Resist composition and pattern forming method

Abstract

The invention relates to a resist composition and a pattern forming method. The present invention provides a non-chemically amplified resist composition having excellent sensitivity and resolution in photolithography using high-energy rays, and a pattern forming method using the resist composition. The resist composition comprises a hypervalent iodine compound represented by the following formula (1), a carboxyl group-containing polymer and a solvent, the carboxyl group-containing polymer contains a repeating unit represented by formula (2), and at least one repeating unit selected from the group consisting of a repeating unit represented by formula (3), a repeating unit represented by formula (4), a repeating unit represented by formula (5), a repeating unit represented by formula (6), and a repeating unit represented by formula (7). # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a resist composition and a patterning method. Background Art

[0002] With the expansion of the IoT market, there is an increasing demand for higher integration, higher speed, and lower power consumption of LSIs, and the miniaturization of pattern rules has been rapidly progressing. In particular, logic devices are driving miniaturization. As the most advanced miniaturization technology, mass production of devices at the 10 nm node using double patterning, triple patterning, and quadruple patterning based on ArF immersion lithography is underway, and research on devices at the 7 nm node using extreme ultraviolet (EUV) lithography with a next-generation wavelength of 13.5 nm is also in progress.

[0003] With the progress of miniaturization, image blurring caused by acid diffusion has become a problem (Non-Patent Document 1). In order to ensure the resolution of fine patterns of 45 nm or less, it has been proposed that not only improving the dissolution contrast proposed hitherto but also controlling acid diffusion is important (Non-Patent Document 2). However, since the chemically amplified resist composition improves sensitivity and contrast by acid diffusion, if the post-exposure bake (PEB) temperature is lowered or the PEB time is shortened to suppress acid diffusion to the limit, the sensitivity and contrast are significantly reduced.

[0004] It is effective to add an acid generator that generates a large-volume acid to suppress acid diffusion. Therefore, copolymerization of an onium salt type acid generator having a polymerizable unsaturated group with a polymer has been proposed. However, in patterning of a resist film with a processing size of 16 nm or less, from the viewpoint of acid diffusion, it is considered that a chemically amplified resist composition cannot form a pattern, and development of a non-chemically amplified resist composition is desired.

[0005] Materials for non-chemically amplified resist compositions, such as polymethyl methacrylate (PMMA). PMMA is a positive resist material in which the main chain is cut and the molecular weight is reduced by EUV irradiation, thereby increasing the solubility of the organic solvent in the developer.

[0006] Hydrogen silsesquioxane (HSQ) is a negative resist material that is insoluble in an alkali developer due to crosslinking caused by the condensation reaction of silanol generated by EUV irradiation. In addition, chlorine-substituted calixarene also functions as a negative resist material. Since these negative resist materials have a small molecular size before crosslinking and no blurring due to acid diffusion, they have a small edge roughness and very high resolution, and are used as pattern transfer materials for indicating the resolution limit of an exposure apparatus. However, the sensitivity of these materials is insufficient and further improvement is required.

[0007] As the main reason that makes material development for EUV lithography difficult, the small number of photons in EUV exposure can be cited. The energy of EUV is much higher than that of ArF excimer laser, and the number of photons in EUV exposure is 1 / 14 of that in ArF exposure. In addition, the size of the pattern formed by EUV exposure is less than half of that in ArF exposure. Therefore, EUV exposure is easily affected by the deviation of the number of photons. The change in the number of photons in the extremely short wavelength radiation light range is shot noise in physical phenomena, and this influence cannot be eliminated. Therefore, so-called Stochastics has attracted attention. Although the influence of shot noise cannot be eliminated, discussions are underway on how to reduce this influence. Not only does the size uniformity (CDU) and line width roughness (LWR) increase due to the influence of shot noise, but the phenomenon of hole blockage is observed with a probability of one in several million. When the hole is blocked, a conduction failure occurs and the transistor does not operate, so it has a negative impact on the performance of the entire device. Considering practical sensitivity, in resist compositions mainly composed of PMMA and HSQ, it is greatly affected by probability theory and cannot obtain the desired resolution performance.

[0008] As a method for reducing the influence of shot noise on the resist side, the introduction of elements with high EUV light absorption has attracted attention. A chemically amplified resist composition containing iodine atoms with high EUV light absorption was proposed in Patent Document 1. However, as described above, the chemically amplified resist composition cannot achieve excellent resolution performance in future EUV lithography with increasingly finer processing dimensions. Especially in line and space, as the pattern size becomes smaller, pattern collapse and line breakage increase significantly, so reducing them will improve the ultimate resolution.

[0009] Patent Document 2 describes a negative resist composition using a tin compound. This is because it is mainly composed of tin elements with high EUV light absorption, so probability theory is improved, and high sensitivity and high resolution can be achieved. However, this so-called metal resist has many problems, such as insufficient solubility in resist solvents, storage stability, and defects caused by residues after etching. Furthermore, since the metal resist is a negative type that mainly becomes insoluble in the developer by becoming a metal oxide in the exposed part, when used for patterning contact holes, an additional inversion treatment step is required, and there are also cost problems.

