Compound, composition for forming lithographic film, resist film, and method for forming resist pattern

Abstract

Provided is a compound having excellent resist sensitivity characteristics as well as excellent solvent solubility, heat resistance, and film-forming properties. Also provided are: a composition for forming a lithographic film, said composition containing the compound; a resist film; and a method for forming a resist pattern. The compound is represented by formula (1). (In formula (1), Ar is a group having a C6-60 aryl group, R1 is an organic group having a sulfonium salt or an iodonium salt, nA is an integer of 1-9, and nB is an integer of 1 or more.)

Description

Compound, composition for forming lithographic film, resist film, and method for forming resist pattern

[0001] The present invention relates to a compound, a composition for forming a lithographic film, a resist film, and a method for forming a resist pattern.

[0002] In the manufacture of semiconductor devices, microfabrication is performed by lithography using photoresist materials. However, in recent years, with the increasing integration and speed of LSIs (large-scale integrated circuits), further miniaturization using pattern rules is required. Conventional resist materials are polymer-based resist materials capable of forming amorphous thin films, such as polymethyl methacrylate, and polymer-based resist materials such as polyhydroxystyrene or polyalkyl methacrylate having an acid-dissociable group. Therefore, lithography materials (photoresist materials) that can accommodate further miniaturization of patterns are being developed. For example, Patent Document 1 discloses a composition containing a resin having structural units derived from an ascorbic acid derivative as a composition for resist films that has high sensitivity and high solubility in solvents.

[0003] International Publication No. 2021 / 049472

[0004] Lithography materials that meet the demands of finer patterns require not only high resist sensitivity but also high levels of basic chemical and physical properties. It has been difficult to obtain lithography materials that simultaneously satisfy all of these requirements. For example, in semiconductor manufacturing processes, solubility in highly safe solvents is required, while film-forming properties and heat resistance are also required. Therefore, there is a need for lithography materials that can simultaneously satisfy all of these requirements. Therefore, the present invention provides a compound that has excellent resist sensitivity characteristics, solvent solubility, heat resistance, and film-forming properties. Another objective of the present invention is to provide a lithography film-forming composition, a resist film, and a method for forming a resist pattern that contain the compound.

[0005] The present inventors have found that a specific ionic compound containing an iodine atom can solve the above problems, and have completed the present invention.

[0006] That is, the present invention is as follows: <1> A compound represented by the following formula (1): (In formula (1), Ar is a group having an aryl group having 6 to 60 carbon atoms, and R １ is an organic group having a sulfonium salt or an iodonium salt, and n Ａ is an integer from 1 to 9, and n Ｂ is an integer of 1 or more.) <2> The compound according to <1> above, wherein Ar is triphenylmethane which may have a substituent. <3> The compound according to <1> above or <2> above, which is represented by the following formula (2): (In formula (2), R １ is an organic group having a sulfonium salt or an iodonium salt, and R ０ is a group selected from the group consisting of a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom; R ２ is a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom. a is an integer of 1 to 5, b is an integer of 0 to 4, c is an integer of 0 to 4, and a+b+c is 1 to 5. d is an integer of 0 to 5, e is an integer of 0 to 5, d+e is 0 to 5, f is an integer of 0 to 5, g is an integer of 0 to 5, f+g is 0 to 5, and b+d+f is 1 or more.) <4> R ２ is a linear or branched alkyl group having 1 to 4 carbon atoms. <5> The compound according to any one of <1> to <4>, which is represented by the following formula (3): (In the formula, R １ is an organic group having a sulfonium salt or an iodonium salt, and R ２is a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom. a is an integer of 1 to 5, b is an integer of 0 to 4, and a+b is 1 to 5.) <6> In the formula (3), R １ is a group represented by the following formula (7) or the following formula (8): (In formula (7) and formula (8), R ３ is a single bond or a divalent group having 1 to 30 carbon atoms which may have a substituent, and R ５ is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, R ７ is an alkyl group having 1 to 4 carbon atoms, h is an integer of 0 to 4, and An － is an anion containing fluorine or iodine. ４ is an alkyl group having 1 to 10 carbon atoms which may have a substituent, or an aryl group having 6 to 10 carbon atoms which may have a substituent.) <7> In the formula (3), R １ is a group represented by the following formula (9): <8> The compound according to any one of <1> to <7>, which is at least one selected from the group consisting of a compound represented by the following formula (4), a compound represented by the following formula (5), and a compound represented by the following formula (6): (In the formula, R １ is an organic group having a sulfonium salt or an iodonium salt, and R ２ is an alkyl group having 1 to 4 carbon atoms.) <9> In the formula (4), the formula (5), or the formula (6), R １ is a group represented by the following formula (9): <10> A lithographic film-forming composition containing the compound according to any one of <1> to <9>. <11> The lithographic film-forming composition according to <10>, further containing a solvent. <12> The lithographic film-forming composition according to <10> or <11>, further containing at least one selected from the group consisting of an acid generator and a crosslinking agent. <13> The lithographic film-forming composition according to any one of <10> to <12>, which is a resist film-forming composition. <14> A resist film formed from the lithographic film-forming composition according to any one of <10> to <13>. <15> A resist underlayer film formed from the lithographic film-forming composition according to any one of <10> to <12>. <16> A method for forming a resist pattern using the lithographic film-forming composition according to any one of <10> to <13>. <17> A method for forming a resist pattern, comprising: forming a resist film on a substrate using the composition for lithography film formation according to any one of <10> to <13>; and exposing and developing the resist film.

[0007] The present invention provides a compound that exhibits excellent resist sensitivity characteristics, solvent solubility, heat resistance, and film-forming properties. It is also possible to provide a lithography film-forming composition, a resist film, and a method for forming a resist pattern, each containing the compound.

[0008] 1 shows an example of sensitivity curves (EB sensitivity evaluation) using the compounds of Examples 1 to 3.

[0009] [Compound Represented by Formula (1)] The compound of the present invention is a compound represented by the following formula (1). (In formula (1), Ar is a group having an aryl group having 6 to 60 carbon atoms, and R １ is an organic group having a sulfonium salt or an iodonium salt, and n Ａ is an integer from 1 to 9, and n Ｂ is an integer of 1 or greater.)

[0010] The compound of the present invention has excellent resist sensitivity characteristics, solvent solubility, heat resistance, and film-forming properties. Therefore, the compound of the present invention is useful as a resist material. The reason why the compound of the present invention has excellent resist sensitivity characteristics, solvent solubility, heat resistance, and film-forming properties is not clear, but it is thought to be as follows. The compound of the present invention is an ionic compound containing an iodine atom, and therefore is thought to have excellent resist sensitivity characteristics. In addition, since the compound has a main skeleton containing an aryl group having 6 to 60 carbon atoms and has a low molecular weight, it is expected that a fine resist pattern will be obtained.

[0011] Unless otherwise defined, the term "substituted" as used herein means that one or more hydrogen atoms in a functional group are substituted with a substituent. Examples of the "substituent" include a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, a thiol group, a heterocyclic group, a linear aliphatic hydrocarbon group having 1 to 20 carbon atoms, a branched aliphatic hydrocarbon group having 3 to 20 carbon atoms, a cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an acyl group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkyloyloxy group having 1 to 20 carbon atoms, an aryloyloxy group having 7 to 30 carbon atoms, and an alkylsilyl group having 1 to 20 carbon atoms.

[0012] In the formula (1), Ar is a group having an aryl group having 6 to 60 carbon atoms. The number of carbon atoms in Ar is preferably 6 to 40, more preferably 10 to 30, and even more preferably 20 to 27. Examples of Ar include a phenyl group, a naphthyl group, an anthracenyl group, a biphenylyl group, a fluorenyl group, and a group having any of these groups, each of which may have a substituent, and is preferably a group having a phenyl group, and more preferably triphenylmethane, which may have a substituent.

[0013] In formula (1), R １ is an organic group having a sulfonium salt or an iodonium salt, and is preferably an organic group having a sulfonium salt. Ａis an integer of 1 to 9, preferably 2 to 6, more preferably 2 to 4, even more preferably 2 or 3, and still more preferably 3. Ｂ is an integer of 1 or more, preferably 1 to 10, more preferably 1 to 5, even more preferably 1 or 2, and still more preferably 2.

[0014] <Compound Represented by Formula (2)> The compound of the present invention is a compound represented by the above formula (1), and is preferably a compound represented by the following formula (2). (In formula (2), R １ is an organic group having a sulfonium salt or an iodonium salt, and R ０ is a group selected from the group consisting of a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom; R ２ is a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom. a is an integer from 1 to 5, b is an integer from 0 to 4, c is an integer from 0 to 4, and a+b+c is 1 to 5. d is an integer from 0 to 5, e is an integer from 0 to 5, d+e is 0 to 5, f is an integer from 0 to 5, g is an integer from 0 to 5, f+g is 0 to 5, and b+d+f is 1 or more.

