Composition, pattern formation method, and article manufacturing method

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 pattern forming method, and an article manufacturing method.

Background Art

[0002] The demand for miniaturization of semiconductor devices, MEMS, and the like has been increasing, and imprint technology, which forms a pattern of an imprint material on a substrate by molding the imprint material on the substrate with a mold, in addition to conventional photolithography technology, has been attracting attention.

[0003] Imprint technology forms the uneven pattern of a mold by bringing the mold into contact with an imprint material coated on a substrate. When processing a substrate using a pattern obtained by this imprint technology as a mask, a process called an inversion process can be applied.

[0004] Patent Document 1 discloses the following inversion process. First, an inversion layer is formed on an uneven pattern (inversion layer forming step), and an inversion layer material is embedded in concave portions. At this time, the inversion layer material is also laminated on the top of the convex portions of the uneven pattern, forming an excess inversion layer. Therefore, the excess inversion layer is removed so as to expose the top surfaces of the convex portions of the uneven pattern of the cured film of the curable composition (excess inversion layer removing step), to expose the inversion layer embedded in the concave portions. Thereafter, using the exposed inversion layer as a mask, the residual film of the uneven pattern (residual film etching step) and the processing layer under the uneven pattern are etched to form an inverted pattern (processing layer processing step).

[0005] In such inversion processes, 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 for flattening the inversion layer by forming it by an inkjet method, and a method for flattening the inversion layer by pressing it with a planar mold. Patent Document 4 discloses forming a flat inversion layer by applying a low-viscosity curable composition by an inkjet method. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-162862 [Patent Document 2] Japanese Patent Publication No. 2018-12806 [Patent Document 3] Japanese Patent Publication No. 2018-98470 [Patent Document 4] Japanese Patent Publication No. 2023-181983 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the materials and methods disclosed in Patent Document 2 do not provide sufficient flatness. Furthermore, the methods disclosed in Patent Documents 3 and 4 require complex processes such as inkjet printing or pressing with a planar mold, resulting in high costs and low productivity (throughput).

[0008] The present invention aims to provide a composition that is advantageous for obtaining 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 is used to form an inverted layer by being applied by spin coating onto a substrate having an initial layer with a textured pattern including recesses and protrusions, reflowed after application and before curing to flatten the surface of the composition, and cured after the reflow, wherein the molar equivalent of polymerizable functional groups of the polymerizable compound containing at least silicon atoms is 300 or more, and the vapor pressure of the polymerizable compound containing at least silicon atoms at 200°C is 0.001 mmHg or less.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, and the silicon atom content of the material obtained by removing the solvent from the composition is 30% by weight or more. [Effects of the Invention]

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

[0011] [Figure 1] This is a schematic diagram illustrating a known inversion process. [Figure 2] This is a schematic diagram illustrating the potential problems that can occur during the reversal process. [Figure 3] This is a schematic diagram explaining the optical nanoimprint lithography method. [Figure 4] This is a schematic diagram showing the flow of the inversion process according to this embodiment. [Figure 5] This is a schematic diagram showing the initial liquid film distribution. [Figure 6] This is a schematic diagram showing the time evolution of the liquid film distribution. [Figure 7] This is a schematic diagram showing the time evolution of the height difference in the liquid film distribution. [Figure 8] This is a schematic diagram showing the elapsed time when the spatial period and height difference are less than 5 nm. [Modes for carrying out the invention]

[0012] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0013] The inventors of the present invention have discovered a composition and process conditions thereof that can achieve high flatness and high productivity (throughput) when providing a new technique related to a composition advantageous for forming an inversion layer.

[0014] [Composition for inversion layer formation] Composition (A) of one embodiment is a composition for spin coating, and can be used for an inversion layer, for example. Composition (A) of one embodiment is a composition comprising at least a polymerizable compound (as) containing at least a silicon atom and a component (d) that is a solvent. Hereinafter, the polymerizable compound (as) containing at least a silicon atom 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 a silicon (Si) atom, a polymerization initiator (b), and a non-polymerizable compound (c).

[0015] <Component (as): Silicon-containing polymerizable compound> In the present 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) induced by heat or light, or a chain reaction (polymerization reaction) induced by polymerization factors (such as radicals and cations) 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 a plurality of types (one or more types) 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 include the following structures. Examples of polymerizable functional groups in group Q include radical polymerizable functional groups. Specifically, radical polymerizable functional groups 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. Group Q, having a polymerizable functional group, may be any group having one of the above polymerizable functional groups.

[0019] [ka]

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

[0021] [ka]

[0022] [ka]

[0023] In groups Q, A, and B having polymerizable functional groups, examples of polymerizable functional groups include radical polymerizable functional groups. Specifically, radical polymerizable functional groups include (meth)acrylate compounds, (meth)acrylamide compounds, vinylbenzene compounds, allyl ether compounds, vinyl compounds, vinyl ether compounds, and maleimide compounds. Group Q having polymerizable functional groups can be any group having one of the above polymerizable functional groups.

[0024] The molar equivalent of polymerizable functional groups in the silicon-containing polymerizable compound (as) shall be 300 or more. 400 or more is preferable, and 500 or more is particularly preferable. By setting the molar equivalent of polymerizable functional groups to 300 or more, the curing shrinkage rate can be reduced.

[0025] The molar equivalent of polymerizable functional groups in a silicon-containing polymerizable compound (as) can be calculated, for example, using the following formula. If the silicon-containing polymerizable compound (as) is composed of multiple types (one or more) polymerizable compounds, it can be calculated as a weighted average of the mole fractions. (Method for calculating the molar equivalent of polymerizable functional groups) (Molecular weight of component (as)) / (Number of polymerizable functional groups in component (as)) Silicon-containing (meth)acrylate compounds are compounds 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 silatoran, Methacryloxypentamethyldisiloxane, (methacryloxymethyl)phenyldimethylsilane, Methacryloxytrimethylsilane, Methacryloxymethyltrimethylsilane, (3-methacryloxy-2-hydroxypropoxypropyl)methylbis(trimethylsiloxy)silane, Methacryloxypropylpentamethyldisiloxane, 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-Methacluroxypropylbis(trimethylsiloxy)methylsilane, 3-Methacluroxypropyldimethylchlorosilane, O-methacryloxy(polyethyleneoxy)trimethylsilane, Poly(methacluroxypropylsilsesquioxane), Methacryloxypropylheptaisorbyl-T8-silsesquioxane, Methacryloxypropyltris(trimethylsiloxy)silane

