Composition for forming resist underlayer film, and resist underlayer film

Abstract

Provided are: a composition for forming a resist underlayer film, the composition being capable of improving sensitivity in an EB exposure method or an EUV exposure method in comparison with the prior art; and a resist underlayer film.　The composition for forming a resist underlayer film contains a polymer (A) and a solvent (B). The resist underlayer film forms a contact angle of 80° or greater with pure water. Additionally, in the composition for forming a resist underlayer film, the polymer (A) contains a fluorine atom.

Description

Composition for forming resist underlayer film and resist underlayer film

[0001] The present invention relates to a composition for forming a resist underlayer film and a resist underlayer film.

[0002] In semiconductor devices such as large-scale integrated circuits (LSIs), the formation of finer patterns is required as integration density increases, and in recent years, the minimum pattern size has reached 100 nm or less. The formation of such finer patterns in semiconductor devices has been made possible by shortening the wavelength of the light source in exposure equipment and improving resist materials. Currently, immersion lithography is used, in which exposure is performed through water using deep ultraviolet ArF (argon fluoride) excimer laser light with a wavelength of 193 nm. Regarding resist materials, various ArF-compatible resist materials based on acrylic resins have been developed.

[0003] Furthermore, as next-generation exposure technologies, EB exposure using an electron beam (EB) or EUV (extreme ultraviolet) exposure using soft X-rays with a wavelength of 13.5 nm as a light source is being studied, and pattern sizes are being further refined to 30 nm or less. However, with such refinement of pattern sizes, line edge roughness (LER) of the resist pattern sidewall and line width roughness (LWR) of the resist pattern increase, raising concerns about adverse effects on device performance. Although studies have been conducted to suppress these issues by optimizing exposure tools, resist materials, and process conditions, satisfactory results have not been obtained. Note that LWR and LER are related, and improving LWR will also improve LER.

[0004] In order to solve the above problems, an invention has been disclosed that relates to a resist underlayer film that is a baked product of a coating film of a composition for forming a resist underlayer film, which contains a polymer having at least one of a unit structure having a polycyclic aromatic hydrocarbon structure and a unit structure having a maleimide structure (see Patent Document 1).

[0005] International Publication No. 2023 / 106364

[0006] In pattern formation by EB exposure or EUV exposure, there is a demand for improving LWR and LER as described above, and also for achieving high sensitivity that enables pattern formation even when exposure energy is low.

[0007] The present invention provides a composition for forming a resist underlayer film and a resist underlayer film that can improve sensitivity compared to conventional methods in an EB exposure method or an EUV exposure method.

[0008] The present inventors conducted extensive research to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved, and completed the present invention having the following gist. That is, the present invention includes the following. [1] A composition for forming a resist underlayer film, comprising a polymer (A) and a solvent (B), wherein the resist underlayer film has a contact angle with water of 80° or more. [2] The composition for forming a resist underlayer film according to [1], wherein the polymer (A) is a polymer containing fluorine atoms. [3] The composition for forming a resist underlayer film according to [1] or [2], wherein the polymer (A) contains 10 mol % or more of fluorine atoms. [4] A composition for forming a resist underlayer film, comprising a polymer (A) and a solvent (B), wherein the polymer (A) contains 10 mol % or more of fluorine atoms. [5] The composition for forming a resist underlayer film according to any one of [1] to [4], wherein the polymer (A) is a polymer having a structural unit represented by the following formula (1): (In formula (1), R １ and R ２ R each independently represents a perfluoroalkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms in which 1 to 12 fluorine atoms have been substituted with one or both of a hydrogen atom and a halogen atom. ３each independently represents an optionally substituted alkyl group having 1 to 3 carbon atoms or a halogen atom. m represents 0 or 1. n represents 2 or 3. p represents 0 to 6, provided that when m = 0, p + n is 6 or less, and when m = 1, p + n is 8 or less. * represents a bond. [6] The composition for forming a resist underlayer film according to any one of [2] to [5], wherein the polymer (A) is a reaction product of a compound having two or more epoxy groups and a fluorine-containing compound having two or more groups reactive with the epoxy group. [7] The composition for forming a resist underlayer film according to any one of [1] to [6], wherein the solvent (B) comprises at least one selected from the group consisting of alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers. [8] The composition for forming a resist underlayer film according to any one of [1] to [7], further comprising a crosslinking agent (C). [9] The composition for forming a resist underlayer film according to [8], wherein the crosslinking agent (C) is at least one selected from the group consisting of aminoplast crosslinking agents and phenoplast crosslinking agents.

[10] The composition for forming a resist underlayer film according to any one of [1] to [9], further comprising a curing catalyst (D).

[11] The composition for forming a resist underlayer film according to any one of [1] to

[10] , which is used in an EUV (extreme ultraviolet) exposure process.

[12] A resist underlayer film that is a cured product of the composition for forming a resist underlayer film according to any one of [1] to

[11] .

[13] A laminate comprising: a semiconductor substrate; and the resist underlayer film according to

[12] .

[14] A method for manufacturing a semiconductor device, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to

[11] ; and forming a resist film on the resist underlayer film.

[15] A pattern forming method comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to

[11] ; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

[0009] According to the present invention, it is possible to provide a composition for forming a resist underlayer film and a resist underlayer film that can improve sensitivity in an EB exposure method or an EUV exposure method compared to conventional methods.

[0010] (Composition for forming a resist underlayer film) One example of the composition for forming a resist underlayer film of the present invention contains a polymer (A) and a solvent (B), and the resist underlayer film has a contact angle with pure water of 80° or more. Another example of the composition for forming a resist underlayer film of the present invention contains a polymer (A) and a solvent (B), and the polymer (A) contains 10 mol % or more of fluorine atoms.

[0011] In order to solve the above problems, the present inventors have conducted extensive research into a composition for forming a resist underlayer film that enables pattern formation even with low exposure energy. As a result, they have found that, when a resist underlayer film is formed, the angle is usually about 40° to 60°, but if the composition for forming a resist underlayer film exhibits strong water repellency, highly sensitive pattern formation can be achieved, and have arrived at the present invention.