[0015] In formula (2), R １ is an organic group having a sulfonium salt or an iodonium salt, and is preferably an organic group having a sulfonium salt. ０is a group selected from the group consisting of a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom, preferably a group selected from the group consisting of a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, and an aryl group having 6 to 10 carbon atoms, more preferably a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, even more preferably a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, still more preferably a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, still more preferably a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, still more preferably a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, still more preferably a hydrogen atom, a methyl group, or an ethyl group, still more preferably a hydrogen atom or a methyl group, and still more preferably a hydrogen atom. ２ is a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom, preferably a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 10 carbon atoms, more preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, even more preferably a linear or branched alkyl group having 1 to 10 carbon atoms, still more preferably a linear or branched alkyl group having 1 to 4 carbon atoms, still more preferably a linear alkyl group having 1 to 4 carbon atoms, still more preferably a methyl group or ethyl group, and even more preferably a methyl group.

[0016] In addition, R ０ , R 2With regard to the above, "a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms" is preferably a group selected from the group consisting of a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, or a cyclic alkyl group having 3 to 10 carbon atoms, and an aryl group having 6 to 10 carbon atoms, more preferably a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, or a cyclic alkyl group having 3 to 10 carbon atoms, even more preferably a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, or a branched alkyl group having 3 to 10 carbon atoms, still more preferably a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, still more preferably a hydrogen atom, or a linear alkyl group having 1 to 4 carbon atoms, still more preferably a hydrogen atom, a methyl group, or an ethyl group, still more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

[0017] a is an integer of 1 to 5, preferably 1 to 4, more preferably 1 to 3, even more preferably 1 to 2, and even more preferably 2. b is an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 0 to 1, and even more preferably 1. c is an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 0 to 1, and even more preferably 0. a + b + c is 1 to 5, preferably 1 to 4, more preferably 1 to 3, even more preferably 2 to 3, and even more preferably 3. d is an integer of 0 to 5, preferably 1 to 5, more preferably 1 to 3, even more preferably 1 to 2, and even more preferably 1. e is an integer of 0 to 5, preferably 0 to 4, more preferably 1 to 3, even more preferably 2 to 3, and even more preferably 2. d+e is 0 to 5, preferably 1 to 5, more preferably 1 to 4, even more preferably 2 to 4, and still more preferably 3. f is an integer of 0 to 5, preferably 1 to 5, more preferably 1 to 3, even more preferably 1 to 2, and still more preferably 1. g is an integer of 0 to 5, preferably 0 to 4, more preferably 1 to 3, even more preferably 2 to 3, and still more preferably 2. f+g is 0 to 5, preferably 1 to 5, more preferably 1 to 4, even more preferably 2 to 4, and still more preferably 3. b+d+f is 1 or greater.

[0018] <Compound Represented by Formula (3)> The compound of the present invention is a compound represented by the formula (1), preferably a compound represented by the formula (2), and more preferably a compound represented by the following formula (3): (In formula (3), R １ is an organic group having a sulfonium salt or an iodonium salt, and R ２is a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom; a is an integer of 1 to 5, b is an integer of 0 to 4, and a+b is 1 to 5.

[0019] In formula (3), R ２ is a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom, and is preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, even more preferably a methyl group or an ethyl group, and still more preferably a methyl group.

[0020] In addition, R ２ With regard to the above, "a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom" is preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, a branched, or cyclic alkyl group having 3 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, even more preferably a methyl group or an ethyl group, and still more preferably a methyl group.

[0021] a is an integer of 1 to 5, preferably 1 to 4, more preferably 1 to 3, even more preferably 1 to 2, and still more preferably 2. b is an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 0 to 1, and still more preferably 1. a+b is 1 to 5, preferably 1 to 4, more preferably 1 to 3, even more preferably 2 or 3, and still more preferably 3.

[0022] In formula (3), R １ is an organic group having a sulfonium salt or an iodonium salt, and is preferably an organic group having a sulfonium salt.

[0023] R １ is more preferably a group represented by the following formula (7) or (8). (In formula (7) and formula (8), R ３ is a single bond or a divalent group having 1 to 30 carbon atoms which may have a substituent, and R ５ is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, R ７ is an alkyl group having 1 to 4 carbon atoms, h is an integer of 0 to 4, and An － is an anion containing fluorine or iodine. ４ represents an alkyl group having 1 to 10 carbon atoms which may have a substituent, or an aryl group having 6 to 10 carbon atoms which may have a substituent.

[0024] In formulas (7) and (8), R ３ is a single bond or a divalent group having 1 to 30 carbon atoms which may have a substituent, preferably a divalent group having 2 to 6 carbon atoms which may have a substituent, more preferably an alkylene group or phenylene group having 2 to 6 carbon atoms, even more preferably an ethylene group, a propylene group, or a phenylene group, still more preferably an ethylene group or a propylene group, and still more preferably an ethylene group. ４ is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, and is preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an octyl group, a decyl group, a cyclohexyl group, a phenyl group, or a naphthyl group, more preferably a methyl group, an ethyl group, or a phenyl group, and even more preferably a methyl group. ５ R is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, preferably an alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an octyl group, a decyl group, or a cyclohexyl group, and even more preferably a methyl group. ７is an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, and more preferably a methyl group. h is an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 0 to 1, and still more preferably 0. An － is an anion containing fluorine or iodine, preferably R ６ SO ３ － (R ６ is a monovalent group containing fluorine or iodine and having 1 to 9 carbon atoms.), PF ６ － , or SbF ６ － and more preferably R ６ SO ３ － (R ６ is a trifluoromethyl group or a nonafluorobutyl group.), PF ６ － , or SbF ６ － and more preferably R ６ SO ３ － (R ６ is a trifluoromethyl group or a nonafluorobutyl group, and even more preferably CF ３ SO ３ － is.

[0025] Therefore, in formula (3), R １ is preferably a group represented by formula (7) or formula (8), and more preferably a group represented by formula (9) below. The wavy lines in formulas (7) to (9) indicate bonds.

[0026] <Compounds Represented by Formula (4), Compounds Represented by Formula (5), and Compounds Represented by Formula (6)> The compound of the present invention is a compound represented by formula (1), preferably a compound represented by formula (2), more preferably a compound represented by formula (3), and even more preferably at least one selected from the group consisting of a compound represented by formula (4), a compound represented by formula (5), and a compound represented by formula (6). From the viewpoint of resist sensitivity characteristics, the compound of the present invention is even more preferably at least one selected from the group consisting of a compound represented by formula (4) and a compound represented by formula (5), and even more preferably a compound represented by formula (5). (In the formula, R １ is an organic group having a sulfonium salt or an iodonium salt, and R ２ is an alkyl group having 1 to 4 carbon atoms.

[0027] In formula (4), formula (5) and formula (6), R ２ is an alkyl group having 1 to 4 carbon atoms, preferably a methyl group. １ is an organic group having a sulfonium salt or an iodonium salt, and is preferably an organic group having a sulfonium salt.

[0028] R １ is more preferably a group represented by the following formula (7) or (8). (In formula (7) and formula (8), R ３ is a single bond or a divalent group having 1 to 30 carbon atoms which may have a substituent, and R ５ is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, R ７ is an alkyl group having 1 to 4 carbon atoms, h is an integer of 0 to 4, and An － is an anion containing fluorine or iodine. ４ represents an alkyl group having 1 to 10 carbon atoms which may have a substituent, or an aryl group having 6 to 10 carbon atoms which may have a substituent.

[0029] In formulas (7) and (8), R ３is a single bond or a divalent group having 1 to 30 carbon atoms which may have a substituent, preferably a divalent group having 2 to 6 carbon atoms which may have a substituent, more preferably an alkylene group or phenylene group having 2 to 6 carbon atoms, even more preferably an ethylene group, a propylene group, or a phenylene group, still more preferably an ethylene group or a propylene group, and still more preferably an ethylene group. ４ is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, and is preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an octyl group, a decyl group, a cyclohexyl group, a phenyl group, or a naphthyl group, more preferably a methyl group, an ethyl group, or a phenyl group, and even more preferably a methyl group. ５ R is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, preferably an alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an octyl group, a decyl group, or a cyclohexyl group, and even more preferably a methyl group. ７ is an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, and more preferably a methyl group. h is an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 0 to 1, and still more preferably 0. An － is an anion containing fluorine or iodine, preferably R ６ SO ３ － (R ６ is a monovalent group containing fluorine or iodine and having 1 to 9 carbon atoms.), PF ６ － , or SbF ６ － and more preferably R ６ SO ３ － (R ６ is a trifluoromethyl group or a nonafluorobutyl group.), PF ６ － , or SbF６ － and more preferably R ６ SO ３ － (R ６ is a trifluoromethyl group or a nonafluorobutyl group, and even more preferably CF ３ SO ３ － is.

[0030] Therefore, in formulas (4), (5), and (6), R １ is preferably a group represented by formula (7) or formula (8), and more preferably a group represented by formula (9) below.

[0031] <Method for Producing Compound> The compound of the present invention may be obtained by any production method, but is preferably produced by the following production method: A suitable method for producing the compound is a production method comprising the steps of condensing a compound represented by the following formula (1a) with a compound represented by the following formula (7a) or a compound represented by the following formula (8a) to obtain a condensate (hereinafter also referred to as a condensation step), and reacting the condensate with a salt having an anion containing fluorine or iodine, and an alkylating agent (hereinafter also referred to as an alkylation step). (In formula (1a), Ar is a group having an aryl group having 6 to 60 carbon atoms, and n Ａ is an integer from 1 to 9, and n Ｂ is an integer of 1 or more. In formula (7a) and formula (8a), R ３ is a single bond or a divalent group having 1 to 30 carbon atoms which may have a substituent, and R ７ is an alkyl group having 1 to 4 carbon atoms, h is an integer of 0 to 4, X is a halogen atom, and in formula (7a), R ４ represents an alkyl group having 1 to 10 carbon atoms which may have a substituent, or an aryl group having 6 to 10 carbon atoms which may have a substituent.