[0026] Examples of commercially available silicon-containing monofunctional (meth)acrylate compounds mentioned above 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 mentioned above include, but are not limited to, the following. SIA0146.0, SIA0150.0 (both 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 at both ends with acryloxypropyl groups Linear polydimethylsiloxane modified at both ends with methacryloxypropyl groups Linear polypropylmethylsiloxane modified at both ends with acryloxypropyl groups. 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 mentioned above 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] Furthermore, based on known literature (for example, "Ultraviolet curable branchedsiloxanes as low-k dielectrics for imprintlithography" by Ogawa et al. (https: / / doi.org / 10.1116 / 1.4770051)), linear modified polydimethylsiloxanes (MA-Si-12) modified with methacryloxypropyl groups at both ends, 8-membered ring siloxanes (8-ring) modified with four methacryloxypropyl groups, and 10-membered ring siloxanes (10-ring) modified with five methacryloxypropyl groups can be synthesized and obtained.

[0036] Examples of commercially available silicon-containing epoxy-modified compounds mentioned above 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 Silicone), 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 mentioned above include, but are not limited to, the following. X-22-169AS, X-22-169B (both manufactured by Shin-Etsu Silicone), 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 mentioned above 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 occurs after the coating step by the spin coating method described later. In the curing step, the solvent (d) is evaporated, while the polymerizable compound (as) must not volatilize. Therefore, it is preferable that the vapor pressure of the polymerizable compound (as), which may contain multiple types, at 200°C is 0.001 mmHg or less. This is to suppress the volatilization of the polymerizable compound (as) during heating in the reflow step and curing step of the inversion layer, which will be described later.

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

[0038] Specific examples of polymerizable compounds (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 mentioned above 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): Silicone-free polymerizable compound> Component (a) is a silicon-free polymerizable compound. In this specification, the silicon-free polymerizable compound is a compound that reacts with polymerization factors (such as radicals) generated from a polymerization initiator (component (b)) and forms a film consisting of a polymer compound through a chain reaction (polymerization reaction).

[0041] Examples of such polymerizable compounds include radical polymerizable compounds. The polymerizable compound that is component (a) may consist of only one type of polymerizable compound, or it may consist of multiple types (one or more types) of polymerizable compounds.

[0042] Examples of radical polymerizable compounds include silicon-free (meth)acrylic compounds, silicon-free styrene compounds, silicon-free vinyl compounds, silicon-free allyl compounds, silicon-free fuma compounds, and silicon-free maleyl compounds.

[0043] Silicon-free (meth)acrylic compounds are compounds having one or more acryloyl groups or methacryloyl groups. Examples of silicon-free monofunctional (meth)acrylic compounds having one acryloyl group or 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 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 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, cynoabenzyl(meth)acrylate, Examples of commercially available silicon-free monofunctional (meth)acrylic compounds mentioned above 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), 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), 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 Industry), 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 Kojin)

[0045] Furthermore, examples of Si-free polyfunctional (meth)acrylic compounds 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, dimethylol tricyclodecane 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-Adamantane dimethanol di(meth)acrylate, Tris(2-Hydoxyethyl)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-Benzene di(meth)acrylate, o-, m- or p-Xylylene di(meth)acrylate

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

[0048] Yupimer® UV SA1002, SA2007 (both 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® PET-30, TMPTA, R-604, DPHA, DPCA-20, -30, -60, -120, HX-620, D-310, D-330 (all manufactured by Nippon Kayaku), Aronix® M208, M210, M215, M220, M240, M305, M309, M310, M315, M325, M400 (all manufactured by Toagosei), Lipoxy® VR-77, VR-60, VR-90 (all manufactured by Showa Polymer), Ogusol EA-0200, Ogusol EA-0300 (all manufactured by Osaka Gas Chemical)

[0049] In the above-mentioned group of compounds, (meth)acrylate means acrylate or methacrylate having an equivalent alcohol residue. (meth)acryloyl group means acryloyl group or methacryloyl group having an equivalent alcohol residue. 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 linked via a block structure of ethylene oxide group. Furthermore, 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 linked via a block structure of propylene oxide group.

[0050] Specific examples of silicon-free 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 iodose Halide styrenes such as ethylene; compounds having a styryl group as a polymerizable functional group, such as 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, and divinylbiphenyl. Specific examples of silicon-free vinyl compounds include, but are not limited to, the following.

[0052] Compounds having a vinyl group as a polymerizable functional group, such as 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; vinylidenes 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, etc.) In this specification, (meth)acrylonitrile is a general term for acrylonitrile and methacrylonitrile.

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

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

[0057] When component (a) is composed of multiple types of compounds having one or more polymerizable functional groups, it is preferable to include both monofunctional and polyfunctional compounds. This is because combining monofunctional and polyfunctional compounds yields a cured film with an excellent balance of performance, 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 occurs after the coating step by the spin coating method described later. In the curing step, the solvent (d) is evaporated, while the polymerizable compound (a) must not volatilize. Therefore, the boiling points of the polymerizable compound (a), which may contain multiple types, are preferably all 250°C or higher, more preferably all 300°C or higher, and even more preferably all 350°C or higher under normal pressure.

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

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

[0061] Specific examples of polymerizable compounds (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)cyclohexanediacrylate (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)benzenediaacrylate (boiling point 408°C, molecular weight 334), 1,4-Bis((2-hydroxyethoxy)methyl)cyclohexanediacrylate (boiling point 445°C, molecular weight 340), 3-Phenoxybenzylacrylate (mPhOBzA, OP2.54, boiling point 367.4℃, vapor pressure 0.0004mmHg at 80℃, molecular weight 254.3),

[0063] [ka]

[0064] 1-Naphthyl acrylate (NaA, OP2.27, boiling point 317°C, vapor pressure 0.0422 mmHg at 80°C, molecular weight 198),

[0065] [ka]

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

[0067] [ka]

[0068] 1-Naphthylmethyl acrylate (Na1MA, OP2.33, boiling point 342.1℃, vapor pressure at 80℃ 0.042 mmHg, molecular weight 212.2)

[0069] [ka]

[0070] 2-Naphthylmethyl acrylate (Na2MA, OP2.33, boiling point 342.1℃, vapor pressure 0.042 mmHg at 80℃, molecular weight 212.2)

[0071] [ka]

[0072] 4-Cyanobenzyl acrylate (CNBzA, OP2.44, boiling point 316°C, molecular weight 187),

[0073] [ka]

[0074] DVBzA (OP2.50, boiling point 304.6°C, vapor pressure at 80°C 0.0848 mmHg, molecular weight 214.3) as shown in the formula below.

