Composition, pattern forming method, and method for manufacturing article

Abstract

To provide a composition advantageous for obtaining high flatness and high productivity (throughput).SOLUTION: The composition for spin coating contains a polymerizable compound containing at least a silicon atom, and a solvent. The viscosity of a material obtained by removing the solvents from the composition is ≥ 10mPa s and ≤ 1, 000mPa s at 23 °C. The silicon atom content of the material obtained by removing the solvent from the composition is 30% by weight or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composition, a patterning method, and a method for manufacturing an article. [Background technology]

[0002] As demand for miniaturization of semiconductor devices and MEMS increases, in addition to conventional photolithography technology, imprint technology, which forms an imprint material on a substrate using a mold and then forms a pattern of the imprint material on the substrate, is attracting attention.

[0003] The imprinting technique involves contacting a mold with an imprint material applied to a substrate to form a concave-convex pattern. The pattern obtained using this imprinting technique is used as a mask to process the substrate, and a process called the inversion process can be applied.

[0004] Patent Document 1 discloses the following inversion process. First, an inversion layer is formed on the concave-convex pattern (inversion layer formation step), and the concave portions are filled with an inversion layer material. At this time, the inversion layer material is also deposited on the tops of the convex portions of the concave-convex pattern, forming an excess inversion layer. Therefore, the excess inversion layer is removed (excess inversion layer removal step) so as to expose the top surfaces of the convex portions of the concave-convex pattern of the cured film of the curable composition, exposing the inversion layer filled in the concave portions. Then, using the exposed inversion layer as a mask, the remaining film of the concave-convex pattern (remaining film etching step) and the underlying processed layer are etched to form an inversion pattern (processed layer processing step).

[0005] In such an inversion process, it is desirable that the surface of the inversion layer be flat. Patent Document 2 discloses a composition consisting of polysiloxane and a high-boiling point solvent as a material capable of forming a flat film. Patent Document 3 discloses a method of flattening an inversion layer by forming it using an inkjet method, and a method of flattening the inversion layer by pressing it with a flat mold. Patent Document 4 discloses forming a flat inversion layer by applying a low-viscosity curable composition using an inkjet method. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-162862 [Patent Document 2] Japanese Patent Application Publication No. 2018-12806 [Patent Document 3] Japanese Patent Application Publication No. 2018-98470 [Patent Document 4] Patent Publication No. 2023-181983 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the flatness is insufficient with the material and method disclosed in Patent Document 2. Furthermore, the methods disclosed in Patent Documents 3 and 4 require complicated processes such as an inkjet method or pressing using a flat mold, which results in high costs and low productivity (throughput).

[0008] An object of the present invention is to provide an advantageous composition for achieving high flatness and high productivity (throughput). [Means for solving the problem]

[0009] One aspect of the present invention relates to a composition for spin coating, the composition comprising a polymerizable compound containing at least silicon atoms and a solvent. The viscosity of the material obtained by removing the solvent from the composition is 10 mPa·s or more and 1,000 mPa·s or less at 23°C. The silicon atom content of the material obtained by removing the solvent from the composition is 30 wt% or more. [Effects of the Invention]

[0010] According to the present invention, an advantageous composition is provided for achieving high flatness and high productivity (throughput). [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram illustrating a known inversion process. [Figure 2] FIG. 1 is a schematic diagram illustrating possible problems that may occur in the inversion process. [Figure 3] 1A and 1B are schematic diagrams illustrating a photo-nanoimprint method. [Figure 4] 1A to 1C are schematic diagrams illustrating a flow of a reversal process according to the present embodiment. [Figure 5] FIG. 1 is a schematic diagram showing an initial liquid film distribution. [Figure 6] FIG. 10 is a schematic diagram showing the change in liquid film distribution over time. [Figure 7] FIG. 10 is a schematic diagram showing the change over time in the height difference of the liquid film distribution. [Figure 8] FIG. 1 is a schematic diagram showing the spatial period and the time elapsed until the height difference falls below 5 nm. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0013] In providing a new technique relating to a composition advantageous for forming an inversion layer, the present inventors have discovered a composition and process conditions that enable high flatness and high productivity (throughput).

[0014] [Inversion layer forming composition] Composition (A) of one embodiment is a composition for spin coating and can be used, for example, for an inversion layer. Composition (A) of one embodiment is a composition containing a polymerizable compound (as) containing at least silicon atoms and a solvent component (d). Hereinafter, the polymerizable compound (as) containing at least silicon atoms is also referred to as a silicon-containing polymerizable compound. Composition (A) of one embodiment may further contain at least one of a polymerizable compound (a) that does not contain silicon (Si) atoms, a polymerization initiator (b), and a non-polymerizable compound (c).

[0015] <Component (as): Silicon-containing polymerizable compound> In this specification, the silicon-containing polymerizable compound (as) is a compound that forms a film made of a polymer compound through a chain reaction (polymerization reaction) caused by heat or light, or a chain reaction (polymerization reaction) caused by a polymerization factor (radical, cation, etc.) generated from a polymerization initiator (component (b)).

[0016] Examples of the silicon-containing polymerizable compound (as) include radically polymerizable compounds and cationically polymerizable compounds. The silicon-containing polymerizable compound (as) may be composed of only one type of polymerizable compound, or may be composed of multiple types (one or more) of polymerizable compounds.

[0017] Examples of the silicon-containing polymerizable compound include (meth)acrylate compounds, (meth)acrylamide compounds, epoxy-modified compounds, alicyclic epoxy-modified compounds, vinylbenzene compounds, allyl ether compounds, vinyl compounds, vinyl ether compounds, and maleimide compounds.

[0018] The silicon-containing polymerizable compound (as) may be linear or branched. Examples thereof include the following structures. The polymerizable functional group in the group Q having a polymerizable functional group may be, for example, a radically polymerizable functional group. Specific examples of the radically polymerizable functional group include (meth)acrylate-based compounds, (meth)acrylamide-based compounds, epoxy-modified compounds, alicyclic epoxy-modified compounds, vinylbenzene-based compounds, allyl ether-based compounds, vinyl-based compounds, vinyl ether-based compounds, and maleimide-based compounds. The group Q having a polymerizable functional group may be any group having the above-mentioned polymerizable functional group.

[0019] [ka]

[0020] Other examples of the silicon-containing polymerizable compound (as) include a silsesquioxane skeleton as shown in formula (1) and a silicone skeleton as shown in formula (2). In formula (1), m+n=8 (8≧m≧1), R1 represents a divalent organic group, and in formula (2), A, B, and R 2、 R3 is independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group, an alkoxy group, a phenyl group, or a hydroxyl group, and t is an integer of 1 to 3, and at least one of A and B is a polymerizable functional group.

[0021] [ka]

[0022] [ka]

[0023] The polymerizable functional group in the groups Q, A, and B having a polymerizable functional group can be, for example, a radically polymerizable functional group. Specific examples of the radically polymerizable functional group include (meth)acrylate compounds, (meth)acrylamide compounds, vinylbenzene compounds, allyl ether compounds, vinyl compounds, vinyl ether compounds, and maleimide compounds. The group Q having a polymerizable functional group may be any group having the above polymerizable functional group.

[0024] The molar equivalent weight of the polymerizable functional group of the silicon-containing polymerizable compound (as) is 300 or more, preferably 400 or more, and particularly preferably 500 or more. By making the molar equivalent weight of the polymerizable functional group 300 or more, the cure shrinkage rate can be reduced.

[0025] The molar equivalent of the polymerizable functional group of the silicon-containing polymerizable compound (as) can be calculated, for example, by the following formula: When the silicon-containing polymerizable compound (as) is composed of multiple types (one or more types) of polymerizable compounds, it can be calculated as a weighted average of the molar fractions. (Method for calculating the molar equivalent of a polymerizable functional group) (Molecular weight of component (as)) / (Number of polymerizable functional groups in component (as)) The silicon-containing (meth)acrylate compound is a compound having one or more acryloyl groups or methacryloyl groups. Examples of monofunctional (meth)acrylate compounds having one silicon-containing acryloyl group or methacryloyl group include, but are not limited to, the following: (2-acryloylethoxy)trimethylsilane, N-(3-acryloyl-2-hydroxypropyl)-3-aminopropyltriethoxysilane, acryloxymethyltrimethoxysilane, (acryloxymethyl)phenethyltrimethoxysilane, acryloxymethyltrimethylsilane, (3-acryloxypropyl)dimethylmethoxysilane, (3-acryloxypropyl)methylbis(trimethylsiloxy)silane, (3-acryloxypropyl)methyldichlorosilane, (3-acryloxypropyl)methyldiethoxysilane, (3-acryloxypropyl)methyldimethoxysilane, (3-acryloxypropyl)trichlorosilane, (3-acryloxypropyl)trimethoxysilane, (3-acryloxypropyl)tris(trimethylsiloxy)silane, acryloxytriisopropylsilane, acryloxytrimethylsilane, methacryloxymethyltrimethoxysilane, O-(methacryloxyethoxy)carbamoylpropylmethyldimethoxysilane, (methacryloxymethyl)bis(trimethylsiloxy)methylsilane, N-(3-methacryloyl-2-hydroxypropyl)-3-aminopropyltriethoxysilane, (methacryloxymethyl)methyldimethoxysilane, (methacryloxymethyl)methyldiethoxysilane, methacryloxymethyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloylpropyltriisopropoxysilane, O-(methacryloxyethyl)-N-(triethoxysilylpropyl)carbamate, methacryloxypropylmethyldimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropyldimethylmethoxysilane, methacryloxypropyldimethylethoxysilane, (methacryloxymethyl)dimethylethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropyl silatrane, methacryloxypentamethyldisiloxane, (methacryloxymethyl)phenyldimethylsilane, methacryloxytrimethylsilane, methacryloxymethyltrimethylsilane, (3-methacryloxy-2-hydroxypropoxypropyl)methylbis(trimethylsiloxy)silane, methacryloxypropyl pentamethyldisiloxane, O-(methacryloxyethyl)-3-[bis(trimethylsiloxy)methylsilyl]propylcarbamate, methacryloxymethyltris(trimethylsiloxy)silane, methacryloxyethoxytrimethylsilane, (3-methacryloxy-2-hydroxypropoxypropyl)methylbis(trimethylsiloxy)silane, methacryloxypropyltris(vinyldimethylsiloxy)silane, methacryloxypropyltris(trimethylsiloxy)silane, 3-methacryloxypropyltriacetoxysilane, methacryloxypropylmethyldichlorosilane, methacryloxypropyltrichlorosilane, 3-methacryloxypropylbis(trimethylsiloxy)methylsilane, 3-methacryloxypropyldimethylchlorosilane, O-methacryloxy(polyethyleneoxy)trimethylsilane, Poly(methacryloxypropylsilsesquioxane), Methacryloxypropylheptaisobutyl-T8-silsesquioxane, Methacryloxypropyltris(trimethylsiloxy)silane