[0032] Unless otherwise defined, in this specification, "alkylation" refers to alkylation or arylation, "alkylating agent" refers to an alkylating agent or an arylating agent, and "alkylation step" refers to an alkylation step or an arylation step.

[0033] In formula (1a), formula (7a), and formula (8a), Ar, n Ａ , n Ｂ , R ３ , R ４ , R ７ , and h are Ar, n in formula (1), formula (7), and formula (8), respectively. Ａ , n Ｂ , R ３ , R ４ , R ７ , and h have the same meanings, and the preferred ranges are also the same.

[0034] According to this production method, the above compounds can be efficiently produced. In formula (7a) and formula (8a), X is a halogen atom, and preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0035] In the condensation step, a compound represented by formula (1a) is condensed with a compound represented by formula (7a) or a compound represented by formula (8a) to obtain a condensate. The compound represented by formula (7a) or the compound represented by formula (8a) can be obtained by, for example, condensing a compound represented by formula (1a) with a compound represented by formula (7a) or formula (8a) 3 a compound in which the —O group is a hydroxyl group, and an X—R 3 -X. The condensation reaction of the compound represented by formula (1a) with the compound represented by formula (7a) or the compound represented by formula (8a) can be carried out, for example, by a method of condensation reaction in the presence of a base. If necessary, a phase transfer catalyst can also be used in combination.

[0036] In the alkylation step, the condensate obtained in the condensation step is reacted with a salt having an anion containing fluorine or iodine and an alkylating agent. The reaction can be carried out, for example, by reacting with an alkali metal salt of the anion or an acid.

[0037] [Lithography film-forming composition] The lithography film-forming composition of the present invention is a lithography film-forming composition containing the compound of the present invention. That is, the lithography film-forming composition of the present invention is a lithography film-forming composition containing a compound represented by formula (1). The lithography film-forming composition of the present invention contains the compound, which has excellent resist sensitivity characteristics, solvent solubility, heat resistance, and film-forming properties, and is therefore suitable as a composition for forming a resist film. That is, the lithography film-forming composition of the present invention is preferably a resist film-forming composition.

[0038] <Solvent> The composition for forming a lithographic film of the present invention may be appropriately adjusted in formulation depending on the intended use, as long as it contains the compound represented by formula (1), but preferably further contains a solvent as a component other than the compound represented by formula (1).

[0039] The solvent is not particularly limited, but examples thereof include ethylene glycol monoalkyl ether acetates, ethylene glycol monoalkyl ethers, propylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ethers, lactate esters, aliphatic carboxylic acid esters, esters other than the above esters, aromatic hydrocarbons, ketones, amides, lactones, and ethers, and is preferably at least one selected from the group consisting of propylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ethers, lactate esters, aliphatic carboxylic acid esters, ketones, and ethers, and more preferably at least one selected from the group consisting of propylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ethers, and ketones.

[0040] Examples of ethylene glycol monoalkyl ether acetates include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, and ethylene glycol mono-n-butyl ether acetate. Examples of ethylene glycol monoalkyl ethers include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether. Examples of propylene glycol monoalkyl ether acetates include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate (PGMEA), propylene glycol mono-n-propyl ether acetate, and propylene glycol mono-n-butyl ether acetate, with propylene glycol monoethyl ether acetate (PGMEA) being preferred. Examples of propylene glycol monoalkyl ethers include propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether, with propylene glycol monomethyl ether (PGME) being preferred.

[0041] Examples of lactic acid esters include methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and n-amyl lactate, with ethyl lactate being preferred. Examples of aliphatic carboxylic acid esters include methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, n-amyl acetate, n-hexyl acetate, methyl propionate, and ethyl propionate, with n-butyl acetate and ethyl propionate being preferred. Examples of esters other than the above esters include methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 3-methoxy-2-methylpropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl 3-methoxy-3-methylpropionate, butyl 3-methoxy-3-methylbutyrate, methyl acetoacetate, methyl pyruvate, ethyl pyruvate, and methyl 2-hydroxyisobutyrate (HBM). Examples of aromatic hydrocarbons include toluene and xylene. Examples of ketones include methyl ethyl ketone (MEK), 2-heptanone, 3-heptanone, 4-heptanone, cyclopentanone (CPN), and cyclohexanone (CHN), with 2-heptanone, cyclopentanone (CPN), and cyclohexanone (CHN) being preferred. Examples of amides include N,N-dimethylformamide (DMF), N-methylacetamide, N,N-dimethylacetamide, and N-methylpyrrolidone. Examples of lactones include γ-butyrolactone. Examples of ethers include anisole. One solvent may be used alone, or two or more solvents may be used in combination.

[0042] The solvent is preferably a safe solvent. The solvent is preferably at least one selected from the group consisting of propylene glycol monoethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclopentanone (CPN), cyclohexanone (CHN), 2-heptanone, anisole, butyl acetate, ethyl propionate, and ethyl lactate, and more preferably at least one selected from the group consisting of propylene glycol monoethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and cyclohexanone (CHN). In the present invention, the compound represented by formula (1) is ionic and can therefore be dissolved in water, and water can be used as the solvent if necessary.

[0043] The content of the solvent is preferably 20 to 99 mass %, more preferably 50 to 99 mass %, even more preferably 60 to 98 mass %, and still more preferably 85 to 97 mass %, based on the total amount of the composition for forming a lithographic film.

[0044] <Other Components> The lithography film-forming composition of the present invention may contain a compound represented by formula (1), and the composition may contain components other than the compound represented by formula (1) and the solvent. The following components are solid components, and are usually dissolved in a solvent and blended into the lithography film-forming composition.

[0045] The lithographic film-forming composition of the present invention may further contain at least one component selected from the group consisting of an acid generator, a crosslinking agent, an acid diffusion controller, and other additives, preferably at least one component selected from the group consisting of an acid generator, a crosslinking agent, and an acid diffusion controller, more preferably at least one component selected from the group consisting of an acid generator and a crosslinking agent, and even more preferably an acid generator and a crosslinking agent.

[0046] The content of the compound represented by formula (1) contained in the lithography film-forming composition of the present invention is preferably 50 to 99.4 mass %, more preferably 55 to 99 mass %, even more preferably 60 to 95 mass %, and still more preferably 65 to 93 mass %, based on the total content of the solid components (total content of the compound represented by formula (1), acid generator, crosslinking agent, acid diffusion controller, and other additives). Within this range, resolution can be improved and line edge roughness (LER) can be reduced.

[0047] (Acid Generator) The lithographic film-forming composition of the present invention may further contain an acid generator, and preferably further contains an acid generator.

[0048] The acid generator is preferably an acid generator that generates an acid directly or indirectly upon irradiation with any one of visible light, ultraviolet light, excimer laser, electron beam, extreme ultraviolet light (EUV), X-ray, and ion beam. As the radiation, ultraviolet light such as g-ray or i-ray may be used, and the use of an excimer laser is preferred because it enables microfabrication. Furthermore, the use of an electron beam, extreme ultraviolet light, X-ray, or ion beam as the high-energy beam is also preferred because it enables microfabrication.

[0049] Examples of the acid generator include compounds disclosed in WO 2017 / 033943. The acid generator is preferably an acid generator having an aromatic ring, and more preferably an acid generator having a sulfonate ion with an aryl group. The acid generator is more preferably at least one selected from the group consisting of diphenyltrimethylphenylsulfonium p-toluenesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluorobutanesulfonate, ditertiarybutyldiphenyliodonium nonafluorobutanesulfonate, and pyridinium p-toluenesulfonate. Use of such an acid generator can reduce line edge roughness.

[0050] The acid generator may preferably further contain a diazonaphthoquinone photoactive compound. The diazonaphthoquinone photoactive compound is not particularly limited as long as it is a compound generally used as a photosensitive component in positive resist compositions. The diazonaphthoquinone photoactive compound is preferably a polymeric diazonaphthoquinone photoactive compound or a non-polymeric diazonaphthoquinone photoactive compound, more preferably a non-polymeric diazonaphthoquinone photoactive compound, even more preferably a non-polymeric diazonaphthoquinone photoactive compound having a molecular weight of 1,500 or less, even more preferably a non-polymeric diazonaphthoquinone photoactive compound having a molecular weight of 1,200 or less, and even more preferably a non-polymeric diazonaphthoquinone photoactive compound having a molecular weight of 1,000 or less. Specific examples of diazonaphthoquinone photoactive compounds include the non-polymeric diazonaphthoquinone photoactive compounds disclosed in WO 2016 / 158881. The diazonaphthoquinone photoactive compounds can be used alone or in combination of two or more.

