Composition, pattern forming method, and article manufacturing method

Abstract

The invention relates to a composition, a pattern forming method and an article manufacturing method. A composition for spin coating comprising a polymerizable compound containing at least silicon atoms and a solvent, in which the viscosity of a material obtained by removing the solvent from the composition is 10 mPa * s or more and 1,000 mPa * s or less, and the content of silicon atoms in the material obtained by removing the solvent from the composition is 30% by weight or more.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a composition, a pattern forming method, and an article manufacturing method. BACKGROUND

[0002] With the increasing demand for miniaturization of semiconductor devices and MEMS, in addition to conventional photolithography techniques, imprint techniques using a mold to form an imprint material on a substrate and form a pattern of the imprint material on the substrate have received widespread attention.

[0003] In the imprint technique, the imprint material applied to the substrate is brought into contact with the mold, thereby forming a concave-convex pattern of the mold. When the substrate is processed using the pattern obtained by the imprint technique as a mask, a step called a reverse process can be applied.

[0004] Japanese Patent Laid-Open No. 2016-162862 discloses the following reverse process. First, a reverse layer is formed on the concave-convex pattern (reverse layer forming step), and the reverse layer material is buried in the concave portion. At this time, the reverse layer material is also stacked on the upper portion of the convex portion of the concave-convex pattern, forming a remaining reverse layer. For this reason, the remaining reverse layer is removed (remaining reverse layer removing step) to expose the top surface of the convex portion of the concave-convex pattern of the cured film of the curable composition, thereby exposing the reverse layer buried in the concave portion. Thereafter, using the exposed reverse layer as a mask, the residual film of the concave-convex pattern (residual film etching step) and a processing target layer as an underlayer are etched, thereby forming a reverse pattern (processing target layer processing step).

[0005] In this reverse process, the surface of the reverse layer is preferably flat. Japanese Patent Laid-Open No. 2018-12806 discloses a composition formed of polysiloxane and a high-boiling-point solvent as a material capable of forming a flat film. Japanese Patent Laid-Open No. 2018-98470 discloses a method of planarizing the reverse layer by forming the reverse layer using an inkjet method, and a method of planarizing by pressing the reverse layer with the aid of a flat mold. Japanese Patent Laid-Open No. 2023-181983 discloses a method of applying a low-viscosity curable composition using an inkjet method to thereby form a flat reverse layer.

[0006] However, when the material and the method disclosed in Japanese Patent Laid-Open No. 2018-12806 are used, the flatness is insufficient. Furthermore, in the methods disclosed in Japanese Patent Laid-Open No. 2018-98470 and Japanese Patent Laid-Open No. 2023-181983, a complex process such as an inkjet method or pressing using a flat mold is required, resulting in high cost and low productivity (production volume). SUMMARY

[0007] The present disclosure provides a composition that is advantageous in obtaining high flatness and high productivity (production volume).

[0008] A first aspect of the present disclosure provides a composition for spin coating, comprising: a polymerizable compound including at least a silicon atom, and a solvent, wherein a viscosity of a material obtained by removing the solvent from the composition is 10 mPa-s or more and 1,000 mPa-s or less, and a content of the silicon atom in the material obtained by removing the solvent from the composition is 30% by weight or more.

[0009] A second aspect of the present disclosure provides a pattern forming method, comprising: applying the composition as defined in the first aspect to a substrate on which an initial layer including a concavo-convex pattern having a concave portion and a convex portion is formed; reflowing the composition after the application; curing the composition after the reflowing to form a reversed layer; removing an upper portion of the reversed layer after the curing to expose a top surface of the convex portion; and etching the initial layer using the remaining reversed layer as an etching mask after the removal to form a reversed pattern.

[0010] The features of the present disclosure will become apparent from the following description of the embodiments with reference to the accompanying drawings. The following description of embodiments is made with examples. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A to F in FIG. 1 are schematic diagrams showing a known reverse process; Figure 1 A to F in FIG. 1 are schematic diagrams showing a known reverse process;

[0012] Figures 2A-2D is a schematic diagram for explaining a problem that can occur in a reverse process;

[0013] Figures 3A-3D is a schematic diagram for explaining a photonic nanoimprint method;

[0014] Figures 4A-4G is a schematic diagram showing a flow of a reverse process according to an embodiment;

[0015] Figure 5 is a schematic diagram showing an initial liquid film distribution;

[0016] Figure 6 is a schematic diagram showing a time-rate change of a liquid film distribution;

[0017] Figure 7 is a schematic diagram showing a time-rate change of a height difference of a liquid film distribution; and

[0018] Figure 8 is a schematic diagram showing a time elapsed for a spatial period and a height difference of less than 5 nm. DETAILED DESCRIPTION

[0019] Hereinafter, the embodiments will be described in detail with reference to the drawings. Note that the following embodiments are not intended to limit the scope of the claims. Various features will be described in the embodiments, but not all of these features are essential, and a plurality of these features can be combined as needed. Furthermore, in the drawings, the same reference numerals are assigned to the same or similar components, and repetitive explanation thereof is omitted.

[0020] When providing a new technology related to a composition for facilitating formation of a reversal layer, the present inventors found a composition and process conditions thereof capable of obtaining high planarity and high productivity (production volume).

[0021] [Composition for Reversal Layer Formation]

[0022] The composition (A) according to one embodiment is a composition for spin coating and can be used, for example, for a reversal layer. The composition (A) according to one embodiment is a composition including: a polymerizable compound (as) containing at least a silicon atom, and a component (d) as a solvent. Hereinafter, the polymerizable compound (as) containing at least a silicon atom will be referred to as a silicon-containing polymerizable compound. The composition (A) according to one embodiment can further include at least one of a polymerizable compound (a) not containing a silicon (Si) atom, a polymerization initiator (b), and a non-polymerizable compound (c).

[0023] <Component (as): Silicon-containing Polymerizable Compound>

[0024] In the present specification, the silicon-containing polymerizable compound (as) is a compound that forms a film made of a high molecular compound by chain reaction (polymerization reaction) with the aid of heat or light or by chain reaction (polymerization reaction) with the aid of a polymerization factor (radical or cation) generated from a polymerization initiator (component (b)).

[0025] Examples of the silicon-containing polymerizable compound (as) are a radical polymerizable compound and a cationic polymerizable compound. The silicon-containing polymerizable compound (as) can be formed of only one type of polymerizable compound, or can be formed of a plurality of types (one or more types) of polymerizable compounds.

[0026] Examples of the silicon-containing polymerizable compound are a (meth)acrylate compound, a (meth)acrylamide compound, an epoxy-modified compound, an alicyclic epoxy-modified compound, a vinylbenzene compound, an aryl ether compound, a vinyl compound, a vinyl ether compound, and a maleimide compound.

[0027] The silicon-containing polymerizable compound (as) can be linear or branched. As the silicon-containing polymerizable compound, for example, the following structures can be used. Examples of the polymerizable functional group in the group Q having a polymerizable functional group are radical polymerizable functional groups. Specific examples of the radical polymerizable functional group are (meth)acrylate-based compounds, (meth)acrylamide-based compounds, epoxy-modified compounds, alicyclic epoxy-modified compounds, vinylbenzene-based compounds, aryl ether-based compounds, vinyl-based compounds, vinyl ether-based compounds, and maleimide-based compounds. The group Q having a polymerizable functional group can be a group having the above-described polymerizable functional group.

[0028]

[0029] Examples of the silicon-containing polymerizable compound (as) are a silsesquioxane skeleton represented by the following formula (1) and a silicon skeleton represented by the following formula (2). Here, in formula (1), m + n = 8 (8 ≥ m ≥ 1), and R1is a divalent organic group. Further, in formula (2), A, B, R2, and R3are independently alkyl groups, cycloalkyl groups, alkoxy groups, phenyl groups, or hydroxyl groups having a carbon number of 1 to 6 (t is an integer of 1 to 3), and at least one of A and B is a polymerizable functional group.

[0030]

[0031]

[0032] Examples of the polymerizable functional group in the group Q having a polymerizable functional group, A, and B are radical polymerizable functional groups. Specific examples of the radical polymerizable functional group are (meth)acrylate-based compounds, (meth)acrylamide-based compounds, vinylbenzene-based compounds, aryl ether-based compounds, vinyl-based compounds, vinyl ether-based compounds, and maleimide-based compounds. The group Q having a polymerizable functional group can be a group having the above-described polymerizable functional group.

[0033] The molar equivalent of the polymerizable functional group of the silicon-containing polymerizable compound (as) is 300 or more. It is preferable that it be 400 or more, and particularly preferably 500 or more. When the molar equivalent of the polymerizable functional group is 300 or more, the curing shrinkage can be reduced.

[0034] The molar equivalent of the polymerizable functional group of the silicon-containing polymerizable compound (as) can be calculated, for example, by the following formula. If the silicon-containing polymerizable compound (as) is formed of a plurality of types (one or more types) of polymerizable compounds, the molar equivalent can be calculated as a weighted average of molar fractions.

[0035] (Method for calculating the molar equivalent of the polymerizable functional group)

[0036] (molecular weight of component (as)) / (number of polymerizable functional groups in component (as))

[0037] The silicon-containing (meth)acrylate-based compound is a compound having one or more acryloyl groups or methacryloyl groups. Silicon-containing monofunctional (meth)acrylate-based compounds having one acryloyl group or methacryloyl group are as follows, but the compounds are not limited to these examples.