[0026] Examples of commercially available silicon-containing monofunctional (meth)acrylate compounds include, but are not limited to, the following: SIA0160.0, SIA0180.0, SIA0182.0, SIA0184.0, SIA0186.0, SIA0190.0, SIA0194.0, SIA0196.0, SIA01 97.0, SIA0198.0, SIA0199.0, SIA0200.0, SIA0200.A1, SIA0210.0, SIA0315.0, SIA0320.0, SIM6483.0, SIM6487.5, SIM6480.76, SIM6481.2, SIM6486.1, SIM6481.1, SIM6481.46, SIM6481.43, SIM6482.0, SI M6487.4, SIM6487.35, SIM6480.8, SIM6486.9, SIM6486.8, SIM6486.5, SIM6486.4, SIM6481.3, SIM6487 .3, SIM6487.1, SIM6487.6, SIM6486.14, SIM6481.48, SIM6481.5, SIM6491.0, SIM6485.6, SIM6481.15 , SIM6487.0, SIM6481.05, SIM6485.8, SIM6481.0, SIM6487.4LI, SIM6481.16, SIM6487.8, SIM6487.6HP , SIM6487.17, SIM6486.7, SIM6487.2, SIM6486.0, SIM6486.2, SIM6487.6-06, SIM6487.6-20, SIM6485 .9, SST-R8C42, SLT-3R01, SIM6486.65 (or above, made by GELEST), TM-0701T, FM-0711, FM-0721, FM-0725 (or above, made by JNC)

[0027] Silicon-containing (meth)acrylamide compounds are compounds having one or more acrylamide groups or methacrylamide groups. Examples of monofunctional (meth)acrylamide compounds having one silicon-containing acrylamide group or methacrylamide group include, but are not limited to, the following: 3-acrylamidopropyltrimethoxysilane, 3-acrylamidopropyltris(trimethylsiloxy)silane

[0028] Examples of commercially available silicon-containing monofunctional (meth)acrylamide compounds include, but are not limited to, the following: SIA0146.0, SIA0150.0 (all manufactured by GELEST)

[0029] Furthermore, examples of polyfunctional (meth)acrylate compounds (polymerizable compounds) having two or more acryloyl groups or methacryloyl groups include, but are not limited to, compounds having a linear polysiloxane skeleton, a cyclic siloxane skeleton, or a silsesquioxane skeleton.

[0030] Examples of compounds having a linear polysiloxane skeleton include the following:

[0031] Linear polydimethylsiloxane modified with acryloxypropyl groups at both ends Linear polydimethylsiloxane modified at both ends with methacryloxypropyl groups Linear polypropylmethylsiloxane modified with acryloxypropyl groups at both ends Linear polypropylmethylsiloxane modified at both ends with methacryloxypropyl groups Examples of compounds having a cyclic siloxane skeleton include the following:

[0032] Cyclic siloxane modified with multiple acryloxypropyl groups Cyclic siloxane modified with multiple methacryloxypropyl groups Examples of compounds having a silsesquioxane skeleton include the following:

[0033] Silsesquioxane modified with multiple acryloxypropyl groups Silsesquioxane modified with multiple methacryloxypropyl groups

[0034] Examples of commercially available silicon-containing polyfunctional (meth)acrylate compounds include, but are not limited to, the following: SIA0200.2, SIA0200.3, SIM6487.42, DMS-R11, DMS-R05, DMS-R22, DMS-R18, DMS-R31, MCT-M11, RM S-992, RTT-1011 (manufactured by GELEST), FM-7711, FM-7721, FM-7725 (manufactured by JNC), X-22-2445 (Shin-Etsu Chemical), AC-SQ TA-100, MAC-SQ TM-100, AC-SQ SI-20, MAC-SQ SI-20 (all manufactured by Toagosei)

[0035] In addition, according to known literature (for example, Ogawa et al., "Ultraviolet curable branched siloxanes as low-k dielectrics for imprint lithography" (https: / / doi.org / 10.1116 / 1.4770051)), linear modified polydimethylsiloxane (MA-Si-12) modified at both ends with methacryloxypropyl groups, 8-membered ring siloxane (8-ring) modified with four methacryloxypropyl groups, and 10-membered ring siloxane (10-ring) modified with five methacryloxypropyl groups can be synthesized and obtained.

[0036] Examples of commercially available silicon-containing epoxy-modified compounds include, but are not limited to, the following: X-22-163, KF-105, X-22-163A, X-22-163B, X-22-163C (all manufactured by Shin-Etsu Silicones), SIB1110.0, SIB1115.0, SIG5820.0, MCR-E11, MCS-E15, DMS-E09, DMS-E11, PMS-E11, EMS-622, MCR-E21, MCT-EP13, DMS-E12, DMS-E21, DMS-EX21 (all manufactured by GELEST) Examples of commercially available silicon-containing alicyclic epoxy-modified compounds include, but are not limited to, the following: X-22-169AS, X-22-169B (all manufactured by Shin-Etsu Silicones), SIB1092.0, DMS-EC17, DMS-EC31, DMS-EC13, ECMS-127, ECMS-227, ECMS-327, ECMS-924, EBP-234, DMS-EC13 (all manufactured by GELEST) Examples of commercially available silicon-containing polyfunctional vinyl compounds include, but are not limited to, the following: DMS-V00, DMS-V21, VMS-T11, MCS-VX15 (all manufactured by GELEST) In one embodiment of the inversion layer formation method, a curing step by heating is performed after the spin coating step described below. In the curing step, the solvent (d) is volatilized, but the polymerizable compound (as) must not volatilize. Therefore, the vapor pressure of the polymerizable compound (as), which may contain multiple types, at 200°C is preferably 0.001 mmHg or less. This is to prevent the polymerizable compound (as) from volatilizing during heating in the inversion layer reflow and curing steps described below.

[0037] The boiling points and vapor pressures of various organic compounds under normal pressure can be calculated using Hansen Solubility Parameters in Practice (HSPiP) 5th Edition. 5.3.04, etc.

[0038] Specific examples of the polymerizable compound (as) having a vapor pressure of 0.001 mmHg or less at 200° C. include, but are not limited to, the following: 1,3-BIS(3-METHACRYLOXYPROPYL)TETRAKIS(TRIMETHYLSILOXY)DISILOXANE, monoMETHACRYLOXYPROPYLFUNCTIONAL TRIS(POLYDIMETHYLSILOXANE), monoMETHACRYLOXYPROPYLTERMINATEDPOLY(3,3,3TRIFLUOROPROPYL)METHYLSILOXANE, monoVINYLTERMINATED POLYDIMETHYLSILOXANE, VINYLTERMINATED POLYDIMETHYLSILOXANE, (METHACRYLOXYPROPYL)METHYLSILOXANE, homopolymer, METHACRYLOXYPROPYLT-STRUCTURE SILOXANE

[0039] Examples of commercially available silicon-containing compounds include, but are not limited to, the following:

[0040] SIB1400.0, MCS-MX11, MCS-MX11, MFR-M15, MCS-V212, DMS-V21, RMS-992, RTT-1011 (all manufactured by GELEST) <Component (a): Silicon-free polymerizable compound> Component (a) is a non-silicon-containing polymerizable compound. In this specification, the non-silicon-containing polymerizable compound is a compound that reacts with a polymerization factor (such as a radical) generated from a polymerization initiator (component (b)) to form a film made of a polymer compound through a chain reaction (polymerization reaction).

[0041] Examples of such polymerizable compounds include radically polymerizable compounds. The polymerizable compound as component (a) may be composed of only one type of polymerizable compound, or may be composed of multiple types (one or more) of polymerizable compounds.

[0042] Examples of the radically polymerizable compound include silicon-free (meth)acrylic compounds, silicon-free styrene-based compounds, silicon-free vinyl-based compounds, silicon-free allyl-based compounds, silicon-free fumaric compounds, and silicon-free maleyl-based compounds.