[0051] The content of the acid generator contained in the lithographic film-forming composition of the present invention is preferably 0.001 to 49 mass %, more preferably 1 to 40 mass %, even more preferably 3 to 30 mass %, and still more preferably 4 to 20 mass %, relative to the total content of the solid components (total content of the compound represented by Formula (1), acid generator, crosslinking agent, acid diffusion controller, and other additives). Within this range, sensitivity can be increased and edge roughness of the pattern profile can be reduced. The acid generators can be used alone or in combination of two or more.

[0052] (Crosslinking Agent) The lithographic film-forming composition of the present invention may further contain a crosslinking agent, and preferably further contains a crosslinking agent. The crosslinking agent contained in the lithographic film-forming composition of the present invention is preferably an acid crosslinking agent. The acid crosslinking agent can intramolecularly or intermolecularly crosslink the compound represented by formula (1) by the acid generated from the acid generator. The inclusion of a crosslinking agent can increase the strength of the resist pattern.

[0053] The acid crosslinking agent is preferably a compound having a crosslinkable group. Examples of the crosslinkable group include, but are not limited to, a hydroxyalkyl group, a carbonyl group, a nitrogen-containing group, a glycidyl-containing group, an aromatic group, a polymerizable multiple bond-containing group, and groups derived therefrom. Hydroxyalkyl groups and groups derived therefrom are preferred. Specifically, hydroxyalkyl groups and groups derived therefrom include hydroxyalkyl groups, alkoxyalkyl groups, acetoxyalkyl groups, etc., preferably at least one selected from the group consisting of hydroxyalkyl groups and alkoxyalkyl groups, more preferably an alkoxymethyl group. Examples of carbonyl groups and groups derived therefrom include formyl groups and carboxyalkyl groups. Examples of nitrogen-containing groups include dimethylaminomethyl groups, diethylaminomethyl groups, dimethylolaminomethyl groups, diethylolaminomethyl groups, and morpholinomethyl groups. Examples of glycidyl-containing groups include glycidyl ether groups, glycidyl ester groups, and glycidylamino groups. Examples of aromatic groups include benzyloxymethyl groups, benzoyloxymethyl groups, aryloxyalkyl groups, and aralkyloxyalkyl groups. Examples of the polymerizable multiple bond-containing group include a vinyl group and an isopropenyl group. Suitable examples of the acid crosslinking agent are listed below, divided into several categories. The type and content of the acid crosslinking agent may be adjusted depending on the type of substrate used when forming the resist pattern.

[0054] Preferred examples of the acid crosslinking agent include methylol group-containing compounds, alkoxyalkyl group-containing compounds, carboxymethyl group-containing compounds, and epoxy compounds. Examples of methylol group-containing compounds include methylol group-containing melamine compounds, methylol group-containing benzoguanamine compounds, methylol group-containing urea compounds, methylol group-containing glycoluril compounds, and methylol group-containing phenolic compounds. Examples of alkoxyalkyl group-containing compounds include alkoxyalkyl group-containing melamine compounds, alkoxyalkyl group-containing benzoguanamine compounds, alkoxyalkyl group-containing urea compounds, alkoxyalkyl group-containing glycoluril compounds, and alkoxyalkyl group-containing phenolic compounds. Examples of carboxymethyl group-containing compounds include carboxymethyl group-containing melamine compounds, carboxymethyl group-containing benzoguanamine compounds, carboxymethyl group-containing urea compounds, carboxymethyl group-containing glycoluril compounds, and carboxymethyl group-containing phenolic compounds. Examples of epoxy compounds include bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, novolac resin-based epoxy compounds, resole resin-based epoxy compounds, and poly(hydroxystyrene)-based epoxy compounds.

[0055] Further examples of the acid crosslinking agent include a compound obtained by introducing the crosslinkable group into an acidic functional group in a compound having a phenolic hydroxyl group to impart crosslinkability, and a resin obtained by introducing the crosslinkable group into an acidic functional group in an alkali-soluble resin to impart crosslinkability. The introduction rate of the crosslinkable group is preferably 5 to 100 mol %, more preferably 10 to 60 mol %, and even more preferably 15 to 40 mol %, based on the total acidic functional groups in the compound having a phenolic hydroxyl group and the alkali-soluble resin. This range is preferable because it allows the crosslinking reaction to occur sufficiently, preventing a decrease in the residual film rate and preventing phenomena such as swelling and meandering of the pattern.

[0056] Further examples of the acid crosslinking agent include alkoxyalkylated urea compounds or resins thereof, alkoxyalkylated glycoluril compounds or resins thereof, phenol derivatives, and compounds having an α-hydroxyisopropyl group. Examples of these compounds or resins include the compounds disclosed in International Publication No. 2017 / 033943. The phenol derivative is a phenol derivative having one to six benzene rings in the molecule and two or more hydroxyalkyl groups or alkoxyalkyl groups throughout the molecule, with the hydroxyalkyl groups or alkoxyalkyl groups bonded to any of the benzene rings.

[0057] The content of the crosslinking agent contained in the lithography film-forming composition of the present invention is preferably 0.5 to 49 mass %, more preferably 0.5 to 40 mass %, even more preferably 1 to 30 mass %, and still more preferably 2 to 20 mass %, based on the total content of the solid components (the total content of the compound represented by Formula (1), acid generator, crosslinking agent, acid diffusion controller, and other additives). A content in this range is preferable because it can suppress dissolution of the resist film in a developer, suppress a decrease in the residual film rate and swelling / wandering of the pattern, and further improve the heat resistance of the resist.

[0058] (Acid Diffusion Controller) The lithographic film-forming composition of the present invention may further contain an acid diffusion controller, and preferably further contains an acid diffusion controller. The acid diffusion controller optionally contained in the lithographic film-forming composition of the present invention controls the diffusion of the acid generated from the acid generator upon irradiation in the resist film, thereby preventing undesirable chemical reactions in unexposed areas. This improves the storage stability of the lithographic film-forming composition, thereby improving resolution. In addition, it is possible to suppress changes in the line width of the resist pattern due to variations in the exposure time before and after radiation exposure, resulting in extremely excellent process stability.

[0059] Examples of the acid diffusion controller include radiolytic basic compounds such as nitrogen atom-containing basic compounds, basic sulfonium compounds, and basic iodonium compounds. Examples of the acid diffusion controller include the compounds disclosed in WO 2017 / 033943. The acid diffusion controller can be used alone or in combination of two or more.

[0060] The content of the acid diffusion controller contained in the lithographic film-forming composition of the present invention is preferably 0.001 to 49% by mass relative to the total content of the solid components (the total content of the compound represented by Formula (1), acid generator, crosslinking agent, acid diffusion controller, and other additives). From the viewpoint of preventing a decrease in sensitivity, developability of unexposed areas, etc., it is more preferably 0.01 to 10% by mass, even more preferably 0.01 to 5% by mass, and still more preferably 0.01 to 3% by mass. Within this range, it is possible to suppress a decrease in resolution and deterioration of the resist pattern shape and dimensional fidelity. Furthermore, there is no deterioration in the shape of the upper layer of the resist pattern when there is a long delay time between electron beam irradiation and post-irradiation heating.

[0061] (Other Additives) The lithography film-forming composition of the present invention may further contain other additives to the extent that the effects of the present invention are not impaired. Examples of other additives include dissolution promoters, dissolution controllers, sensitizers, surfactants, and organic carboxylic acids or phosphorus oxoacids or derivatives thereof. Examples of other additives include the compounds disclosed in WO 2017 / 033943. The total content of other additives contained in the lithography film-forming composition of the present invention is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, and even more preferably 0% by mass, relative to the total content of the solid components (the total content of the compound represented by Formula (1), the acid generator, the crosslinking agent, the acid diffusion controller, and other additives). It is even more preferable that the composition is free of other additives.

[0062] <Method for producing a lithography film-forming composition> The method for producing a lithography film-forming composition of the present invention is not particularly limited, but is preferably a method in which the components are dissolved in a solvent to form a homogeneous solution. If necessary, the solution obtained may be filtered to remove impurities. The filter used for filtration preferably has a pore size of about 0.2 μm.

[0063] The lithographic film-forming composition of the present invention may contain a resin to the extent that the effects of the present invention are not impaired. Examples of resins include novolak resins, polyvinylphenols, polyacrylic acid, polyvinyl alcohol, and styrene-maleic anhydride resins. The total content of resins contained in the lithographic film-forming composition of the present invention is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, still more preferably 0 parts by mass, and even more preferably zero parts by mass, relative to 100 parts by mass of the compound represented by Formula (1).

[0064] [Resist film] The resist film of the present invention is a resist film formed from the lithography film-forming composition. As described above, the lithography film-forming composition is a lithography film-forming composition containing a compound represented by formula (1), and therefore has excellent resist sensitivity characteristics and is an excellent raw material for forming a resist film. The resist film of the present invention can be formed from the lithography film-forming composition by the method described below in the method for forming a resist pattern.

[0065] The resist film of the present invention can be obtained as an amorphous film by known methods such as spin coating, etc. Depending on the type of developer used, either a positive resist pattern or a negative resist pattern can be obtained.