[0012] The contact angle of water is measured using a fully automatic contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.) with a water volume of 3.0 μl, after the sample has been left standing for 3 seconds after contact with the sample, followed by 5 measurements at 5 seconds, and 5 measurements at 7 seconds, for a total of 15 measurements, and the average value can be calculated. The water used in the contact angle measurement is preferably pure water.

[0013] <Polymer (A)> The polymer (A) is preferably a polymer containing fluorine atoms. The type of organic group formed by the fluorine atoms contained in the polymer (A) is not particularly limited, and the amount of fluorine atoms contained in the polymer (A) is also not particularly limited, as long as the effects of the present invention are not impaired.

[0014] The polymer (A) is preferably a polymer containing 10 mol% or more of fluorine atoms relative to all atoms in the polymer. The polymer (A) preferably contains 11 mol% or more of fluorine atoms, and particularly preferably contains 12 mol% or more of fluorine atoms. When the polymer (A) contains a predetermined number of fluorine atoms or more, the required exposure dose in the EB exposure method or EUV exposure method is reduced, and sensitivity is likely to be improved. There is no upper limit for the amount of fluorine atoms contained in the polymer (A), but from the viewpoint of film formability, it is preferably 20 mol% or less.

[0015] The polymer (A) is preferably a polymer having a structural unit represented by the following formula (1): (In formula (1), R １ and R ２ R each independently represents a perfluoroalkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms in which 1 to 12 fluorine atoms have been substituted with one or both of a hydrogen atom and a halogen atom. ３ each independently represents an optionally substituted alkyl group having 1 to 3 carbon atoms or a halogen atom; m represents 0 or 1; n represents 2 or 3; and p represents 0 to 6, provided that when m = 0, p + n is 6 or less, and when m = 1, p + n is 8 or less; * represents a bond.

[0016] The perfluoroalkyl group having 1 to 6 carbon atoms may be linear, branched, or cyclic, with linear being preferred. Examples of the perfluoroalkyl group having 1 to 6 carbon atoms include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a 2,2,2-trifluoro-1-(trifluoromethyl)ethyl group, a nonafluorobutyl group, an undecafluoropentyl group, and a tridecafluorohexyl group. In consideration of the effect of reducing the exposure dose in pattern formation, a trifluoromethyl group is preferred.

[0017] In the perfluoroalkyl group having 1 to 6 carbon atoms, 1 to 12 fluorine atoms may be substituted with either or both of a hydrogen atom and a halogen atom. Examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0018] Examples of alkyl groups having 1 to 3 carbon atoms include methyl, ethyl, n-propyl, i-propyl, and cyclopropyl groups. Of these, methyl is preferred. p is 0 to 6, preferably 0 to 3, and particularly preferably 0 or 1.

[0019] Examples of the structural unit represented by formula (1) include the following structural units. * represents a bond.

[0020] The proportion of the structural unit represented by formula (1) in polymer (A) is not particularly limited, but the proportion (mass %) of the structural unit represented by formula (1) relative to the total mass of polymer (A) may be, for example, 5 mol % to 60 mol %, or 10 mol % to 40 mol %, and preferably 30 mol % or more and 40 mol % or less. Polymer (A) may contain a structure other than the structural unit represented by formula (1).

[0021] <<Compound having two or more epoxy groups>> Examples of the polymer (A) containing a structural unit represented by formula (1) include a reaction product of a compound having two or more epoxy groups and a fluorine-containing compound having two or more groups reactive with the epoxy groups. The compound having two or more epoxy groups is not particularly limited, and examples thereof include a diepoxy compound, a triepoxy compound, a tetraepoxy compound, and a polymer having an epoxy group. The compound having two or more epoxy groups is preferably a diepoxy compound or a triepoxy compound, and more preferably a diepoxy compound.

[0022] Examples of compounds having two or more epoxy groups include compounds represented by the following structures:

[0023] In formulas (A1) to (A3), E １ is a group represented by the following formula (a-1): (In the formula, m1 is an integer of 0 to 4, m2 is 0 or 1, m3 is 0 or 1, and m4 is 1 or 2; when m3 is 1, m1 and m2 cannot be 0 at the same time. * represents a bond.)

[0024] In formulas (A4) to (A10), E ２ is a group represented by the following formula (a-2): (In the formula, m5 is an integer of 0 to 4, m6 is 0 or 1, m7 is 0 or 1, and m8 is 1 or 2. * represents a bond.)

[0025] In formulas (A1) and (A2), R １ａ and R ２ａ each independently represents a hydrogen atom; an alkyl group of 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom; an alkenyl group of 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom; an alkynyl group of 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom; a benzyl group or a phenyl group, and the phenyl group may be substituted with at least one monovalent group selected from the group consisting of an alkyl group of 1 to 6 carbon atoms, a halogen atom, an alkoxy group of 1 to 6 carbon atoms, a nitro group, a cyano group and an alkylthio group of 1 to 6 carbon atoms.

[0026] In formula (A3), R ３ａ represents a hydrogen atom; an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom; an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom; an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom; a benzyl group; a phenyl group; or any of the above E １ wherein the phenyl group may be substituted with at least one monovalent group selected from an alkyl group having 1 to 10 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms.

[0027] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, a cyclobutyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, and a 1-ethyl-n-propyl group. Cyclopentyl group, 1-methylcyclobutyl group, 2-methylcyclobutyl group, 3-methylcyclobutyl group, 1,2-dimethylcyclopropyl group, 2,3-dimethylcyclopropyl group, 1-ethylcyclopropyl group, 2-ethylcyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2- Dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3 -ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,Examples include a 3-trimethyl-cyclopropyl group, a 1-ethyl-2-methyl-cyclopropyl group, a 2-ethyl-1-methyl-cyclopropyl group, a 2-ethyl-2-methyl-cyclopropyl group, and a 2-ethyl-3-methyl-cyclopropyl group.