[0010] Prior Art Documents

[0011] Patent Documents

[0012] [Patent Document 1] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-5224

[0013] [Patent Document 2] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-503482

[0014] Non-Patent Literature

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

[0016] [Non-Patent Literature 2] SPIE Vol.6520 p65203L-1 (2007) Summary of the Invention

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

[0018] The present invention has been completed in view of the above circumstances, and an object thereof is to provide a chemically amplified resist composition excellent in sensitivity and ultimate resolution in lithography using high-energy rays, particularly electron beam (EB) lithography and EUV lithography, and a pattern forming method using the resist composition.

[0019] [Means for Solving the Problems]

[0020] The inventors of the present invention repeatedly conducted in-depth studies to achieve the above object, and as a result, found that a resist composition mainly composed of a specific hypervalent iodine compound and a polymer having a carboxyl group and a specific cyclic structure provides a resist film having extremely high sensitivity and excellent resolution, and is extremely effective for precise microfabrication, thereby completing the present invention.

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

[0022] 1. A resist composition comprising a hypervalent iodine compound represented by the following formula (1), a carboxyl group-containing polymer, and a solvent,

[0023] The carboxyl group-containing polymer includes a repeating unit represented by the following formula (2) and at least one selected from the repeating units represented by the following formula (3), the repeating unit represented by the following formula (4), the repeating unit represented by the following formula (5), the repeating unit represented by the following formula (6), and the repeating unit represented by the following formula (7).

[0024] [Chemical Formula 1]

[0025]

[0026] In the formula, n is an integer of 0 to 5.

[0027] R 1 and R 2 are each independently a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may contain a hetero atom. In addition, R 1 and R 2 may be bonded to each other and form a ring together with the carbon atom to which they are bonded and the atoms between the carbon atoms.

[0028] R 3 is a halogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may also contain a heteroatom.

[0029] [Chemical formula 2]

[0030]

[0031] In the formula, a is an integer from 0 to 2. b is an integer satisfying 0 ≤ b ≤ 5 + 2a. c is an integer from 0 to 2.

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

[0033] X A represents a single bond, a phenylene group, a naphthylene group or *-C(=O)-O-X A1 -, X A1 is a saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, and the saturated alkylene group may contain at least one selected from a hydroxyl group, an ether bond, an ester bond and a lactone ring. * represents a bonding bond to a carbon atom of the main chain.

[0034] X B each independently represents -CH2- or -O-.

[0035] R 11 represents a hydroxyl group, a halogen atom, a nitro group, a sulfo group, a carboxyl group, an isocyanate group, a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom, -N(R 11A )(R 11B ), -P(R 11C )(R 11D ), -B(OR 11E )(OR 11F ), -O-R 11G , -C(=O))-O-R 11G , -O-C(=O)-R 11G , R 11A and R 11B each independently is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. R[[ID=I59]] 11C and R 11D each independently is a hydrocarbon group having 1 to 20 carbon atoms. R 11E and R 11F each independently is a hydrocarbon group having 1 to 20 carbon atoms. Further, R 11E and R 11F may be bonded to each other and form a ring together with the boron atom to which they are bonded. R 11G each independently is a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom.

[0036] R 12 、R 13and R 15 ~R 17 Each independently is a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. Further, R 12 and R 13 may be bonded to each other and together with the carbon atom to which they are bonded form a ring, and R 15 and R 16 and / or R 16 and R 17 may be bonded to each other and together with the carbon atom to which they are bonded form a ring.

[0037] R 14 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom.

[0038] 2. A laminate comprising a substrate and a resist film obtained from the resist composition of 1. on the substrate.

[0039] 3. The laminate of 2., wherein an underlayer film is provided between the substrate and the resist film.

[0040] 4. A pattern forming method comprising: a step of forming a resist film on a substrate or on the underlayer film of a substrate on which an underlayer film is laminated, using the resist composition of 1.; a step of exposing the resist film with i-ray, KrF excimer laser, ArF excimer laser, electron beam, or extreme ultraviolet ray; and a step of developing the exposed resist film with a developer.

[0041] 5. The pattern forming method of 4., wherein the developer is an organic solvent.

[0042] [Effects of the Invention]

[0043] The resist composition of the present invention is particularly useful in forming fine patterns, taking into account high sensitivity and high resolution especially in i-ray, KrF excimer laser, ArF excimer laser, EB lithography, and EUV lithography. Detailed Description of the Invention

[0044] [Resist Composition]

[0045] The resist composition of the present invention contains a specified hypervalent iodine compound and a carboxyl group-containing polymer as main components.

[0046] [Hypervalent Iodine Compound]

[0047] The above hypervalent iodine compound is a three-coordinate hypervalent iodine compound represented by the following formula (1).

[0048] [Chemical Formula 3]

[0049]

[0050] In formula (1), n is an integer from 0 to 5.