[0066] In the case of a positive resist pattern, the dissolution rate of the amorphous film formed by spin-coating the lithography film-forming composition in a developer at 23°C is preferably 5 Å / sec or less, more preferably 0.0005 to 5 Å / sec. A dissolution rate within this range allows the resist to be insoluble in the developer, thereby improving resolution. This is presumably because the change in solubility of the compound represented by formula (1) before and after exposure increases the contrast at the interface between the exposed portion that dissolves in the developer and the unexposed portion that does not dissolve in the developer. Furthermore, the composition is effective in reducing line edge roughness and defects.

[0067] In the case of a negative resist pattern, the dissolution rate of the amorphous film formed by spin-coating the lithography film-forming composition in a developer at 23°C is preferably 10 Å / sec or more. A dissolution rate within this range is suitable for resists and improves resolution. This is presumably because the micro-surface portion of the compound represented by formula (1) dissolves, reducing line edge roughness. It also has the effect of reducing defects. The dissolution rate can be measured by immersing the amorphous film in a developer at 23°C for a predetermined time, and measuring the film thickness before and after immersion visually, by an ellipsometer, a QCM (quartz crystal microbalance) method, or the like.

[0068] In the case of a positive resist pattern, the dissolution rate in a developer at 23°C of the portion of the amorphous film formed by spin-coating the lithography film-forming composition, which has been exposed to radiation such as an excimer laser (preferably a KrF excimer laser), extreme ultraviolet light, an electron beam, or an X-ray, is preferably 10 Å / sec or more. A dissolution rate within this range is suitable for the resist, improving resolution. This is presumably because the micro-surface portion of the compound represented by formula (1) dissolves, reducing line edge roughness. It also has the effect of reducing defects.

[0069] In the case of a negative resist pattern, the dissolution rate in a developer at 23°C of the portion of the amorphous film formed by spin-coating the lithography film-forming composition, which has been exposed to radiation such as an excimer laser (preferably a KrF excimer laser), extreme ultraviolet light, electron beam, or X-ray, is preferably 5 Å / sec or less, more preferably 0.0005 to 5 Å / sec. A dissolution rate within this range allows the resist to be insoluble in the developer, thereby improving resolution. This is presumably because the change in solubility of the compound represented by formula (1) before and after exposure increases the contrast at the interface between the exposed portion, which dissolves in the developer, and the unexposed portion, which does not dissolve in the developer. Furthermore, the composition is effective in reducing line edge roughness and defects.

[0070] [Resist Underlayer Film] The resist underlayer film of the present invention is a resist underlayer film formed from the lithography film-forming composition. As described above, the lithography film-forming composition is a lithography film-forming composition containing a compound represented by formula (1), and therefore is capable of improving the resist sensitivity characteristics of an upper layer photoresist and is also excellent as a raw material for forming a resist underlayer film. The resist underlayer film of the present invention can be suitably used as an underlayer of a photoresist (upper layer) used in a multilayer resist method. The resist underlayer film of the present invention can be formed by any method, as long as it is formed from the lithography film-forming composition, and known techniques can be applied. For example, a resist underlayer film can be formed by applying the lithography film-forming composition to a substrate by a known coating or printing method such as spin coating or screen printing, and then removing the organic solvent.

[0071] [Method of Forming a Resist Pattern] The method of forming a resist pattern of the present invention is a method of forming a resist pattern using the lithography film-forming composition. More specifically, it is a method of forming a resist pattern comprising the steps of forming a resist film on a substrate using the lithography film-forming composition, and exposing and developing the resist film. The formed resist pattern can also be used as an upper layer resist in a multilayer process. Furthermore, when the lithography film-forming composition is used as a material for forming a resist underlayer film, the method of forming a resist pattern of the present invention is preferably a method of forming a resist pattern comprising the steps of forming a resist underlayer film on a substrate using the lithography film-forming composition, forming at least one photoresist layer on the underlayer film, and exposing and developing the photoresist layer.

[0072] <Step of Forming a Resist Film> The method for forming a resist pattern of the present invention includes a step of forming a resist film on a substrate using the lithography film-forming composition. Examples of methods for forming a resist film include coating the lithography film-forming composition on a substrate by a coating method such as spin coating, cast coating, or roll coating. Conventional substrates can be used as the substrate, including substrates for electronic components and substrates with a wiring pattern formed thereon. Examples of substrates include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Examples of materials for the wiring pattern include copper, aluminum, nickel, and gold. The substrate may also have an inorganic or organic film formed thereon. Examples of inorganic films include inorganic antireflective films (inorganic BARC). Examples of organic films include organic antireflective films (organic BARC). The substrate may be surface-treated with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) or the like.

[0073] The substrate coated with the lithography film-forming composition may be heated. The heating conditions may be adjusted appropriately depending on the components of the composition, but are preferably 20 to 250° C., more preferably 20 to 150° C. Heating is preferred because it improves the adhesion of the resist film to the substrate.

[0074] <Exposure Step> The method for forming a resist pattern of the present invention includes a step of exposing the formed resist film. In this step, the resist film is exposed to light in a desired pattern. The exposure is carried out with a type of radiation selected from the group consisting of visible light, ultraviolet light, excimer laser, electron beam, extreme ultraviolet light (EUV), X-rays, and ion beam. The exposure conditions may be adjusted appropriately depending on the formulation of the lithography film-forming composition.

[0075] The lithography film-forming composition containing the compound represented by formula (1) is particularly suitable for use when the exposure light is extreme ultraviolet (EUV) or X-rays, from the viewpoint of improving sensitivity. This is thought to be because the compound represented by formula (1) contains an iodine atom, which has excellent absorption ability for the exposure light and contributes to the absorption of the exposure light.

[0076] It is preferable to heat the substrate having the resist film after irradiation. The heating conditions may be appropriately adjusted depending on the formulation of the composition for forming a lithography film, but are preferably 20 to 250° C., more preferably 20 to 150° C. Heating allows a highly accurate fine pattern to be stably formed by exposure.

[0077] <Developing Step> The method for forming a resist pattern of the present invention includes the steps of exposing the formed resist film and developing it. This step is a step of developing the exposed resist film with a developer. This step forms a target resist pattern. The lithographic film-forming composition of the present invention crosslinks upon exposure and becomes insoluble in water and organic solvents, so either an aqueous developer such as water or an alkaline developer, or an organic solvent-based developer can be used.

[0078] The developer is preferably a solvent whose solubility parameter (SP value) is close to that of the compound represented by formula (1). The solvent is preferably a polar solvent, a hydrocarbon solvent, or an alkaline aqueous solution. Examples of the polar solvent include ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. The developer more preferably contains a polar solvent, and even more preferably contains at least one solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. A developer containing the solvent is preferred because it can improve resist performance such as the resolution and roughness of the resist pattern. Examples of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, hydrocarbon solvents, and alkaline aqueous solutions include those disclosed in WO 2017 / 033943.

[0079]

[0033] A plurality of the solvents may be mixed, and the developer may contain water or other solvents as long as the effects of the present invention are not impaired. When an organic solvent (a polar solvent or a hydrocarbon solvent) is used in the developer, the water content of the developer is preferably less than 70% by mass, more preferably less than 50% by mass, even more preferably less than 30% by mass, still more preferably less than 10% by mass, and even more preferably substantially free of water.

[0080] The content of the organic solvent (polar solvent and hydrocarbon solvent) in the developer is preferably 30% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, even more preferably 70% by mass or more and 100% by mass or less, still more preferably 90% by mass or more and 100% by mass or less, and still more preferably 95% by mass or more and 100% by mass or less.

[0081] The vapor pressure of the developer at 20°C is preferably 5 kPa or less, more preferably 3 kPa or less, and even more preferably 2 kPa or less. When the vapor pressure of the developer is within this range, evaporation of the developer on the substrate or in the developing cup is suppressed, improving the temperature uniformity within the wafer surface, and as a result, improving the dimensional uniformity within the wafer surface. Examples of developers having such vapor pressure include the developers disclosed in International Publication No. 2017 / 033943.

[0082] The developer used in the present invention may be a solvent capable of dissolving the compound represented by formula (1), such as propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether acetate (PGMEA), butyl acetate, methyl 2-hydroxyisobutyrate (HBM), ethyl lactate, acetonitrile, cyclohexanone, cyclopentanone, tetrahydrofuran (THF), water, or an aqueous tetramethylammonium hydroxide solution (aqueous TMAH solution). Preferably, at least one solvent selected from the group consisting of PGME, PGMEA, water, and an aqueous TMAH solution may be used. The concentration of the aqueous TMAH solution is not particularly limited, but may be 0.001 to 2.5% by mass.

[0083] From the viewpoint of environmental safety, the developer is preferably an aqueous developer such as an alkaline developer. For example, an aqueous TMAH solution, water, or the like can be used as the aqueous developer.

[0084] The developer may contain a surfactant. Examples of the surfactant include nonionic surfactants and ionic surfactants, and a nonionic surfactant is preferred. The surfactant is preferably at least one selected from the group consisting of fluorine-based surfactants and silicone-based surfactants, and more preferably at least one selected from the group consisting of nonionic fluorine-based surfactants and nonionic silicone-based surfactants. Examples of fluorine-based surfactants and silicone-based surfactants include those described in JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, U.S. Pat. Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, and 5,824,451.