[0028] Examples of the alkenyl group having 2 to 10 carbon atoms include ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylethenyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 2-ethylethenyl, 1 ...ethyl-2-propylethenyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 2-ethylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-1-propenyl, 1-methyl-2-propenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethenyl, 1-ethyl-2-propylethen methyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group, 1-methyl -1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2-pentenyl group, 2-methyl-3-pentenyl group, 2-methyl-4-pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group, 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group , 4-methyl-3-pentenyl group, 4-methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1,2-dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group, 2,3-dimethyl-1-butenyl group, 2,3-dimethyl-2-butenyl group, 2,3-dimethyl-3-butenyl group, 2-i-propyl-2-propenyl group, 3,3-dimethyl-1-butenyl group, 1-ethyl-1-butenyl group, 1-ethyl-2-butenyl group, 1-ethyl-3-butenyl group, 1-n-propyl-1-propenyl group, 1-n-propyl-2-propenyl group, 2-ethyl-1-butenyl group, 2-ethyl-2-butenyl group, 2-ethyl-3-butenyl group, 1,1,2-trimethyl-2-propenyl group, 1-t-butylethenyl group, 1-methyl-1-ethyl-2-propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl-1-propenyl group, 1-i- Examples of the cyclopentyl group include a propyl-2-propenyl group, a 1-methyl-2-cyclopentenyl group, a 1-methyl-3-cyclopentenyl group, a 2-methyl-1-cyclopentenyl group, a 2-methyl-2-cyclopentenyl group, a 2-methyl-3-cyclopentenyl group, a 2-methyl-4-cyclopentenyl group, a 2-methyl-5-cyclopentenyl group, a 2-methylene-cyclopentyl group, a 3-methyl-1-cyclopentenyl group, a 3-methyl-2-cyclopentenyl group, a 3-methyl-3-cyclopentenyl group, a 3-methyl-4-cyclopentenyl group, a 3-methyl-5-cyclopentenyl group, a 3-methylene-cyclopentyl group, a 1-cyclohexenyl group, a 2-cyclohexenyl group, and a 3-cyclohexenyl group.

[0029] Examples of the alkynyl group having 2 to 10 carbon atoms include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 4-methyl-1-pentynyl group, and a 3-methyl-1-pentynyl group.

[0030] The phrase "optionally interrupted by an oxygen atom or a sulfur atom" means, for example, that a carbon atom in the saturated carbon chain of the alkyl group, alkenyl group, or alkynyl group is replaced with an oxygen atom or a sulfur atom. For example, in an alkyl group, alkenyl group, or alkynyl group, when any carbon atom is replaced with an oxygen atom, the group contains an ether bond, and when any carbon atom is replaced with a sulfur atom, the group contains a thioether bond.

[0031] Halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0032] Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, an s-butoxy group, a t-butoxy group, an n-pentoxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy group, an n-hexyloxy group, a 1-methyl-n-pentyloxy group, a 2-methyl-n-pentyloxy group, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy group, a n-hexyloxy group, a 1-methyl-n-pentyloxy group, a 2-methyl-n-pentyloxy group, a 3-methyl-n-butoxy group, a 2-methyl-n-pentyloxy group, a 2-methyl-n-but ... Examples of the alkyl group include a 1-methyl-n-pentyloxy group, a 4-methyl-n-pentyloxy group, a 1,1-dimethyl-n-butoxy group, a 1,2-dimethyl-n-butoxy group, a 1,3-dimethyl-n-butoxy group, a 2,2-dimethyl-n-butoxy group, a 2,3-dimethyl-n-butoxy group, a 3,3-dimethyl-n-butoxy group, a 1-ethyl-n-butoxy group, a 2-ethyl-n-butoxy group, a 1,1,2-trimethyl-n-propoxy group, a 1,2,2-trimethyl-n-propoxy group, a 1-ethyl-1-methyl-n-propoxy group, and a 1-ethyl-2-methyl-n-propoxy group.

[0033] Examples of the alkylthio group having 1 to 6 carbon atoms include an ethylthio group, a butylthio group, and a hexylthio group.

[0034] In formulas (A4) to (A10), R ４ａ each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; -W- represents a single bond, -CH ２ -, -C(CH ３ ) ２ -, -C(CF ３ ) ２ -, -CO-, -O-, -OCH ２ -CH(OH)-CH ２ O-, -S- or SO ２n1 represents an integer of 2 to 4. X represents 0 or 1. When X = 1, the oxygen atom forms an ether bond to bridge the aromatic rings, and when X = 0, there is no ether bond to bridge the aromatic rings. n2 represents an integer of 2 to 4. n3 and n4 each independently represent an integer of 0 to 4, and n3 + n4 is 2 to 4. n5 represents an integer of 2 to 4. n6 and n7 each independently represent an integer of 0 to 4, and n6 + n7 is 2 to 4. n8 to n11 each independently represent an integer of 0 to 4, and n8 + n9 + n10 + n11 is 2 to 4. n12 and n13 each independently represent an integer of 0 to 5, and n12 + n13 is 2 to 4. n14 is 5-n12 when X is 0, and 4-n12 when X is 1. n15 is 5-n13 when X is 0, and 4-n13 when X is 1.

[0035] Examples of the alkyl group having 1 to 10 carbon atoms and the alkenyl group having 2 to 10 carbon atoms include the same as those mentioned above.

[0036] In the present invention, among these epoxy compounds, the epoxy compounds represented by formulae (A3), (A6) and (A10) are preferred from the viewpoint of reactivity with the polymer (A), and in particular, those having the following embodiments can be more preferably used.

[0037] In the formula, E １ , E ２ , R ４a , n3, n4, and n12 to n15 are the same as above, and R ３ａ’ represents a hydrogen atom; an alkyl group of 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group of 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group of 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, and the phenyl group may be substituted with at least one monovalent group selected from an alkyl group of 1 to 6 carbon atoms, a halogen atom, an alkoxy group of 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group of 1 to 6 carbon atoms.

[0038] Specific examples of the epoxy compounds represented by the above formulas (A1) to (A10) include, but are not limited to, the following compounds.