[0038] (2-acryloyloxyethyl)trimethylsilane,

[0039] N-(3-acryloyl-2-hydroxypropyl)-3-aminopropyltriethoxysilane,

[0040] acryloyloxymethyltrimethoxysilane,

[0041] (acryloyloxymethyl)phenethyltrimethoxysilane,

[0042] acryloyloxymethyltrimethylsilane,

[0043] (3-acryloyloxypropyl)dimethylmethoxysilane,

[0044] (3-acryloyloxypropyl)methylbis(trimethylsiloxy)silane,

[0045] (3-acryloyloxypropyl)methyldichlorosilane,

[0046] (3-acryloyloxypropyl)methyldiethoxysilane,

[0047] (3-acryloyloxypropyl)methyldimethoxysilane,

[0048] (3-acryloyloxypropyl)trichlorosilane,

[0049] (3-acryloyloxypropyl)trimethoxysilane,

[0050] (3-acryloyloxypropyl)tris(trimethylsiloxy)silane,

[0051] acryloyloxytriisopropylsilane,

[0052] acryloyloxytrimethylsilane,

[0053] methacryloyloxymethyltrimethoxysilane,

[0054] O-(methacryloyloxyethoxy)carbamoylpropylmethyldimethoxysilane,

[0055] (methacryloyloxymethyl)bis(trimethylsiloxy)methylsilane,

[0056] N-(3-methacryloyl-2-hydroxypropyl)-3-aminopropyltrimethoxysilane,

[0057] (methacryloyloxymethyl)methyl dimethoxysilane,

[0058] (methacryloyloxymethyl)methyl diethoxysilane,

[0059] methacryloyloxymethyl triethoxysilane,

[0060] methacryloyloxypropyl trimethoxysilane,

[0061] methacryloylpropyl triisopropoxysilane,

[0062] O-(methacryloyloxyethyl)-N-(triethoxysilylpropyl) carbamate,

[0063] methacryloyloxypropyl methyl dimethoxysilane,

[0064] methacryloyloxypropyl methyl diethoxysilane,

[0065] methacryloyloxypropyl dimethyl methoxysilane,

[0066] methacryloyloxypropyl dimethyl ethoxysilane,

[0067] (methacryloyloxymethyl)dimethyl ethoxysilane,

[0068] methacryloyloxypropyl triethoxysilane,

[0069] methacryloxypropyl silatrane,

[0070] methacryloxy pentamethyldisiloxane,

[0071] (methacryloyloxymethyl)phenyl dimethyl silane,

[0072] methacryloxytrimethyl silane,

[0073] methacryloyloxymethyl trimethyl silane,

[0074] (3-methacryloyloxy-2-hydroxypropoxypropyl)methyl bis(trimethylsiloxy)silane,

[0075] methacryloyloxypropyl pentamethyldisiloxane,

[0076] O-(methacryloyloxyethyl)-3-[bis(trimethylsiloxy)methylsilyl]propyl carbamate,

[0077] Methacryloxymethyltris(trimethylsiloxy)silane,

[0078] Methacryloxyethoxytrimethylsilane,

[0079] (3-Methacryloxy-2-hydroxypropoxypropyl)methylbis(trimethylsiloxy)silane,

[0080] Methacryloxypropyltris(vinyldimethylsiloxy)silane,

[0081] Methacryloxypropyltris(trimethylsiloxy)silane,

[0082] 3-Methacryloxypropyltriacetoxysilane,

[0083] Methacryloxypropylmethyldichlorosilane,

[0084] Methacryloxypropyltrichlorosilane,

[0085] 3-Methacryloxypropylbis(trimethylsiloxy)methylsilane,

[0086] 3-Methacryloxypropyldimethylchlorosilane,

[0087] O-methacryloyloxy (polyvinyloxy) trimethylsilane,

[0088] Poly(methacryloyloxypropyl silsesquioxane),

[0089] Methacryloxypropylheptaisobutyl-T8-silsesquioxane and

[0090] Methacryloxypropyltris(trimethylsiloxy)silane.

[0091] Examples of commercially available products containing silicon-containing monofunctional (meth)acrylic compounds are as follows, but the product is not limited to these examples.

[0092] SIA0160.0, SIA0180.0, SIA0182.0, SIA0184.0, SIA0186.0, SIA0190.0, SIA0194.0, SIA0196.0, SIA0197.0, 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, SIM6487.4, 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, and SIM6486.65 (manufactured by GELEST), and TM-0701T, FM-0711, FM-0721, and FM-0725 (manufactured by JNC).

[0093] The silicon-containing (meth)acrylamide-based compound is a compound having one or more acrylamide groups or methacrylamide groups. Silicon-containing monofunctional (meth)acrylamide-based compounds having one acrylamide group or methacrylamide group are as follows, but the compounds are not limited to these examples. 3-Acrylamidopropyltrimethoxysilane and 3-acrylamidopropyltris(trimethylsiloxy)silane.

[0094] Examples of commercially available products of the above-described silicon-containing monofunctional (meth)acrylamide-based compounds are as follows, but the products are not limited to these examples.

[0095] SIA0146.0 and SIA0150.0 (manufactured by GELEST).

[0096] Examples of the multifunctional (meth)acrylate compound (polymerizable compound) having two or more acryloyl groups or methacryloyl groups are compounds having a linear polysiloxane skeleton, a cyclic siloxane skeleton, or a silsesquioxane skeleton, but the compound is not limited to these examples.

[0097] Examples of the compound having a linear polysiloxane skeleton are as follows.

[0098] linear dimethylpolysiloxane modified at both terminals with acryloxypropyl groups,

[0099] linear dimethylpolysiloxane modified at both terminals with methacryloxypropyl groups,

[0100] linear dimethylpolysiloxane modified at both terminals with acryloxypropyl groups,

[0101] linear dimethylpolysiloxane modified at both terminals with methacryloxypropyl groups.

[0102] Examples of the compound having a cyclic siloxane skeleton are as follows.

[0103] cyclic siloxane modified with a plurality of acryloxypropyl groups, and

[0104] cyclic siloxane modified with a plurality of methacryloxypropyl groups.

[0105] Examples of the compound having a silsesquioxane skeleton are as follows.

[0106] silsesquioxane modified with a plurality of acryloxypropyl groups, and

[0107] silsesquioxane modified with a plurality of methacryloxypropyl groups.

[0108] Examples of commercially available products of the above-described silicon-containing multifunctional (meth)acrylate compound are as follows, but the product is not limited to these examples.

[0109] SIA0200.2, SIA0200.3, SIM6487.42, DMS-R11, DMS-R05, DMS-R22, DMS-R18, DMS-R31, MCT-M11, RMS-992, RTT-1011 (manufactured by GELEST), FM-7711, FM-7721, FM-7725 (manufactured by JNC), X-22-2445 (manufactured by Shin-Etsu Chemical), and AC-SQ TA-100, MAC-SQ TM-100, AC-SQ SI-20, MAC-SQ SI-20 (manufactured by TOAGOSEI).

[0110] In addition, according to known literature (for example, Ogawa et al., "Ultraviolet curable branched siloxanes as low-k dielectrics for imprint lithography" (https: / / doi.org / 10.1116 / 1.4770051)), a linear modified polydimethylsiloxane modified at both terminals with a methacryloxypropyl group (MA-Si-12), an 8-membered cyclic siloxane modified with four methacryloxypropyl groups (8-ring), and a 10-membered cyclic siloxane modified with five methacryloxypropyl groups (10-ring) can be synthesized and obtained.

[0111] Examples of commercially available products of the above-described silicon-containing epoxy-modified compounds are as follows, but the products are not limited to these examples.

[0112] X-22-163, KF-105, X-22-163A, X-22-163B, X-22-163C (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, and DMS-EX21 (manufactured by GELEST).

[0113] Examples of commercially available products of the above-described silicon-containing alicyclic epoxy-modified compounds are as follows, but the products are not limited to these examples.

[0114] X-22-169AS, X-22-169B (manufactured by Shin-Etsu Silicone), SIB1092.0, DMS-EC17, DMS-EC31, DMS-EC13, ECMS-127, ECMS-227, ECMS-327, ECMS-924, EBP-234, and DMS-EC13 (manufactured by GELEST).

[0115] Examples of commercially available products of the above-described silicon-containing multifunctional vinyl compounds are as follows, but the products are not limited to these examples.

[0116] DMS-V00, DMS-V21, VMS-T11, and MCS-VX15 (manufactured by GELEST).

[0117] In the reverse layer forming method according to one embodiment, after the step by means of the spin coating method described later, a curing step by means of heating occurs. In the curing step, the solvent (d) volatilizes, but the polymerizable compound (as) must not volatilize. Therefore, a plurality of types of polymerizable compound (as) each of which has a vapor pressure of 0.001 mmHg or less at 200°C can be included. This is intended to suppress volatilization of the polymerizable compound (as) at the time of heating in the reflow step (described later) and the curing step of the reverse layer.

[0118] Note that the boiling point and vapor pressure of each organic compound at normal pressure can be calculated by, for example, Hansen Solubility Parameters in Practice (HSPiP) 5th edition. 5.3.04 in practice.

[0119] Specific examples of the polymerizable compound (as) having a vapor pressure of 0.001 mmHg or less at 200°C are as follows, but the compound is not limited to these examples.

[0120] 1,3-bis(3-methacryloyloxypropyl)tetra(trimethylsiloxy)disiloxane,

[0121] monomethacryloyloxypropyl-functional tris(polydimethylsiloxane),

[0122] monomethacryloyloxypropyl-terminated poly(3,3,3 trifluoropropyl)methylsiloxane,

[0123] monovinyl-terminated polydimethylsiloxane,

[0124] vinyl-terminated polydimethylsiloxane,

[0125] (methacryloyloxypropyl)methylsiloxane, homopolymer,

[0126] methacryloyloxypropyl T-silicone.

[0127] Examples of commercially available products of the above-described silicon-containing compounds are as follows, but the products are not limited to these examples.

[0128] SIB 1400.0, MCS-MX11, MCS-MX11, MFR-M15, MCS-V212, DMS-V21, RMS-992, and RTT-1011 (manufactured by GELEST).