[0075] [ka]

[0076] DPhPA (OP2.38, boiling point 354.5°C, vapor pressure 0.0022 mmHg at 80°C, molecular weight 266.3) as shown in the formula below.

[0077] [ka]

[0078] PhBzA (OP2.29, boiling point 350.4℃, vapor pressure 0.0022mmHg at 80℃, molecular weight 238.3) as shown in the formula below.

[0079] [ka]

[0080] FLMA (OP2.20, boiling point 349.3°C, vapor pressure 0.0018 mmHg at 80°C, molecular weight 250.3) as shown in the formula below.

[0081] [ka]

[0082] ATMA (OP2.13, boiling point 414.9°C, vapor pressure 0.0001 mmHg at 80°C, molecular weight 262.3) as shown in the formula below.

[0083] [ka]

[0084] DNaMA (OP2.00, boiling point 489.4°C, vapor pressure <0.0001 mmHg at 80°C, molecular weight 338.4) as shown in the formula below.

[0085] [ka]

[0086] Tricyclodecanedimethanol diacrylate (DCPDA, OP3.29, boiling point 342°C, vapor pressure 0.0024 mmHg at 80°C, molecular weight 304),

[0087] [ka]

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

[0089] [ka]

[0090] 1-Phenylethane-1,2-diyldiaacrylate (PhEDA, OP3.20, vapor pressure 0.0057 mmHg at 80°C, 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 0.0017 mmHg at 80°C, molecular weight 260),

[0093] [ka]

[0094] The formula shown below is VmXDA (OP3.00, boiling point 372.4°C, vapor pressure at 80°C 0.0005 mmHg, molecular weight 272.3)

[0095] [ka]

[0096] BPh44DA (OP2.63, boiling point 444°C, vapor pressure at 80°C <0.0001 mmHg, molecular weight 322.3) as shown in the formula below.

[0097] [ka]

[0098] BPh43DA (OP2.63, boiling point 439.5°C, vapor pressure at 80°C <0.0001 mmHg, molecular weight 322.3) as shown in the formula below.

[0099] [ka]

[0100] DPhEDA (OP2.63, boiling point 410°C, vapor pressure <0.0001 mmHg at 80°C, molecular weight 322.3) as shown in the formula below.

[0101] [ka]

[0102] BPMDA (OP2.68, boiling point 465.7°C, vapor pressure at 80°C <0.0001 mmHg, molecular weight 364.4) as shown in the formula below.

[0103] [ka]

[0104] Na13MDA (OP2.71, boiling point 438.8°C, vapor pressure <0.0001 mmHg at 80°C, molecular weight 296.3) as shown in the formula below.

[0105] [ka]

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

[0107] The component (as) of the material obtained by removing the solvent from composition (A) preferably contains 30% by weight or more silicon (Si) atoms. The mechanical strength of the cured film of the composition is increased by the inclusion of 30% by weight or more Si atoms in component (as).

[0108] The silicon (Si) atom content in the material obtained by removing the solvent from composition (A) can be calculated, for example, using the following formula.

[0109] (Method for calculating the silicon (4) 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 component (a), which may contain multiple types, may be polymers having polymerizable functional groups. Such polymers preferably contain at least a ring structure, such as an aromatic structure, an aromatic heterocyclic structure, or an alicyclic structure. For example, it is preferable to contain at least one of the constituent units represented by any of the following formulas (3) to (8).

[0110] [ka]

[0111] In equations (3) to (8), each substituent R is a substituent that independently contains a substructure containing an aromatic ring, 1 is a hydrogen atom or a methyl group. In this specification, the portion of the constituent unit represented by formulas (3) to (8), excluding R, is used as the main chain of a specific polymer. The formula weight of substituent R is 80 or more, preferably 100 or more, more preferably 130 or more, and even more preferably 150 or more. In practice, the upper limit of the formula weight of substituent R is 500 or less.

[0112] Polymers having polymerizable functional groups are typically compounds with a weight-average molecular weight of 500 or more, preferably 1,000 or more, and more preferably 2,000 or more. There is no specific upper limit for the weight-average molecular weight, but for example, 50,000 or less is preferred. By setting the weight-average molecular weight above the lower limit mentioned above, the boiling point can be set to 250°C or higher, and the mechanical properties after curing can be further improved. Furthermore, by setting the weight-average molecular weight below the upper limit mentioned above, solubility in solvents is high, fluidity is maintained immediately after the coating process by the spin coating method without the viscosity becoming too high, and flatness due to reflowability can be expected to be further improved. In this invention, unless otherwise specified, the weight-average molecular weight (Mw) refers to that measured by gel permeation chromatography (GPC).

[0113] Specific examples of polymerizable functional groups in polymers include (meth)acryloyl groups, epoxy groups, oxetane groups, methylol groups, methylol ether groups, and vinyl ether groups. From the viewpoint of ease of polymerization, (meth)acryloyl groups are particularly preferred.

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

[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 polymerization factors (radicals, cations, etc.) by heat or light. Specifically, polymerization initiators include radical generators that generate radicals by heat or light, and acid generators that generate protons (H+) by heat or light. Radical generators are mainly used when the polymerizable component (A) contains a radical polymerizable compound. On the other hand, acid generators are mainly used when the polymerizable component (A) contains a cationic 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-hexyl peroxyisopropyl monocarbonate, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, and t-butyl peroxyisopropyl carbonates, peroxyketals such as 1,1-bis(t-hexyl peroxy)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-carbonnitrile).

[0117] Examples of thermal acid generators include known iodonium salts, sulfonium salts, phosphonium salts, and ferrocenes. Specifically, 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, X-rays, charged particle beams such as electron beams, radiation). Component (b) may consist of only one type of photopolymerization initiator or may consist of multiple types of photopolymerization initiators.