[0051] In formula (1), R 1 and R 2 are each independently a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may also contain a heteroatom. Further, R 1 and R 2 may be bonded to each other and together with the carbon atom to which they are attached and the carbon atoms between them form a ring. Examples of the aforementioned halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The aforementioned hydrocarbon group having 1 to 10 carbon atoms may be saturated or unsaturated and may be any of linear, branched, and cyclic. As specific examples thereof, alkyl groups having 1 to 10 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group, a tert-pentyl group, a n-hexyl group, a n-octyl group, a 2-ethylhexyl group, a n-nonyl group, a n-decyl group, etc.; cyclic saturated hydrocarbon groups having 3 to 10 carbon atoms such as 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 2,6 decyl group, an adamantyl group, etc.; alkenyl groups having 2 to 10 carbon atoms such as a vinyl group, an allyl group, etc.; aryl groups having 6 to 10 carbon atoms such as a phenyl group, a naphthyl group, etc.; groups obtained by combining them, etc. Further, a part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and a part of -CH2- of the aforementioned hydrocarbon group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc. As a result, it may contain a hydroxyl group, a cyano group, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), etc. R 1 and R 2 are preferably hydrocarbon groups having 1 to 4 carbon atoms.

[0052] In formula (1), R 3 is a halogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may also contain a heteroatom. When n is 2 to 5, each R 3They may be the same as or different from each other. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The hydrocarbon group having 1 to 40 carbon atoms may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group, a tert-pentyl group, a n-hexyl group, a n-octyl group, a 2-ethylhexyl group, a n-nonyl group, a n-decyl group; cyclic saturated hydrocarbon groups having 3 to 40 carbon atoms such as 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 2,6 decyl group, an adamantyl group, an adamantylmethyl group; aryl groups having 6 to 40 carbon atoms such as a phenyl group, a naphthyl group, an anthryl group, etc. In addition, part or all of the hydrogen atoms of the above hydrocarbon group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and part of -CH2- of the above hydrocarbon group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc. As a result, it may contain a hydroxyl group, a cyano group, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), etc.

[0053] Specific examples of the hypervalent iodine compound represented by the formula (1) include the compounds shown below, but are not limited thereto.

[0054] [Formula 4]

[0055]

[0056] [Chemical Formula 5]

[0057]

[0058] [Chemical Formula 6]

[0059]

[0060] [Chemical Formula 7]

[0061]

[0062] [Chemical Formula 8]

[0063]

[0064] [Chemical Formula 9]

[0065]

[0066] [Polymer containing a carboxyl group]

[0067] The carboxyl group-containing polymer described above contains a repeating unit represented by the following formula (2) and at least one repeating unit selected from the repeating units represented by the following formula (3), the repeating unit represented by the following formula (4), the repeating unit represented by the following formula (5), the repeating unit represented by the following formula (6), and the repeating unit represented by the following formula (7).

[0068] [Chemical formula 10]

[0069]

[0070] In formulas (2) to (7), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0071] In formula (2), X A represents a single bond, a phenylene group, a naphthylene group, or *-C(=O)-O-X A1 -. X A1 is a saturated alkylene group having 1 to 10 carbon atoms, a phenylene group, or a naphthylene group, and the saturated alkylene group may contain at least one selected from a hydroxyl group, an ether bond, an ester bond, and a lactone ring. * represents a bonding bond to a carbon atom of the main chain.

[0072] In formula (3), a is an integer of 0 to 2. b is an integer satisfying 0 ≤ b ≤ 5 + 2a.

[0073] In formula (3), R 11 represents a hydroxyl group, a halogen atom, a nitro group, a sulfo group, a carboxyl group, an isocyanate group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, -N(R 11A )(R 11B ), -P(R 11C )(R 11D ), -B(OR 11E )(OR 11F ), -O-R 11G , -C(=O))-O-R 11G , -O-C(=O)-R 11G . R 11A and R 11B are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. R 11C and R 11D are each independently a hydrocarbon group having 1 to 20 carbon atoms. R 11E and R 11F are each independently a hydrocarbon group having 1 to 20 carbon atoms. Additionally, R 11E and R 11F may be bonded to each other and together with the boron atom to which they are bonded form a ring. R 11G are each independently a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0074] In formula (4), c is an integer from 0 to 2.

[0075] In formula (4), X B Each independently represents -CH2- or -O-.

[0076] In formulas (4) and (7), R 12 、R 13 and R 15 ~R 17 Each independently is a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. Additionally, R 12 and R 13 may be bonded to each other and together with the carbon atom to which they are bonded form a ring, and R 15 and R 16 and / or R 16 and R 17 may be bonded to each other and together with the carbon atom to which they are bonded form a ring.

[0077] In formula (6), R 14 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom.

[0078] R 11 、R 12 、R 13 and R 15 ~R 17 The halogen atoms represented, for example, are fluorine atom, chlorine atom, bromine atom, iodine atom, etc.

[0079] R 11 ~R 17 and R 11A ~R 11G The hydrocarbon groups represented may be saturated or unsaturated, and may be linear, branched or cyclic. As specific examples thereof, alkyl groups having 1 to 20 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, n-decyl, etc.; cycloalkyl saturated hydrocarbon groups having 3 to 20 carbon atoms such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 decyl, adamantyl, etc.; alkenyl groups having 2 to 20 carbon atoms such as vinyl, allyl, etc.; aryl groups having 6 to 20 carbon atoms such as phenyl, naphthyl, etc.; groups obtained by combining them, etc. Additionally, R 11 ~R 17 and R 11GThe represented hydrocarbon group, a part or all of the hydrogen atoms of which may be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and a part of its -CH2- may be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc. As a result, it may contain a hydroxyl group, a cyano group, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), etc.

[0080] Specific examples of the repeating unit represented by the formula (2) include, but are not limited to, the following examples. In the following formulas, R A Is the same as above.