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] The compound (C) having two or more epoxy groups may be a compound other than the compounds listed above. For example, it may be a compound having an alicyclic structure. Examples of the compound (C) having an alicyclic structure include the following compounds.

[0051] <<Fluorine-Containing Compound Having Group Reactive with Epoxy Group>> The fluorine-containing compound having two or more groups reactive with an epoxy group is preferably a fluorine-containing compound represented by the following formula (1-A): (In formula (1-A), R １ , R ２ , R ３ , m, n, and p are the same as in formula (1).

[0052] Specific examples of the fluorine-containing compound represented by the above formula (1-A) include, but are not limited to, the following compounds.

[0053] The reaction between a compound having two or more epoxy groups and a compound having two or more fluorine-containing groups reactive with epoxy groups may be carried out, for example, in the presence of a catalyst. Examples of the catalyst include quaternary phosphonium salts such as tetrabutylphosphonium bromide and ethyltriphenylphosphonium bromide, and quaternary ammonium salts such as benzyltriethylammonium chloride. The amount of catalyst used can be selected appropriately from the range of 0.1 to 10% by mass based on the total mass of the reaction raw materials used in the reaction. The optimal reaction temperature and time can be selected, for example, from the ranges of 80 to 160°C and 2 to 50 hours.

[0054] The molecular weight of the polymer (A) is not particularly limited. The lower limit of the weight average molecular weight of the polymer (A) is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight average molecular weight of the polymer (A) is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000.

[0055] <Solvent (B)> The solvent (B) contained in the composition for forming a resist underlayer film is not particularly limited as long as it can uniformly dissolve the components contained therein, such as the polymer (A), but is preferably an organic solvent generally used in chemical solutions for semiconductor lithography processes. The solvent (B) preferably contains at least one selected from the group consisting of alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers. Specific examples of the solvent (B) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and the like. Examples of the solvent include cyclopentane, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents can be used alone or in combination of two or more.

[0056] Among these solvents (B), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, methyl 2-hydroxyisobutyrate, and cyclohexanone are preferred, with propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate being particularly preferred.

[0057] <Crosslinking Agent (C)> The composition for forming a resist underlayer film preferably further contains a crosslinking agent (C). The crosslinking agent (C) has a structure different from that of the polymer (A).

[0058] The crosslinking agent (C) is preferably an aminoplast crosslinking agent or a phenoplast crosslinking agent. The aminoplast crosslinking agent is an addition condensation product of a compound having an amino group, such as melamine or guanamine, with formaldehyde. The phenoplast crosslinking agent is an addition condensation product of a compound having a phenolic hydroxy group with formaldehyde.

[0059] Examples of the crosslinking agent (C) include compounds having two or more of the following structures. (In the structure, R １０１ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms. * represents a bond.) The bond is bonded to, for example, a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0060] R １０１ is preferably a hydrogen atom, a methyl group, an ethyl group or a group represented by the following structure. (In the structure, R １０２ represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond.

[0061] The crosslinking agent (C) is preferably a melamine compound, a guanamine compound, a glycoluril compound, a urea compound, or a compound having a phenolic hydroxy group, which may be used alone or in combination of two or more.

[0062] Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine have been methoxymethylated, or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine have been acyloxymethylated, or a mixture thereof.

[0063] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof; tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof; and the like.

[0064] Examples of glycoluril compounds include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which one to four methylol groups of tetramethylol glycoluril are methoxymethylated or mixtures thereof, and compounds in which one to four methylol groups of tetramethylol glycoluril are acyloxymethylated or mixtures thereof.

[0065] The glycoluril compound may be, for example, a glycoluril derivative represented by the following formula (1E). (In formula (1E), four R １ each independently represents a methyl group or an ethyl group, R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

[0066] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0067] The glycoluril derivative represented by formula (1E) can be obtained, for example, by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0068] (In formula (2E), R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group; R ４ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0069] (In formula (3d), R １ represents a methyl group or an ethyl group.

[0070] Examples of glycoluril derivatives represented by formula (2E) include compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include compounds represented by formulas (3d-1) and (3d-2) below.

[0071] Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, tetramethylol urea compounds in which one to four methylol groups are methoxymethylated, or mixtures thereof, and tetramethoxyethyl urea.

[0072] Examples of the compound having a phenolic hydroxy group include compounds represented by the following formula (G-1) or (G-2). (In formula (G-1) and formula (G-2), Q １ represents a single bond or a monovalent organic group. １ and R ４ R represents an alkyl group having 2 to 10 carbon atoms, or an alkyl group having 2 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms. ２ and R ５ R represents a hydrogen atom or a methyl group. ３ and R ６ n represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. １ is 1≦n １ an integer ≦3, n ２ is 2≦n ２ an integer ≦5, n ３ is 0≦n ３ an integer ≦3, n ４ is 0≦n ４ an integer ≦3, 3≦(n １ +n ２ +n ３ +n ４ ) represents an integer ≦6. ５ is 1≦n５ an integer ≦3, n ６ is 1≦n ６ an integer ≦4, n ７ is 0≦n ７ an integer ≦3, n ８ is 0≦n ８ an integer ≦3, 2≦(n ５ +n ６ +n ７ +n ８ ) represents an integer of ≦5. m1 represents an integer of 2 to 10.

[0073] Examples of compounds having a phenolic hydroxy group include compounds represented by the following formula (G-3) or formula (G-4): The compound represented by formula (G-1) or formula (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or formula (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms. (In formula (G-3) and formula (G-4), Q ２ represents a single bond or a divalent organic group. ８ , R ９ , R １１ and R １２ R represents a hydrogen atom or a methyl group. ７ and R １０ n represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. ９ is 1≦n ９ an integer ≦3, n １０ is 2≦n １０ an integer ≦5, n １１ is 0≦n １１ an integer ≦3, n １２ is 0≦n １２ an integer ≦3, 3≦(n ９ +n １０ +n １１ +n １２ ) represents an integer ≦6. １３ is 1≦n １３ an integer ≦3, n １４ is 1≦n １４ an integer ≦4, n １５ is 0≦n １５ an integer ≦3, n １６ is 0≦n １６an integer ≦3, 2≦(n １３ +n １４ +n １５ +n １６ ) represents an integer of ≦5. m2 represents an integer of 2 to 10. ２ In the above, the m2-valent organic group includes, for example, an m2-valent organic group having 1 to 4 carbon atoms.