[0119] Examples of radical generators include, but are not limited to, the following: 2,4,5-triarylimidazole dimers which may have substituents 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, 2-(o- or p-methoxyphenyl)-4,5-diphenylimidazole dimer; benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler 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 and 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-phenantaraquinone, 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;Acyl phosphine 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-benzoyl oxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-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 mentioned above 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), Yubekrill P36 (manufactured by UCB)

[0121] Of the radical generators mentioned above, component (b) is preferably an acylphosphine oxide polymerization initiator. The acylphosphine oxide polymerization initiators among the radical generators mentioned above are as follows: Acyl phosphine 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] Specifically, as a photoacid generator, 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-butoxynaphthyltetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-butoxynaphthyltetrahydrothiophenium bis(trifluoromethanesulfonyl)imide anion, 4,7-di-n-butoxynaphthyltetrahydrothiophenium bis(nonafluorobutylsulfonyl)imide anion, and 4,7-di-n-butoxynaphthyltetrahydrothiophenium 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 trifluoromethanesulfonate, o-nitrobenzyl trifluoromethanesulfonate, and o-nitrobenzyl-p-toluenesulfonate; Sulfonimide compounds such as N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)-4-butylnaphthylimide, N-(trifluoromethylsulfonyloxy)-4-propylthionaphthylimide, N-(4-methylphenylsulfonyloxy)succinimide, N-(4-methylphenylsulfonyloxy)phthalimide, N-(4-methylphenylsulfonyloxy)diphenylmaleimide, N-(4-methylphenylsulfonyloxy)bicyclo[2.2.1]hepto-5-ene-2,3-dicarboximide, N-(4-fluorophenylsulfonyloxy)bicyclo[2.1.1]heptan-5,6-oxy-2,3-dicarboximide, N-(4-fluorophenylsulfonyloxy)naphthylimide, and N-(10-camphor-sulfonyloxy)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; These are some examples.

[0123] The proportion of component (b) in composition (A) is preferably 0.1% by weight or more and 50% by weight or less, relative to the total mass of component (a), component (b), and component (c) described later, i.e., the total mass of all components excluding solvent (d). Furthermore, the proportion of component (b) in composition (A) is more preferably 0.1% by weight or more and 20% by weight or less, and even more preferably 1% by weight or more and 20% by weight or less, relative to the total mass of all components excluding solvent (d). By increasing the proportion of component (b) to 0.1% by weight or more, the curing speed of the composition can be increased and the reaction efficiency can be improved. Furthermore, by increasing the proportion of component (b) to 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 components (a) and (b) described above, composition (A) may further contain a non-polymerizable compound as component (c), depending on the purpose. Examples of such component (c) include compounds that do not have polymerizable functional groups such as (meth)acryloyl groups and that do not have the ability to generate the polymerization factors (radicals) described above on their own. Examples of non-polymerizable compounds include sensitizers, surfactants, polymerization inhibitors, antioxidants, polymer components, and other additives. Component (c) may contain multiple types of the compounds described above.

[0125] Sensitizers are compounds added as needed to accelerate polymerization reactions or improve the reaction conversion rate. Sensitizers may be used individually or in combination of two or more types.

[0126] Examples of sensitizers include sensitizing dyes. Sensitizing dyes 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 or electron transfer from the excited sensitizing dye to component (b), the photopolymerization initiator. 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, camphaquinone derivatives, acridine dyes, thiopyrillium 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 less than 250°C under normal pressure. Component (d) can be a solvent in which components (a), (b), and (c) dissolve, such as an alcohol-based solvent, a ketone-based solvent, an ether-based solvent, an ester-based solvent, or a nitrogen-containing solvent. Component (d) can be used alone or in combination of two or more types. The boiling point of component (d) under normal pressure should be 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 should be less than 250°C, preferably 200°C or lower. If the boiling point of component (d) under normal pressure is less than 80°C, the volatilization rate will be too fast in the coating process described later, making it impossible to obtain a uniform film. Furthermore, if the boiling point of component (d) at atmospheric pressure is 250°C or higher, there is a risk that volatilization during the baking process after the coating process, described later, may be insufficient, and component (d) may remain 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; polyhydric alcohol 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-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, phenthone

[0130] Examples of ether-based solvents include the following: Ethyl ether, iso-propyl 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 ester solvents include the following: Diethyl carbonate, methyl acetate, ethyl acetate, amyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl 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 ether acetate Ethers, diethylene glycol acetate mono-n-butyl ether, propylene glycol acetate monomethyl ether, propylene glycol acetate monoethyl ether, propylene glycol acetate monopropyl ether, propylene glycol acetate monobutyl ether, dipropylene glycol acetate monomethyl ether, dipropylene glycol acetate monoethyl ether, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, iso-amyl 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] Of the solvents mentioned above, ether-based solvents and ester-based solvents are preferred. More preferably, from the viewpoint of excellent film-forming properties, are ether-based solvents and ester-based solvents having a glycol structure.

[0134] Furthermore, the following are even more desirable: Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol acetate monomethyl ether, propylene glycol acetate monoethyl ether, propylene glycol acetate monopropyl ether Furthermore, propylene glycol monomethyl ether acetate is particularly preferred. Ethyl)isocyanurate di(meth)acrylate is also a good example.

[0135] Preferred solvents are those having at least one of the following structures: ester structure, ketone structure, hydroxyl group, or ether structure. Specifically, these are solvents selected individually or in mixtures thereof from propylene glycol monomethyl ether acetate (boiling point 146°C), propylene glycol monomethyl ether, cyclohexanone, 2-heptanone, γ-butyrolactone, and ethyl lactate.

[0136] Furthermore, as component (d), a polymerizable compound having a boiling point of 80°C or higher and less than 250°C under normal pressure can also be used. Examples of polymerizable compounds having a boiling point of 80°C or higher 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 total volume of composition (A) is considered to be 100%, the content of solvent (d) is preferably 95% by volume or more. If the content of solvent (d) is less than 95% by volume, it is difficult to obtain a thin film in the coating process by the spin coating method.

[0138] <Temperature during compounding of composition (A)> When preparing composition (A), it is preferable to mix and dissolve at least components (as), (a), (b), and (d) under predetermined temperature conditions. Specifically, the predetermined temperature conditions may be in the range of 0°C to 100°C. The same applies when composition (A) contains component (c).