[0081] [Chemical formula 11]

[0082]

[0083] [Chemical formula 12]

[0084]

[0085] As specific examples of the repeating unit represented by the formula (3), those shown below can be cited, but are not limited to these. It should be noted that in the following formulas, R A Is the same as above.

[0086] [Chemical formula 13]

[0087]

[0088] [Chemical formula 14]

[0089]

[0090] [Chemical formula 15]

[0091]

[0092] [Chemical formula 16]

[0093]

[0094] [Chemical formula 17]

[0095]

[0096] [Chemical formula 18]

[0097]

[0098] As specific examples of the repeating unit represented by the formula (4), the following repeating units can be cited, but are not limited to these. It should be noted that in the following formulas, R A And X BSame as above.

[0099] [Chemical Formula 19]

[0100]

[0101] [Chemical Formula 20]

[0102]

[0103] [Chemical Formula 21]

[0104]

[0105] [Chemical Formula 22]

[0106]

[0107] [Chemical Formula 23]

[0108]

[0109] As specific examples of the repeating unit represented by formula (6), those shown below can be cited, but are not limited to these. It should be noted that in the following formulas, R A Same as above.

[0110] [Chemical Formula 24]

[0111]

[0112] [Chemical Formula 25]

[0113]

[0114] As specific examples of the repeating unit represented by formula (7), the repeating units shown below can be cited, but are not limited to these. It should be noted that in the following formulas, R A Same as above.

[0115] [Chemical Formula 26]

[0116]

[0117] [Chemical Formula 27]

[0118]

[0119] In the above carboxyl group-containing polymer, the content ratio (molar ratio) of the repeating unit represented by formula (2) and the repeating unit other than the repeating unit represented by formula (2) is preferably the repeating unit represented by formula (2): the repeating unit other than the repeating unit represented by formula (2) =  10:90 to 90:10, more preferably 15:85 to 85:15, and still more preferably 20:80 to 80:20.

[0120] The weight average molecular weight (Mw) of the above carboxyl group-containing polymer is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. It should be noted that in the present invention, Mw is a polystyrene conversion measurement value by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0121] In addition, when the above carboxyl group-containing polymer has a wide Mw / Mn distribution, since there are polymers with low molecular weight and high molecular weight, foreign substances may be observed on the pattern after exposure, or the shape of the pattern may deteriorate. Therefore, as the pattern rules are miniaturized, the influence of Mw and Mw / Mn tends to become larger. Therefore, in order to obtain a resist composition suitable for a fine pattern size, the Mw / Mn of the above carboxyl group-containing polymer is preferably a narrow dispersion of 1.0 to 2.0.

[0122] As a method for synthesizing the above carboxyl group-containing polymer, for example, a method of adding a radical polymerization initiator to a monomer providing the above repeating unit in an organic solvent and heating it to polymerize can be cited.

[0123] Examples of the organic solvent used in the polymerization reaction include: toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, cyclopentanone, cyclohexanone, methyl ethyl ketone (MEK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), γ-butyrolactone (GBL), etc. Examples of the above polymerization initiator 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, lauroyl peroxide, etc. The addition amount of these initiators is preferably 0.01 to 25 mol% relative to the total of the polymerized monomers. The reaction temperature is preferably 50 to 150°C, more preferably 60 to 100°C. The reaction time is preferably 2 to 24 hours, and from the viewpoint of production efficiency, more preferably 2 to 12 hours.

[0124] The above polymerization initiator can be added to the above monomer solution and supplied to the reaction kettle, or an initiator solution can be prepared separately from the above monomer solvent and supplied to the reaction kettle independently. Since there is a possibility of polymerization reaction due to free radicals generated from the initiator during the standby time and the formation of ultra-high molecular weight substances, from the perspective of quality control, it is advisable to prepare the monomer solution and the initiator solution independently and carry out dropping. The acid-labile group can be directly the group introduced into the monomer, or can be protected or partially protected after polymerization. In addition, in order to adjust the molecular weight, known chain transfer agents such as dodecane mercaptan and 2-mercaptoethanol can also be used in combination. In this case, the addition amount of these chain transfer agents is preferably 0.01 to 20 mol% relative to the total amount of the polymerized monomers.

[0125] It should be noted that the amounts of the respective monomers in the above monomer solution can be appropriately set, for example, in such a way that the ideal content ratio of the above repeating units is achieved.

[0126] In the resist composition of the present invention, the above hypervalent iodine compound and the above carboxyl group-containing polymer are preferably contained in such a way that the molar ratio of the hypervalent iodine compound to the carboxylic acid repeating unit-containing ratio in the above polymer is 10:90 to 90:10, more preferably in such a way that it is 20:80 to 80:20, and still more preferably in such a way that it is 30:70 to 70:30. The above hypervalent iodine compound can be used alone as one kind, or two or more kinds having different composition ratios, Mw and / or Mw / Mn can be used in combination. The above carboxyl group-containing polymer can be used alone as one kind, or two or more kinds having different composition ratios, Mw and / or Mw / Mn can be used in combination.