[0129] <component (a): silicon-free polymerizable compound>

[0130] The component (a) is a silicon-free polymerizable compound. In the present specification, a silicon-free polymerizable compound is a compound that reacts with a polymerization factor (e.g., a radical) generated from a polymerization initiator (component (b)) and forms a film made of a high molecular compound through chain reaction (polymerization reaction).

[0131] Examples of the polymerizable compound as described above are radical polymerizable compounds. The polymerizable compound as the component (a) can be formed of only one type of polymerizable compound, or can be formed of a plurality of types (one or more types) of polymerizable compounds.

[0132] Examples of the radical polymerizable compound are silicon-free (meth)acrylic compounds, silicon-free styrene compounds, silicon-free vinyl compounds, silicon-free allyl compounds, silicon-free fumaric acid compounds, and silicon-free maleic acid compounds.

[0133] The silicon-free (meth)acrylic compound is a compound having one or more acryloyl groups or methacryloyl groups. Examples of the silicon-free monofunctional (meth)acrylic compound having one acryloyl group or methacryloyl group are as follows, but the compound is not limited to these examples.

[0134] 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, isoborneol (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, borneol (meth) acrylate, tricyclodecyl (meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopentenyl (meth) 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, (meth) acrylic acid Propyl acrylate, isopropyl acrylate, butyl acrylate, pentyl acrylate, isobutyl acrylate, tert-butyl acrylate, pentyl acrylate, isoamyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, isodecanyl acrylate, undecyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate, isostearyl acrylate, benzyl acrylate, tetrahydrofurfuryl acrylate, (methyl) Butoxyethyl acrylate, ethoxydiethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, diacetone (meth)acrylamide, isobutoxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, tert-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, and cyano benzyl (meth) acrylate.

[0135] Examples of commercially available products of the above-described silicon-free monofunctional (meth) acryl compound are as follows, but the product is not limited to these examples.

[0136] ARONIX® M101, M102, M110, M111, M113, M117, M5700, TO-1317, M120, M150, and M156 (manufactured by TOAGOSEI), MEDOL 10, MIBDOL 10, CHDOL 10, MMDOL 30, MEDOL 30, MIBDOL 30, CHDOL 30, LA, IBXA, 2-MTA, HPA, and Viscoat #150, #155, #158, #190, #192, #193, #220, #2000, #2100, and #2150 (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, and OPP-EA (manufactured by KYOEISHA CHEMICAL), KAYARAD ® TC110S, R-564, and R-128H (manufactured by NIPPON KAYAKU), NKEster AMP-10G, AMP-20G, and A-LEN-10 (manufactured by SHIN-NAKAMURA CHEMICAL), FA-511A, 512A, and 513A (manufactured by Hitachi Chemical), PHE, CEA, PHE-2, PHE-4, BR-31, BR-31M, and BR-32 (manufactured by DKS), VP (manufactured by BASF), and ACMO, DMAA, and DMAPAA (manufactured by Kohjin).

[0137] Examples of commercially available products of the silicon-free multifunctional (meth) acryl compound having two or more acryloyl groups or methacryloyl groups are as follows, but the compound is not limited to these examples.

[0138] trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO- and PO-modified trimethylolpropane tri(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,3-adamantanediol di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(acryloyloxy)isocyanurate, bis(hydroxymethyl)tricyclodecane di(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, EO-modified 2,2-bis(4-((meth)acryloyloxy)phenyl)propane, PO-modified 2,2-bis(4-((meth)acryloyloxy)phenyl)propane, EO- and PO-modified 2,2-bis(4-((meth)acryloyloxy)phenyl)propane, o-, m- or p-phenylene di(meth)acrylate, and o-, m- or p-xylylene di(meth)acrylate.

[0139] Examples of commercially available products of the above-described silicon-free polyfunctional (meth)acrylic compounds are as follows, but the products are not limited to these examples.

[0140] Yupimer ® UV SA1002 and SA2007 (manufactured by Mitsubishi Chemical), Viscoat #195, #230, #215, #260, #335HP, #295, #300, #360, #700, GPT and 3PA (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 and DPE-6A (manufactured by KYOEISHA CHEMICAL), KAYARAD ® PET-30, TMPTA, R-604, DPHA, DPCA-20, -30, -60 and -120, HX-620, D-310 and D-330 (manufactured by NIPPON KAYAKU), ARONIX® M208, M210, M215, M220, M240, M305, M309, M310, M315, M325, and M400 (manufactured by TOAGOSEI), Ripoxy ® VR-77, VR-60, and VR-90 (manufactured by Showa Highpolymer), OGSOL EA-0200 and OGSOL EA-0300 (manufactured by Osaka Gas Chemicals).

[0141] Note that, in the above compound groups, (meth)acrylate refers to acrylate or methacrylate having an alcohol residue equivalent to acrylate. (Meth)acryloyl refers to acryloyl or methacryloyl having an alcohol residue equivalent to acryloyl. EO indicates ethylene oxide, and EO-modified compound A indicates a compound in which the (meth)acrylic acid residue and the alcohol residue of compound A are bonded via a block structure of an ethylene oxide group. Furthermore, PO indicates propylene oxide, and PO-modified compound B indicates a compound in which the (meth)acrylic acid residue and the alcohol residue of compound B are bonded via a block structure of a propylene oxide group.

[0142] Specific examples of the silicon-free styrene compounds are as follows, but the compounds are not limited to these examples.

[0143] Alkylstyrenes such as styrene, 2,4-dimethyl-a-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; halogenated styrenes such as fluorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, dibromostyrene, and iodostyrene; and 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-vinyl naphthalene, 2-vinyl naphthalene, 4-vinyl-p-terphenyl, 1-vinylanthracene, a-methylstyrene, o-isopropenyltoluene, m-isopropenyltoluene, p-isopropenyltoluene, 2,3-dimethyl-a-methylstyrene, 3,5-dimethyl-a-methylstyrene, p-isopropyl-a-methylstyrene, a-ethylstyrene, a-chlorostyrene, divinylbenzene, diisopropylbenzene, and divinylbiphenyl.

[0144] Specific examples of the non-silicon vinyl-based compounds are as follows, but the compounds are not limited to these examples.

[0145] 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; compounds having a vinyl group as a polymerizable functional group such as a vinylidene halide such as vinylidene chloride, a vinyl ester of an organic carboxylic acid and a derivative thereof (for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, and divinyl adipate), and a (meth)acrylonitrile.

[0146] Note that, in the present specification, (meth)acrylonitrile is a general term for acrylonitrile and methacrylonitrile.

[0147] Examples of the non-silicon allyl-based compounds are as follows, but the compounds are not limited to these examples.

[0148] Allyl acetate, allyl benzoate, diallyl adipate, diallyl terephthalate, diallyl isophthalate, and diallyl phthalate.

[0149] Examples of the silicon-free fumaric acid-based compound are as follows, but the compound is not limited to these examples.

[0150] dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, di-sec-butyl fumarate, diisobutyl fumarate, di-n-butyl fumarate, di-2-ethylhexyl fumarate, and dibenzyl fumarate.

[0151] Examples of the silicon-free maleic acid-based compound are as follows, but the compound is not limited to these examples.

[0152] dimethyl maleate, diethyl maleate, diisopropyl maleate, di-sec-butyl maleate, diisobutyl maleate, di-n-butyl maleate, di-2-ethylhexyl maleate, and dibenzyl maleate.

[0153] Other examples of the silicon-free radical polymerizable compound are as follows, but the compound is not limited to these examples.

[0154] dialkyl esters of itaconic acid and derivatives thereof (e.g., dimethyl itaconate, diethyl itaconate, diisopropyl itaconate, di-sec-butyl itaconate, diisobutyl itaconate, di-n-butyl itaconate, di-2-ethylhexyl itaconate, and dibenzyl itaconate), N-vinylamide derivatives of organic carboxylic acids (e.g., N-methyl-N-vinylacetamide), and maleimides and derivatives thereof (e.g., N-phenylmaleimide and N-cyclohexylmaleimide).

[0155] If component (a) is formed of a plurality of types of compounds having one or more polymerizable functional groups, it is preferable to include both monofunctional compounds and polyfunctional compounds. This is because if monofunctional compounds and polyfunctional compounds are combined, a cured film having good balanced properties, such as high mechanical strength, high dry etching resistance, and high heat resistance, can be obtained.

[0156] In the reverse layer forming method according to one embodiment, after the application step by means of the spin coating method described later, a curing step by means of heating occurs. In the curing step, the solvent (d) volatilizes, but the polymerizable compound (a) must not volatilize. Therefore, of the polymerizable compound (a) that can include a plurality of types of compounds, the boiling point of all of the compounds under normal pressure is preferably 250°C or higher, more preferably 300°C or higher, and further preferably 350°C or higher.

[0157] The boiling point of the polymerizable compound (a) is almost related to the molecular weight. Therefore, the molecular weight of all of the polymerizable compound (a) is preferably 200 or higher, more preferably 240 or higher, and further preferably 250 or higher. However, even when the molecular weight is 200 or lower, if the boiling point is 250°C or higher, the compound is preferably usable as the polymerizable compound (a) of the present disclosure.

[0158] Note that the respective boiling points of various organic compounds at normal pressure can be calculated, for example, by Hansen Solubility Parameters in Practice (HSPiP) 5th edition. 5.3.04 in practice.

[0159] Specific examples of the polymerizable compound (component (a)) having a boiling point of 250°C or higher are, for example, the following, but the compound is not limited to these examples.