[0074] Examples of the compound represented by formula (G-1) or formula (G-2) include the following compounds:

[0075] Examples of the compound represented by formula (G-3) or formula (G-4) include the following compounds: The above compound is available as a product of Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. An example of the product is TMOM-BP, a product name of Asahi Organic Chemicals Co., Ltd.

[0076] Among these, glycoluril compounds are preferred, specifically tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, tetramethylol glycoluril compounds in which one to four methylol groups have been methoxymethylated or mixtures thereof, and tetramethylol glycoluril compounds in which one to four methylol groups have been acyloxymethylated or mixtures thereof, with tetramethoxymethyl glycoluril being more preferred.

[0077] The molecular weight of the crosslinking agent (C) is not particularly limited, but is preferably 500 or less.

[0078] The content of the crosslinking agent (C) in the composition for forming a resist underlayer film is not particularly limited, but is, for example, 1% by mass to 70% by mass, and preferably 5% by mass to 60% by mass, relative to the polymer (A).

[0079] <Curing Catalyst (D)> The composition for forming a resist underlayer film preferably further contains a curing catalyst (D). Examples of the curing catalyst include an acid generator. While either a thermal acid generator or a photoacid generator can be used as the acid generator, it is preferable to use a thermal acid generator. Examples of the thermal acid generator include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-toluenesulfonate (pyridinium-p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium-p-hydroxybenzenesulfonic acid (pyridinium p-phenolsulfonate salt), pyridinium-trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, and hydroxybenzoic acid.

[0080] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0081] Examples of the onium salt compound include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate; and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0082] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0083] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0084] The acid generators may be used singly or in combination of two or more.

[0085] When an acid generator is used, the content of the acid generator relative to the crosslinking agent described below is, for example, 0.1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass.

[0086] <Other Components> A surfactant may be further added to the composition for forming a resist underlayer film in order to prevent pinholes, striations, etc., and further improve coating properties for surface unevenness. Any polymer other than the polymer (A) may also be added. Examples of such polymers include the polymers described in International Publication No. 2013 / 018802 and polymers containing hydroxyarene.

[0087] Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate; nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as Eftop EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, and R-30 (trade names, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by AGC Inc.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants to be added is usually 2.0 mass % or less, and preferably 1.0 mass % or less, based on the total solid content of the composition for forming a resist underlayer film. These surfactants may be added alone or in combination of two or more.

[0088] The solid content of the composition for forming a resist underlayer film of the present invention, that is, the content of components excluding the solvent, is, for example, 0.01% by mass to 10% by mass.

[0089] (Resist Underlayer Film) The resist underlayer film of the present invention is a cured product of the composition for forming a resist underlayer film described above. The resist underlayer film can be produced, for example, by applying the composition for forming a resist underlayer film described above onto a semiconductor substrate and baking the applied composition.

[0090] Examples of semiconductor substrates onto which the resist underlayer film-forming composition can be applied include silicon wafers, germanium wafers, and wafers of compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0091] When a semiconductor substrate having an inorganic film formed on its surface is used, the inorganic film can be formed by, for example, ALD (atomic layer deposition), CVD (chemical vapor deposition), reactive sputtering, ion plating, vacuum deposition, or spin coating (spin-on glass: SOG). Examples of the inorganic film include a polysilicon film, a silicon oxide film, a silicon nitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium nitride oxide film, a tungsten film, a gallium nitride film, and a gallium arsenide film.

[0092] The resist underlayer film-forming composition of the present invention is applied to such a semiconductor substrate by a suitable application method such as a spinner or coater. The composition is then baked using a heating means such as a hot plate to form a resist underlayer film. The baking conditions are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 to 60 minutes. A baking temperature of 120°C to 350°C and a baking time of 0.5 to 30 minutes are preferred, and a baking temperature of 150°C to 300°C and a baking time of 0.8 to 10 minutes are more preferred.

[0093] The thickness of the resist underlayer film may be, for example, 0.001 μm (1 nm) to 10 μm, 0.002 μm (2 nm) to 1 μm, 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.001 μm (1 nm) to 0.05 μm (50 nm), 0.002 μm (2 nm) to 0.05 μm (50 nm), 0.003 μm (3 nm) to 0.05 μm (50 nm), 0.004 μm (4 nm) to 0.05 μm (50 nm), 0.005 μm ( 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.003 μm (3 nm) to 0.01 μm (10 nm), 0.005 μm (5 nm) to 0.01 μm (10 nm), 0.003 μm (3 nm) to 0.006 μm (6 nm), or 0.005 μm (5 nm).

[0094] The method for measuring the film thickness of the resist underlayer film in this specification is as follows: Name of measuring device: Ellipso film thickness measuring device RE-3100 (SCREEN Corporation) SWE (single wavelength ellipsometer) mode Arithmetic mean of 8 points (for example, measuring 8 points at 1 cm intervals in the X direction of the wafer)

[0095] (Laminate) The laminate of the present invention includes a semiconductor substrate and the resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrates described above. The resist underlayer film is disposed on the semiconductor substrate, for example.

[0096] (Method for manufacturing a semiconductor element, method for forming a pattern) The method for manufacturing a semiconductor element of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, and forming a resist film on the resist underlayer film.

[0097] The pattern forming method of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, forming a resist film on the resist underlayer film, irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0098] Usually, a resist layer is formed on the resist underlayer film. The thickness of the resist layer is preferably 200 nm or less, more preferably 150 nm or less, even more preferably 100 nm or less, and particularly preferably 80 nm or less. The thickness of the resist layer is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more.