[0085] The amount of the surfactant used is preferably from 0.001 to 5% by mass, more preferably from 0.005 to 2% by mass, and even more preferably from 0.01 to 0.5% by mass, based on the total amount of the developer.

[0086] Examples of development methods include the dipping method, the puddle method, the spray method, and the dynamic dispensing method. The dipping method is a method in which a substrate is immersed in a tank filled with a developer for a certain period of time. The puddle method is a method in which the developer is piled up on the surface of the substrate by surface tension and left to stand for a certain period of time to develop. The spray method is a method in which the developer is sprayed onto the surface of the substrate. The dynamic dispensing method is a method in which the developer is continuously dispensed onto a substrate rotating at a constant speed while a developer dispensing nozzle is scanned at a constant speed. The development time is not particularly limited, but is preferably 10 to 90 seconds.

[0087] <Other Steps> The method of forming a resist pattern of the present invention may include the following steps in addition to the steps described above.

[0088] After the development step, a step of stopping the development while replacing the solvent with another solvent may be carried out.

[0089] It is preferable to include a step of cleaning with a rinse solution containing an organic solvent (rinsing step) after the development step. The rinse solution is preferably a solvent that does not dissolve the resist pattern, more preferably a solution containing an organic solvent or water. The rinse solution preferably contains at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents, more preferably at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, and amide solvents, even more preferably at least one organic solvent selected from the group consisting of alcohol solvents and ester solvents, still more preferably a monohydric alcohol, even more preferably a monohydric alcohol having 5 or more carbon atoms.

[0090] The monohydric alcohol includes linear, branched, and cyclic monohydric alcohols, and is preferably at least one selected from the group consisting of 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, and 4-octanol, and more preferably 1-hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, and 3-methyl-1-butanol. A mixture of two or more organic solvents may be used, or the solvent may contain an organic solvent other than those mentioned above.

[0091] The water content in the organic solvent-based rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less. When the water content is within this range, better development characteristics can be obtained. The rinse liquid may contain a surfactant. The vapor pressure of the rinse liquid at 20°C is preferably 0.05 to 5 kPa, more preferably 0.1 to 5 kPa, and even more preferably 0.12 to 3 kPa. When the vapor pressure of the rinse liquid is within this range, the temperature uniformity within the wafer surface is further improved, and swelling due to penetration of the rinse liquid is further suppressed, resulting in better dimensional uniformity within the wafer surface.

[0092] The cleaning method is preferably a spin coating method, a dipping method, or a spray method, and more preferably a spin coating method. It is more preferable to perform cleaning by a spin coating method, and then rotate the substrate at a rotation speed of 2000 rpm to 4000 rpm after cleaning to remove the rinse solution from the substrate. The spin coating method is a method in which the rinse solution is continuously applied onto a substrate rotating at a constant speed, the dipping method is a method in which the substrate is immersed in a tank filled with the rinse solution for a certain period of time, and the spray method is a method in which the rinse solution is sprayed onto the substrate surface. There are no particular limitations on the time for rinsing the pattern, but it is preferably 10 to 90 seconds.

[0093] After forming the resist pattern, a patterned wiring substrate can be obtained by etching, which can be performed by a known method such as dry etching using plasma gas or wet etching using an alkaline solution, cupric chloride solution, ferric chloride solution, or the like.

[0094] After forming the resist pattern, plating may be performed. The plating method is not particularly limited, but examples thereof include copper plating, solder plating, nickel plating, and gold plating.

[0095] The remaining resist pattern after etching can be stripped using an organic solvent. Examples of the organic solvent include, but are not limited to, propylene glycol monoethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and ethyl lactate. Examples of the stripping method include, but are not limited to, a dipping method and a spray method. The wiring substrate on which the resist pattern is formed may be a multilayer wiring substrate and may have small-diameter through-holes. The wiring substrate may be formed by a lift-off method. The lift-off method is a method in which a resist pattern is formed, a metal is vapor-deposited in a vacuum, and then the resist pattern is dissolved in a solution.

[0096] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

[0097] [Evaluation 1] <Solubility> The solubility of the compound was confirmed in the following solvents at room temperature (25°C). The solvents tested were PGME (propylene glycol monomethyl ether), PGMEA (propylene glycol monoethyl ether acetate), water, a 2.38 mass% TMAH aqueous solution (tetramethylammonium hydroxide aqueous solution), and a 0.238 mass% TMAH aqueous solution. For the above solvents, the solubility was evaluated as "good" when 2 mg or more of the compound was dissolved in 2 g of the solvent.

[0098] <Thermal Stability (Heat Resistance)> Thermal stability was evaluated by measuring the 5% weight loss temperature (Td5%) and the 10% weight loss temperature (Td10%) using a thermogravimetric analyzer (TGA) TGA-50 / 50H (manufactured by Shimadzu Corporation) under nitrogen at a heating rate of 10°C / min. The higher the 5% weight loss temperature (Td5%) and the 10% weight loss temperature (Td10%), the more excellent the thermal stability.

[0099] <Film Formability> An acetonitrile solution of the compound (30 mg of compound, 0.97 g of acetonitrile) was applied by spin coating at 3000 rpm for 30 seconds onto a silicon wafer treated with hexamethyldisilazane (HMDS), and then heated at 100°C for 30 seconds to form a thin film. The film thickness was measured using a film thickness measuring device (Ellipsometer SE-101 (manufactured by Photonic Lattice Inc.) and a surface profiling system Dektak-XT (manufactured by Bruker) (measurement wavelength: 636 nm). The thicknesses of the films that could be formed are shown in Table 1, and these were evaluated as having good film formability.

[0100] <Resist Sensitivity Characteristics> In a methyl ethyl ketone (MEK) solution of the compound (30 mg of compound, 0.97 g of MEK), 10% by mass of TPS-109 (triphenylsulfonium trifluoromethanesulfonate) (manufactured by Midori Chemical Co., Ltd.) as an acid generator and 100 mol % by mass of TOA (tri-n-octylamine) as an acid diffusion controller were dissolved, and the solution was filtered through a 0.20 μm PTFE syringe filter to obtain a solution for evaluation. Next, the solution for evaluation was applied by spin coating to a silicon wafer treated with hexamethyldisilazane (HMDS) at 3000 rpm for 30 seconds to form a thin film. Next, the thin film was pre-exposure baked (PB) at 90°C for 60 seconds to obtain a film for evaluation.

[0101] (EB Sensitivity Evaluation) The obtained evaluation film was exposed using an electron beam lithography system (EB lithography) (EB-ENGINE System, manufactured by Hamamatsu Photonics K.K.) (accelerating voltage: 50 keV, exposed area size: 1 cm × 1 cm). Next, the exposed silicon wafer (exposed evaluation film) was subjected to post-exposure baking (PEB) at 90°C for 30 seconds. The post-exposure baked silicon wafer was developed by immersing it in a 2.38% by mass aqueous TMAH solution at room temperature for 30 seconds, and then rinsed with deionized water for 10 seconds and dried. The film thickness was measured using an SE-101 ellipsometer (manufactured by Photonic Lattice Co., Ltd.), and a sensitivity curve was obtained. The exposure dose at which 70% or more of the initial film thickness remained was defined as the sensitivity. The lower the exposure dose at which the film remained, the better the resist sensitivity.

[0102] [Compounds] Ionic compounds containing iodine atoms were synthesized in Examples 1 to 3. Example 1 (Preparation of IMDP-BEPMSion)

[0103] The ionic compound IMDF-BEPMSion was produced according to the reaction formula above. 2,6-Dimethylphenol (DMP) and 4-iodobenzaldehyde (IBA) were reacted in ethanol using concentrated hydrochloric acid as a catalyst under reflux conditions at 90°C for 24 hours to obtain the corresponding iodine-containing compound IMDP. Subsequently, the iodine-containing compounds IMDP and BEPMS were reacted in DMF in the presence of potassium carbonate as a base at 80°C for 48 hours. The hydroxyl groups of the iodine-containing compound IMDP were reacted with BEPMS to obtain the corresponding IMDP-BEPMS in a 29% yield. Next, the resulting IMDP-BEPMS was reacted with silver trifluoromethanesulfonate and iodomethane in acetonitrile (dehydrated) at room temperature for 24 hours to obtain the corresponding ionic compound IMDP-BEPMSion in an 84% yield. The results of the evaluation of the solubility, heat resistance, and film-forming properties of the obtained IMDP-BEPMSion are shown in Table 1. The results of the evaluation of the EB sensitivity are shown in FIG.

[0104] Example 2 (Production of 2H-IMDP-BEPMSion)

[0105] The ionic compound 2H-IMDP-BEPMSion was produced according to the reaction scheme above. 2H-IMDP-BEPMSion was obtained in the same manner as in Example 1, except that DISA was used instead of 4-iodobenzaldehyde (IBA). The intermediate 2H-IMDP was obtained from DISA in a yield of 75%, 2H-IMDP-BEPMS was obtained from 2H-IMDP in a yield of 47%, and the final product 2H-IMDP-BEPMSion was obtained from 2H-IMDP-BEPMS in a yield of 80%. The solubility, film-forming ability, and heat resistance of the resulting ionic compound 2H-IMDP-BEPMSion were evaluated, and the results are shown in Table 1. The EB sensitivity evaluation results are also shown in Figure 1.

