exposed using an ASML-manufactured EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple illumination, wafer dimensions pitch 64 nm, mask of a hole pattern with +20% bias), baked (PEB) on a hot plate at the temperature listed in Table 5 for 60 seconds, and developed with the developer listed in Table 5 for 30 seconds to obtain a hole pattern with dimensions of 32 nm.

[0353] The following evaluation was performed on the obtained resist patterns. The results are shown in Table 5.

[0354] [Sensitivity Evaluation]

[0355] The above contact hole pattern was observed using a measuring SEM (CG-6300) manufactured by Hitachi High-Tech Corporation, and the optimal exposure amount Eop (mJ / cm²) that obtains a hole pattern of 32 nm was determined and used as the sensitivity.

[0356] [CDU Evaluation]

[0357] The dimensions of 50 hole patterns obtained by irradiating with the optimal exposure amount were measured, and the value of three times the standard deviation (σ) calculated from the result (3σ) was set as the CDU. The smaller this value, the more uniform the hole diameter pattern is obtained.

[0358] [Limited Resolution Assessment]

[0359] From the optimal exposure amount at which the above hole pattern is formed, the limiting hole diameter (nm) at which the hole pattern is formed by gradually decreasing the exposure amount was determined using a measuring SEM (CG-6300) manufactured by Hitachi High-Tech Corporation, and this was set as the limiting resolution (nm). A smaller value indicates superior limiting resolution and the ability to form patterns with finer hole diameters.

[0360]

[0361] From the results shown in Table 5, when comparing Examples 3-1 to 3-3 and Examples 3-4 to 3-6, it was found that the addition of a thermal acid generator allowed the carboxylic acid derivative compound to be reacted with the carboxylic acid at a low temperature prebaking, thereby enabling the formation of a pattern. Additionally, when comparing Examples 3-17 to 3-20, it was found that the prebaking temperature could be adjusted depending on the type of substituent of the carboxylic acid derivative. Furthermore, when comparing Examples 3-1 to 3-20 with Comparative Examples 3-1 and 3-2, it was found that using a carboxylic acid derivative allowed for the formation of a resist pattern with excellent CDU. Moreover, when compared to Comparative Examples 3-3 and 3-4, which are chemically amplified resist compositions using an acid catalytic reaction, it was found to have excellent sensitivity, resolution, and CDU.