[0099] The resist film formed on the resist underlayer film by a known method (e.g., resist coating and baking) is not particularly limited as long as it is responsive to light or electron beam (EB) used for irradiation. Both negative and positive photoresists can be used. In this specification, resists responsive to EB are also referred to as photoresists. Examples of photoresists include positive photoresists composed of a novolak resin and a 1,2-naphthoquinone diazide sulfonic acid ester; chemically amplified photoresists composed of a binder having a group that decomposes in an acid to increase the alkaline dissolution rate and a photoacid generator; chemically amplified photoresists composed of a low-molecular-weight compound that decomposes in an acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator; chemically amplified photoresists composed of a binder having a group that decomposes in an acid to increase the alkaline dissolution rate, a low-molecular-weight compound that decomposes in an acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator; and resists containing metal elements. Examples of such photoresists include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 (trade names) manufactured by Shin-Etsu Chemical Co., Ltd. Further examples include fluorine-containing polymer photoresists such as those described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0100] Also, WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO201 9 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-18 1857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc., radiation-sensitive resin compositions, so-called resist compositions such as high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited to these.

[0101] Examples of the resist composition include the following compositions.

[0102] An actinic ray-sensitive or radiation-sensitive resin composition comprising: Resin A having a repeating unit having an acid-decomposable group in which a polar group is protected with a protecting group that is cleaved by the action of an acid; and a compound represented by the following general formula (121):

[0103] In the general formula (121), m represents an integer of 1 to 6. １ and R ２ each independently represents a fluorine atom or a perfluoroalkyl group. １ is -O-, -S-, -COO-, -SO ２ - or -SO ３ - represents. ２ represents an alkylene group which may have a substituent or a single bond. １ represents a cyclic organic group which may have a substituent. ＋ represents a cation.

[0104] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, comprising a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to Periods 3 to 7 of Groups 3 to 15 of the periodic table.

[0105] A radiation-sensitive resin composition comprising: a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-dissociable group; and an acid generator.

[0106] In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. １ is a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, multiple R １ are the same or different. ２ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ３ is a monovalent group having 1 to 20 carbon atoms containing the above acid-dissociable group. Z is a single bond, an oxygen atom, or a sulfur atom. R ４is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0107] A resist composition comprising: a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group; and an acid generator.

[0108] [In the formula, R ２ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom; X １ represents a single bond, —CO—O—*, or —CO—NR ４ -*, * represents a bond to -Ar, R ４ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have one or more groups selected from the group consisting of a hydroxy group and a carboxyl group.]

[0109] Examples of the resist film include the following.

[0110] A resist film comprising a base resin comprising a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to a polymer main chain upon exposure:

[0111] (In formula (a1) and formula (a2), R Ａ are each independently a hydrogen atom or a methyl group. １ and R ２ are each independently a tertiary alkyl group having 4 to 6 carbon atoms. ３ are each independently a fluorine atom or a methyl group, and m is an integer of 0 to 4. １ X is a single bond, a phenylene group, or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ is a single bond, an ester bond, or an amide bond.

[0112] Examples of resist materials include the following:

[0113] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0114] (In formula (b1) and formula (b2), R Ａ is a hydrogen atom or a methyl group. １ is a single bond or an ester group. ２ is a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group or a lactone ring-containing group; and X ２ At least one hydrogen atom contained in X is substituted with a bromine atom. ３ Rf is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group. １ ~Rf ４ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. １ and Rf ２ may combine to form a carbonyl group. １ ~R ５ are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, in which some or all of the hydrogen atoms may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and in which some of the methylene groups constituting these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonate ester group. １ and R ２may be bonded to form a ring together with the sulfur atom to which they are attached.

[0115] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0116] (In formula (a), R Ａ is a hydrogen atom or a methyl group. １ is a hydrogen atom or an acid labile group. ２ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ X is a single bond, a phenylene group, or a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. ２ is -O-, -O-CH ２ - or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. However, m+u is an integer of 1 to 4.

[0117] A resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and a fluorine additive component (F) that exhibits decomposition in an alkaline developer, wherein the fluorine additive component (F) comprises a fluororesin component (F1) that has a structural unit (f1) that includes a base dissociable group, and a structural unit (f2) that includes a group represented by the following general formula (f2-r-1):

[0118] [In formula (f2-r-1), Rf ２１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, a hydroxyalkyl group, or a cyano group. n" is an integer of 0 to 2. * is a bond.

[0119] The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0120] [In formulas (f1-1) and (f1-2), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group that does not have an acid-dissociable site. A ａｒｙｌ represents a divalent aromatic cyclic group which may have a substituent. ０１ is a single bond or a divalent linking group. ２ are each independently an organic group having a fluorine atom.

[0121] Coatings, coating solutions, and coating compositions include, for example:

[0122] A coating comprising a metal oxo-hydroxo network with organic ligands via metal carbon bonds and / or metal carboxylate bonds.

[0123] Inorganic oxo / hydroxo-based compositions.

[0124] a coating solution comprising an organic solvent; a first organometallic composition having the formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (where 0<z≦2 and 0<(z+x)≦4), formula R′ ｎ SnX ４－ｎ wherein n=1 or 2, or mixtures thereof, where R and R′ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn, or a combination thereof; and a hydrolyzable metal compound having the formula MX′ ｖ wherein M is a metal selected from groups 2 to 16 of the periodic table of the elements, v is a number from 2 to 6, and X' is a ligand having a hydrolyzable M-X bond or a combination thereof.

[0125] an organic solvent and a solution of the formula RSnO （３／２－ｘ／２） (OH) ｘand a first organometallic compound of the formula: wherein 0<x<3, wherein the solution contains from about 0.0025M to about 1.5M tin, and R is an alkyl or cycloalkyl group having from 3 to 31 carbon atoms, the alkyl or cycloalkyl group being bonded to the tin at a secondary or tertiary carbon atom.

[0126] An aqueous inorganic patterning precursor solution comprising a mixture of water, metal suboxide cations, polyatomic inorganic anions, and radiation-sensitive ligands comprising peroxide groups.