[0106] Example 3 (Production of 4H-IMDP-BEPMSion)

[0107] The ionic compound 4H-IMDP-BEPMSion was produced according to the above reaction scheme. 4H-IMDP-BEPMSion was obtained in the same manner as in Example 1, except that HDSA was used instead of 4-iodobenzaldehyde (IBA). The intermediate 4H-IMDP was obtained from HDSA in a yield of 62%, 4H-IMDP-BEPMS was obtained from 4H-IMDP in a yield of 59%, and the final product 4H-IMDP-BEPMSion was obtained from 4H-IMDP-BEPMS in a yield of 81%. The results of the solubility, film-forming ability, and heat resistance evaluations of the obtained ionic compound 4H-IMDP-BEPMSion are shown in Table 1. The results of the EB sensitivity evaluation are shown in Figure 1.

[0108]

[0109] The results in Table 1 show that all of the compounds of the examples have high solubility in solvents, excellent film-forming properties, and high heat resistance. Furthermore, as shown in Figure 1, the compound of Example 1 was exposed to electron beams at a fluence of 500 μC / cm ２ , and the compound of Example 2 is 700 μC / cm ２ , and the compound of Example 3 is 900 μC / cm ２and showed excellent negative resist sensitivity characteristics. Furthermore, it was found that the compound of this example exhibited excellent solubility in water and low-concentration alkaline aqueous solutions, and was also excellent in environmental safety. Therefore, it is clear that the compound of the present invention is excellent as a material for forming a lithography film, and particularly as a material for forming a resist film.

[0110] [Lithography Film-Forming Composition] Comparative Synthesis Example 1 (Synthesis of Modified Dimethylnaphthalene Formaldehyde Resin CR-1) A 10 L four-neck flask equipped with a Dimroth condenser, a thermometer, and a stirring blade and capable of being opened to the bottom was prepared. Into this four-neck flask, 1.09 kg (7 mol, manufactured by Mitsubishi Gas Chemical Co., Inc.), 2.1 kg of 40% by weight aqueous formalin solution (28 mol as formaldehyde, manufactured by Mitsubishi Gas Chemical Co., Inc.), and 0.97 mL of 98% by weight sulfuric acid (manufactured by Kanto Chemical Co., Inc.) were charged under a nitrogen stream, and the mixture was refluxed at 100°C under normal pressure (atmospheric pressure) for 7 hours. Subsequently, 1.8 kg of ethylbenzene (manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent) was added as a diluent to the reaction solution. After allowing to stand, the lower aqueous phase was removed. The mixture was then neutralized and washed with water, and the ethylbenzene and unreacted 1,5-dimethylnaphthalene were distilled off under reduced pressure to obtain 1.25 kg of a light brown solid dimethylnaphthalene formaldehyde resin. The number average molecular weight Mn of the resulting dimethylnaphthalene formaldehyde resin was 562.

[0111] Next, a four-neck flask with an internal volume of 0.5 L equipped with a Dimroth condenser, a thermometer, and a stirring blade was prepared. Under a nitrogen stream, 100 g (0.51 mol) of the dimethylnaphthalene formaldehyde resin and 0.05 g of paratoluenesulfonic acid were charged into this four-neck flask, heated to 190°C, and stirred for 2 hours. Subsequently, 52.0 g (0.36 mol) of 1-naphthol was added, and the temperature was further raised to 220°C, allowing the reaction to proceed for 2 hours. After dilution with ethylbenzene as a solvent, the mixture was neutralized and washed with water. The solvent was then removed under reduced pressure to obtain 126.1 g of a modified dimethylnaphthalene formaldehyde resin (CR-1) as a black-brown solid. The resulting resin (CR-1) had an Mn of 885, an Mw of 2220, and an Mw / Mn of 2.51. The Mn, Mw, and Mw / Mn of the resin (CR-1) were determined in terms of polystyrene by gel permeation chromatography (GPC) analysis under the following measurement conditions: Apparatus: Shodex GPC-101 (product of Showa Denko K.K.) Column: KF-80M x 3 Eluent: THF Flow rate: 1 mL / min Temperature: 40°C

[0112] Synthesis Example 1 (Synthesis of Acrylic Resin AC-1) A reaction solution was prepared by dissolving 4.15 g of 2-methyl-2-methacryloyloxyadamantane, 3.00 g of methacryloyloxy-γ-butyrolactone, 2.08 g of 3-hydroxy-1-adamantyl methacrylate, and 0.38 g of azobisisobutyronitrile in 80 mL of tetrahydrofuran. Under a nitrogen atmosphere, the reaction solution was stirred while maintaining the temperature at 63°C, and polymerization was carried out for 22 hours. Thereafter, the reaction solution was added dropwise to 400 mL of n-hexane. The resulting resin was coagulated and purified, and the resulting white powder was filtered and then dried overnight at 40°C under reduced pressure to obtain acrylic resin AC-1 represented by the following formula:

[0113] (In the formula, "40", "40", and "20" indicate the ratio of each structural unit and do not indicate that it is a block copolymer.)

[0114] Examples A1 to A6 and Comparative Example A1 (Preparation of Lithography Film-Forming Compositions) Lithography film-forming compositions having the compositions shown in Table 2 were prepared using the compounds obtained in Examples 1 to 3 and CR-1 obtained in Comparative Synthesis Example 1. In addition, a lithography film-forming composition using a novolak resin (PSM4357 (model number) manufactured by Gunei Chemical Industry Co., Ltd.) was also prepared as a reference for etching resistance evaluation.

[0115] The acid generator, acid diffusion controller, crosslinker, and organic solvent used were as follows: In Table 2, the numbers in parentheses indicate the blend amounts (parts by mass). <Acid generator> TPS-109 (trade name: triphenylsulfonium trifluoromethanesulfonate, manufactured by Midori Chemical Co., Ltd.) DTDPI (di-tert-butyldiphenyliodonium nonafluorobutanesulfonate, manufactured by Midori Chemical Co., Ltd.) <Acid diffusion controller> TOA (tri-n-octylamine, manufactured by Kanto Chemical Co., Ltd.) <Crosslinking agent> Nikalac MW-100LM (trade name: methylated melamine resin, manufactured by Sanwa Chemical Co., Ltd.) Nikalac MX270 (trade name: alkylated urea resin, manufactured by Sanwa Chemical Co., Ltd.) TMOM-BP (trade name: 3,3'5,5'-tetrakis(methoxymethyl)-[1,1'-biphenyl]-4,4'-diol, manufactured by Honshu Chemical Industry Co., Ltd.) <Organic solvent> PGME (propylene glycol monomethyl ether, manufactured by Kanto Chemical Co., Ltd.) PGMEA (manufactured by Kanto Chemical Co., Ltd.) Propylene glycol monomethyl ether acetate)

[0116]

[0117] [Compounds] Examples 4 to 6 (Production of IMDP2-BEPMSion, IMDP3-BEPMSion, and M-IMDP-BEPMSion) Ionic compounds containing iodine atoms were synthesized in the same manner as in Example 1, except that DMP and IBA in Example 1 were replaced with the raw materials shown in Table 3.

[0118]

[0119] The raw materials used in Examples 4 to 6 and the compounds obtained are shown below.

[0120] [Lithography film-forming compositions, resist films] Examples A7 to A9 (Preparation of lithography film-forming compositions) Lithography film-forming compositions having the compositions shown in Table 4 were prepared in the same manner as in Example A1, except that the compounds obtained in Examples 4 to 6 were used in Example A1.

[0121]

[0122] [Evaluation 2] (1) Formation of Resist Film The lithography film-forming compositions (Examples A1 to A9 and Comparative Example A1) shown in Tables 2 and 4 were spin-coated onto a silicon wafer that had been treated with hexamethyldisilazane (HMDS). Then, a pre-exposure bake (PB) was performed in an oven at 110°C to form a resist film with a thickness of 40 nm.

[0123] (2) Formation of Resist Pattern The resist film obtained in (1) above was irradiated with an electron beam using an electron beam lithography system (ELS-7500, manufactured by Elionix Co., Ltd., 50 keV) in a 1:1 line-and-space setting with 50 nm spacing. After irradiation, the resist film was heated at 110°C for 90 seconds and immersed in a developer for 60 seconds for development. The resist film was then washed with ultrapure water for 30 seconds and dried to form a resist pattern. In Examples A1 to A9, a 2.38% by mass aqueous solution of TMAH was used as the developer, and in Comparative Example A1, propylene glycol monomethyl ether (PGME) was used as the developer.

[0124] The shape of the resulting L / S (1:1) resist pattern with 50 nm spacing was observed using an electron microscope (product name: S-4800) manufactured by Hitachi, Ltd. The resist pattern shape after development was evaluated according to the following criteria. The results are shown in Tables 5 and 6. (Evaluation Criteria) A: No pattern collapse, and rectangularity was better than that of Comparative Example A1. B: The rectangularity was better than that of Comparative Example A1, but pattern collapse was observed in 1 to 3 places within an area of ​​1 μm × 1.5 μm. C: Equivalent to or inferior to Comparative Example A1. In Comparative Example A1, pattern collapse was observed in the resist pattern shape after development, and rectangularity was poor.