[0043] The non-silicon-containing (meth)acrylic compound is a compound having one or more acryloyl groups or methacryloyl groups. Examples of non-silicon-containing monofunctional (meth)acrylic compounds having one acryloyl group or one methacryloyl group include, but are not limited to, the following: Phenoxyethyl (meth)acrylate, phenoxy-2-methylethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, 2-phenylphenoxyethyl (meth)acrylate, 4-phenylphenoxyethyl (meth)acrylate, 3-(2-phenylphenyl)-2-hydroxypropyl (meth)acrylate, EO-modified p-cumylphenol (meth)acrylate, 2-bromophenoxyethyl (meth)acrylate, 2,4-dibromophenoxyethyl (meth)acrylate, 2,4,6-Tribromophenoxyethyl (meth)acrylate, EO-modified phenoxy (meth)acrylate, PO-modified phenoxy (meth)acrylate, polyoxyethylene nonylphenyl ether (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, bornyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate t)acrylate, cyclohexyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, acryloylmorpholine, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pliers (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, benzyl (meth)acrylate, Tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, diacetone (meth)acrylamide, isobutoxymethyl (meth)acrylamide, N,N-dimethyl(meth)acrylamide, t-octyl(meth)acrylamide, dimethylaminoethyl(meth)acrylate, diethylaminoethyl(meth)acrylate, 7-amino-3,7-dimethyloctyl(meth)acrylate, N,N-diethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, 1- or 2-naphthyl(meth)acrylate, 1- or 2-naphthylmethyl(meth)acrylate, 3- or 4-phenoxybenzyl(meth)acrylate, chinoabenzyl(meth)acrylate, Examples of commercially available products of the above-mentioned silicon-free monofunctional (meth)acrylic compounds include, but are not limited to, the following.

[0044] Aronix (registered trademark) M101, M102, M110, M111, M113, M117, M5700, TO-1317, M120, M150, M156 (all manufactured by Toagosei), MEDOL10, M IBDOL10, CHDOL10, MMDOL30, MEDOL30, MIBDOL30, CHDOL30, LA, IBXA, 2-MTA, HPA, Viscoat #150, #155, #158, #19 0, #192, #193, #220, #2000, #2100, #2150 (all manufactured by Osaka Organic Chemical Industry Co., Ltd.), light acrylate BO-A, EC-A, DMP-A, THF-A, HOP-A, HOA-MPE, HOA-MPL, PO-A, P-200A, NP-4EA, NP-8EA, epoxy ester M-600A, POB-A, OPP-EA (all manufactured by Kyoeisha Chemical Industry Co., Ltd.), KAYARAD (registered trademark) TC110S, R-564, R-128H (all manufactured by Nippon Kayaku), NK Ester AMP-10G, AMP-20G, A-LEN-10 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), FA-511A, 512A, 513A (all manufactured by Hitachi Chemical), PHE, CEA, PHE-2, PHE-4, BR-31, BR-31M, BR-32 (all manufactured by Daiichi Kogyo Seiyaku), VP (manufactured by BASF), ACMO, DMAA, DMAPAA (all manufactured by Kohjin)

[0045] Furthermore, examples of the Si-free polyfunctional (meth)acrylic compound having two or more acryloyl groups or methacryloyl groups include, but are not limited to, the following:

[0046] Trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO,PO-modified trimethylolpropane tri(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1, 9-Nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,3-adamantanedimethanol di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(acryloyloxy)isocyanurate, bis(hydroxymethyl)tricyclodecane di(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, EO-modified 2,2-bis(4-((meth)acryloxy)phenyl)propane, PO-modified 2,2-bis(4-((meth)acryloxy)phenyl)propane, EO,PO-modified 2,2-bis(4-((meth)acryloxy)phenyl)propane, o-, m-, or p-benzenedi(meth)acrylate, o-, m-, or p-xylylenedi(meth)acrylate

[0047] Examples of commercially available products of the above-mentioned silicon-free polyfunctional (meth)acrylic compounds include, but are not limited to, the following.

[0048] Iupimer (registered trademark) UV SA1002, SA2007 (all manufactured by Mitsubishi Chemical), Viscoat #195, #230, #215, #260, #335HP, #295, #300, #360, #700, GPT, 3PA (all manufactured by Osaka Organic Chemical Industry), Light Acrylate 4EG-A, 9EG-A, NP-A, DCP-A, BP-4EA, BP-4PA, TMP-A, PE-3A, PE-4A, DPE-6A (all manufactured by Kyoeisha Chemical), KAYARAD (registered trademark) PET-30, TMPTA, R-604, DPHA, DPCA-20, -30, -60, -120, HX-620, D-310, D-330 (all manufactured by Nippon Kayaku), Aronix (registered trademark) M208, M210, M215, M220, M240, M305, M309, M310, M315, M325, M400 (all manufactured by Toagosei), Lipoxy (registered trademark) VR-77, VR-60, VR-90 (all manufactured by Showa Polymer), Oxol EA-0200, Oxol EA-0300 (all manufactured by Osaka Gas Chemicals)

[0049] In the above-mentioned compound group, (meth)acrylate means acrylate or methacrylate having an alcohol residue equivalent thereto. (Meth)acryloyl group means acryloyl group or methacryloyl group having an alcohol residue equivalent thereto. EO represents ethylene oxide, and EO-modified compound A represents a compound in which the (meth)acrylic acid residue and alcohol residue of compound A are bonded via an ethylene oxide group block structure. PO represents propylene oxide, and PO-modified compound B represents a compound in which the (meth)acrylic acid residue and alcohol residue of compound B are bonded via a propylene oxide group block structure.

[0050] Specific examples of non-silicon-containing styrene-based compounds include, but are not limited to, the following:

[0051] Alkylstyrenes such as styrene, 2,4-dimethyl-α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 2,6-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, 2,4,6-trimethylstyrene, 2,4,5-trimethylstyrene, pentamethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, 2,4-diisopropylstyrene, butylstyrene, hexylstyrene, heptylstyrene, and octylstyrene; fluorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, dibromostyrene, and iodine Halogenated styrenes such as styrene; nitrostyrene, acetylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2-vinylbiphenyl, 3-vinylbiphenyl, 4-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, 4-vinyl-p-terphenyl, 1-vinylanthracene, α-methylstyrene, o-isopropenyltoluene, m-isopropenyltoluene, p-isopropenyltoluene, 2,3-dimethyl-α-methylstyrene, 3,5-dimethyl-α-methylstyrene, p-isopropyl-α-methylstyrene, α-ethylstyrene, α-chlorostyrene, divinylbenzene, diisopropylbenzene, divinylbiphenyl, and other compounds having a styryl group as a polymerizable functional group. Specific examples of the non-silicon-containing vinyl compound include, but are not limited to, the following:

[0052] Vinylpyridine, vinylpyrrolidone, vinylcarbazole, vinyl acetate, and acrylonitrile; conjugated diene monomers such as butadiene, isoprene, and chloroprene; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene halides such as vinylidene chloride; vinyl esters of organic carboxylic acids and their derivatives (vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, divinyl adipate, etc.), (meth)acrylonitrile, and other compounds having a vinyl group as a polymerizable functional group. In this specification, (meth)acrylonitrile is a general term for acrylonitrile and methacrylonitrile.

[0053] Examples of non-silicon-containing allylic compounds include, but are not limited to, the following: Allyl acetate, allyl benzoate, diallyl adipate, diallyl terephthalate, diallyl isophthalate, diallyl phthalate Examples of non-silicon-containing fumaric compounds include, but are not limited to:

[0054] Dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, di-sec-butyl fumarate, diisobutyl fumarate, di-n-butyl fumarate, di-2-ethylhexyl fumarate, dibenzyl fumarate Examples of non-silicon-containing maleyl compounds include, but are not limited to, the following:

[0055] Dimethyl maleate, diethyl maleate, diisopropyl maleate, di-sec-butyl maleate, diisobutyl maleate, di-n-butyl maleate, di-2-ethylhexyl maleate, dibenzyl maleate

[0056] Examples of other non-silicon-containing radical polymerizable compounds include, but are not limited to, the following: Dialkyl esters of itaconic acid and their derivatives (dimethyl itaconate, diethyl itaconate, diisopropyl itaconate, di-sec-butyl itaconate, diisobutyl itaconate, di-n-butyl itaconate, di-2-ethylhexyl itaconate, dibenzyl itaconate, etc.), N-vinylamide derivatives of organic carboxylic acids (N-methyl-N-vinylacetamide, etc.), maleimide and its derivatives (N-phenylmaleimide, N-cyclohexylmaleimide, etc.)

[0057] When component (a) is composed of multiple compounds each having one or more polymerizable functional groups, it preferably contains a monofunctional compound and a polyfunctional compound, because the combination of a monofunctional compound and a polyfunctional compound provides a cured film with an excellent balance of properties, such as high mechanical strength, high dry etching resistance, and high heat resistance.

[0058] In one embodiment of the inversion layer formation method, a curing step by heating is performed after the spin coating step described below. In the curing step, the solvent (d) is volatilized, but the polymerizable compound (a) must not volatilize. Therefore, the boiling points of the polymerizable compounds (a), which may be present in multiple types, at atmospheric pressure are preferably all 250°C or higher, more preferably all 300°C or higher, and even more preferably all 350°C or higher.

[0059] The boiling point of the polymerizable compound (a) generally correlates with the molecular weight. Therefore, the polymerizable compounds (a) preferably all have a molecular weight of 200 or more, more preferably all have a molecular weight of 240 or more, and even more preferably all have a molecular weight of 250 or more. However, even if the molecular weight is 200 or less, if the boiling point is 250°C or more, it can be preferably used as the polymerizable compound (a) of the present invention.

[0060] The boiling points of various organic compounds under normal pressure can be calculated using Hansen Solubility Parameters in Practice (HSPiP) 5th Edition 5.3.04 or the like.