[0160] Dicyclopentyl acrylate (boiling point = 262°C, molecular weight = 206)

[0161] Dicyclopentenyl acrylate (boiling point = 270°C, molecular weight = 204)

[0162] 1,3-Cyclohexanedimethanol diacrylate (boiling point = 310°C, molecular weight = 252)

[0163] 1,4-Cyclohexanedimethanol diacrylate (boiling point = 339°C, molecular weight = 252)

[0164] 4-Hexylresorcinol diacrylate (boiling point = 379°C, molecular weight = 302)

[0165] 6-Phenylhexane-1,2-diol diacrylate (boiling point = 381°C, molecular weight = 302)

[0166] 7-Phenylheptane-1,2-diol diacrylate (boiling point = 393°C, molecular weight = 316)

[0167] 1,3-Bis((2-hydroxyethoxy)methyl)cyclohexane diacrylate (boiling point = 403°C, molecular weight = 340)

[0168] 8-Phenyloctane-1,2-diol diacrylate (boiling point = 404°C, molecular weight = 330)

[0169] 1,3-Bis((2-hydroxyethoxy)methyl)benzene diacrylate (boiling point = 408°C, molecular weight = 334)

[0170] 1,4-Bis((2-hydroxyethoxy)methyl)cyclohexane diacrylate (boiling point = 445°C, molecular weight = 340)

[0171] 3-Phenoxybenzyl acrylate (mPhOBzA, OP = 2.54, boiling point = 367.4°C, vapor pressure at 80°C = 0.0004 mmHg, molecular weight = 254.3)

[0172]

[0173] 1 -Naphthyl acrylate (NaA, OP = 2.27, boiling point = 317°C, vapor pressure at 80°C = 0.0422 mm Hg, molecular weight = 198)

[0174]

[0175] 2-Phenylphenoxyethyl acrylate (PhPhOEA, OP = 2.57, boiling point = 364.2°C, vapor pressure at 80°C = 0.0006 mm Hg, molecular weight = 268.3)

[0176]

[0177] 1 -Naphthyl methyl acrylate (Na1MA, OP = 2.33, boiling point = 342.1 °C, vapor pressure at 80°C = 0.042 mm Hg, molecular weight = 212.2)

[0178]

[0179] 2-Naphthyl methyl acrylate (Na2MA, OP = 2.33, boiling point = 342.1 °C, vapor pressure at 80°C = 0.042 mm Hg, molecular weight = 212.2)

[0180]

[0181] 4-Cyanobenzyl acrylate (CNBzA, OP = 2.44, boiling point = 316°C, molecular weight = 187)

[0182]

[0183] DVBzA (OP = 2.50, boiling point = 304.6°C, vapor pressure at 80°C = 0.0848 mm Hg, molecular weight = 214.3) represented by the following formula

[0184]

[0185] DPhPA (OP = 2.38, boiling point = 354.5°C, vapor pressure at 80°C = 0.0022 mm Hg, molecular weight = 266.3) represented by the following formula

[0186]

[0187] PhBzA (OP = 2.29, boiling point = 350.4°C, 80°C vapor pressure = 0.0022 mm Hg, molecular weight = 238.3) represented by the following formula

[0188]

[0189] FLMA (OP = 2.20, boiling point = 349.3°C, 80°C vapor pressure = 0.0018 mm Hg, molecular weight = 250.3) represented by the following formula

[0190]

[0191] ATMA (OP = 2.13, boiling point = 414.9°C, 80°C vapor pressure = 0.0001 mm Hg, molecular weight = 262.3) represented by the following formula

[0192]

[0193] DNaMA (OP = 2.00, boiling point = 489.4°C, 80°C vapor pressure < 0.0001 mm Hg, molecular weight = 338.4) represented by the following formula

[0194]

[0195] Tricyclodecanedimethanol diacrylate (DCPDA, OP = 3.29, boiling point = 342°C, 80°C vapor pressure < 0.0024 mm Hg, molecular weight = 304)

[0196]

[0197] p-xylylene diacrylate (mXDA, OP = 3.20, boiling point = 336°C, 80°C vapor pressure < 0.0043 mm Hg, molecular weight = 246)

[0198]

[0199] 1-phenylethane-1,2-diyl diacrylate (PhEDA, OP = 3.20, 80°C vapor pressure < 0.0057 mm Hg, boiling point = 354°C, molecular weight = 246)

[0200]

[0201] 2-phenyl-1,3-propanediol diacrylate (PhPDA, OP = 3.18, boiling point = 340°C, 80°C vapor pressure < 0.0017 mm Hg, molecular weight = 260)

[0202]

[0203] VmXDA (OP = 3.00, boiling point = 372.4°C, vapor pressure at 80°C = 0.0005 mm Hg, molecular weight = 272.3) represented by the following formula

[0204]

[0205] BPh44DA (OP = 2.63, boiling point = 444°C, vapor pressure at 80°C < 0.0001 mm Hg, molecular weight = 322.3) represented by the following formula

[0206]

[0207] BPh43DA (OP = 2.63, boiling point = 439.5°C, vapor pressure at 80°C < 0.0001 mm Hg, molecular weight = 322.3) represented by the following formula

[0208]

[0209] DPhEDA (OP = 2.63, boiling point = 410°C, vapor pressure at 80°C < 0.0001 mm Hg, molecular weight = 322.3) represented by the following formula

[0210]

[0211] BPMDA (OP = 2.68, boiling point = 465.7°C, vapor pressure at 80°C < 0.0001 mm Hg, molecular weight = 364.4) represented by the following formula

[0212]

[0213] Na13MDA (OP = 2.71, boiling point = 438.8°C, vapor pressure at 80°C < 0.0001 mm Hg, molecular weight = 296.3) represented by the following formula

[0214]

[0215] The blending ratio of the component (as) in the composition (A) is preferably 40% by mass or more and 99% by mass or less with respect to the sum of the component (as) and the sum of the component (a), the component (b) (described later), and the component (c) (described later) (i.e., the total mass of all components except for the solvent (d)). The blending ratio is more preferably 50% by mass or more and 95% by mass or less, and further preferably 60% by mass or more and 90% by mass or less. When the blending ratio of the component (as) is 40% by mass or more, the mechanical strength of the cured film of the composition increases. In addition, when the blending ratio of the component (as) is 99% by mass or less, the blending ratios of the components (b) and (c) can be increased, and properties such as a high polymerization rate can be obtained.

[0216] The component (as) in the material obtained by removing the solvent from the composition (A) preferably contains 30% by mass or more of silicon (Si) atoms. If the component (as) contains 30% by mass or more of Si atoms, the mechanical strength of the cured film of the composition is high.

[0217] The content of silicon (Si) atoms in the material obtained by removing the solvent from the composition (A) can be calculated, for example, by the following formula.

[0218] (Method for calculating the content of silicon (Si) atoms)

[0219] (weight of the component (as)) x (content of Si atoms in the component (as)) / (weight of the component (as) + weight of the component (a) + weight of the component (b) + weight of the component (c))

[0220] At least a part of the component (a) which can include various types of additive components can be a polymer having a polymerizable functional group. The polymer preferably contains at least a cyclic structure such as an aromatic structure, an aromatic heterocyclic structure, or an alicyclic structure. For example, the polymer preferably contains at least one of the structural units represented by the following formulas (3) to (8):

[0221]

[0222] In the formulas (3) to (8), the substituent R is a substituent including a partial structure each independently containing an aromatic ring, and R 1 is a hydrogen atom or a methyl group. In the present specification, in the constitutional unit represented by the formulas (3) to (8), the moiety other than R is the main chain of the specific polymer. The formula weight of the substituent R is 80 or more, preferably 100 or more, more preferably 130 or more, and further preferably 150 or more. The upper limit of the formula weight of the substituent R is practically 500 or less.

[0223] The polymer having a polymerizable functional group is generally a compound having a weight average molecular weight of 500 or more. The weight average molecular weight is preferably 1,000 or more, and more preferably 2,000 or more. The upper limit of the weight average molecular weight is not particularly limited, but is preferably, for example, 50,000 or less. When the weight average molecular weight is set to be the above lower limit or more, the boiling point can be set to be 250°C or more, further improving the mechanical properties after curing. Furthermore, it is expected that when the weight average molecular weight is set to be the above upper limit or less, the solubility to a solvent increases, and since the viscosity is not too high, the flowability immediately after the application step by spin coating is maintained, and further improvement in planarity by reflow property can be obtained. Note that the weight average molecular weight (Mw) in the present disclosure is a molecular weight measured by gel permeation chromatography (GPC), unless otherwise explicitly stated.

[0224] Specific examples of the polymerizable functional group of the polymer are a (meth)acryloyl group, an epoxy group, an oxetanyl group, a methylol group, a methylol ether group, and a vinyl ether group. From the viewpoint of ease of polymerization, a (meth)acryloyl group is particularly advantageous.

[0225] When the polymer having a polymerizable functional group is added as at least a part of component (a), the blending ratio can be freely set as long as the blending ratio falls within the viscosity prescribed range described later. For example, the blending ratio of the polymer is preferably 0.1% by mass or more and 60% by mass or less, more preferably 0.1% by mass or more and 50% by mass or less, and further preferably 0% by mass or more and 40% by mass or less, with respect to the total mass of all components except for the solvent (d). When the blending ratio of the polymer having a polymerizable functional group is set to be 0.1% by mass or more, the heat resistance, dry etching resistance, mechanical strength, and low volatility can be improved. Furthermore, when the blending ratio of the polymer having a polymerizable functional group is set to be 60% by mass or less, the blending ratio can be made to fall within the range prescribed for the upper limit of the viscosity (described later).

[0226] <component (b): polymerization initiator>

[0227] Component (b) is a polymerization initiator. In the present specification, a thermal polymerization initiator is a compound that generates the above-described polymerization factor (radical or cation) by heat or light. More specifically, examples of the polymerization initiator are a radical generator that generates a radical by heat or light, and an acid generator that generates a proton (H+) by heat or light. The radical generator is mainly used in the case where the polymerizable component (a) contains a radical polymerizable compound. On the other hand, the acid generator is mainly used in the case where the polymerizable component (a) contains a cationic polymerizable compound. As the polymerization initiator (b) according to the present disclosure, a thermal polymerization initiator (bt) and / or a photopolymerization initiator (bp) can be used.