[0125] (3) Etching Resistance The lithography film-forming compositions (Examples A1 to A9 and Comparative Example A1) shown in Tables 2 and 4 were spin-coated onto silicon wafers treated with hexamethyldisilazane (HMDS). Then, a pre-exposure bake (PB) was performed in an oven at 110°C to form a resist film with a thickness of 40 nm. An etching test was performed on the resist film, and the etching rate was measured. The etching conditions are shown below.

[0126] (Etching conditions) Etching equipment: RIE-10NR (product name) manufactured by Samco Corporation Output: 50 W Pressure: 20 Pa Time: 2 minutes Etching gas: Ar gas Flow rate: CF ４ Gas flow rate: 0 ２ Gas flow rate = 50:5:5 (sccm)

[0127] The etching resistance of each resist film was evaluated according to the following criteria, using the etching rate of the resist film obtained from the etching resistance evaluation composition using a novolac resin as the standard. (Evaluation Criteria) A: The etching rate was less than -10% compared to the novolac resin resist film. B: The etching rate was -10% or more but less than 0% compared to the novolac resin resist film. C: The etching rate was 0% or more compared to the novolac resin resist film.

[0128] The resist pattern shapes and etching resistance of Examples A1 to A9 and Comparative Example A1 were evaluated. The evaluation results are shown in Tables 5 and 6.

[0129]

[0130] [Lithography film-forming compositions, resist underlayer films, resist films] Examples B1 to B7 (Preparation of lithography film-forming compositions) Using the compounds obtained in Examples 1 and 2, lithography film-forming compositions having the formulations shown in Table 7 were prepared. The obtained lithography film-forming compositions were used to form resist underlayer films and resist films. The acid generators, crosslinkers, and organic solvents used were as follows. In Table 7, the numbers in parentheses indicate the blend amounts (parts by mass).

[0131] <Acid generator> DTDPI (di-tert-butyldiphenyliodonium nonafluoromethanesulfonate, manufactured by Midori Chemical Co., Ltd.) TPS-109 (trade name, triphenylsulfonium trifluoromethanesulfonate, manufactured by Midori Chemical Co., Ltd.) PPTS (pyridinium paratoluenesulfonate, manufactured by Kanto Chemical Co., Ltd.) <Crosslinking agent> Nikalac MX-270 (trade name, alkylated urea resin, manufactured by Sanwa Chemical Co., Ltd.) Nikalac MW-100LM (trade name, methylated melamine resin, manufactured by Sanwa Chemical Co., Ltd.) TMOM-BP (trade name, 3,3'5,5'-tetrakis(methoxymethyl)-[1,1'-biphenyl]-4,4'-diol, manufactured by Honshu Chemical Industry Co., Ltd.) <Organic solvent> PGME (propylene glycol monomethyl ether, manufactured by Kanto Chemical Co., Ltd.) PGMEA (propylene glycol monomethyl ether acetate, manufactured by Kanto Chemical Co., Ltd.)

[0132]

[0133] Examples B8 to B10 (Preparation of lithography film-forming compositions) Lithography film-forming compositions having the compositions shown in Table 8 were prepared in the same manner as in Example B1, except that the compounds obtained in Examples 4 to 6 were used in Example B1. The obtained lithography film-forming compositions were used to form resist underlayer films and resist films.

[0134]

[0135] [Evaluation 3] (1) Formation of Resist Underlayer Film Each of the lithography film-forming compositions shown in Tables 7 and 8 was spin-coated onto a silicon wafer that had been treated with hexamethyldisilazane (HMDS), and then pre-exposure baked (PB) at 240°C for 60 seconds and then at 400°C for 120 seconds to prepare a resist underlayer film (resist film as an underlayer film) having a thickness of 70 nm.

[0136] (2) Formation of Resist Film: An ArF resist solution was applied to the resist underlayer film formed in (1) above and baked at 130°C for 60 seconds to form a photoresist film with a thickness of 140 nm. The ArF resist solution was prepared by blending 5 parts by weight of AC-1 obtained in Synthesis Example 1, 1 part by weight of triphenylsulfonium nonafluorobutanesulfonate, 2 parts by weight of tributylamine, and 92 parts by weight of PGMEA. The photoresist film was then exposed using an electron beam lithography system "ELS-7500" (product name, manufactured by Elionix Co., Ltd., 50 keV). A post-exposure bake (PEB) was then performed at 115°C for 90 seconds, followed by development for 60 seconds with a 2.38% by weight aqueous TMAH solution to obtain a positive resist pattern. In Comparative Example B1, a photoresist film was formed directly on a silicon wafer in the same manner as in Example B1, except that no underlayer film was formed, and a positive resist pattern was obtained.

[0137] The results of observing defects in the resulting 55 nm L / S (1:1) and 80 nm L / S (1:1) resist patterns are shown in Table 9. In the table, "Good" in the results of "resist pattern after development" indicates that no pattern collapse was observed in the formed resist pattern, and "Bad" indicates that pattern collapse was observed in the formed resist pattern. Furthermore, as a result of the above observation, the smallest line width at which there was no pattern collapse and good rectangularity was used as an index for evaluation of "resolution." The results are shown in Table 9.

[0138]

[0139] The resolution and the resist patterns after development of Examples B8 to B10 were evaluated in the same manner as in Example B1. The evaluation results are shown in Table 10.

[0140] From the results of the examples, it can be seen that the resist pattern formed using the lithography film-forming composition using the compound represented by formula (1) of the present invention is free from pattern collapse and has excellent resolution. It can also be seen that the resist film formed using the lithography film-forming composition using the compound represented by formula (1) of the present invention has excellent etching resistance. From the above, it can be seen that the lithography film-forming composition of the present invention is excellent as a material for forming a resist film or a resist underlayer film. It can also be seen that the resist pattern formed using the lithography film-forming composition has excellent resolution.

Claims

A compound represented by the following formula (1): (In formula (1), Ar is a group having an aryl group having 6 to 60 carbon atoms, and R １ is an organic group having a sulfonium salt or an iodonium salt, and n Ａ is an integer from 1 to 9, and n Ｂ is an integer of 1 or greater.) 　 The compound according to claim 1 , wherein Ar is an optionally substituted triphenylmethane. 　 The compound according to claim 2, represented by the following formula (2): (In formula (2), R １ is an organic group having a sulfonium salt or an iodonium salt, and R ０ is a group selected from the group consisting of a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom; R ２ is a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom. a is an integer from 1 to 5, b is an integer from 0 to 4, c is an integer from 0 to 4, and a+b+c is 1 to 5. d is an integer from 0 to 5, e is an integer from 0 to 5, d+e is 0 to 5, f is an integer from 0 to 5, g is an integer from 0 to 5, f+g is 0 to 5, and b+d+f is 1 or more. R ２ The compound according to claim 3, wherein is a linear or branched alkyl group having 1 to 4 carbon atoms. 　 The compound according to claim 3, represented by the following formula (3): (In the formula, R １ is an organic group having a sulfonium salt or an iodonium salt, and R ２ is a group selected from the group consisting of a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a halogen atom; a is an integer of 1 to 5, b is an integer of 0 to 4, and a+b is 1 to 5. 　 In the formula (3), R １ The compound according to claim 5, wherein is a group represented by the following formula (7) or the following formula (8): (In formula (7) and formula (8), R ３ is a single bond or a divalent group having 1 to 30 carbon atoms which may have a substituent, and R ５ is an alkyl group having 1 to 10 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent, R ７ is an alkyl group having 1 to 4 carbon atoms, h is an integer of 0 to 4, and An － is an anion containing fluorine or iodine. ４ represents an alkyl group having 1 to 10 carbon atoms which may have a substituent, or an aryl group having 6 to 10 carbon atoms which may have a substituent. 　 In the formula (3), R １ The compound according to claim 5, wherein is a group represented by the following formula (9): The compound according to any one of claims 1 to 7, which is at least one selected from the group consisting of a compound represented by the following formula (4), a compound represented by the following formula (5), and a compound represented by the following formula (6): (In the formula, R １ is an organic group having a sulfonium salt or an iodonium salt, and R ２ is an alkyl group having 1 to 4 carbon atoms. 　 In the formula (4), the formula (5), or the formula (6), R １ The compound according to claim 8, wherein is a group represented by the following formula (9): 　 A lithography film-forming composition comprising the compound according to claim 1. 　 The lithographic film-forming composition according to claim 10 , further comprising a solvent. 　 The lithographic film-forming composition according to claim 10, further comprising at least one selected from the group consisting of an acid generator and a crosslinking agent. 　 The composition for forming a lithography film according to claim 10, which is a composition for forming a resist film. 　 A resist film formed from the composition for forming a lithographic film according to any one of claims 10 to 13. 　 A resist underlayer film formed from the composition for forming a lithographic film according to any one of claims 10 to 12. 　 A method for forming a resist pattern, which comprises using the composition for forming a lithographic film according to any one of claims 10 to 13. 　 A step of forming a resist film on a substrate using the composition for lithography film formation according to any one of claims 10 to 13; and a step of exposing the resist film to light and developing it; A method for forming a resist pattern, comprising:

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