[0127] Irradiation with light or electron beams is carried out, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-line, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet), or EB (electron beam) can be used. The composition for forming a resist underlayer film of the present invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet: 13.5 nm) irradiation, more preferably for EUV (extreme ultraviolet) exposure. The irradiation energy of the electron beam and the exposure dose of light are not particularly limited.

[0128] After irradiation with light or electron beams and before development, baking (PEB: Post Exposure Bake) may be performed. The baking temperature is not particularly limited, but is preferably 60° C. to 150° C., more preferably 70° C. to 120° C., and particularly preferably 75° C. to 110° C. The baking time is not particularly limited, but is preferably 1 second to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 3 minutes.

[0129] For example, an alkaline developer is used for development. The development temperature can be, for example, 5°C to 50°C. The development time can be, for example, 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of alkalis such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-butylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole and piperidine). Furthermore, the aqueous solutions of the alkalis can be used by adding an appropriate amount of alcohols (e.g., isopropyl alcohol) or a nonionic surfactant. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants and the like can also be added to these developers. Alternatively, development may be carried out with an organic solvent such as butyl acetate instead of an alkaline developer, and the portions of the photoresist where the alkaline dissolution rate is not improved may be developed.

[0130] Next, the resist underlayer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but dry etching is preferred. If the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed. If the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed. Thereafter, the semiconductor substrate is processed by a known method (e.g., dry etching), thereby manufacturing a semiconductor device.

[0131] The present invention will be explained in more detail below with reference to synthesis examples and examples, but the present invention is not limited to the following examples.

[0132] In the examples, the apparatus and conditions used for molecular weight measurement are as follows. The molecular weight of the polysiloxane used in the present invention is the molecular weight obtained by GPC analysis in terms of polystyrene. The GPC measurement conditions may be, for example, a GPC apparatus (trade name HLC-8220GPC, manufactured by Tosoh Corporation), a GPC column (trade names Shodex (registered trademark) KF803L, KF802, KF801, manufactured by Showa Denko K.K.), a column temperature of 40°C, tetrahydrofuran as eluent (elution solvent), a flow rate (flow rate) of 1.0 mL / min, and polystyrene (manufactured by Showa Denko K.K.) as a standard sample.

[0133] [1] Polymer Synthesis <Synthesis Example 1> 3.00 g of monoallyl diglycidyl isocyanurate (manufactured by Shikoku Chemical Industry Co., Ltd.), 4.60 g of 1,3-bis(hexafluoro-α-hydroxyisopropyl)benzene (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.13 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 18.00 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 4,000 in terms of standard polystyrene. The polymer obtained in this Synthesis Example has structural units represented by the following formulas (1a) and (2a).

[0134] Synthesis Example 2 4.00 g of 3',6'-Bis(2-oxiranylmethoxy)spiro[9H-fluorene-9,9'-[9H]xanthene] (manufactured by Taoka Chemical Co., Ltd., trade name: TBIS-RXG), 6.20 g of 1,3-bis(hexafluoro-α-hydroxyisopropyl)benzene (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.17 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 24.20 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 120°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and the solubility in propylene glycol monomethyl ether was good. GPC analysis showed that the polymer in the obtained solution had a weight average molecular weight, in terms of standard polystyrene, of 5000. The polymer obtained in this synthesis example has structural units represented by the following formulas (1b) and (2a).

[0135] Synthesis Example 3 7.00 g of monomethyldiglycidyl isocyanurate (manufactured by Shikoku Chemical Industry Co., Ltd.), 3.59 g of 1,3-bis(hexafluoro-α-hydroxyisopropyl)benzene (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.10 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 24.92 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 120°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and the solubility in propylene glycol monomethyl ether was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 4,000 in terms of standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1c) and (2a).

[0136] Synthesis Example 4 4.00 g of 4-tert-butylbenzene-1,2-diol / 1-chloro-2,3-epoxydipropane polycondensate (manufactured by DIC Corporation, product name: EPICRON HP-820), 4.25 g of 1,3-bis(hexafluoro-α-hydroxyisopropyl)benzene (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.12 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 12.56 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 120°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and the solubility in propylene glycol monomethyl ether was good. GPC analysis revealed that the polymer in the obtained solution had a weight average molecular weight of 4,000 in terms of standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1d) and (2a).

[0137] Comparative Synthesis Example 1 7.00 g of monoallyl diglycidyl isocyanuric acid (Shikoku Chemical Industry Co., Ltd.), 3.84 g of resorcinol (Tokyo Chemical Industry Co., Ltd.), and 0.30 g of tetrabutylphosphonium bromide (ACROSS) were added to 25.98 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, demonstrating good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 6,000 in terms of standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2b).

[0138] Comparative Synthesis Example 2 10.00 g of monoallyl diglycidyl isocyanurate (manufactured by Shikoku Chemical Industry Co., Ltd.), 16.74 g of 2,2,2-bis4-carbohydroxyphenylhexafluoropropane (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.42 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 40.75 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, demonstrating good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 5,000 in terms of standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (2c).

[0139] The fluorine atoms contained in each polymer are shown in the table below.

[0140]

[0141] [2] Preparation of Compositions for Forming Resist Underlayer Films (Examples and Comparative Examples) The polymers obtained in Synthesis Examples 1 to 4, Comparative Synthesis Example 1, and Comparative Synthesis Example 2 above, and a commercially available polymer, crosslinking agent, curing catalyst, and solvent were mixed in the proportions shown in Table 2, and the mixture was filtered through a 0.1 μm fluororesin filter to prepare solutions of compositions for forming resist underlayer films.

[0142] The meanings of the abbreviations in Table 1 are as follows: PL-LI: tetramethoxymethyl glycoluril Py-PSA: pyridinium-p-hydroxybenzenesulfonic acid PGME: propylene glycol monomethyl ether PGMEA: propylene glycol monomethyl ether acetate The amount of each additive is shown in parts by mass, and the amount of the solvent is shown in composition ratio.