[0139] <Viscosity of the composition> Composition (A) is applied by a spin coating method during the coating process. 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 the solvent (d) of composition (A) has evaporated, i.e., the material from which solvent (d) has been removed from composition (A), may have a viscosity of, for example, 10 mPa·s to 10,000 mPa·s at 23°C. The viscosity of the material from which solvent (d) has been removed from composition (A) may be 10 mPa·s to 2800 mPa·s at 23°C, preferably 10 mPa·s to 600 mPa·s, and more preferably 10 mPa·s to 500 mPa·s. 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 1000 mPa·s or less, reflowability due to fluidity, as described later, can be obtained.

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

[0142] For filtration using a filter, it is preferable to mix the above-mentioned components (as), (a), (b), and (c) to obtain a mixture, and then filter the mixture using, for example, a filter with a pore size of 0.001 μm or more and 5.0 μm or less. When filtration using a filter, it is even more preferable to perform it in multiple stages or repeat it many times (circulating filtration). The liquid filtered by the filter may be filtered again, or multiple filters with different pore sizes may be used for filtration. Examples of filters used for filtration include, but are not particularly limited to, filters made of polyethylene resin, polypropylene resin, fluororesin, and nylon resin. By going through such a purification process, impurities such as particles mixed into composition (A) can be removed. This prevents impurities mixed into composition (A) from unintentionally causing irregularities in the inversion layer and resulting in pattern defects.

[0143] When composition (A) is used to manufacture semiconductor integrated circuits, it is preferable to avoid, as much as possible, the inclusion of metal atoms (metallic impurities) in composition (A) in order to avoid interfering with the operation of the product. The concentration of metal impurities in composition (A) is preferably 10 ppm or less, and more preferably 100 ppb or less.

[0144] <Initial curing film formation process> Figure 3 is a schematic diagram showing the optical nanoimprint method used in the initial curing film formation process in this embodiment. The optical nanoimprint method forms an initial cured film having a desired shape on a substrate through four main steps. Specifically, first, a curable composition 8 is applied (supplied) to the pattern formation region on the substrate 1 shown in Figure 3(A) (placement step). Next, the curable composition 8 is molded using a mold 9 with a pattern formed on it, as shown in Figure 3(B) (mold contact step). Then, the curable composition 8 is cured by irradiating it with light, as shown in Figure 3(C), to form a cured film 11 (light irradiation step). After that, the mold 9 shown in Figure 3(D) is separated from the cured film 11 (release step). Thus, by a series of steps having the placement step to the release step in this order, a cured film 11 having a desired uneven pattern shape (a pattern shape that follows the uneven shape of the mold 9) at a desired position can be obtained. In this embodiment, in the initial curing film formation step, the repeated units (shots) from the placement step to the demolding step are performed on multiple regions on the substrate 1, thereby forming a patterned cured film 11 on multiple regions on the substrate 1.

[0145] <Reversal Process> Figure 1 is a schematic diagram showing a known inversion process. The inversion process will be explained using Figure 1. Figure 1(A) is a schematic diagram showing the initial curing film formation process described above. In the inversion process, as shown schematicly in Figure 1(A), a cured film 11 having an uneven pattern 2 including convex portions 12 and concave portions 13 is formed on the substrate 1 as the initial curing film formation process. In other words, the initial curing film formation process can be said to be a process of forming an uneven pattern. As shown in Figure 1(A), the portion (base portion) under the uneven pattern 2 in the cured film 11 is called the residual film 3. The residual film 3 is unnecessary in the etching process after pattern formation and needs to be removed, and is removed in a later process. Methods for forming the cured film 11 having an uneven pattern 2 on the substrate 1 in the initial curing film formation process include, for example, optical nanoimprint lithography and photolithography. In this embodiment, as an example, the uneven pattern 2 is formed by optical nanoimprint lithography, but it is not limited to this.

[0146] The substrate 1 may be, for example, a silicon wafer. The substrate 1 may have a separate layer to be processed on its surface, and furthermore, other layers may be formed beneath the layer to be processed. In addition to silicon wafers, the substrate 1 can be arbitrarily selected from known semiconductor device substrates such as aluminum, titanium-tungsten alloy, aluminum-silicon alloy, aluminum-copper-silicon alloy, silicon oxide, and silicon nitride. The outermost layer to be processed on the substrate 1 may have improved adhesion to the curable composition through surface treatment such as silane coupling treatment, silazane treatment, or deposition of an organic thin film.

[0147] In this embodiment, the curable composition is a composition containing at least a polymerizable compound and a polymerization initiator. It may also further contain a non-polymerizable compound or a solvent as needed. The non-polymerizable compound is at least one selected from the group consisting of sensitizers, hydrogen donors, internal release agents, surfactants, antioxidants, polymer components, etc. In this embodiment, it is assumed that there is a certain layer to be processed on the substrate 1. In the initial cured film formation step, the process from placement to release is carried out on the layer to be processed on the substrate 1 using a curable composition having an inorganic element content of 1% by weight or less, preferably one that does not contain inorganic elements such as silicon atoms. This makes it possible to form a cured film 11 having a pattern including convex portions 12 and concave portions 13 on the substrate 1. As the curable composition, for example, the curable composition described in Japanese Patent Application Publication No. 2016-162862 can be used, but is not limited thereto.

[0148] Figure 1(B) is a schematic diagram showing the inversion layer formation process. The inversion layer formation process is performed after the initial cured film formation process. In the inversion layer formation process, an inversion layer 4 is formed on the cured film 11 having the formed uneven pattern 2. The inversion layer 4 is used as a mask for etching the cured film 11 in the residual film etching process described later. For this reason, it is required to have a sufficient etching selectivity ratio with respect to the curable composition forming the cured film 11. Here, the portion of the inversion layer 4 that is on top of the cured film 11 is called the excess inversion layer 5.

[0149] Figure 1(C) is a schematic diagram showing the excess inversion layer removal process. The excess inversion layer removal process is performed after the inversion layer formation process. In the excess inversion layer removal process, the excess inversion layer 5 is removed. Specifically, the inversion layer 4 (excess inversion layer 5) is removed until the upper part (top surface 12a) of the convex portion 12 of the cured film 11 having the uneven pattern 2 is exposed. Figure 1(C) shows the state after the inversion layer 4 (excess inversion layer 5) has been removed and the top surface 12a of the convex portion 12 is exposed.