[0127] [Solvent]

[0128] The resist composition of the present invention contains a solvent. There is no particular limitation on the solvent as long as it can dissolve the aforementioned hypervalent iodine compound, the carboxyl group-containing polymer, and the following other components and form a film. As such a solvent, an organic solvent is preferred. For example, ketones such as cyclohexanone, methyl-2-n-amyl ketone, and methyl isoamyl ketone can be cited; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, methyl 2-hydroxyisobutyrate, and 4-methyl-2-pentanol can be cited; 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 can be cited; 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 monoter-butyl ether acetate can be cited; carboxylic acids such as formic acid, acetic acid, and propionic acid can be cited; lactones such as γ-butyrolactone can be cited; and their mixed solvents, etc.

[0129] In the resist composition of the present invention, the content of the aforementioned solvent is preferably an amount such that the solid content concentration in the resist composition becomes 0.1% by mass to 20% by mass, more preferably an amount that becomes 0.1% by mass to 15% by mass, and even more preferably an amount that becomes 0.1% by mass to 10% by mass. It should be noted that in the present invention, the solid content refers to the total of the components other than the solvent among all the components of the resist composition.

[0130] [Other components]

[0131] The resist composition of the present invention may further contain a surfactant. As the aforementioned surfactant, a fluorine-based and / or silicone-based surfactant is preferred. As such a surfactant, the surfactant described in paragraph

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

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

[0132] When the resist composition of the present invention contains the aforementioned surfactant, its content is preferably 0.0001 to 2% by mass in the total solid content. The above surfactant can be used alone or in combination of two or more.

[0133] The resist composition of the present invention may further contain a radical scavenger. By adding a radical scavenger, the light reaction in optical lithography can be controlled and the sensitivity can be adjusted.

[0134] As the above radical scavenger, hindered phenols, quinones, hindered amines, thiol compounds, etc. can be cited. Specifically, as hindered phenols, dibutylhydroxytoluene (BHT), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), etc. can be cited. As quinones, 4-methoxyphenol (p-methoxyphenol), hydroquinone, etc. can be cited. As hindered amines, 2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-N-oxyl, etc. can be cited. As thiols, dodecanethiol, hexadecanethiol, etc. can be cited.

[0135] When the resist composition of the present invention contains the above radical scavenger, its content is preferably 0.01 to 10% by mass in all the solid content. The above radical scavenger can be used alone or in combination of two or more.

[0136] As described above, the resist composition of the present invention contains a hypervalent iodine compound and a carboxyl group-containing polymer as main components, but does not contain a polymer having an acid-labile group and a photoacid generator contained in a known chemically amplified resist composition. However, the resist composition of the present invention, particularly by EB or EUV exposure, the exposed portion becomes soluble in the developer, and a positive-type pattern can be formed. The mechanism is not yet fully understood, but is speculated as follows, for example.

[0137] The hypervalent iodine compound used in the present invention is a tricoordinate compound in which an aryl group represented by the formula (1) is bonded to two carboxylate ligands. It is considered that by mixing such a tricoordinate iodide with a carboxylic acid compound, an exchange of carboxylate ligands occurs in the equilibrium reaction. At this time, if the original carboxylate ligand can be removed by some method, a hypervalent iodine compound having a new ligand is generated. For example, iodobenzene diacetate, which is relatively easy to obtain as a hypervalent iodine compound, is mixed with a carboxylic acid compound having a large molecular weight, and the generated low-boiling acetic acid is removed, thereby completing the ligand exchange. Here, when the carboxylic acid compound is a polymer, it becomes a high-molecular-weight hypervalent iodine compound in which the polymers are crosslinked by the hypervalent iodine compound.

[0138] A polymer crosslinked by a hypervalent iodine compound is formed during film formation. Since even if such a crosslinked polymer is synthesized in advance, they cannot be dissolved in most organic solvents, a solution cannot be prepared. It is speculated that this is because the hypervalent iodine compound, which originally has low solubility in solvents due to large polarization, has further deteriorated solubility by using a carboxylic acid-containing polymer as a high-molecular-weight body as a ligand. Therefore, it is preferable to remove the original low-molecular carboxylic acid component during film formation and the subsequent baking step to complete the ligand exchange reaction and form a resist film at the same time.

[0139] The resist film obtained from the resist composition of the present invention has very low solubility in organic solvents because it contains a polymer crosslinked by a hypervalent iodine compound generated during film formation. However, it is decomposed by light to become a monovalent iodine compound, and at the same time, the crosslinking between the polymers is released and the molecular weight is also reduced. As a result, it is speculated that the exposed portion becomes soluble in the developer, which is an organic solvent, and functions as a positive-type resist composition.

[0140] The polymer used in the resist composition of the present invention is a copolymer containing a carboxyl group-containing unit represented by the formula (2) and a repeating unit represented by any one of the formulas (3) to (7). The units represented by any one of the formulas (3) to (7) all have a rigid structure with a cyclic structure. Therefore, for example, the collapse resistance is excellent in line and space formation, and the etching resistance is also improved.

[0141] Based on the above speculation, the resist composition of the present invention is a non-chemically amplified resist composition and does not require a polymer having an acid-labile group and a photoacid generator as in a known chemically amplified resist composition. Therefore, adverse effects caused by acid diffusion (such as blurring of images) will not occur, and fine patterns can be resolved.

[0142] The resist composition of the present invention is extremely effective particularly in EUV lithography. This is due to iodine having a high absorption ability for EUV light. That is, shot noise can be reduced, and higher resolution and low LWR can be achieved.