[0061] Specific examples of the polymerizable compound (a) having a boiling point of 250° C. or higher include, but are not limited to, the following:

[0062] Dicyclopentanyl acrylate (boiling point 262°C, molecular weight 206), Dicyclopentenyl acrylate (boiling point 270°C, molecular weight 204), 1,3-cyclohexanedimethanol diacrylate (boiling point 310°C, molecular weight 252), 1,4-cyclohexanedimethanol diacrylate (boiling point 339°C, molecular weight 252), 4-hexylresorcinol diacrylate (boiling point 379°C, molecular weight 302), 6-phenylhexane-1,2-diol diacrylate (boiling point 381°C, molecular weight 302), 7-phenylheptane-1,2-diol diacrylate (boiling point 393°C, molecular weight 316), 1,3-bis((2-hydroxyethoxy)methyl)cyclohexane diacrylate (boiling point 403°C, molecular weight 340), 8-phenyloctane-1,2-diol diacrylate (boiling point 404°C, molecular weight 330), 1,3-bis((2-hydroxyethoxy)methyl)benzenediacrylate (boiling point 408°C, molecular weight 334), 1,4-bis((2-hydroxyethoxy)methyl)cyclohexane diacrylate (boiling point 445°C, molecular weight 340), 3-phenoxybenzyl acrylate (mPhOBzA, OP 2.54, boiling point 367.4°C, vapor pressure at 80°C 0.0004mmHg, molecular weight 254.3),

[0063] [ka]

[0064] 1-naphthyl acrylate (NaA, OP 2.27, boiling point 317°C, vapor pressure at 80°C 0.0422mmHg, molecular weight 198),

[0065] [ka]

[0066] 2-Phenylphenoxyethyl acrylate (PhPhOEA, OP2.57, boiling point 364.2°C, vapor pressure at 80°C 0.0006mmHg, molecular weight 268.3)

[0067] [ka]

[0068] 1-Naphthylmethyl acrylate (Na1MA, OP 2.33, boiling point 342.1°C, vapor pressure at 80°C 0.042mmHg, molecular weight 212.2)

[0069] [ka]

[0070] 2-Naphthylmethyl acrylate (Na2MA, OP 2.33, boiling point 342.1°C, vapor pressure at 80°C 0.042mmHg, molecular weight 212.2)

[0071] [ka]

[0072] 4-cyanobenzyl acrylate (CNBzA, OP 2.44, boiling point 316°C, molecular weight 187),

[0073] [ka]

[0074] DVBzA (OP 2.50, boiling point 304.6°C, vapor pressure 0.0848mmHg at 80°C, molecular weight 214.3) shown in the formula below

[0075] [ka]

[0076] DPhPA (OP 2.38, boiling point 354.5°C, vapor pressure 0.0022mmHg at 80°C, molecular weight 266.3) shown in the formula below

[0077] [ka]

[0078] PhBzA (OP 2.29, boiling point 350.4°C, vapor pressure at 80°C 0.0022mmHg, molecular weight 238.3) shown in the formula below

[0079] [ka]

[0080] FLMA (OP 2.20, boiling point 349.3°C, vapor pressure 0.0018mmHg at 80°C, molecular weight 250.3) shown in the formula below

[0081] [ka]

[0082] ATMA (OP 2.13, boiling point 414.9°C, vapor pressure 0.0001mmHg at 80°C, molecular weight 262.3) shown in the formula below

[0083] [ka]

[0084] DNaMA (OP 2.00, boiling point 489.4°C, vapor pressure at 80°C <0.0001mmHg, molecular weight 338.4) shown in the formula below

[0085] [ka]

[0086] Tricyclodecane dimethanol diacrylate (DCPDA, OP 3.29, boiling point 342°C, vapor pressure at 80°C 0.0024mmHg, molecular weight 304),

[0087] [ka]

[0088] m-Xylylene diacrylate (mXDA, OP3.20, boiling point 336°C, vapor pressure at 80°C 0.0043mmHg, molecular weight 246),

[0089] [ka]

[0090] 1-phenylethane-1,2-diyl diacrylate (PhEDA, OP 3.20, vapor pressure at 80°C 0.0057 mmHg, boiling point 354°C, molecular weight 246),

[0091] [ka]

[0092] 2-phenyl-1,3-propanediol diacrylate (PhPDA, OP3.18, boiling point 340°C, vapor pressure at 80°C 0.0017mmHg, molecular weight 260),

[0093] [ka]

[0094] VmXDA (OP 3.00, boiling point 372.4℃, vapor pressure 0.0005mmHg at 80℃, molecular weight 272.3) shown in the formula below

[0095] [ka]

[0096] BPh44DA (OP 2.63, boiling point 444°C, vapor pressure at 80°C <0.0001mmHg, molecular weight 322.3) shown in the formula below

[0097] [ka]

[0098] BPh43DA (OP 2.63, boiling point 439.5°C, vapor pressure at 80°C <0.0001mmHg, molecular weight 322.3) shown in the formula below

[0099] [ka]

[0100] DPhEDA (OP 2.63, boiling point 410°C, vapor pressure at 80°C <0.0001mmHg, molecular weight 322.3) shown in the formula below

[0101] [ka]

[0102] BPMDA (OP 2.68, boiling point 465.7℃, vapor pressure at 80℃ <0.0001mmHg, molecular weight 364.4) shown in the formula below

[0103] [ka]

[0104] Na13MDA (OP 2.71, boiling point 438.8℃, vapor pressure at 80℃ <0.0001mmHg, molecular weight 296.3) shown in the formula below

[0105] [ka]

[0106] The proportion of component (as) in composition (A) is preferably 40% by weight or more and 99% by weight or less, based on the total mass of component (as), component (a), component (b) described below, and component (c) described below, i.e., the total mass of all components excluding solvent (d). Furthermore, a proportion of component (as) of 50% by weight or more and 95% by weight or less is more preferable, and a proportion of 60% by weight or more and 90% by weight or less is even more preferable. By setting the proportion of component (as) to 40% by weight or more, the mechanical strength of a cured film of the composition is increased. Furthermore, by setting the proportion of component (as) to 99% by weight or less, the proportions of components (b) and (c) can be increased, resulting in properties such as a fast polymerization rate.

[0107] Component (as), the material remaining after removing the solvent from composition (A), preferably contains 30% by weight or more of silicon (Si) atoms. By containing 30% by weight or more of Si atoms in component (as), the mechanical strength of a cured film of the composition is increased.

[0108] The content of silicon (Si) atoms in the material remaining after removing the solvent from composition (A) can be calculated, for example, by the following formula.

[0109] (Calculation method for silicon (Si) atom content) (weight of component (as)) x (Si atom content in component (as)) / (weight of component (as) + weight of component (a) + weight of component (b) + weight of component (c)) At least a portion of the component (a), of which multiple types may be added, may be a polymer having a polymerizable functional group. Such a polymer preferably contains at least a ring structure such as an aromatic structure, an aromatic heterocyclic structure, or an alicyclic structure. For example, it preferably contains at least one type of constitutional unit represented by any of the following formulas (3) to (8).

[0110] [ka]

[0111] In formulas (3) to (8), the substituents R are each independently a substituent containing a partial structure containing an aromatic ring, and R 1 is a hydrogen atom or a methyl group. In this specification, in the structural units represented by formulas (3) to (8), the portion other than R is the main chain of a specific polymer. The formula weight of the substituent R is 80 or more, preferably 100 or more, more preferably 130 or more, and even more preferably 150 or more. It is practical that the upper limit of the formula weight of the substituent R is 500 or less.

[0112] The polymer having a polymerizable functional group is typically a compound having a weight-average molecular weight of 500 or more, preferably 1,000 or more, and more preferably 2,000 or more. The upper limit of the weight-average molecular weight is not particularly limited, but is preferably 50,000 or less. By setting the weight-average molecular weight at or above the above-mentioned lower limit, the boiling point can be set to 250°C or higher, thereby further improving the mechanical properties after curing. Furthermore, by setting the weight-average molecular weight at or below the above-mentioned upper limit, high solubility in solvents and a viscosity that is not too high can be achieved, maintaining fluidity immediately after the application process by spin coating, and further improving flatness due to reflowability. In the present invention, the weight-average molecular weight (Mw) refers to that measured by gel permeation chromatography (GPC), unless otherwise specified.

[0113] Specific examples of the polymerizable functional group possessed by the polymer include a (meth)acryloyl group, an epoxy group, an oxetane group, a methylol group, a methylol ether group, a vinyl ether group, etc. From the viewpoint of ease of polymerization, a (meth)acryloyl group is particularly preferred.

[0114] When a polymer having a polymerizable functional group is added as at least a part of component (a), its blending ratio can be freely set as long as it falls within the viscosity specification described below. For example, it is preferably 0.1% by weight or more and 60% by weight or less, more preferably 0.1% by weight or more and 50% by weight or less, and even more preferably 0% by weight or more and 40% by weight or less, based on the total mass of all components excluding solvent (d). By setting the blending ratio of the polymer having a polymerizable functional group to 0.1% by weight or more, it is possible to improve heat resistance, dry etching resistance, mechanical strength, and low volatility. Furthermore, by setting the blending ratio of the polymer having a polymerizable functional group to 60% by weight or less, it is possible to fall within the upper limit of the viscosity specification described below.

[0115] <Component (b): Polymerization initiator> Component (b) is a polymerization initiator. In this specification, a thermal polymerization initiator is a compound that generates the above-mentioned polymerization factors (radicals, cations, etc.) by heat or light. Specifically, the polymerization initiator may be a radical generator that generates radicals by heat or light, or an acid generator that generates protons (H+) by heat or light. A radical generator is mainly used when the polymerizable component (A) contains a radically polymerizable compound. On the other hand, an acid generator is mainly used when the polymerizable component (A) contains a cationically polymerizable compound. As the polymerization initiator (b) of the present invention, a thermal polymerization initiator (bt) and / or a photopolymerization initiator (bp) can be used.

[0116] <Component (bt): Thermal polymerization initiator> Examples of thermal radical generators include organic peroxides and azo compounds. Examples of organic peroxides include, but are not limited to, peroxyesters such as t-hexylperoxyisopropyl monocarbonate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-3,5,5-trimethylhexanoate, and t-butylperoxyisopropyl carbonate; peroxyketals such as 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane; and diacyl peroxides such as lauroyl peroxide. Examples of azo compounds include, but are not limited to, azonitriles such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 1,1'-azobis(cyclohexane-1-carbonitrile).

[0117] Examples of thermal acid generators include known iodonium salts, sulfonium salts, phosphonium salts, ferrocenes, etc. Specific examples include, but are not limited to, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroborate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium hexafluoroborate.