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

[0151] Figure 1(E) is a schematic diagram showing the processing steps for the workpiece layer. The processing steps for the workpiece layer are performed after the residual film etching step. In the processing steps for the workpiece layer, an inverted pattern is transferred to the workpiece layer of the substrate 1. In the processing steps for the workpiece layer, the workpiece layer on the substrate 1 is etched using the inverted pattern 14 formed in the residual film etching step as a processing mask, thereby obtaining (forming) a substrate 1 having a pattern on the workpiece layer. Figure 1(E) shows a substrate 1 having a pattern on the workpiece layer.

[0152] Figure 1(F) is a schematic diagram showing the inversion pattern removal process. The inversion pattern removal process is the final step of the inversion process, following the processing of the workpiece layer. In the inversion pattern removal process, the inversion pattern 14, which is the processing mask, is removed.

[0153] In the inversion process, as mentioned above, depending on the uneven shape of the uneven pattern 2 of the cured film 11 and the formation conditions of the inversion layer 4, it may not be possible to form the desired inversion pattern. This problem will be explained using Figure 2. Figure 2 is a schematic diagram illustrating the problems that may occur in the inversion process. Figure 2(A) is a schematic diagram showing the inversion layer formation process S200. When the uneven shape of the uneven pattern 2 is large, for example, as shown in Figure 2(A), the inversion layer 4 may not be formed uniformly, and the film thickness of the inversion layer 4 formed on the convex parts 12 of the uneven pattern 2 may become too thick compared to the film thickness of the inversion layer 4 formed on the concave parts 13.

[0154] Figure 2(B) is a schematic diagram showing the excess inversion layer removal step 201. The excess inversion layer removal step 201 is performed following the inversion layer formation step S200. If the process proceeds to the next step, the excess inversion layer removal step 201, in the state shown in Figure 2(A), the cured film 11 on the bottom surface 13a of the recess 13 may be exposed before the excess inversion layer 5 is completely removed in order to expose the top surface 12a of the convex portion 12. If the excess inversion layer 5 is then removed to further expose the top surface 12a of the convex portion 12 of the cured film 11, the cured film 11 made of the curable composition of the recess 13 may be damaged, as shown in the excess inversion layer removal step 202 in Figure 2(C).

[0155] Furthermore, in the subsequent residual film etching process 203 shown in Figure 2(D), the inversion layer 4, which should be present in the recessed area 13, is absent. As a result, the curable composition (cured film 11) does not remain in the area 7 that is intended to be preserved, making it impossible to form the desired inversion pattern. Because this can occur, it is desirable that the inversion layer 4 be formed by flattening it on the cured film 11.

[0156] The pattern formation method (pattern processing method) in this embodiment will be described in detail below. Generally speaking, the pattern formation method of this embodiment may include: a coating step of applying the above composition onto a substrate on which an initial layer containing a recessed and convex pattern is formed; a reflow step of reflowing the composition after the coating step; a curing step of curing the composition after the reflow step to form an inverted layer; a removal step of removing the upper part of the inverted layer after the curing step so as to expose the top surfaces of the convex portions; and an etching step of using the remaining inverted layer as an etching mask to etch the initial layer and form an inverted pattern after the removal step.

[0157] Figure 4 is a schematic diagram showing the flow of the inversion process according to this embodiment. Figure 4(A) is a schematic diagram showing the initial cured film formation step S300 according to this embodiment. The initial cured film formation step S300 according to this embodiment is the same as the initial curing film formation step of the inversion process shown earlier, so its explanation is omitted.

[0158] <Coating Process> Figure 4(B) is a schematic diagram showing the coating process S301 of composition (A) according to this embodiment. In this process, composition (A) is coated onto a cured film 11 having an uneven pattern 2 to form an inverted layer 4. Specifically, an inverted layer 4 is formed by the spin coating method, having an inverted layer 4a that constitutes the portion from the peaks to the valleys and an inverted layer 4b that constitutes the portion from the valleys to the cured film 13. In this case, if the uneven shape of the cured film 11 is large, the inverted layer 4a immediately after the completion of spin coating will have height differences 15 due to the influence of the unevenness, making it difficult to form it flat. The inverted layer 4a tends to be formed unevenly as shown in Figure 4(B).

[0159] <Reflow Process> Figure 4(C) is a schematic diagram showing the reflow process S302 of composition (A) according to this embodiment. In this embodiment, planarization is achieved by applying a reflow process to the inverted layer 4a immediately after spin coating is completed. That is, in this embodiment, the inverted layer 4 becomes flat after the reflow process following the formation of the inverted layer 4a, meaning that the unevenness difference 15 of the inverted layer 4a becomes flat. In the reflow process, planarization by reflow begins immediately after spin coating, and the step difference 15 of the excess layer 5 shown in Figure 4(C) can be, for example, 15 nm or less. The reflow may be carried out in a room temperature environment of 23°C or in a heated environment. The temperature at which this reflow process is carried out can be appropriately adjusted depending on the composition of the composition, but is usually 23°C to 120°C, preferably 50°C to 100°C. The time for carrying out this reflow process is usually 0.1 seconds to 100 seconds, preferably 5 seconds to 60 seconds. Furthermore, the average thickness of the resulting film is not particularly limited, but is usually between 10 nm and 1,000 nm, and preferably between 20 nm and 500 nm.

[0160] <Curing process> The curing of composition (A) is shown in Figure 4(D), which is a schematic diagram illustrating the curing process S303 of the inverted layer, where the height difference of the excess layer 5 is ±15 nm or less. This can be done by heating composition (A), but is not limited to that. Heating is performed, for example, at a temperature of 30°C to 400°C, preferably 80°C to 250°C, and particularly preferably 90°C to 220°C. The heating time can be 10 seconds to 600 seconds. The curing process can be carried out using a known heating device such as a hot plate or an oven.

[0161] The curing of composition (A) may be carried out by irradiation with light. The irradiation light is selected according to the sensitivity wavelength of composition (A). Specifically, the irradiation light is appropriately selected from ultraviolet light, X-rays, or electron beams with a wavelength of 150 nm to 400 nm. It is particularly preferable that the irradiation light be ultraviolet light. This is because many commercially available curing aids (photopolymerization initiators) are compounds that are sensitive to ultraviolet light.

[0162] The curing of composition (A) may be carried out in combination with the curing by heating described above and the curing by light irradiation described above.