[0143] As an EUV resist composition capable of forming fine patterns, a metal resist having a metal tin compound, which has the same high absorption ability for EUV light as iodine atoms, as a main component has been reported (for example, Patent Document 2). However, as described above, such a metal resist has many problem points such as insufficient solubility in a solvent, storage stability, and defects caused by residues generated after etching due to the inclusion of elemental metal. On the other hand, since the resist composition of the present invention does not use a metal element, it is more advantageous than the metal resist in terms of defects, and there is no problem with solubility in a solvent. In addition, by using the resist composition of the present invention, since a positive pattern is formed by non-development or development with an organic solution, for example, in a contact hole formation step, a reversal treatment step by negative development is not required. From these viewpoints, it can be said that the resist composition of the present invention is more advantageous than the metal resist.

[0144] Japanese Patent Application Laid-Open No. 2015-180928 and Japanese Patent Application Laid-Open No. 2018-95853 describe a resist composition containing a hypervalent iodine compound as an additive and a resist composition in which a hypervalent iodine compound is bonded to the polymer backbone of a base polymer. However, as the characteristics of the resist compositions described in these documents, only improvement of line edge roughness is described, and the possibility of photodecomposition of the hypervalent iodine compound is not mentioned at all, nor is the possibility of functioning as a material for a non-chemically amplified resist composition mentioned at all. Furthermore, based on the description of the blending amount and specific examples, the hypervalent iodine compound does not become the main component. Therefore, it is considered that a material capable of reducing shot noise in EUV lithography and forming fine patterns as a material for a non-chemically amplified resist composition as in the present invention cannot be conceived from these patent documents. That is, it can be said that the present invention clearly provides a novel resist composition and a pattern forming method.

[0145] [Pattern Forming Method]

[0146] When the resist composition of the present invention is used in the manufacture of various integrated circuits, known lithography methods can be used. For example, as a pattern formation method, a method including the following steps can be cited: a step of forming a resist film on a substrate or on the underlying film of a substrate having an underlying film laminated thereon using the above-described resist composition; a step of exposing the resist film with the aforementioned high-energy rays; and a step of developing the exposed resist film with a developer as needed.

[0147] First, the resist composition of the present invention is coated on a substrate for integrated circuit manufacturing, or on the underlying film of a substrate (such as Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflection film, etc.) having an underlying film laminated thereon, on a substrate for mask circuit manufacturing, or on the underlying film of a substrate (such as Cr, CrO, CrON, MoSi2, SiO2) having an underlying film laminated thereon, and is coated by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, blade coating, etc. so that the coating thickness becomes 0.01 to 2 μm. It is prebaked on a hot plate, preferably at 60 to 200 °C for 10 seconds to 30 minutes, more preferably at 80 to 180 °C for 30 seconds to 20 minutes, to form a resist film. It should be noted that the underlying film refers to a film formed between the substrate and the resist film in a multi-layer resist process. As the aforementioned underlying film, there is no particular limitation, and conventionally known underlying films can be used.

[0148] Next, the resist film is exposed using high-energy rays. As the aforementioned high-energy rays, ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, γ-rays, synchrotron radiation, etc. can be cited. When using ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, γ-rays, synchrotron radiation, etc. as the aforementioned high-energy rays, directly or using a mask for forming a target pattern, the exposure dose is preferably 1 to 300 mJ / cm 2 or so, more preferably 10 to 200 mJ / cm 2 or so for irradiation. In the case of using EB as the high-energy line, directly or using a mask for forming a target pattern, the exposure dose is preferably 0.1 to 8000 μC / cm 2 or so, more preferably 0.5 to 1500 μC / cm 2 or so for drawing. It should be noted that the resist composition of the present invention is particularly suitable for fine patterning using EB or EUV among high-energy rays.

[0149] PEB needs to be performed after exposure. At this time, it is preferably carried out under the conditions of baking on a hot plate or in an oven at 30 to 150 °C for 10 seconds to 30 minutes, more preferably at 60 to 120 °C for 30 seconds to 20 minutes after exposure.

[0150] After exposure or PEB, development is carried out using a developer as needed to form a pattern. In the present invention, by developing with an organic solvent, the exposed portion can be dissolved, and a positive pattern can be obtained. As the developer used at this time, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, isopropyl alcohol, n-butanol, n-pentanol, formic acid, acetic acid, propionic acid, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, hexyl acetate, cyclohexyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl phenylacetate, benzyl formate, phenethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, 2-propanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, 4-methyl-2-pentanol, toluene, anisole, xylene and other organic solvents can be mentioned. These organic solvents can be used alone or in combination of two or more.

[0151] After development, rinsing is carried out as needed. As the rinsing liquid, a solution that is miscible with the developer and does not dissolve the resist film is preferably used. As such a solvent, an alcohol having 3 to 10 carbon atoms, an ether compound having 8 to 12 carbon atoms, an alkane, alkene, alkyne, or aromatic solvent having 6 to 12 carbon atoms is preferably used.

[0152] By carrying out rinsing, collapse of the resist pattern and generation of defects can be reduced. In addition, rinsing is not essential, and by not carrying out rinsing, the amount of solvent used can be reduced.