[0118] <Component (bp): Photopolymerization initiator> Component (bp) is a photopolymerization initiator. In this specification, a photopolymerization initiator is a compound that senses light of a predetermined wavelength and generates the above-mentioned polymerization factors (radicals, cations, etc.). Specifically, a photopolymerization initiator is a polymerization initiator that generates radicals, cations, etc. in response to light (infrared rays, visible light, ultraviolet rays, far ultraviolet rays, charged particle rays such as X-rays and electron beams, or radiation). Component (b) may be composed of only one type of photopolymerization initiator, or may be composed of multiple types of photopolymerization initiators.

[0119] Examples of the radical generator include, but are not limited to, the following: 2,4,5-Triarylimidazole dimers which may have a substituent, such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, and 2-(o- or p-methoxyphenyl)-4,5-diphenylimidazole dimer; benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone Benzophenone derivatives such as 4-methoxy-4'-dimethylaminobenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, and 4,4'-diaminobenzophenone; α-amino aromatic ketone derivatives such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one; 2-ethylanthraquinone, phenanthrenequinone, 2-t-butylanthraquinone, octamethylanthraquinone, and 1,2-benz Quinones such as anthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraraquinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone; benzoin ether derivatives such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin derivatives such as benzoin, methylbenzoin, ethylbenzoin, and propylbenzoin; benzyl benzyl derivatives such as dimethyl ketal; acridine derivatives such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; N-phenylglycine derivatives such as N-phenylglycine; acetophenone derivatives such as acetophenone, 3-methylacetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, and 2,2-dimethoxy-2-phenylacetophenone; thioxanthone derivatives such as thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, and 2-chlorothioxanthone;Acylphosphine oxide derivatives such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; oxime ester derivatives such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one;

[0120] Examples of commercially available radical generators include, but are not limited to, the following: Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur 1116, 1173, Lucirin (registered trademark) TPO, LR8893, LR8970 (all manufactured by BASF), Ubecryl P36 (manufactured by UCB)

[0121] Of the above-mentioned radical generators, the component (b) is preferably an acylphosphine oxide-based polymerization initiator. Among the above-mentioned radical generators, the acylphosphine oxide-based polymerization initiator is as follows: Acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide

[0122] Specific examples of the photoacid generator include: Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium tetrafluoroborate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, 4-t-butylphenyl diphenylsulfonium trifluoromethanesulfonate, 4-t- Onium salt compounds such as butylphenyl diphenylsulfonium benzenesulfonate, 4,7-di-n-butoxynaphthyl tetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-butoxynaphthyl tetrahydrothiophenium bis(trifluoromethanesulfonyl)imide anion, 4,7-di-n-butoxynaphthyl tetrahydrothiophenium bis(nonafluorobutylsulfonyl)imide anion, and 4,7-di-n-butoxynaphthyl tetrahydrothiophenium tris(nonafluorobutylsulfonyl)methide; Halogen-containing compounds such as 1,10-dibromo-n-decane, 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane, phenyl-bis(trichloromethyl)-s-triazine, 4-methoxyphenyl-bis(trichloromethyl)-s-triazine, styryl-bis(trichloromethyl)-s-triazine, and naphthyl-bis(trichloromethyl)-s-triazine; Sulfone compounds such as 4-trisphenacylsulfone, mesitylphenacylsulfone, and bis(phenylsulfonyl)methane; sulfonic acid compounds such as benzoin tosylate, pyrogallol tristrifluoromethanesulfonate, o-nitrobenzyl trifluoromethanesulfonate, and o-nitrobenzyl-p-toluenesulfonate; sulfonimide compounds such as N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)-4-butyl-naphthylimide, N-(trifluoromethylsulfonyloxy)-4-propylthio-naphthylimide, N-(4-methylphenylsulfonyloxy)succinimide, N-(4-methylphenylsulfonyloxy)phthalimide, N-(4-methylphenylsulfonyloxy)diphenylmaleimide, N-(4-methylphenylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(4-fluorophenylsulfonyloxy)bicyclo[2.1.1]heptane-5,6-oxy-2,3-dicarboximide, N-(4-fluorophenylsulfonyloxy)naphthylimide, and N-(10-camphorsulfonyloxy)naphthylimide; diazomethane compounds such as bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, cyclohexylsulfonyl-1,1-dimethylethylsulfonyldiazomethane, and bis(1,1-dimethylethylsulfonyl)diazomethane; Examples include:

[0123] The blending ratio of component (b) in composition (A) is preferably 0.1% by weight to 50% by weight, based on the total weight of components (a), (b), and (c) described below, i.e., the total weight of all components excluding solvent (d). Furthermore, the blending ratio of component (b) in composition (A) is more preferably 0.1% by weight to 20% by weight, and even more preferably 1% by weight to 20% by weight, based on the total weight of all components excluding solvent (d). By incorporating component (b) in a ratio of 0.1% by weight or more, the curing rate of the composition can be increased, improving reaction efficiency. Furthermore, by incorporating component (b) in a ratio of 50% by weight or less, a cured film with a certain degree of mechanical strength can be obtained.

[0124] <Component (c): Non-polymerizable compound> In addition to the above-described components (a) and (b), composition (A) may further contain a non-polymerizable compound as component (c) depending on various purposes. Examples of such component (c) include compounds that do not have a polymerizable functional group such as a (meth)acryloyl group and that do not independently have the ability to generate the above-described polymerization factors (radicals). Examples of non-polymerizable compounds include sensitizers, surfactants, polymerization inhibitors, antioxidants, polymer components, and other additives. Component (c) may contain multiple types of the above-described compounds.

[0125] The sensitizer is a compound that is added as needed for the purpose of accelerating the polymerization reaction and improving the reaction conversion rate. One type of sensitizer may be used alone, or two or more types may be used in combination.

[0126] Examples of sensitizers include sensitizing dyes, which are compounds that are excited by absorbing light of a specific wavelength and interact with the photopolymerization initiator, which is component (b). Here, the interaction refers to energy transfer, electron transfer, etc. from the excited sensitizing dye to the photopolymerization initiator, which is component (b). Specific examples of sensitizing dyes include, but are not limited to, the following: Anthracene derivatives, anthraquinone derivatives, pyrene derivatives, perylene derivatives, carbazole derivatives, benzophenone derivatives, thioxanthone derivatives, xanthone derivatives, coumarin derivatives, phenothiazine derivatives, camphorquinone derivatives, acridine dyes, thiopyrylium salt dyes, merocyanine dyes, quinoline dyes, styrylquinoline dyes, ketocoumarin dyes, thioxanthene dyes, xanthene dyes, oxonol dyes, cyanine dyes, rhodamine dyes, pyrylium salt dyes

[0127] <Component (d): Solvent> Composition (A) contains, as component (d), a solvent having a boiling point of 80°C or higher and lower than 250°C under normal pressure. Examples of component (d) include solvents in which components (a), (b), and (c) dissolve, such as alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and nitrogen-containing solvents. Component (d) can be used alone or in combination of two or more. The boiling point of component (d) under normal pressure is 80°C or higher, preferably 140°C or higher, and particularly preferably 150°C or higher. The boiling point of component (d) under normal pressure is lower than 250°C and preferably 200°C or lower. If the boiling point of component (d) under normal pressure is lower than 80°C, the evaporation rate will be too fast in the coating step described below, making it impossible to obtain a uniform film. Furthermore, if the boiling point of component (d) under normal pressure is 250° C. or higher, component (d) may not volatilize sufficiently in the baking step after the coating step described below, resulting in component (d) remaining in the film.

[0128] Examples of alcohol-based solvents include the following: Methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, s Monoalcohol solvents such as ec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, and cresol; polyalcohol solvents such as ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 1,2-hexanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, and glycerin.

[0129] Examples of ketone solvents include the following: Acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl isobutyl ketone, methyl n-pentyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, diisobutyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, fenchone

[0130] Examples of ether solvents include the following: Ethyl ether, isopropyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol diethyl ether, 2-n-butoxyethanol, 2-n-hexoxyethanol, 2-phenoxyethanol, 2-(2-ethylbutoxy)ethanol, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, 1-n-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran

[0131] Examples of the ester solvent include the following: Diethyl carbonate, methyl acetate, ethyl acetate, amyl acetate γ-butyrolactone, γ-valerolactone, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl acetate Ether, Diethylene Glycol Mono-n-Butyl Ether Acetate, Propylene Glycol Monomethyl Ether Acetate, Propylene Glycol Monoethyl Ether Acetate, Propylene Glycol Monopropyl Ether Acetate, Propylene Glycol Monobutyl Ether Acetate, Dipropylene Glycol Monomethyl Ether Acetate, Dipropylene Glycol Monoethyl Ether Acetate, Glycol Diacetate, Methoxytriglycol Acetate, Ethyl Propionate, n-Butyl Propionate, Isoamyl Propionate, Diethyl Oxalate, Di-n-Butyl Oxalate, Methyl Lactate, Ethyl Lactate, n-Butyl Lactate, n-Amyl Lactate, Diethyl Malonate, Dimethyl Phthalate, Diethyl Phthalate

[0132] Examples of nitrogen-containing solvents include the following: N-Methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, N-methylpyrrolidone

[0133] Among the above-mentioned solvents, ether-based solvents and ester-based solvents are preferred, and from the viewpoint of excellent film-forming properties, ether-based solvents and ester-based solvents having a glycol structure are more preferred.

[0134] Furthermore, the following are more preferred: Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate Furthermore, particularly preferred is propylene glycol monomethyl ether acetate. Other examples include ethyl isocyanurate di(meth)acrylate.

[0135] A preferred solvent is a solvent having at least one of an ester structure, a ketone structure, a hydroxyl group, and an ether structure, specifically, a solvent selected from propylene glycol monomethyl ether acetate (boiling point 146°C), propylene glycol monomethyl ether, cyclohexanone, 2-heptanone, γ-butyrolactone, and ethyl lactate, either singly or in combination.