Claims

Claim 1 A resist composition comprising at least one ultra-autogenous iodine compound represented by any one of the following formulas (1) to (4), a carboxylic acid derivative compound, and a solvent, wherein the carboxylic acid derivative compound is a polymer comprising a carboxylic acid derivative compound represented by the following formula (5) or a carboxylic acid derivative repeating unit represented by the following formula (6). (In the equation, m1 is 0, 1, or 2. When m1 is 0, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, or 5, and 1 ≤ n1 + n2 ≤ 6. When m1 is 1, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, or 7, and 1 ≤ n1 + n2 ≤ 8. When m1 is 2, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9, and 1 ≤ n1 + n2 ≤ 10. n3 is 1 or 2. n4 is 0, 1, 2, 3, or 4, provided that 1 ≤ n3 + n4 ≤ 5. n5 is 1 or 2. n6 is 0, 1, 2, 3, or 4, provided that 1 ≤ n5 + n6 ≤ 5. n7 is 0, 1, 2, 3, or 4. n8 is 1, 2, 3, or 4. m2 is 0, 1, or 2. When m2 is 0, n9 is 0, 1, 2, 3, or 4. When m2 is 1, n9 is 0, 1, 2, 3, 4, 5, or 6. R 1 ~R 8 is a hydrocarbyl group having 1 to 10 carbon atoms, which may each independently contain a halogen atom or a heteroatom. Also, R 1 and R 2 , R 3 and R 4 , R 5 and R 6 , or R 7 and R 8 These may combine with each other to form a ring together with the carbon atoms they bond to and the atoms between these carbon atoms. 11 ~R 14 is a hydrocarbyl group having 1 to 40 carbon atoms, which may each independently contain a halogen atom or a heteroatom. When n2 is 2 or greater, each R 11 They may be identical or different from each other, and multiple R 11 These may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n4 is 2 or greater, each R 12 They may be identical or different from each other, and multiple R 12 They may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n6 is 2 or greater, each R 13 They may be identical or different from each other, and multiple R 13 These may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. When n7 is 2 or greater, each R 14 They may be identical or different from each other, and multiple R 14 They may bond with each other to form a ring together with the carbon atom of the aromatic ring to which they bond. 15 When (n8) having 1 to 40 carbon atoms is a hydrocarbon group or (n8) having 2 to 40 carbon atoms is a heterocyclic group, and n8 is 2, R 15 may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, a sulfonyl group, or a thioketone bond. Additionally, the above (n8) may be substituted with a hydrocarbon group or a group in which part or all of the hydrogen atoms of the heterocyclic group of (n8) are substituted with a group containing a heteroatom, and the above (n8) may be substituted with a group containing a heteroatom for part of the -CH2- of the hydrocarbon group, and R 14 and R 15 They may bond with each other to form a ring together with the carbon atoms they bond to and the atoms between these carbon atoms. 16 It is a hydrocarbyl group having 1 to 10 carbon atoms that may contain a halogen atom or a heteroatom. 17 It is a hydrocarbyl group having 1 to 40 carbon atoms that may contain a halogen atom or a heteroatom. When n9 is 2 or greater, each R 17 They may be identical or different. Also, multiple R 17 These may combine with each other to form a ring together with the carbon atom of the aromatic ring to which they are bonded. 18 is a carbonyl group, or a hydrocarbylene group having 1 to 10 carbon atoms that may contain heteroatoms. *1 and *2 represent bonding losses with carbon atoms of the aromatic ring in the formula. Note that *1 and *2 are bonded to adjacent carbon atoms of the aromatic ring. (In the formula, p is 1, 2, 3, or 4.R 21 When p of C1–40 is a hydrocarbon group or p of C2–40 is a heterocyclic group, and p is 2, R 21 It 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. Additionally, some or all of the hydrogen atoms of the hydrocarbon group or the heterocyclic group p may be substituted with a group containing a heteroatom, and some of the -CH2- of the hydrocarbon group p may be substituted with a group containing a heteroatom. 22 is a single bond or a hydrocarbylene group having 1 to 10 carbon atoms, and some or all of the hydrogen atoms of this hydrocarbylene group may be substituted with a group containing a heteroatom, or some of the -CH2- of this hydrocarbylene group may be substituted with a group containing a heteroatom. When p is 2, 3, or 4, each R 22 They may be identical or different. 23 ~R 26 is a hydrocarbyl group having 1 to 40 carbon atoms, which may each independently contain a halogen atom or a heteroatom. Also, R 23 and R 24 They may bond with each other to form a ring together with the carbon and oxygen atoms to which they bond, and R 25 and R 26 These may combine with each other to form a ring together with the carbon and oxygen atoms to which they bond. A is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. A is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-OX A1 -is. X A1 is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and this saturated hydrocarbylene group may include a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * indicates a bond loss with a carbon atom of the main chain.) Claim 2 A resist composition according to claim 1, wherein the polymer containing the carboxylic acid derivative repeating unit does not contain repeating units containing acid instability groups other than the repeating unit represented by formula (6). Claim 3 A laminate comprising a substrate and a resist film obtained from a resist composition described in claim 1 or 2 on the substrate. Claim 4 In paragraph 3, a laminate having a resist lower layer between the substrate and the resist film. Claim 5 In paragraph 3, the above resist film is a laminate in which the above ultra-electron is formed by the ligand exchange of an iodine compound and a carboxylic acid derivative compound. Claim 6 A pattern forming method comprising: a process of forming a resist film on a substrate or on a lower layer of a substrate having a lower layer laminated thereon, using a resist composition described in claim 1 or 2; a process of exposing the resist film to i-rays, a KrF excimer laser, an ArF excimer laser, an electron beam, or extreme ultraviolet rays; and a process of developing the exposed resist film using a developer.

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