[0163] <Removal process of excess inverted layer> Figure 4(E) is a schematic diagram showing the excess inversion layer removal process. The excess inversion layer removal process is performed after the inversion layer formation process. In the excess inversion layer removal process, the excess inversion layer 5 is removed. Specifically, the inversion layer 4 (excess inversion layer 5) is removed until the upper part (top surface 12a) of the convex portion 12 of the cured film 11 having the uneven pattern 2 is exposed. Figure 4(E) shows the state in which the inversion layer 4 (excess inversion layer 5) has been removed and the top surface 12a of the convex portion 12 is exposed. In this embodiment, the height difference of the inversion layer 4 can be flattened to, for example, ±15 nm by the reflow process described above. This makes it possible to remove the excess inversion layer 5 without damaging the concave portion 13 of the cured film 11, as shown in Figure 2(C).

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

[0165] Figure 4(F) is a schematic diagram showing the residual film etching process. The residual film etching process is performed after the excess inversion layer removal process. In the residual film etching process, the residual film 3 of the cured film 11 is removed. In the residual film etching process, the inversion layer 4 remaining in the recesses 13 of the uneven pattern 2 after the excess inversion layer removal process is used as a processing mask. Using this processing mask, etching is performed starting from the protrusions 12 of the uneven pattern 2 that were exposed after the removal of the inversion layer 4 in the excess inversion layer removal process. Etching continues until the surface 1a of the substrate 1 (the layer to be processed) is exposed, and this process forms an inverted pattern (hereinafter referred to as the inverted pattern 14) on the layer to be processed of the substrate 1, with the unevenness reversed from the uneven pattern 2 of the curable composition. Figure 4(F) shows the state in which the residual film 3 has been etched and the inverted pattern 14 has been formed on the layer to be processed of the substrate 1.

[0166] Figure 4(G) is a schematic diagram showing the processing steps for the workpiece layer. The processing steps for the workpiece layer are performed after the residual film etching step. In the processing steps for the workpiece layer, an inverted pattern is transferred to the workpiece layer on the substrate 1. In the processing steps for the workpiece layer, the workpiece layer on the substrate 1 is etched using the inverted pattern 14 formed in the residual film etching step as a processing mask, thereby obtaining (forming) a substrate 1 having a workpiece layer with a pattern formed on it. Figure 4(G) shows a substrate 1 having a workpiece layer with a pattern formed on it.

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

[0168] [Product manufacturing method] The inverted pattern formed by the pattern formation method in this embodiment can be used as is as a component of at least a part of various articles. Alternatively, the inverted pattern can be temporarily used as a processing mask for etching or ion implantation of the layer to be processed on the substrate. In the processing steps for the layer to be processed on the substrate, after etching or ion implantation is performed on the layer, the inverted pattern, which served as the processing mask, is removed. This allows for the manufacture of various articles.

[0169] The inverted pattern formed by the pattern formation method in this embodiment can be used as is as a component of at least a part of various articles. Alternatively, the inverted pattern can be temporarily used as a processing mask for etching or ion implantation of the layer to be processed on the substrate. In the processing process of the layer to be processed on the substrate, after etching or ion implantation is performed on the layer to be processed, the inverted pattern, which is the processing mask, is removed. This allows for the manufacture of various articles. 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] Articles include electrical circuit elements, optical elements, MEMS, recording elements, sensors, or molds. Examples of electrical circuit elements include volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, as well as semiconductor elements such as LSI, CCD, image sensors, and FPGAs. If the layer to be processed is an insulating layer, it can be used as an interlayer insulating film included in the aforementioned semiconductor memories and semiconductor elements.

[0171] The processed layer having a pattern shape obtained through the initial curing film formation process and the inversion pattern removal process can be used as an optical component (including when used as a part of an optical component) such as a diffraction grating or polarizer to obtain an optical element. In such cases, the optical element can have at least a substrate and a processed layer having a pattern shape on this substrate. Examples of optical elements include microlenses, light guides, waveguides, anti-reflective coatings, diffraction gratings, polarizers, color filters, light-emitting elements, displays, and solar cells.

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

[0173] <Other Embodiments> Although 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 its gist. Furthermore, each embodiment may be combined. [Examples] To supplement the embodiments described above, more specific examples will be explained. [Examples]

[0174] In this embodiment, numerical calculations demonstrate that the inverted layer 4a is planarized by applying a reflow process to the inverted layer 4a immediately after spin coating is completed.

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

[0176] In the reflow process, the reflow temperature is adjusted as needed, and this initial liquid film distribution is flattened on the hardened film 11, which is a solid film, by flow. In this example, the flow process was calculated by solving the Navier-Stokes equation (Equation 1), which is approximated as a thin film with a free surface (lubrication theory). 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 set to 1000 cP and the surface tension to 35 mN / m.

[0177]

number

[0178] Figure 5 shows the initial liquid film distribution. In Figure 5, 501 is the cured film 11, and 502 is the inversion layer 4a. In Figure 5, the horizontal axis represents spatial coordinates, and the vertical axis represents height. As shown by 501, the cured film 11 has a spatial period of 8 μm in total, consisting of a recess of 4 μm and a convex portion of 4 μm. In other words, the left and right sides of Figure 5 represent periodic boundary conditions. The height of the cured film 11 was set to 100 nm.

[0179] The inversion layer 4a was made with a uniform thickness of 65 nm. Therefore, as shown in 502, the inversion layer 4a is distributed on 501 with a uniform film thickness. In the actual spin coating process, the distribution is thought to be smoother than the discontinuous step shape shown in 502, but we believe that by estimating the relaxation time based on the discontinuous shape of 502, we can evaluate the upper limit of the relaxation time.

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

[0181] Figure 7 shows the time evolution of the elevation difference of the liquid film distribution. The horizontal axis represents elapsed time, and the vertical axis represents the elevation difference of the liquid film. The time evolution of the elevation difference of the inversion layer 4a, 701, reaches its maximum value after about 0.1 seconds, then decays, becoming almost flat after 100 seconds. 702 shows the line where the elevation difference is 5 nm, and from the intersection of 701 and 702, it can be seen that the elevation difference falls below 5 nm after 100 seconds.

[0182] The same calculations as above were performed by changing the spatial period of the cured film 11 to 4um, 2um, and 1um, and the elapsed time at which 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 obtained by calculation, and the solid line in 802 is the result of the power fit. The function system in 802 is 1.25 × 10⁻¹⁰ -2 ×λ 4 It was found that the elapsed time during which the height difference falls below 5 nm is proportional to the fourth power of the spatial period of the cured film 11.