[0136] Furthermore, as component (d), a polymerizable compound having a boiling point of 80° C. or more and less than 250° C. under normal pressure can also be used. Examples of polymerizable compounds having a boiling point of 80° C. or more and less than 250° C. under normal pressure include the following: Cyclohexyl acrylate (198°C), benzyl acrylate (229°C), isobornyl acrylate (245°C), tetrahydrofurfuryl acrylate (202°C), trimethylcyclohexyl acrylate (232°C), isooctyl acrylate (217°C), n-octyl acrylate (228°C), ethoxyethoxyethyl acrylate (boiling point 230°C), divinylbenzene (193°C), 1,3-diisopropenylbenzene (218°C), styrene (145°C), α-methylstyrene (165°C)

[0137] When the entire composition (A) is taken as 100% by volume, the content of the solvent (d) is preferably 95% by volume or more. If the content of the solvent (d) is less than 95% by volume, it is difficult to obtain a thin film in the coating step by spin coating.

[0138] <Temperature when compounding composition (A)> When preparing composition (A), at least components (as), (a), (b), and (d) are mixed and dissolved under a predetermined temperature condition. Specifically, the predetermined temperature condition can be in the range of 0°C to 100°C. The same applies when composition (A) also contains component (c).

[0139] <Viscosity of the composition> In the coating process, composition (A) is applied by spin coating. Therefore, the viscosity of composition (A) is preferably 2 mPa·s or less at 23°C. If the viscosity of composition (A) is greater than 2 mPa·s, it is difficult to obtain a thin film.

[0140] The material remaining after volatilizing solvent (d) from composition (A), i.e., the material from which solvent (d) has been removed, may have a viscosity at 23°C of, for example, 10 mPa·s or more and 10,000 mPa·s or less. The viscosity of the material from which solvent (d) has been removed from composition (A) may be 10 mPa·s or more and 2,800 mPa·s or less at 23°C, preferably 10 mPa·s or more and 600 mPa·s or less, and more preferably 10 mPa·s or more and 500 mPa·s or less. The material from which solvent (d) has been removed from composition (A) may also be referred to as composition (A'). By making the viscosity of composition (A') at 23°C 1,000 mPa·s or less, the reflowability due to fluidity described below can be achieved.

[0141] <Impurities contained in composition (A)> It is preferable that composition (A) contains as few impurities as possible. Here, impurities refer to substances other than the above-mentioned components (as), (a), (b), (c), and (d). Therefore, composition (A) is preferably obtained through a purification process. Such a purification process is preferably filtration using a filter.

[0142] Regarding filtration using a filter, it is preferable to mix the above-described components (as), (a), (b), and (c) to obtain a mixture, and then filter the mixture, for example, through a filter with a pore size of 0.001 μm to 5.0 μm. When filtration is performed using a filter, it is more preferable to perform the filtration in multiple stages or repeatedly multiple times (circulating filtration). Furthermore, the liquid filtered through the filter may be filtered again, or it may be filtered using multiple filters with different pore sizes. Examples of filters used for filtration include, but are not limited to, filters made of polyethylene resin, polypropylene resin, fluororesin, and nylon resin. Through this purification process, impurities such as particles mixed in composition (A) can be removed. This prevents impurities mixed in composition (A) from accidentally causing unevenness in the inversion layer, which can result in pattern defects.

[0143] When composition (A) is used to manufacture a semiconductor integrated circuit, it is preferable to minimize the inclusion of impurities containing metal atoms (metal impurities) in composition (A) so as not to impair the operation of the product. The concentration of metal impurities contained in composition (A) is preferably 10 ppm or less, and more preferably 100 ppb or less.

[0144] <Initial hardened film formation process> FIG. 3 is a schematic diagram illustrating the photo-nanoimprinting method used in the step of forming an initial cured film in this embodiment. The photo-nanoimprinting method involves four broad steps to form an initial cured film having a desired shape on a substrate. Specifically, first, a curable composition 8 is applied (supplied) to a pattern formation region on a substrate 1 (see FIG. 3(A)) (placement step). Next, the curable composition 8 is molded using a mold 9 with a pattern formed thereon (see FIG. 3(B)) (mold contact step). Then, the curable composition 8 is cured by irradiating it with light (see FIG. 3(C)) to form a cured film 11 (light irradiation step). Thereafter, the mold 9 is separated from the cured film 11 (mold release step) (see FIG. 3(D)). Through the series of steps from the placement step to the mold release step, in this order, a cured film 11 having a desired concave-convex pattern shape (a pattern shape that follows the concave-convex shape of the mold 9) at a desired position can be obtained. In this embodiment, in the process of forming the initial hardened film, a repeating unit (shot) from the placement process to the demolding process is performed on multiple regions on the substrate 1, thereby forming a patterned hardened film 11 in multiple regions on the substrate 1.

[0145] <Inversion process> FIG. 1 is a schematic diagram illustrating a known inversion process. The inversion process will be described using FIG. 1. FIG. 1(A) is a schematic diagram illustrating the above-described initial cured film formation process. In the inversion process, as shown in FIG. 1(A), a cured film 11 having a concave-convex pattern 2 including protrusions 12 and recesses 13 is formed on a substrate 1 as the initial cured film formation process. In other words, the initial cured film formation process can be considered a process of forming a concave-convex pattern. As shown in FIG. 1(A), the portion (base portion) of the cured film 11 below the concave-convex pattern 2 is referred to as a residual film 3. The residual film 3 is unnecessary in the etching process after pattern formation and must be removed in a later process. Methods for forming the cured film 11 having the concave-convex pattern 2 on a substrate 1 in the initial cured film formation process include, for example, photonanoimprinting and photolithography. In this embodiment, the concave-convex pattern 2 is formed by photonanoimprinting as an example, but is not limited to this.

[0146] The substrate 1 may be, for example, a silicon wafer. The substrate 1 may have a separate workable layer on its surface, and another layer may be formed below the workable layer. In addition to a silicon wafer, the substrate 1 may be selected from any of the materials known as substrates for semiconductor devices, such as aluminum, titanium-tungsten alloy, aluminum-silicon alloy, aluminum-copper-silicon alloy, silicon oxide, and silicon nitride. The outermost workable layer of the substrate 1 may be subjected to a surface treatment such as silane coupling treatment, silazane treatment, or formation of an organic thin film to improve adhesion to the curable composition.

[0147] In this embodiment, the curable composition contains at least a polymerizable compound and a polymerization initiator. It may further contain a non-polymerizable compound or a solvent, if necessary. The non-polymerizable compound is at least one selected from the group consisting of sensitizers, hydrogen donors, internal mold release agents, surfactants, antioxidants, and polymer components. In this embodiment, a certain workpiece layer is present on the substrate 1. In the initial cured film formation process, the steps from the placement process to the release process are performed on the workpiece layer of the substrate 1 using a curable composition containing 1 wt. % or less of inorganic elements, preferably containing no inorganic elements such as silicon atoms. This allows a cured film 11 having a pattern including protrusions 12 and recesses 13 to be formed on the substrate 1. Examples of the curable composition include, but are not limited to, those described in JP 2016-162862 A.

[0148] FIG. 1(B) is a schematic diagram showing the inversion layer formation step. The inversion layer formation step is performed following the initial cured film formation step. In the inversion layer formation step, an inversion layer 4 is formed on the cured film 11 having the formed concavo-convex pattern 2. The inversion layer 4 is used as a mask for etching the cured film 11 in the remaining film etching step described below. For this reason, it is required that the inversion layer 4 have a sufficient etching selectivity with the curable composition that forms the cured film 11. Here, the portion of the inversion layer 4 that exists above the cured film 11 is called the excess inversion layer 5.

[0149] FIG. 1(C) is a schematic diagram showing the process of removing the excess inversion layer. The process of removing the excess inversion layer is performed following the process of forming the inversion layer. In the process of removing the excess inversion layer, the excess inversion layer 5 is removed. Specifically, the inversion layer 4 (excess inversion layer 5) is removed until the upper portions (top surfaces 12a) of the convex portions 12 of the cured film 11 having the concave-convex pattern 2 are exposed. FIG. 1(C) shows the state in which the inversion layer 4 (excess inversion layer 5) has been removed and the top surfaces 12a of the convex portions 12 are exposed.

[0150] FIG. 1(D) is a schematic diagram showing the remaining film etching step. The remaining film etching step is performed following the excess inversion layer removal step. In the remaining film etching step, the remaining film 3 of the cured film 11 is removed. In the remaining film etching step, the inversion layer 4 remaining in the recesses 13 of the uneven pattern 2 in the excess inversion layer removal step is used as a processing mask. Using this processing mask, etching is performed starting from the protrusions 12 of the uneven pattern 2 exposed in the excess inversion layer removal step. Etching continues until the surface 1a of the substrate 1 (the processing layer) is exposed. This step forms a pattern (hereinafter referred to as the inversion pattern 14) on the processing layer that is the inverse of the uneven pattern 2 of the curable composition. FIG. 1(D) shows the state in which the remaining film 3 has been etched and the inversion pattern 14 has been formed on the substrate 1 (the processing layer).

[0151] FIG. 1(E) is a schematic diagram showing the process of processing the layer to be processed. The process of processing the layer to be processed is performed after the remaining film etching process. In the process of processing the layer to be processed, a reverse pattern is transferred to the layer to be processed of the substrate 1. In the process of processing the layer to be processed, the reverse pattern 14 formed in the remaining film etching process is used as a processing mask to etch the layer to be processed on the substrate 1, thereby obtaining (forming) a substrate 1 having a pattern in the layer to be processed. FIG. 1(E) shows a substrate 1 having a pattern in the layer to be processed.