[0228] <component (bt): thermal polymerization initiator>

[0229] Examples of the thermal radical generator are organic peroxides and azo compounds. Examples of the organic peroxides are peroxyesters such as t-hexyl peroxyisopropyl monocarbonate, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate and t-butyl peroxyisopropyl carbonate, peroxyketals such as 1,1-bis(t-hexyl peroxy) 3,3,5-trimethylcyclohexane, and diacyl peroxides such as lauryl peroxide, but the organic peroxides are not limited to these. Examples of the azo compounds are azonitriles such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile) and 1,1'-azobis(cyclohexane-1-carbonitrile), but the azo compounds are not limited to these.

[0230] Examples of the acid generator are known iodonium salts, sulfonium salts, phosphonium salts and ferrocenium salts. More specifically, diphenyl iodonium hexafluoroantimonate, diphenyl iodonium hexafluorophosphate, diphenyl iodonium hexafluoroborate, triphenyl sulfonium hexafluoroantimonate and triphenyl sulfonium hexafluoroborate can be used, but the acid generator is not limited to these.

[0231] <Component (bp): photopolymerization initiator>

[0232] Component (bp) is a photopolymerization initiator. In the present specification, the photopolymerization initiator is a compound which senses light having a predetermined wavelength and generates the polymerization factor (radical or cation) described above. More specifically, the photopolymerization initiator is a polymerization initiator which generates a radical or a cation by light (infrared light, visible light, ultraviolet light, far ultraviolet light, X-rays, a charged particle beam such as an electron beam, or a radioactive ray). Component (bp) can be formed of only one type of photopolymerization initiator, or can be formed of a plurality of types of photopolymerization initiators.

[0233] Examples of the radical generator are as follows, but the radical generator is not limited to these examples.

[0234] 2,4,5-triarylimidazole dimers which can have substituents, such as 2-(o-chlorophenyl)-4,5-diphenyl imidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl) imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenyl imidazole dimer, and 2-(o- or p-methoxyphenyl)-4,5-diphenyl imidazole dimer; benzophenone derivatives, such as benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, and 4,4'-diaminobenzophenone; α-amino aromatic ketone derivatives, such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propane-1-one; quinones, such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-benzanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraanthraquinone, 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 derivatives, such as benzyl dimethyl ketal; acridine derivatives, such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; N-phenylglycine derivatives, such as N-phenylglycine; phenylacetone derivatives, such as phenylacetone, 3-methylphenylacetone, phenylacetone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, and 2,2-dimethoxy-2-phenylacetophenone; thioxanthone derivatives, such as thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, and 2-chlorothioxanthone; acylphosphine oxide derivatives, such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; oxime ester derivatives, such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, and 1-(O-acetyloxime); and xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, and 2-hydroxy-2-methyl-1-phenylpropane-1-one.

[0235] Examples of commercially available products of the above radical generators are as follows, but the products are not limited to these examples.

[0236] Irgacure 184, 369, 651, 500, 819, 907, 784 and 2959, CGI-1700, -1750 and -1850, CG24-61, Darocur 1116 and 1173, Lucirin ® TPO, LR8893 and LR8970 (manufactured by BASF) and Ubecryl P36 (manufactured by UCB).

[0237] Among the above radical generators, component (b) is preferably an acylphosphine oxide-based polymerization initiator. Note that among the above radical generators, the acylphosphine oxide-based polymerization initiator is as follows.

[0238] An acylphosphine oxide compound such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0239] Specific examples of the photoacid generator are

[0240] An onium salt compound such as diphenyliodonium triflate, diphenyliodonium p-toluenesulfonate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium tetrafluoroborate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, 4-tert-butylphenyl diphenylsulfonium triflate, 4-tert-butylphenyl diphenylsulfonium benzene sulfonate, 4,7-di-n-butoxynaphthyl tetrahydrothiophenium triflate, 4,7-di-n-butoxynaphthyl tetrahydrothiophenium bis(trifluoromethane-sulfonyl)imide anion, 4,7-di-n-butoxynaphthyl tetrahydrothiophenium bis(nonafluorobutyl-sulfonyl)imide anion, and 4,7-di-n-butoxynaphthyl tetrahydrothiophenium tris(nonafluorobutylsulfonyl)methide;

[0241] A halogen-containing compound 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;

[0242] A sulfone compound such as 4-trityl methyl sulfone, methylbenzoylmethyl sulfone, and bis(benzenesulfonyl)methane;

[0243] A sulfonate compound such as benzoylmethyl sulfonate, pyrogallic acid tri-trifluoromethanesulfonate, o-nitrobenzyl trifluoromethanesulfonate, and o-nitrobenzyl p-toluenesulfonate;

[0244] Sulfonimide compounds such as N-(trifluoromethylsulfonyloxy)succinimide, N- (trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)-4-butyl naphthalimide, N-(trifluoromethylsulfonyloxy)-4-propylthio naphthalimide, N-(4-methylphenylsulfonyloxy)succinimide, N-(4-methylphenylsulfonyloxy)phthalimide, N-(4-methylphenylsulfonyloxy)diphenylmaleimide, N-(4-methylphenylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboxyimide, N-(4-fluorophenylsulfonyloxy)bicyclo[2.1.1]heptane-5,6-oxo-2,3-dicarboxyimide, N-(4-fluorophenylsulfonyloxy)naphthalimide, and N-(10-camphorsulfonyloxy)naphthalimide; and

[0245] Diazomethane compounds such as bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, methylsulfonyl-p-toluenesulfonyl diazomethane, cyclohexylsulfonyl-1,1-dimethylethylsulfonyl diazomethane, and bis(1,1-dimethylethylsulfonyl)diazomethane.

[0246] The blending ratio of component (b) in the composition (A) is preferably 0.1% by mass or more and 50% by mass or less, relative to the total mass of all components except for the solvent (d), that is, components (a), (b), and (component (c) to be described later). Further, the blending ratio of component (b) in the composition (A) is more preferably 0.1% by mass or more and 20% by mass or less, and further preferably 1% by mass or more and 20% by mass or less, relative to the total mass of all components except for the solvent (d). When the blending ratio of component (b) is set to 0.1% by mass or more, the curing speed of the composition increases, so the reaction efficiency can be improved. Further, when the blending ratio of component (b) is set to 50% by mass or less, a cured film having a certain degree of mechanical strength can be obtained.

[0247]

[0248] The composition (A) can contain, as component (c), a non-polymerizable compound in addition to the above-described components (a) and (b). Examples of component (c) are compounds that do not contain a polymerizable functional group such as a (meth)acryloyl group and do not have the ability to generate the aforementioned polymerization factor (radical) alone. Examples of the non-polymerizable compound are sensitizers, surfactants, polymerization inhibitors, antioxidants, polymer components, and other additives. Component (c) can contain a plurality of types of the above-described compounds.

[0249] ​The sensitizer is a compound that is appropriately added for the purpose of promoting the polymerization reaction and improving the reaction conversion rate. As the sensitizer, one type of compound can be used alone, or two or more types of compounds can be used by mixing them.

[0250] Examples of the sensitizer are sensitizing dyes. The sensitizing dye is a compound that is excited by absorbing light having a specific wavelength and has an interaction with the photopolymerization initiator as component (b).

[0251] The "interaction" mentioned here is energy transfer or electron transfer from the sensitizing dye in the excited state to the photopolymerization initiator as component (b). Specific examples of the sensitizing dye are as follows, but the sensitizing dye is not limited to these examples.

[0252] anthracene derivatives, anthraquinone derivatives, pyrene derivatives, perylene derivatives, carbazole derivatives, benzophenone derivatives, thioxanthone derivatives, xanthone derivatives, coumarin derivatives, phenothiazine derivatives, camphorquinone derivatives, acridine dyes, thioxonium salt-based dyes, merocyanine-based dyes, quinoline-based dyes, styrylquinoline-based dyes, coumarone-based dyes, thioxanthone-based dyes, xanthone-based dyes, oxonol-based dyes, cyanine-based dyes, rhodamine-based dyes, and pyridinium salt-based dyes.

[0253] <component (d): solvent>

[0254] The composition (A) includes a solvent having a boiling point of 80°C or higher and less than 250°C under normal pressure as component (d). Component (d) is a solvent that dissolves components (a), (b), and (c). Examples are alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and nitrogen-containing solvents. As component (d), one type of component can be used alone, or two or more types of components can be used by combining them. The boiling point of component (d) under normal pressure is 80°C or higher, preferably 140°C or higher, and particularly preferably 150°C or higher. The boiling point of component (d) under normal pressure is less than 250°C, and preferably 200°C or lower. If the boiling point of component (d) under normal pressure is less than 80°C, the volatilization rate in the application step described later is too high, and it is not possible to obtain a uniform film. In addition, if the boiling point of component (d) under normal pressure is 250°C or higher, it is possible that volatilization is insufficient in the baking step after the application step described later, and thus component (d) remains in the film.

[0255] Examples of the alcohol-based solvent are as follows.

[0256] Monohydric alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol, t-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-dimethylheptan-4-ol, n-decanol, sec-undecanol, trimethyl nonyl alcohol, sec-tetradecanol, sec-heptadecanol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, and cresol; and polyhydric alcohol solvents such as ethylene glycol, 1,2-propanediol, 1,3-butanediol, 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 glycerol.

[0257] Examples of ketone solvents are as follows.

[0258] Acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, diisobutyl ketone, trimethyl nonyl ketone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetylacetone, diacetone alcohol, phenylacetone, and fenthion.

[0259] Examples of ether solvents are as follows.