[0183] Furthermore, considering that generally, lower viscosity leads to a faster planarization rate, the above results indicate that when the period of the cured film 11 is approximately 8 μm, if the viscosity is 1000 cP or less, it can be planarized to a height difference of less than 5 nm in an elapsed time of 100 seconds or less. It was found that this elapsed time is proportional to the fourth power of the period.

[0184] This specification and drawings include the following disclosures: (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 the following features. (Item 2) The solvent content relative to the total composition is 95 w% or more. The composition according to item 1, characterized by the features described above. (Item 3) The composition has a viscosity of less than 2 mPa·s at 23°C. A composition according to item 1 or 2, characterized by the features described above. (Item 4) The vapor pressure of the material obtained by removing the solvent from the composition is 0.001 mmHg or less at 200°C. A composition according to any one of items 1 to 3, characterized by the features described herein. (Item 5) The molar equivalent of polymerizable functional groups is 300 or more. A composition according to any one of items 1 to 4, characterized by the above. (Item 6) The polymerizable compound has a linear polysiloxane skeleton. A composition according to any one of items 1 to 5, characterized by the features described herein. (Item 7) The polymerizable compound has a cyclic siloxane skeleton. A composition according to any one of items 1 to 5, characterized by the features described herein. (Item 8) The polymerizable compound has a silsesquioxane skeleton. A composition according to any one of items 1 to 5, characterized by the features described herein. (Item 9) The composition is used to form an inversion layer. A composition according to any one of items 1 to 8, characterized by the above. (Item 10) A coating step of applying the composition described in any one of items 1 to 9 onto a substrate on which an initial layer has been formed that includes an uneven pattern having recesses and protrusions, A reflow step is performed after the coating step, in which the composition is reflowed. A curing step is performed after the reflow step to cure the composition and form an inverted layer, A removal step is performed after the hardening step to remove the upper part of the inverted layer so as to expose the top surface of the protrusion, an etching step of, after the removing step, using the remaining inversion layer as an etching mask to etch the initial layer to form an inversion pattern; A pattern forming method comprising: (Item 11) the reflow step is performed for a time of 0.1 seconds or more and 100 seconds or less, the pattern forming method according to Item 10, characterized in that: (Item 12) the reflow step comprises reflowing the inversion layer at a temperature of 23°C or higher and 120°C or lower, the pattern forming method according to Item 10 or 11, characterized in that: (Item 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 any one of Items 10 to 12, characterized in that: (Item 14) the curing step comprises irradiating the inversion layer with light, the pattern forming method according to any one of Items 10 to 13, characterized in that: (Item 15) a pattern forming step of carrying out the pattern forming method according to any one of Items 10 to 14; a processing step of processing a substrate that has been subjected to the pattern forming step to obtain an article; a method for manufacturing an article, comprising: (Miscellaneous) The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the claims are appended to disclose the scope of the present invention.

Claims

1. A composition for spin coating comprising a polymerizable compound containing at least silicon atoms and a solvent, The composition is applied by spin coating onto a substrate having an initial layer with a textured pattern including recesses and protrusions, reflowed after application and before curing to flatten the surface of the composition, and cured after the reflow to form an inverted layer. The molar equivalent of polymerizable functional groups in the polymerizable compound containing at least the silicon atoms is 300 or more. The polymerizable compound containing at least the aforementioned silicon atoms has a vapor pressure of 0.001 mmHg or less at 200°C. 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. A composition characterized in that the silicon atom content of the material obtained by removing the solvent from the composition is 30% by weight or more.

2. The composition according to claim 1, characterized in that the content of the solvent relative to the total composition is 95% by volume or more.

3. The composition according to claim 1, characterized in that the composition has a viscosity of less than 2 mPa·s at 23°C.

4. The composition according to claim 1, characterized in that it comprises a plurality of polymerizable compounds containing at least one silicon atom, and the vapor pressure of each of the polymerizable compounds containing at least one silicon atom at 200°C is 0.001 mmHg or less.

5. The composition according to claim 1, characterized in that the molar equivalent of polymerizable functional groups of the polymerizable compound containing at least one silicon atom is 400 or more.

6. The composition according to claim 1, characterized in that the polymerizable compound has a linear polysiloxane skeleton.

7. The composition according to claim 1, characterized in that the polymerizable compound has a cyclic siloxane skeleton.

8. The composition according to claim 1, characterized in that the polymerizable compound has a silsesquioxane skeleton.

9. The composition according to claim 1, characterized in that the composition is planarized by the reflow process such that the height difference on the surface of the composition is 15 nm or less.

10. A coating step involves applying a composition containing a polymerizable compound having at least silicon atoms and a solvent to a substrate on which an initial layer having an uneven pattern with recesses and protrusions has been formed, by a spin-coating method. After the coating step, a reflow step is performed to reflow the surface of the composition to flatten it. A curing step is performed after the reflow step to cure the composition and form an inverted layer, A removal step is performed after the hardening step to remove the upper part of the inverted layer so as to expose the top surface of the protrusion, The process includes, after the removal step, an etching step in which the remaining inversion layer is used as an etching mask to etch the initial layer and form an inversion pattern, The composition has a molar equivalent of 300 or more polymerizable functional groups of the polymerizable compound, a vapor pressure of 0.001 mmHg or less at 200°C of the polymerizable compound containing at least one silicon atom, a viscosity of 10 mPa·s or more and 1,000 mPa·s or less at 23°C of the material from which the solvent has been removed from the composition, and a silicon atom content of 30% by weight or more of the material from which the solvent has been removed from the composition. A pattern forming method characterized by the following.

11. The pattern forming method according to claim 10, characterized in that the reflow process is carried out for a period of time of 0.1 seconds or more and 100 seconds or less.

12. The pattern forming method according to claim 10, characterized in that the reflow step includes reflowing the composition at a temperature of 23°C or higher and 120°C or lower.

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

14. The pattern forming method according to claim 10, characterized in that the curing step includes irradiating the composition with light.

15. A method for manufacturing an article, comprising a pattern forming step of carrying out the pattern forming method described in claim 10, and a processing step of processing the substrate that has undergone the pattern forming step to obtain an article.

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