[0143]

[0144] [3] Elution Test in Photoresist Solvent The resist underlayer film-forming compositions of Examples 1, 2, 3, and 4 and Comparative Examples 1 and 2 were each applied to a silicon wafer, a semiconductor substrate, using a spinner. The silicon wafer was placed on a hot plate and baked at 205°C for 1 minute to form a resist underlayer film (film thickness: 5 nm). These resist underlayer films were immersed in a mixed solvent of propylene glycol monomethyl ether (70 vol%) and propylene glycol monomethyl ether acetate (30 vol%), which is used as a solvent for the photoresist-forming composition, at room temperature for 1 minute, and then heated at 100°C for 30 seconds to remove the solvent, after which the film thickness was measured. The results of the solvent resistance test are shown below. A film thickness reduction rate (nm film thickness reduction before and after test / nm film thickness of resist underlayer film × 100) of 2% or less (1 Å) was evaluated as "good," and a film thickness reduction rate of more than 2% was evaluated as "poor" (Table 3).

[0145]

[0146] [4] Contact Angle Measurement Each of the resist underlayer film-forming compositions of Examples 1, 2, 3, and 4 and Comparative Examples 1 and 2 was applied to a silicon wafer, which was a semiconductor substrate, using a spinner. The silicon wafer was placed on a hot plate and baked at 205°C for 1 minute to form a resist underlayer film (film thickness: 5 nm). The contact angle with pure water was then measured using a contact angle meter (DM701) manufactured by Kyowa Interface Science Co., Ltd. The amount of pure water dropped was 3.0 µl. After dropping, measurements were taken at 5 points 3 seconds after dropping, 5 points after dropping, and 5 points after dropping, and the average value of the 15 points was recorded as the contact angle (Table 4).

[0147]

[0148] The underlayer films formed using the compositions for forming resist underlayer films of Examples 1 to 4 all had contact angles with pure water of 80° or more. In contrast, the underlayer films formed using the compositions for forming resist underlayer films of Comparative Examples 1 and 2 had contact angles with pure water of less than 80°.

[0149] [5] Formation of a Positive Resist Pattern Using an Electron Beam Lithography Apparatus The resist underlayer film-forming compositions of Examples 1, 2, and Comparative Example 1 were each applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a 5 nm-thick resist underlayer film. An EUV positive resist solution (containing a methacrylic polymer) was spin-coated onto the resist underlayer film and heated at 130°C for 60 seconds to form an EUV resist film. The resist film was exposed under specified conditions using an electron beam lithography apparatus (ELS-G130). After exposure, the resist was baked at 90°C for 60 seconds (PEB), cooled to room temperature on a cooling plate, and developed with an alkaline developer (2.38% TMAH), forming a line-and-space resist pattern with a CD of 25 nm and a pitch of 50 nm. A scanning electron microscope (CG4100, manufactured by Hitachi High-Technologies Corporation) was used to measure the resist pattern. The exposure dose required to obtain a pattern with a CD size of 25 nm in the formation of the resist pattern is shown in Table 5. The lower the figure, the lower the exposure dose required to obtain the desired pattern (Table 5).

[0150]

[0151] Comparing Examples 1 and 2 with Comparative Examples 1 and 2, it was found that the exposure dose required to obtain a 25 nm CD pattern was reduced and sensitivity was improved in Examples 1 and 2. The minimum sizes at which patterns can be resolved in Example 1 and Comparative Example 2 are shown below.

[0152]

[0153] Comparing Example 1 and Comparative Example 2, it was confirmed that a finer pattern could be formed in Example 1. This improvement in adhesion is suggested to be due to improved affinity with the resist resulting from hydrophobicity caused by the increased amount of fluorine atoms introduced.

Claims

1. A composition for forming a resist underlayer film, comprising a polymer (A) and a solvent (B), the resist underlayer film having a contact angle with water of 80° or more.

2. The composition for forming a resist underlayer film according to claim 1, wherein the polymer (A) is a polymer containing a fluorine atom.

3. The composition for forming a resist underlayer film according to claim 2, wherein the polymer (A) is a polymer containing 10 mol % or more of the fluorine atoms.

4. A composition for forming a resist underlayer film, comprising a polymer (A) and a solvent (B), wherein the polymer (A) is a polymer containing 10 mol % or more of fluorine atoms.

5. The composition for forming a resist underlayer film according to claim 2 or 4, wherein the polymer (A) is a polymer having a structural unit represented by the following formula (1): (In formula (1), R １ and R ２ R each independently represents a perfluoroalkyl group having 1 to 6 carbon atoms or a perfluoroalkyl group having 1 to 6 carbon atoms in which 1 to 12 fluorine atoms have been substituted with either or both of a hydrogen atom and a halogen atom. ３ each independently represents an optionally substituted alkyl group having 1 to 3 carbon atoms or a halogen atom; m represents 0 or 1; n represents 2 or 3; p represents 0 to 6; provided that when m=0, p+n is 6 or less, and when m=1, p+n is 8 or less; * represents a bond.

6. The composition for forming a resist underlayer film according to any one of claims 2 to 4, wherein the polymer (A) is a reaction product of a compound having two or more epoxy groups and a fluorine-containing compound having two or more groups reactive with the epoxy groups.

7. The composition for forming a resist underlayer film according to any one of claims 1 to 4, wherein the solvent (B) comprises at least one selected from the group consisting of alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers.

8. The composition for forming a resist underlayer film according to any one of claims 1 to 4, further comprising a crosslinking agent (C).

9. The composition for forming a resist underlayer film according to claim 8, wherein the crosslinking agent (C) is at least one selected from the group consisting of aminoplast crosslinking agents and phenoplast crosslinking agents.

10. The composition for forming a resist underlayer film according to any one of claims 1 to 4, further comprising a curing catalyst (D).

11. The composition for forming a resist underlayer film according to any one of claims 1 to 4, which is used in an EUV (extreme ultraviolet) exposure process.

12. A resist underlayer film which is a cured product of the composition for forming a resist underlayer film according to any one of claims 1 to 4.

13. A laminate comprising: a semiconductor substrate; and the resist underlayer film according to claim 12.

14. A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 4; and a step of forming a resist film on the resist underlayer film.

15. A pattern formation method comprising the steps of: forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 4; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

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