[0260] Ethyl ether, isopropyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, oxirane, 1,2-epoxypropane, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol diethyl ether, 2-n-butoxyethanol, 2-n-hexyloxyethanol, 2-phenoxyethanol, 2-(2-ethylbutoxy)ethanol, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraglycol 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, and 2-methyltetrahydrofuran.

[0261] Examples of ester solvents are as follows.

[0262] Diethyl carbonate, methyl acetate, ethyl acetate, amyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-amyl acetate, sec-amyl acetate, 3-methoxybutyl acetate, methylamyl 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, di... Glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, ethylene glycol diacetate, methoxytriethylene glycol acetate, ethyl propionate, n-butyl propionate, isoamyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-pentyl lactate, diethyl malonate, dimethyl phthalate, and diethyl phthalate.

[0263] Examples of nitrogen-containing solvents are as follows:

[0264] N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, and N-methylpyrrolidone.

[0265] Among the solvents mentioned above, ether-based and ester-based solvents are advantageous. Note that from the perspective of good film-forming properties, ether-based and ester-based solvents, each having a diol structure, are more advantageous.

[0266] Further advantageous examples of solvents are as follows.

[0267] Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and propylene glycol monopropyl ether acetate.

[0268] A particularly advantageous example is propylene glycol monomethyl ether acetate. Note that di(meth)acrylate of ethyl isocyanurate is also advantageous.

[0269] Preferred solvents are solvents having at least one of an ester structure, a ketone structure, a hydroxyl group, and an ether structure. More specifically, preferred solvents are solvents or mixtures of solvents selected from propylene glycol monomethyl ether acetate (boiling point = 146 °C), propylene glycol monomethyl ether, cyclohexanone, 2-heptanone, γ-butyrolactone, and ethyl lactate.

[0270] Polymerizable compounds with a boiling point above 80°C and below 250°C at atmospheric pressure can also be used as component (d). Examples of polymerizable compounds with a boiling point above 80°C and below 250°C at atmospheric pressure are as follows.

[0271] Cyclohexyl acrylate (boiling point = 198°C), benzyl acrylate (boiling point = 229°C), isobornyl acrylate (boiling point = 245°C), tetrahydrofurfuryl acrylate (boiling point = 202°C), trimethylcyclohexyl acrylate (boiling point = 232°C), isooctyl acrylate (217°C), n-octyl acrylate (boiling point = 228°C), ethoxyethoxyethyl acrylate (boiling point = 230°C), divinylbenzene (boiling point = 193°C), 1,3-diisopropenylbenzene (boiling point = 218°C), styrene (boiling point = 145°C), and α-methylstyrene (boiling point = 165°C).

[0272] The content of the solvent (d) is preferably 95 vol% or more when the entirety of the composition (A) is 100 vol%. If the content of the solvent (d) is less than 95 vol%, it is difficult to obtain a thin film in the application step by means of the spin coating method.

[0273] <When blending the composition (A)>

[0274] When the composition (A) is prepared, at least the components (as), (a), (b), and (d) are mixed and dissolved under predetermined temperature conditions. More specifically, the predetermined temperature conditions can be 0°C or higher and 100°C or lower. Note that this is equally applicable to the case where the composition (A) includes the component (c).

[0275] <Viscosity of the composition>

[0276] The composition (A) is applied in the application step by the spin coating method. Therefore, the viscosity of the composition (A) is preferably 2 mPa-s or less at 23°C. If the viscosity of the composition (A) is more than 2 mPa-s, it is difficult to obtain a thin film.

[0277] The viscosity of the material remaining after the solvent (d) of the composition (A) is volatilized, that is, the material obtained by removing the solvent (d) from the composition (A), can be, for example, 10 mPa-s or more and 1,000 mPa-s or less at 23°C. The viscosity of the material obtained by removing the solvent (d) from the composition (A) can be 10 mPa-s or more and 2,800 mPa-s or less at 23°C. The viscosity is preferably 10 mPa-s or more and 600 mPa-s or less, more preferably 10 mPa-s or more and 500 mPa-s or less. The material obtained by removing the solvent (d) from the composition (A) can also be expressed as a composition (A'). When the viscosity of the composition (A') at 23°C is set to 1,000 mPa-s or less, the reflow property by means of the flowability described later can be obtained.

[0278] <Impurities mixed in the composition (A)>

[0279] Composition (A) preferably includes as few impurities as possible. Note that impurities refer to components other than the above-mentioned components (as), (a), (b), (c), and (d). Thus, composition (A) is advantageously a composition obtained through a refining step. Such a refining step is preferably filtration using a filter.

[0280] As this filtration using a filter, it is advantageous to mix the above-mentioned components (as), (a), (b), and (c) to obtain a mixture, and to filter the mixture by using, for example, a filter having a pore diameter of 0.001 μm or more and 5.0 μm or less. When filtration is performed using a filter, it is more advantageous to perform filtration in multiple stages, or to repeatedly perform filtration a plurality of times (recycle filtration). The liquid filtered once through a filter can also be re-filtered, or filtration can be performed by using filters having different pore diameters. Examples of filters used for filtration are filters made of, for example, polyethylene resin, polypropylene resin, fluororesin, and nylon resin, but the filter is not particularly limited. Impurities such as particles mixed in composition (A) can be removed by the refining step as described above. Thus, it is possible to prevent pattern defects caused by impurities mixed in composition (A) from forming unintended unevenness in the reverse layer.

[0281] When composition (A) is used in order to manufacture a semiconductor integrated circuit, it is advantageous to avoid mixing metal atom-containing impurities (metal impurities) in composition (A) as much as possible, so as not to hinder the operation of the product. The concentration of metal impurities contained in composition (A) is preferably 10 ppm or less, more preferably 100 ppb or less.

[0282] <Initial cured film forming step>

[0283] Figures 3A-3D A schematic view of the photo-nanoimprint method used in the initial cured film forming step in the present embodiment is shown. In the photo-nanoimprint method, an initial cured film having a desired shape is formed on a substrate through about four steps. More specifically, first, a curable composition 8 is applied (supplied) to a pattern formation region on a substrate 1 (arrangement step) as shown. Next, the curable composition 8 is shaped using a mold 9 on which a pattern is formed as shown (mold contact step). Then, as shown, the curable composition 8 is irradiated with light and thus cured, thereby forming a cured film 11 (light irradiation step). Thereafter, the mold 9 is separated from the cured film 11 (mold separation step), and the cured film 11 is transferred to a transfer substrate 12 (transfer step), thereby forming a pattern on the transfer substrate 12. Figure 3A Figure 3B Figure 3C Figure 3D ​​​The mold 9 shown is separated from the cured film 11 (demolding step). Thus, by sequentially including a series of steps from the configuration step to the demolding step, a cured film 11 having a desired raised / lower pattern shape (a pattern shape consistent with the raised / lower shape of the mold 9) at the desired location can be obtained. In this embodiment, in the initial cured film formation step, a repeated unit (one shot) from the configuration step to the demolding step is performed on multiple regions on the substrate 1, thereby forming a patterned cured film 11 in multiple regions on the substrate 1.

[0284] <Reverse Process>

[0285] Figure 1 A to Figure 1 F in the diagram illustrates a known inversion process. (Refer to...) Figure 1 A to Figure 1 The F in the text describes the inversion process. Figure 1 A in the diagram illustrates the initial cured film formation steps described above. In the reverse process, as... Figure 1 In diagram A, it is schematically shown that, as the initial curing film formation step, a curing film 11 with a raised / lower pattern 2 is formed on a substrate 1. This raised / lower pattern 2 includes protrusions 12 and recesses 13. That is, the initial curing film formation step can be considered the step of forming the raised / lower pattern. Figure 1 As shown in Figure A, the portion below the raised / lower pattern 2 in the cured film 11 (the substrate portion) is called the residual film 3. The residual film 3 needs to be removed because it is unnecessary in the etching step after pattern formation, and therefore is removed in a subsequent step. As a method for forming the cured film 11 with the raised / lower pattern 2 on the substrate 1 in the initial cured film formation step, photoimprinting or photolithography can be used, for example. In this embodiment, as an example, the raised / lower pattern 2 is formed by photoimprinting, but the method is not limited to this.

[0286] As substrate 1, a silicon wafer may be used, for example. Substrate 1 may have a processing target layer on its surface alone, or other layers may be formed beneath the processing target layer. Furthermore, in addition to a silicon wafer, substrate 1 may be freely selected from those known as semiconductor device substrates, such as aluminum, titanium-tungsten alloy, aluminum-silicon alloy, aluminum-copper-silicon alloy, silicon oxide, and silicon nitride. Note that the processing target layer on the uppermost surface of substrate 1 may be treated by surface treatments such as silane coupling treatment, silazane treatment, or deposition of an organic thin film, thereby improving adhesion to the curable composition.

[0287] In the present embodiment, the curable composition is a composition containing at least a polymerizable compound and a polymerization initiator. The curable composition can 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 a sensitizer, a hydrogen donor, an internal release agent, a surfactant, an antioxidant, and a polymer component. In the present embodiment, a predetermined processing target layer is present on the substrate 1. In the initial cured film formation step, the processing target layer of the substrate 1 is subjected to processing including the disposition step to the release step using a curable composition in which the inorganic element content is 1% by weight or less, preferably free from inorganic elements such as silicon atoms. Thereby, the cured film 11 having a pattern including the protrusions 12 and the depressions 13 can be formed on the substrate 1. As the curable composition, for example, the curable composition described in Japanese Patent Laid-Open No. 2016-162862 can be used, but the curable composition is not limited thereto.