[0152] 1(F) is a schematic diagram showing the step of removing the reverse pattern. The step of removing the reverse pattern is the final step of the reversal process, which is performed after the step of processing the processing layer. In the step of removing the reverse pattern, the reverse pattern 14, which is the processing mask, is removed.

[0153] As mentioned above, in the inversion process, depending on the uneven shape of the concave-convex pattern 2 of the cured film 11 and the conditions for forming the inversion layer 4, the desired inversion pattern may not be formed. This drawback will be explained using FIG. 2. FIG. 2 is a schematic diagram illustrating a drawback that may occur in the inversion process. FIG. 2(A) is a schematic diagram showing the inversion layer formation step S200. When the concave-convex shape of the concave-convex pattern 2 is large, the inversion layer 4 may not be formed uniformly as shown in FIG. 2(A), and the film thickness of the inversion layer 4 formed on the convex portions 12 of the concave-convex pattern 2 may be too thick compared to the film thickness of the inversion layer 4 formed on the concave portions 13.

[0154] FIG. 2(B) is a schematic diagram showing the excess inversion layer removal step 201. The excess inversion layer removal step 201 is performed after the inversion layer formation step S200. If the next step, the excess inversion layer removal step 201, is performed in the state shown in FIG. 2(A), the cured film 11 on the bottom surface 13a of the recessed portion 13 may be exposed first before the excess inversion layer 5 is completely removed to expose the top surface 12a of the protrusion 12. If an attempt is made to further remove the excess inversion layer 5 to expose the top surface 12a of the protrusion 12 of the cured film 11, the cured film 11 made of the curable composition in the recessed portion 13 may be damaged, as shown in the excess inversion layer removal step 202 in FIG. 2(C).

[0155] 2(D), the inversion layer 4 acting as a mask in the recesses 13 is absent, and the curable composition (cured film 11) does not remain in the desired locations 7, making it impossible to form the desired inversion pattern. To prevent this from happening, it is desirable to form the inversion layer 4 flattened on the cured film 11.

[0156] The pattern forming method (pattern processing method) of this embodiment will be described in detail below. Generally, the pattern forming method of this embodiment may include the following steps: a coating step of coating the above-mentioned composition on a substrate on which an initial layer including a concave-convex pattern having concaves and convex parts is formed; a reflow step of reflowing the composition after the coating step; a hardening step of hardening the composition after the reflow step to form an inversion layer; a removal step of removing an upper part of the inversion layer after the hardening step to expose the top surface of the convex part; and an etching step of etching the initial layer using the remaining inversion layer as an etching mask after the removal step to form an inversion pattern.

[0157] 4A and 4B are schematic diagrams showing the flow of the reversal process according to this embodiment. Fig. 4A is a schematic diagram showing the initial hardened film forming step S300 according to this embodiment. The initial hardened film forming step S300 according to this embodiment is the same as the initial hardened film forming step in the reversal process shown above, so a description thereof will be omitted.

[0158] <Coating process> FIG. 4(B) is a schematic diagram showing the coating step S301 of the composition (A) according to this embodiment. In this step, the composition (A) is coated onto a cured film 11 having a concave-convex pattern 2 to form an inversion layer 4. Specifically, a spin coating method is used to form the inversion layer 4, which includes an inversion layer 4a that constitutes the portion of the inversion layer 4 from the peaks to the valleys and an inversion layer 4b that constitutes the portion from the valleys to the cured film 13. In this case, if the cured film 11 has a large concave-convex shape, the inversion layer 4a is affected by the concave-convex shape, resulting in height differences 15 in the inversion layer 4a immediately after spin coating, making it difficult to form a flat inversion layer. The inversion layer 4a is likely to be formed unevenly, as shown in FIG. 4(B).

[0159] <Reflow process> FIG. 4(C) is a schematic diagram illustrating the reflow step S302 for the composition (A) according to this embodiment. In this embodiment, the reflow step is performed on the inversion layer 4a immediately after spin coating to achieve planarization. In other words, the inversion layer 4 in this embodiment becomes flat after the reflow step is performed after the formation of the inversion layer 4a, meaning that the unevenness 15 of the inversion layer 4a is flattened. In the reflow step, planarization by reflow begins immediately after spin coating, and the unevenness 15 of the excess layer 5 shown in FIG. 4(C) can be, for example, 15 nm or less. Reflow can be performed at room temperature (23°C) or in a heated environment. The temperature at which this reflow step is performed can be adjusted appropriately depending on the composition of the composition, but is typically 23°C to 120°C, preferably 50°C to 100°C. The time required for this reflow step is typically 0.1 seconds to 100 seconds, preferably 5 seconds to 60 seconds. The average thickness of the resulting film is not particularly limited, but is usually 10 nm or more and 1,000 nm or less, and preferably 20 nm or less and 500 nm or less.

[0160] <Curing process> Curing of composition (A) is a schematic diagram showing the curing step S303 of the inversion layer in which the height difference of the excess layer 5 shown in FIG. 4(D) is ±15 nm or less. Curing of composition (A) can be performed by heating composition (A), but is not limited to this. Heating is performed at a temperature of, for example, 30°C or higher and 400°C or lower, preferably 80°C or higher and 250°C or lower, and particularly preferably 90°C or higher and 220°C or lower. The heating time can be 10 seconds or higher and 600 seconds or lower. The curing step can be performed using a known heater such as a hot plate or oven.

[0161] The composition (A) may be cured by irradiating it with light. The irradiating light is selected depending on the wavelength to which the composition (A) is sensitive. Specifically, the irradiating light is appropriately selected from ultraviolet light having a wavelength of 150 nm or more and 400 nm or less, X-rays, electron beams, etc. It is particularly preferable that the irradiating light is ultraviolet light. This is because many of the commercially available curing aids (photopolymerization initiators) are compounds that are sensitive to ultraviolet light.

[0162] The composition (A) may be cured by a combination of the above-mentioned curing by heating and the above-mentioned curing by light irradiation.

[0163] <Excess inversion layer removal process> FIG. 4(E) is a schematic diagram showing the process of removing the excess inversion layer. The process of removing the excess inversion layer is performed following the process of forming the inversion layer. In the process of removing the excess inversion layer, the excess inversion layer 5 is removed. Specifically, the inversion layer 4 (excess inversion layer 5) is removed until the upper portions (top surfaces 12a) of the convex portions 12 of the cured film 11 having the concave-convex pattern 2 are exposed. FIG. 4(E) shows the state in which the inversion layer 4 (excess inversion layer 5) has been removed and the top surfaces 12a of the convex portions 12 are exposed. In this embodiment, the reflow process described above can flatten the height difference of the inversion layer 4 to, for example, ±15 nm. This allows the excess inversion layer 5 to be removed without damaging the concave portions 13 of the cured film 11, as shown in FIG. 2(C).

[0164] The method for removing the excess inversion layer 5 is not particularly limited, but dry etching, for example, can be used. A known dry etching apparatus can be used for the dry etching. The source gas for dry etching is selected appropriately depending on the elemental composition of the inversion layer 4. Examples of suitable gases include fluorocarbon gases such as CF4, CHF4, C2F6, C3F8, C4F8, C5F8, C4F6, CCl2F2, and CBrF3, and halogen gases such as CCl4, BCl3, PCl3, SF6, and Cl2. These gases can also be used in combination.

[0165] FIG. 4(F) is a schematic diagram showing the remaining film etching step. The remaining film etching step is performed following the excess inversion layer removal step. In the remaining film etching step, the remaining film 3 of the cured film 11 is removed. In the remaining film etching step, the inversion layer 4 remaining in the recesses 13 of the uneven pattern 2 in the excess inversion layer removal step is used as a processing mask. Using this processing mask, etching is performed starting from the protrusions 12 of the uneven pattern 2 exposed by removing the inversion layer 4 in the excess inversion layer removal step. Etching continues until the surface 1a of the substrate 1 (the processing layer) is exposed. This step forms a pattern (hereinafter referred to as an inversion pattern 14) in the processing layer of the substrate 1 that is the inverse of the uneven pattern 2 of the curable composition. FIG. 4(F) shows the state in which the remaining film 3 has been etched and the inversion pattern 14 has been formed in the processing layer of the substrate 1.

[0166] FIG. 4(G) is a schematic diagram showing the process of processing the processable layer. The process of processing the processable layer is performed after the remaining film etching process. In the process of processing the processable layer, a reverse pattern is transferred to the processable layer of the substrate 1. In the process of processing the processable layer, the reverse pattern 14 formed in the remaining film etching process is used as a processing mask to etch the processable layer on the substrate 1, thereby obtaining (forming) a substrate 1 having a processable layer on which a pattern is formed. FIG. 4(G) shows a substrate 1 having a processable layer on which a pattern is formed.

[0167] Next, the reverse pattern removal step is carried out. The reverse pattern removal step is the final step of the reversal process. In the reverse pattern removal step, the reverse pattern 14, which is the processing mask, is removed after the processing layer of the substrate 1 is processed.

[0168] [Product manufacturing method] The reverse pattern formed by the pattern formation method of this embodiment can be used as is as at least a part of a component of various articles. The reverse pattern can also be temporarily used as a processing mask for etching or ion implantation of a process layer on a substrate. After etching or ion implantation of the process layer on the substrate during the processing step, the reverse pattern serving as a processing mask is removed. This allows various articles to be manufactured.

[0169] The reverse pattern formed by the pattern formation method of this embodiment can also be used as is as at least a part of a component of various articles. The reverse pattern is also temporarily used as a processing mask for etching, ion implantation, or the like of a process layer on a substrate. After etching, ion implantation, or the like is performed on the process layer on the substrate during the process of the process layer, the reverse pattern serving as the processing mask is removed. This allows various articles to be manufactured. In other words, the article manufacturing method may include a pattern formation step and a processing step of processing the substrate that has undergone the pattern formation step to obtain an article.