[0153] Examples

[0154] Hereinafter, synthesis examples, examples and comparative examples are shown to specifically illustrate the present invention, but the present invention is not limited to the following examples.

[0155] [1] Synthesis of polymer

[0156] The monomers used in the synthesis of the polymer are as described above.

[0157] [Chemical formula 28]

[0158]

[0159] [Chemical formula 29]

[0160]

[0161] [Chemical formula 30]

[0162]

[0163] [Chemical formula 31]

[0164]

[0165] [Chemical formula 32]

[0166]

[0167] [Synthesis Example 1] Synthesis of Polymer P-1

[0168] Under a nitrogen atmosphere, 56 g of monomer a-1, 36 g of monomer b-1, 5.4 g of V-601 (manufactured by Fuji Photo Film Co., Ltd.) and 180 g of MEK were measured in a flask to prepare a monomer-polymerization initiator solution. Under a nitrogen atmosphere, 55 g of MEK was placed in another flask, heated to 80 °C with stirring, and then the aforementioned monomer-polymerization initiator solution was added dropwise over 4 hours. After the addition was completed, stirring was continued for 2 hours while maintaining the temperature of the polymerization solution at 80 °C, and then it was cooled to room temperature. The resulting 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 then vacuum dried at 50 °C for 20 hours to obtain a white powder polymer P-1 (yield 90 g, yield 98%). The Mw of polymer P-1 was 8000, and Mw / Mn was 1.42. It should be noted that Mw is a polystyrene conversion measurement value obtained by GPC using THF as a solvent.

[0169] [Chemical formula 33]

[0170]

[0171] [Synthesis Examples 2 to 26] Synthesis of Polymers P-2 to P-26

[0172] Except for changing the types and mixing ratios of the respective monomers, the polymers shown in Table 1 below were synthesized by the same method as in Synthesis Example 1.

[0173] [Table 1]

[0174]

[0175] [2] Preparation of Resist Composition

[0176] [Examples 1-1 to 1-26, Comparative Examples 1-1 to 1-3]

[0177] In addition, a hypervalent iodine compound and a polymer were dissolved in a solvent containing 0.01% by mass of a surfactant (PF-636, manufactured by Omnova Solutions Inc.) according to the composition shown in Table 2 below, and the resulting solution was filtered through a 0.2-μm Teflon (registered trademark) filter to prepare resist compositions (R-01 to R-26 and CR-01). In addition, a hypervalent iodine compound and a polymer were dissolved in a solvent containing 0.01% by mass of a surfactant (PF-636, manufactured by Omnova Solutions Inc.) according to the composition shown in Table 3 below, and the resulting solution was filtered through a 0.2-μm Teflon (registered trademark) filter to prepare resist compositions (CR-02 to CR-03).

[0178] [Table 2]

[0179]

[0180]

[0181] [Table 3]

[0182]

[0183] In Tables 2 and 3, the hypervalent iodine compounds (I-1 to I-3), photoacid generator PAG-1, sensitivity adjuster Q-1, and solvent are as described above.

[0184] [Chemical Formula 34]

[0185]

[0186] [Chemical Formula 35]

[0187]

[0188] [Chemical Formula 36]

[0189]

[0190] · Solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0191] AcOH (acetic acid)

[0192] GBL (γ-butyrolactone)

[0193] [3] EUV Lithography Evaluation (1)

[0194] [Examples 2-1 to 2-26, Comparative Examples 2-1 to 2-3]

[0195] Each of the resist compositions (R-01 to R-26, CR-01 to CR-03) was spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content: 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd. was formed to a film thickness of 20 nm, and pre-baked (PAB) for 60 seconds at the temperature shown in Table 4 using a hot plate to fabricate a resist film with a film thickness of 40 nm. For the aforementioned resist film, after exposing a pattern of 36 nm line and space (LS) 1:1 using an EUV scanner NXE3400 (NA 0.33, σ 0.9, 90° dipole illumination) manufactured by ASML, PEB was performed for 60 seconds at the temperature shown in Table 4 on a hot plate, and then development was carried out for 30 seconds using the developer shown in Table 4 to form an LS pattern with a space width of 18 nm and a pitch of 36 nm.

[0196] For the obtained resist pattern, the following evaluations were performed. The results are shown in Table 4.

[0197] [Sensitivity evaluation]

[0198] The aforementioned LS pattern was observed using a length-measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, and the optimum exposure dose Eop (mJ / cm 2 ) at which an LS pattern with a space width of 18 nm and a pitch of 36 nm could be obtained was determined and taken as the sensitivity.

[0199] [LWR evaluation]

[0200] For the LS pattern obtained by irradiation at the optimum exposure dose, the dimensions at 10 locations in the length direction of the space width were measured using a length-measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, and three times the standard deviation (σ) (3σ) was determined from the results and taken as the LWR. The smaller this value, the smaller the roughness and the more uniform the pattern of the space width that can be obtained.

[0201] [Limit resolution evaluation]

[0202] Using a length-measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, the limit line width (nm) at which resolution could be achieved when forming a pattern by gradually increasing the exposure dose from the optimum exposure dose for forming the aforementioned LS pattern was determined and taken as the limit resolution (nm). The smaller this value, the more excellent the limit resolution and the finer the pattern that can be formed.