[0288] Figure 1 B in FIG. 1 is a schematic view showing the reverse layer formation step. The reverse layer formation step is performed after the initial cured film formation step. In the reverse layer formation step, the reverse layer 4 is formed on the cured film 11 having the relief pattern 2 formed. The reverse layer 4 serves as a mask, and thereby the cured film 11 is etched in the residual film etching step described later. Therefore, the reverse layer needs to have sufficient etching selectivity to the curable composition forming the cured film 11. Here, the portion of the reverse layer 4 remaining on the cured film 11 is referred to as the remaining reverse layer 5.

[0289] Figure 1 C in FIG. 1 is a schematic view showing the remaining reverse layer removal step. The remaining reverse layer removal step is performed after the reverse layer formation step. In the remaining reverse layer removal step, the remaining reverse layer 5 is removed. More specifically, the reverse layer 4 (the remaining reverse layer 5) is removed until the upper portion (the top surface 12a) of the protrusion 12 of the cured film 11 having the relief pattern 2 is exposed. Figure 1 C in FIG. 1 shows a state in which the reverse layer 4 (the remaining reverse layer 5) is removed and the top surface 12a of the protrusion 12 is exposed.

[0290] Figure 1 D in FIG. 1 is a schematic view showing the residual film etching step. The residual film etching step is performed after the remaining reverse layer removal step. In the residual film etching step, the residual film 3 of the cured film 11 is removed. In the residual film etching step, the reverse layer 4 remaining in the depression 13 of the relief pattern 2 in the remaining reverse layer removal step is used as a processing mask. Using this processing mask, etching is performed from the protrusion 12 of the relief pattern 2 also exposed in the remaining reverse layer removal step as a starting point. The etching is continued until the surface 1a of the substrate 1 (of the processing target layer) is exposed, and by this step, a pattern having a relief pattern reversed from the relief pattern 2 of the curable composition (hereinafter referred to as a reversed pattern 14) is formed on the processing target layer. Figure 1D in FIG. 6 shows a state in which the residual film 3 is etched and the reverse pattern 14 is formed on the processing target layer of the substrate 1.

[0291] Figure 1 E in FIG. 6 is a schematic diagram showing a processing target layer processing step. The processing target layer processing step is performed after the residual film etching step. In the processing target layer processing step, the reverse pattern is transferred to the processing target layer on the substrate 1. In the processing target layer processing step, the processing target layer on the substrate 1 is etched using the reverse pattern 14 formed in the residual film etching step as a mask, thereby obtaining (forming) the substrate 1 having a pattern in the processing target layer. Figure 1 E in FIG. 6 shows the substrate 1 having a pattern in the processing target layer.

[0292] Figure 2A-2D F in FIG. 6 is a schematic diagram showing a reverse pattern removing step. The reverse pattern removing step is the last step of the reverse process, which is performed after the processing target layer processing step. In the reverse pattern removing step, the reverse pattern 14 as a processing mask is removed.

[0293] In the reverse process, depending on the concavo-convex shape of the concavo-convex pattern 2 of the cured film 11 or the formation conditions of the reverse layer 4, it can be impossible to form a desired reverse pattern. This problem will be described with reference to Figures 2A-2D . Figure 2A is a schematic diagram for explaining a problem that can occur in the reverse process. Figure 2A is a schematic diagram showing the reverse layer forming step S200. For example, in the case where the concavo-convex shape of the concavo-convex pattern 2 is large, the reverse layer 4 is formed unevenly, as shown in Figure 2B , the film thickness of the reverse layer 4 formed on the convex portion 12 of the concavo-convex pattern 2 can be larger than the film thickness of the reverse layer 4 formed on the concave portion 13.

[0294] Figure 2A is a schematic diagram showing the remaining reverse layer removing step S201. The remaining reverse layer removing step S201 is performed after the reverse layer forming step S200. If the process proceeds to the remaining reverse layer removing step S201 as the next step in the state shown in Figure 2C , the cured film 11 on the bottom surface 13a of the concave portion 13 can be exposed before the remaining reverse layer 5 is completely removed to expose the top surface 12a of the convex portion 12. If the remaining reverse layer 5 is further removed to expose the top surface 12a of the convex portion 12 in this state, the cured film 11 of the concave portion 13 made of the curable composition can be damaged, as shown in Figure 2D , the remaining reverse layer removing step S202 in FIG. 6.

[0295] Further, the Figures 4A-4GAs shown in the residual film etching step S203, since the resist layer 4, which should be present as a mask in the recessed portion 13, is missing, the curable composition (cured film 11) does not remain in the portion 7 where it should remain, and the desired resist pattern cannot be formed. Since this can occur, it is preferable to form the resist layer 4 flat on the cured film 11.

[0296] The pattern forming method (pattern processing method) according to the present embodiment will be described in detail below. In summary, the pattern forming method according to the present embodiment can include: an application step of applying the above composition to a substrate on which an initial layer including a concave-convex pattern having a recessed portion and a protruding portion is formed; a reflow step of reflowing the composition after the application step; a curing step of curing the composition after the reflow step to form a resist layer; a removal step of removing an upper portion of the resist layer after the curing step to expose a top surface of the protruding portion; and an etching step of etching the initial layer using the remaining resist layer as an etching mask after the removal step, thereby forming a resist pattern.

[0297] Figure 4A is a schematic view showing the resist process according to the present embodiment. Figure 4B is a schematic view showing the initial cured film forming step S300 according to the present embodiment. The initial cured film forming step S300 according to the present embodiment is the same as the initial cured film forming step of the above resist process, and the description thereof will be omitted.

[0298] <APPLICATION STEP>

[0299] Figure 4B is a schematic view showing the application step S301 of the composition (A) according to the present embodiment. In this step, the composition (A) is applied to the cured film 11 having the concave-convex pattern 2, thereby forming the resist layer 4. More specifically, the resist layer 4 including the resist layer 4a (forming a portion of the resist layer 4 from the top to the bottom) and the resist layer 4b (forming a portion of the resist layer 4 from the bottom to the recessed portion 13) is formed by a spin coating method. At this time, if the concave-convex shape of the cured film 11 is large, there is a possibility that a height difference 15 is generated in the resist layer 4a immediately after the spin coating is completed, influenced by the concave-convex shape. Therefore, it is difficult to form a flat resist layer. As shown in Figure 4C , the resist layer 4a is likely to form a concave-convex shape.

[0300] <REFLOW STEP>

[0301] Figure 4CA schematic diagram of the reflow step S302 of the composition (A) according to the present embodiment is shown. In the present embodiment, the reflow step is performed on the inversion layer 4a immediately after the completion of the spin coating, thereby planarizing the inversion layer. That is, the inversion layer 4 according to the present embodiment is planarized by the reflow step after the formation of the inversion layer 4a, and reduces the height difference 15 of the inversion layer 4a. In the reflow step, the planarization by the reflow is started immediately after the completion of the spin coating, Figure 4D The height difference 15 of the remaining layer 5 shown in FIG. 6 can be, for example, 15 nm or less. The reflow can be performed in a room temperature environment of 23°C or can be performed in a heated environment. The temperature at which the reflow step is performed can be appropriately adjusted by the blending composition of the composition, and is generally 23°C or higher and 120°C or lower, and is preferably 50°C or higher and 100°C or lower. Note that the time at which the reflow step is performed is generally 0.1 seconds or more and 100 seconds or less, and is preferably 5 seconds or more and 60 seconds or less. Furthermore, the average thickness of the resulting film is not particularly limited, and is generally 10 nm or more and 1,000 nm or less, and is preferably 20 nm or more and 500 nm or less.

[0302] <solidification step>

[0303] Figure 4E A schematic diagram of the solidification step S303 of the inversion layer in which the height difference of the remaining layer 5 is ±15 nm or less is shown. The solidification can be performed by heating the composition (A), but the method is not limited thereto. The heating is performed, for example, at 30°C or higher and 400°C or lower, preferably at 80°C or higher and 250°C or lower, and particularly preferably at 90°C or higher and 220°C or lower. The heating time can be 10 seconds or more and 600 seconds or less. The solidification step can be performed using a known heating device such as a hot plate or an oven.

[0304] The solidification of the composition (A) can be performed by light irradiation. The irradiation light is selected according to the photosensitive wavelength of the composition (A). More specifically, the irradiation light is appropriately selected from ultraviolet rays, X-rays, and electron beams each having a wavelength of 150 nm or more and 400 nm or less. Note that the irradiation light is particularly preferably ultraviolet rays. This is because many of the commercially available compounds as the solidification aid (photopolymerization initiator) have sensitivity to ultraviolet rays.

[0305] The solidification of the composition (A) can be performed using both the solidification by heating described above and the solidification by light irradiation described above.

[0306] <remaining inversion layer removal step>

[0307] Figure 4EAn illustration showing the remaining reversal layer removing step is shown. The remaining reversal layer removing step is performed after the reversal layer forming step. In the remaining reversal layer removing step, the remaining reversal layer 5 is removed. More specifically, the reversal layer 4 (remaining reversal layer 5) is removed until the upper portion (top surface 12a) of the convex portion 12 of the cured film 11 having the relief pattern 2 is exposed. Figure 2C An illustration showing a state in which the reversal layer 4 (remaining reversal layer 5) is removed and the top surface 12a of the convex portion 12 is exposed is shown. In the present embodiment, by the reflow step described above, the height difference of the reversal layer 4 can be reduced to, for example, ± 15 nm. Therefore, as shown, the remaining reversal layer 5 can be removed without damaging the concave portion 13 of the cured film 11. Figure 4F An illustration showing a state in which the reversal layer 4 (remaining reversal layer 5) is removed and the top surface 12a of the convex portion 12 is exposed is shown. In the present embodiment, by the reflow step described above, the height difference of the reversal layer 4 can be reduced to, for example, ± 15 nm. Therefore, as shown, the remaining reversal layer 5 can be removed without damaging the concave portion 13 of the cured film 11.