[0170] The article may be an electric circuit element, an optical element, a MEMS, a recording element, a sensor, or a mold. Examples of the electric circuit element include volatile or nonvolatile semiconductor memory such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensor, and FPGA. If the processed layer is an insulating layer, it can be used as an interlayer insulating film included in the semiconductor memory or semiconductor element.

[0171] The patterned layer obtained through the initial cured film formation process and the reverse pattern removal process can be used as an optical component such as a diffraction grating or a polarizing plate (including as a component of an optical component) to obtain an optical element. In such cases, an optical element can be obtained that has at least a substrate and a patterned layer on the substrate. Examples of optical elements include microlenses, light guides, waveguides, anti-reflection films, diffraction gratings, polarizing elements, color filters, light-emitting elements, displays, solar cells, etc.

[0172] Examples of MEMS include DMDs, microchannels, and electromechanical conversion elements. Examples of recording elements include optical disks such as CDs and DVDs, magnetic disks, magneto-optical disks, and magnetic heads. Examples of sensors include magnetic sensors, optical sensors, and gyro sensors. Examples of molds include molds for imprinting.

[0173] <Other embodiments> While the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments and various modifications and changes are possible within the scope of the present invention. In addition, the respective embodiments may be combined. [Example] To supplement the above-described embodiment, a more specific example will be described. [Example]

[0174] In this example, it is shown by numerical calculation that the inversion layer 4a can be flattened by performing a reflow process on the inversion layer 4a immediately after the completion of spin coating.

[0175] The inversion layer 4a is formed as a liquid film by the centrifugal force of the spin coating method during the coating process. Because it is formed mainly by centrifugal force, in this numerical calculation, the inversion layer 4a is assumed to be a liquid film of uniform thickness, regardless of the unevenness of the cured film 11, and this is used as the initial liquid film distribution.

[0176] In the reflow process, the reflow temperature is adjusted as necessary, and the initial liquid film distribution is flattened by flow onto the solid film, the hardened film 11. In this example, this flow process was calculated by solving the Navier-Stokes equation (Equation 1), which is a thin film approximation (lubrication theory) with a free surface. In Equation 1, h is the height of the liquid film, μ is the viscosity coefficient, and σ is the surface tension coefficient. In this example, the viscosity of the inversion layer 4a was 1000 cP and the surface tension was 35 mN / m.

[0177]

number

[0178] Figure 5 shows the initial liquid film distribution. In Figure 5, 501 is the hardened film 11, and 502 is the inversion layer 4a. The horizontal axis of Figure 5 represents spatial coordinates, and the vertical axis represents height. As shown by 501, the hardened film 11 had a spatial period of 8um in total, with recesses of 4um and protrusions of 4um. In other words, the left and right sides of Figure 5 were subject to periodic boundary conditions. The height of the hardened film 11 was set to 100nm.

[0179] The inversion layer 4a has a uniform thickness of 65 nm. Therefore, as shown in 502, the inversion layer 4a is distributed with a uniform film thickness on top of 501. In an actual spin coating process, it is thought that the distribution will be more gradual rather than the stepped, discontinuous shape shown in 502. However, we believe that if we estimate the relaxation time using the discontinuous shape of 502, we will be able to evaluate the upper limit of the relaxation time.

[0180] Figure 6 shows the change in the liquid film distribution over time. In Figure 6, 501 is the hardened film 11, and 602 is the distribution of the inversion layer 4a at each time. Please refer to the legend in the upper right of Figure 6 to see which time each curve in 602 corresponds to. This shows that the liquid film gradually flattens over time, becoming almost flat after 100 seconds.

[0181] Figure 7 shows the change over time in the height difference of the liquid film distribution. The horizontal axis is the elapsed time, and the vertical axis is the height difference of the liquid film. It can be seen that the time change 701 in the height difference of the inversion layer 4a reaches a maximum value after about 0.1 seconds, then decays and becomes almost flat after 100 seconds. 702 indicates the line where the height difference is 5 nm, and the intersection of 701 and 702 shows that the height difference falls below 5 nm after 100 seconds.

[0182] The same calculation as above was performed by changing the spatial period of the cured film 11 to 4 um, 2 um, and 1 um, and the elapsed time until the height difference fell below 5 nm was determined. The results are shown in Figure 8. The horizontal axis is the spatial period of the cured film 11, and the vertical axis is the elapsed time. The dots in 801 represent the elapsed time determined by calculation, and the solid line in 802 is the result of a power fit. The function system in 802 is 1.25 x 10 -2 ×λ 4 It was found that the time elapsed until the height difference became less than 5 nm was proportional to the fourth power of the spatial period of the cured film 11.

[0183] Also, taking into consideration that the flattening speed generally increases with decreasing viscosity, the above results show that when the period of the cured film 11 is about 8 μm and the viscosity is 1000 cP or less, flattening to a height difference of less than 5 nm can be achieved in 100 seconds or less. It was found that this elapsed time is proportional to the fourth power of the period.

[0184] The present specification and drawings include the following disclosure. (Item 1) A composition for spin coating comprising a polymerizable compound containing at least silicon atoms and a solvent, the viscosity of the material obtained by removing the solvent from the composition is 10 mPa s or more and 1,000 mPa s or less at 23°C; the silicon atom content of the material obtained by removing the solvent from the composition is 30% by weight or more; A composition characterized by: (Item 2) The content of the solvent relative to the entire composition is 95 wt % or more. 2. The composition according to item 1, (Item 3) the composition has a viscosity of less than 2 mPa·s at 23°C; 3. The composition according to item 1 or 2, (Item 4) The vapor pressure of the material obtained by removing the solvent from the composition at 200°C is 0.001 mmHg or less. 4. The composition according to any one of items 1 to 3, (Item 5) The molar equivalent of the polymerizable functional group is 300 or more; 5. The composition according to any one of items 1 to 4, (Item 6) the polymerizable compound has a linear polysiloxane skeleton; 6. The composition according to any one of items 1 to 5, (Item 7) the polymerizable compound has a cyclic siloxane skeleton; 6. The composition according to any one of items 1 to 5, (Item 8) the polymerizable compound has a silsesquioxane skeleton; 6. The composition according to any one of items 1 to 5, (Item 9) The composition is used to form an inversion layer. 9. The composition according to any one of items 1 to 8, (Item 10) A coating step of coating the composition according to any one of items 1 to 9 onto a substrate on which an initial layer including a relief pattern having recesses and protrusions is formed; a reflow step of reflowing the composition after the application step; a curing step after the reflow step of curing the composition to form an inversion layer; a removing step of removing an upper portion of the inversion layer so as to expose a top surface of the convex portion after the hardening step; an etching step of etching the initial layer using the remaining inversion layer as an etching mask to form an inversion pattern after the removing step; A pattern forming method comprising the steps of: (Item 11) The reflow step is carried out for a time period of 0.1 seconds or more and 100 seconds or less. 11. The pattern forming method according to item 10. (Item 12) the reflow step includes reflowing the inversion layer at a temperature of 23° C. or higher and 120° C. or lower. 12. The pattern forming method according to item 10 or 11, (Item 13) In the curing step, the inversion layer is cured at a temperature of 150°C or higher and 300°C or lower. 13. The pattern forming method according to any one of items 10 to 12, (Item 14) the curing step includes irradiating the inversion layer with light. 14. The pattern forming method according to any one of items 10 to 13, (Item 15) A pattern formation step in which the pattern formation method according to any one of items 10 to 14 is carried out; a processing step of processing the substrate that has undergone the pattern forming step to obtain an article; A method for manufacturing an article, comprising: (others) The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

Claims

1. A composition for spin coating comprising a polymerizable compound containing at least silicon atoms and a solvent, the viscosity of the material obtained by removing the solvent from the composition is 10 mPa·s or more and 1,000 mPa·s or less at 23°C; the silicon atom content of the material obtained by removing the solvent from the composition is 30% by weight or more; A composition characterized by:

2. The content of the solvent relative to the entire composition is 95 wt % or more. The composition of claim 1 .

3. The composition has a viscosity of less than 2 mPa s at 23°C. The composition of claim 1 .

4. the vapor pressure of the material obtained by removing the solvent from the composition at 200°C is 0.001 mmHg or less; The composition of claim 1 .

5. The molar equivalent of the polymerizable functional group is 300 or more. The composition of claim 1 .

6. the polymerizable compound has a linear polysiloxane skeleton; The composition of claim 1 .

7. the polymerizable compound has a cyclic siloxane skeleton; The composition of claim 1 .

8. the polymerizable compound has a silsesquioxane skeleton; The composition of claim 1 .

9. The composition is used to form an inversion layer. The composition of claim 1 .

10. a coating step of coating the composition according to any one of claims 1 to 9 onto a substrate on which an initial layer including a concave-convex pattern having concave and convex portions has been formed; a reflow step of reflowing the composition after the application step; a curing step after the reflow step of curing the composition to form an inversion layer; a removing step of removing an upper portion of the inversion layer so as to expose a top surface of the convex portion after the hardening step; an etching step of etching the initial layer using the remaining inversion layer as an etching mask to form an inversion pattern after the removing step; A pattern forming method comprising the steps of:

11. The reflow step is carried out for a time period of 0.1 seconds or more and 100 seconds or less. The pattern forming method according to claim 10 .

12. the reflow step includes reflowing the inversion layer at a temperature of 23° C. or higher and 120° C. or lower. The pattern forming method according to claim 10 .

13. In the curing step, the inversion layer is cured at a temperature of 150° C. or higher and 300° C. or lower. The pattern forming method according to claim 10 .

14. the curing step includes irradiating the inversion layer with light. The pattern forming method according to claim 10 .

15. a pattern formation step in which the pattern formation method according to claim 10 is carried out; a processing step of processing the substrate that has undergone the pattern forming step to obtain an article; A method for manufacturing an article, comprising:

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