[0203] [Table 4]

[0204]

[0205]

[0206] Developer: nBA (butyl acetate)

[0207] TMAH (2.38 mass% aqueous solution of tetramethylammonium hydroxide)

[0208] As can be seen from the results shown in Table 4, the resist composition of the present invention is excellent in sensitivity, LWR, and resolution in the formation of LS patterns based on EUV exposure.

[0209] [4] EUV lithography evaluation (2)

[0210] [Examples 3-1 to 3-26, Comparative Examples 3-1 to 3-3]

[0211] Each resist composition (R-01 to R-26, CR-01 to CR-03) was spin-coated on a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (Si content: 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd. was formed with a film thickness of 20 nm, and PAB was performed for 60 seconds at the temperature described in Table 5 using a hot plate to produce a resist film with a film thickness of 50 nm. Subsequently, the aforementioned resist film was exposed using an EUV scanner NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask for a hole pattern with a pitch of 64 nm and a +20% deviation in the on-wafer size), PEB was performed for 60 seconds at the temperature described in Table 5 on a hot plate, and development was performed for 30 seconds using the developer described in Table 5 to obtain a hole pattern with a size of 32 nm.

[0212] The obtained resist pattern was evaluated as follows. The results are shown in Table 5.

[0213] [Sensitivity evaluation]

[0214] The aforementioned contact hole pattern was observed using a length-measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, and the optimum exposure dose Eop (mJ / cm 2 ) for obtaining a hole pattern with a size of 22 nm was obtained and used as the sensitivity.

[0215] [CDU evaluation]

[0216] The sizes of 50 hole patterns obtained by irradiation at the optimum exposure dose were measured, and three times the standard deviation (σ) calculated from the results (3σ) was used as the CDU. The smaller this value, the more uniform the pattern of the hole diameter can be obtained.

[0217] [Limit resolution evaluation]

[0218] Using a length-measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, the limiting aperture (nm) at which resolution is achieved when forming a hole pattern while gradually reducing the exposure dose from the optimum exposure dose for forming the aforementioned hole pattern was obtained and used as the limit resolution (nm). The smaller this value, the more excellent the limit resolution, and the finer the pattern of the hole diameter can be formed.

[0219] [Table 5]

[0220]

[0221]

[0222] As can be seen from the results shown in Table 5, the resist composition of the present invention is excellent in sensitivity, CDU, and resolution in the formation of contact hole patterns based on EUV exposure.

Claims

1. A resist composition comprising a hypervalent iodine compound represented by the following formula (1), a carboxyl group-containing polymer, and a solvent. The carboxyl group-containing polymer contains a repeating unit represented by the following formula (2) and at least one repeating unit selected from repeating units represented by the following formula (3), repeating unit represented by the following formula (4), repeating unit represented by the following formula (5), repeating unit represented by the following formula (6), and repeating unit represented by the following formula (7). In the formula, n is an integer from 0 to 5. R 1 and R 2 each independently represents a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may also contain a hetero atom. Further, R 1 and R 2 may be bonded to each other to form a ring together with the carbon atom to which they are bonded and the atoms between the carbon atoms R 3 is a halogen atom, or a hydrocarbon group having 1 to 40 carbon atoms which may also contain a heteroatom, In the formula, a is an integer from 0 to 2, b is an integer satisfying 0 ≤ b ≤ 5 + 2a, and c is an integer from 0 to 2. R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, X A represents a single bond, a phenylene group, a naphthylene group or *-C(=O)-O-X A1 -, X A1 is a saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, and the saturated alkylene group may contain at least one selected from a hydroxyl group, an ether bond, an ester bond and a lactone ring, and * represents a bonding bond to a carbon atom of the main chain X B each independently represents -CH2- or -O- R 11 represents a hydroxyl group, a halogen atom, a nitro group, a sulfo group, a carboxyl group, an isocyanate group, a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom, -N(R 11A )(R 11B ), -P(R 11C )(R 11D ), -B(OR 11E )(OR 11F ), -O-R 11G , -C(=O))-O-R 11G , -O-C(=O)-R 11G , where R 11A and R 11B are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, R 11C and R 11D are each independently a hydrocarbon group having 1 to 20 carbon atoms, R 11E and R 11F are each independently a hydrocarbon group having 1 to 20 carbon atoms, and further, R 11E and R 11F may be bonded to each other and together with the boron atom to which they are bonded form a ring, and R 11G are each independently a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. R 12 、R 13 and R 15 ~R 17 each independently represents a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. Further, R 12 and R 13 may be bonded to each other and together with the carbon atom to which they are bonded form a ring, and R 15 and R 16 and / or R 16 and R 17 may be bonded to each other and together with the carbon atom to which they are bonded form a ring. R 14 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom.

2. A laminate comprising a substrate and a resist film obtained from the resist composition according to claim 1 on the substrate.

3. The laminate according to claim 2, wherein, A lower layer film is provided between the substrate and the resist film.

4. A pattern forming method, comprising: a step of forming a resist film on a substrate or on the lower layer film of a substrate on which a lower layer film is laminated, using the resist composition according to claim 1; a step of exposing the resist film with i-ray, KrF excimer laser, ArF excimer laser, electron beam, or extreme ultraviolet ray; and a step of developing the exposed resist film with a developer.

5. The pattern forming method according to claim 4, wherein, The developer is an organic solvent.

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