[0308] The method of removing the remaining reversal layer 5 is not particularly limited, and, for example, dry etching can be used. Known dry etching apparatuses can be used for dry etching. The source gas of the dry etching is appropriately selected depending on the elemental composition of the reversal layer 4, and fluorocarbon gases such as CF4, CHF4, C2F6, C3F8, C4F8, C5F8, C4F6, CCl2F2, and CBrF3, or halogen gases such as CCl4, BCl3, PCI3, SF6, and Cl2 can be used. Note that these gases can also be used as a gas mixture.

[0309] Figure 4F An illustration showing the residual film etching step is shown. The residual film etching step is performed after the remaining reversal layer removing step. In the residual film etching step, the residual film 3 of the cured film 11 is removed. In the residual film etching step, the reversal layer 4 remaining in the concave portion 13 of the relief pattern 2 in the remaining reversal layer removing step is used as a processing mask. Using this processing mask, etching is performed from the convex portion 12 of the relief pattern 2 that is also exposed by removing the reversal layer 4 in the remaining reversal layer removing step as a starting point. The etching is continued until the surface la of the substrate 1 (of the processing target layer) is exposed, and by this step, a pattern having a relief pattern reversed from the relief pattern 2 of the curable composition (hereinafter referred to as a reversed pattern 14) is formed on the processing target layer of the substrate 1. Figure 4G An illustration showing a state in which the residual film 3 is etched and the reversed pattern 14 is formed on the processing target layer of the substrate 1 is shown.

[0310] Figure 4G An illustration showing the processing target layer processing step is shown. The processing target layer processing step is performed after the residual film etching step. In the processing target layer processing step, the reversed pattern is transferred to the processing target layer on the substrate 1. In the processing target layer processing step, the reversed pattern 14 formed in the residual film etching step is used as a processing mask, and the processing target layer on the substrate 1 is etched, thereby obtaining (forming) the substrate 1 having the processing target layer on which the pattern is formed. Figure 5A substrate 1 having a processed target layer on which a pattern is formed is shown.

[0311] Next, a reverse pattern removing step is performed. The reverse pattern removing step is the last step of the reverse process. In the reverse pattern removing step, the reverse pattern 14 serving as a processing mask is removed after the processed target layer of the substrate 1 is processed.

[0312] [Product manufacturing method]

[0313] The reverse pattern formed by the pattern forming method according to the present embodiment can be directly used as a constituent member of at least some of various products. Further, the reverse pattern is temporarily used as a processing mask for etching or ion implantation to a processed target layer on a substrate. In the processing step of the processed target layer on the substrate, the reverse pattern serving as a processing mask is removed after etching or ion implantation to the processed target layer. Thus, various products can be manufactured.

[0314] That is, the product manufacturing method can include a pattern forming step, and a processing step of processing a substrate that has undergone the pattern forming step to thereby obtain a product.

[0315] The product is, for example, a circuit element, an optical element, a MEMS, a recording element, a sensor, or a mold. Examples of the circuit element are volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensor, and FPGA. If the processed target layer is an insulating layer, it can be used as an interlayer dielectric film included in the above-described semiconductor memories or semiconductor elements.

[0316] The processed target layer having the pattern shape obtained by the initial cured film forming step to the reverse pattern removing step can be used as an optical member (or one member of an optical member), such as a diffraction grating or a polarizing plate. In a case like this, an optical element including at least a substrate and a processed target layer having a pattern shape on the substrate can be obtained. Examples of the optical element are microlens, light guide, waveguide, anti-reflection film, diffraction grating, polarizer, color filter, light emitting element, display, and solar cell.

[0317] Examples of the MEMS are DMD, microchannel, and electromechanical transducer. Examples of the recording element are optical disks such as CD and DVD, magnetic disk, magneto-optical disk, and magnetic head. Examples of the sensor are magnetic sensor, optical sensor, and gyro sensor. Examples of the mold are a mold for imprinting.

[0318] [Other embodiments]

[0319] The preferred embodiments of the present disclosure have been described above. The present disclosure is not limited to these embodiments, and various changes and modifications can be made without departing from the scope of the present disclosure. Furthermore, the embodiments can be combined.

[0320] [Embodiment]

[0321] To supplement the above-described embodiments, a more specific embodiment will be described.

[0322] [Embodiment 1]

[0323] In this embodiment, the planarization of the reversal layer 4a performed by the reflow step on the reversal layer 4a immediately after the spin coating is completed will be described using numerical calculation.

[0324] For the reversal layer 4a, a liquid film is formed by the centrifugal force of the spin coating method during the application step. The film is mainly formed by the centrifugal force. Therefore, in this numerical calculation, it is assumed that a liquid film having a uniform thickness is formed as the reversal layer 4a, independently of the concave-convex shape of the solidified film 11, and an initial liquid film distribution is formed.

[0325] In the reflow step, the reflow condition temperature is adjusted as needed, and the initial liquid film distribution is planarized by flowing on the solidified film 11 as a solid film. In this embodiment, the flow process is calculated using the Navier-Stokes equation (Equation (1)) that has been subjected to a thin film approximation (lubrication theory) in the case of a free surface. In Equation (1), h is the height of the liquid film, μ is the viscosity coefficient, and σ is the surface tension coefficient. In this embodiment, the viscosity of the reversal layer 4a is 1,000 cP, and the surface tension is 35 mN / m.

[0326] ...(1)

[0328] Figure 5 The initial liquid film distribution is shown. Figure 5 In FIG. 5, 501 indicates the solidified film 11, and 502 indicates the reversal layer 4a. Figure 5 The abscissa in FIG. 5 indicates the spatial coordinate, and the ordinate indicates the height. As shown by 501, the spatial period of the entire solidified film 11 is 8 μm, in which the period of the concave portion is 4 μm, and the period of the convex portion is 4 μm. That is, the solidified film 11 has a periodic structure. Figure 6 The left and right ends of FIG. 5 indicate a periodic boundary condition. The height of the solidified film 11 is 100 nm.

[0329] The inversion layer 4a has a uniform thickness of 65 nm. Therefore, as shown in 502, the inversion layer 4a is distributed with a uniform film thickness on 501. It can be assumed that in the actual spin coating step, the resulting shape is not a stepped discontinuous shape as shown in 502, but a more gradual distribution. By estimating the relaxation time of the discontinuous shape in 502, the upper limit of the relaxation time can be evaluated.

[0330] Figure 6 The time rate variation of the liquid film distribution is shown. Figure 6 In the diagram, 501 represents the cured film 11, and 602 represents the distribution of the reversal layer 4a at different times. For the correspondence between the curve for 602 and time, please refer to [link to relevant documentation]. Figure 7 The legend in the upper right corner shows that flattening gradually progresses over time, and the membrane becomes essentially flat after 100 seconds.

[0331] Figure 8 The time-rate variation of the height difference in the liquid film distribution is shown. The horizontal axis represents elapsed time, and the vertical axis represents the height difference of the liquid film. It was found that the time-rate variation of the height difference in inversion layer 4a, 701, reaches its maximum after approximately 0.1 seconds, then decays progressively, and the film becomes essentially flat after 100 seconds. 702 represents the line with a height difference of 5 nm. The intersection of 701 and 702 indicates that the height difference is less than 5 nm after 100 seconds.

[0332] While changing the spatial period of the cured film 11 to 4μm, 2μm, and 1μm, the same calculations as above were performed, and the elapsed time when the height difference was less than 5nm was obtained. The results are shown in... ​ The horizontal axis represents the spatial period of the cured film 11, and the vertical axis represents the elapsed time. Point 801 represents the calculated elapsed time, and the solid line 802 represents the result of the power-law fitting. The function system 802 is found to be 1.25 × 10⁻⁶. -2 × λ 4 Furthermore, the time elapsed when the height difference is less than 5 nm is proportional to the fourth power of the spatial period of the cured film 11.

[0333] Furthermore, considering that planarization typically occurs faster with lower viscosity, the above results indicate that, with a curing period of approximately 8 μm for the cured film 11, if the viscosity is below 1,000 cP, the film is planarized to a height difference of less than 5 nm within an elapsed time of less than 100 seconds. It was found that the elapsed time is proportional to the fourth power of the period.

[0334] While this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A composition for spin coating comprising: a polymerizable compound containing at least a silicon atom, and a solvent, wherein a material obtained by removing the solvent from the composition has a viscosity of 10 mPa-s or more and 1,000 mPa-s or less, and a content of silicon atoms in the material obtained by removing the solvent from the composition is 30% by mass or more.

2. The composition according to claim 1, wherein a content of the solvent in the entire composition is 95% by mass or more.

3. The composition according to claim 1, wherein the composition has a viscosity of less than 2 mPa-s at 23°C.

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

5. The composition according to claim 1, wherein a molar equivalent of a polymerizable functional group is 300 or more.

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

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

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

9. The composition according to claim 1, wherein the composition is used for forming a reversal layer.

10. A pattern forming method comprising: applying a composition defined in any one of claims 1 to 9 to a substrate on which an initial layer including a concavo-convex pattern having a concave portion and a convex portion is formed; after the application, reflowing the composition; after the reflowing, curing the composition to form a reversal layer; after the curing, removing an upper portion of the reversal layer to expose a top surface of the convex portion; and after the removing, etching the initial layer using the remaining reversal layer as an etching mask to form a reversal pattern.

11. The method according to claim 10, wherein the reflowing is performed for a time of 0.1 seconds or more and 100 seconds or less.

12. The method according to claim 10, wherein at the reflowing, the reversal layer is reflowed at a temperature of 23°C or more and 120°C or less.

13. The method according to claim 10, wherein at the curing, the reversal layer is cured at a temperature of 150°C or more and 300°C or less.

14. The method according to claim 10, wherein the curing includes irradiating the reversal layer with light.

15. An article manufacturing method comprising: performing a pattern forming method defined in claim 10; and processing a substrate that has undergone the performance of the pattern forming method, thereby obtaining an article.

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