Curable composition, inversion pattern forming method, film forming method, and article manufacturing method

Abstract

Provided is a novel technique relating to a curable composition. The curable composition contains a polymerizable compound, a photopolymerization initiator, and a solvent. The polymerizable compound contains a polymerizable silicon compound, the viscosity of the curable composition at 23 DEG C is 2-60 mPa * s, and the viscosity of the curable composition at 23 DEG C in a state in which the solvent has been removed is 30-10000 mPa * s. And the content of the solvent relative to the entire curable composition is 5-95% by volume (inclusive).

Description

Technical Field

[0001] The present invention relates to a curable composition, a reverse pattern forming method, a film forming method and an article manufacturing method. Background Art

[0002] For semiconductor devices and MEMS, the requirements for miniaturization are getting higher and higher, and as a micro-patterning technology, imprinting technology (optical imprinting technology) has received great attention as a micro-manufacturing technology. In imprinting technology, the curable composition is cured in a state where a mold with a fine concave-convex pattern formed on the surface is in contact with the curable composition supplied (applied) to the substrate. Therefore, the pattern of the mold is transferred to the cured film of the curable composition, thereby forming a pattern on the substrate. According to imprinting technology, a fine pattern (structure) of several nanometers can be formed on the substrate (see patent document 1).

[0003] Here will be described an example of a pattern forming method using an imprinting technique. First, a curable composition in liquid form is discretely dripped (arranged) in a pattern forming area on a substrate. The droplets of the curable composition arranged in the pattern forming area are expanded on the substrate. This phenomenon may be referred to as pre-expansion. Next, the mold is pressed onto the curable composition on the substrate. Therefore, the droplets of the curable composition are expanded to the entire gap area between the substrate and the mold by capillary phenomenon. This phenomenon may be referred to as expansion. Through capillary phenomenon, the curable composition fills the concave portion forming the mold pattern. This phenomenon may be referred to as filling. The time until expansion and filling are completed may be referred to as filling time. If the filling of the curable composition is completed, the curable composition is irradiated with light to cure the curable composition. Then, the mold is detached from the cured curable composition on the substrate. By performing these steps, the pattern of the mold is transferred to the curable composition on the substrate, and a pattern of the curable composition is formed.

[0004] The lithography step of manufacturing semiconductor devices requires the flattening of substrates. For example, in the extreme ultraviolet exposure technology (EUV) as a lithography technology that has attracted attention in recent years, with the advancement of miniaturization, the depth of focus of the projected image is reduced, so the concavo-convexity on the substrate surface supplied with the curable composition must be reduced to less than tens of nm. In the imprinting technology, a flatness comparable to EUV is also required to improve the filling performance and line width accuracy of the curable composition (see non-patent document 1). As a flattening technology, it is known that a technology for obtaining a flat surface in the following manner is: a droplet of a curable composition corresponding to the concavo-convexity is discretely dripped on an uneven substrate, and the curable composition is cured in a state where a mold with a flat surface is in contact with the curable composition (see patent documents 2 and 3).

[0005] However, in the conventional pattern forming method or planarization technology, if the mold is brought into contact with the liquid droplets dropped on the substrate in a state where the liquid droplets are not in contact with each other, the bubbles involved between the liquid droplets in the space between the liquid droplets and the substrate become larger. Therefore, it takes a long time for the bubbles to diffuse to the mold and / or the substrate and disappear, which may be one of the factors that reduce productivity (production volume). Citation List Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6,584,578 Patent Document 2: Japanese Patent Laid-Open No. 2019-140394 Patent Document 3: US-2020-0286740 Patent Document 4: Japanese Patent Laid-Open No. 2009-503139 Non-patent literature

[0007] Non-patent document 1: Proc. SPIE 11324-11 (2020) Summary of the invention

[0008] The present invention provides a new technology related to curable compositions.

[0009] According to one aspect of the present invention, there is provided a curable composition containing a polymerizable compound, a photopolymerization initiator and a solvent, wherein the polymerizable compound includes a polymerizable silicon compound, the viscosity of the curable composition at 23°C is greater than 2 mPa·s and less than 60 mPa·s, the viscosity of the curable composition in a state in which the solvent is removed at 23°C is greater than 30 mPa·s and less than 10000 mPa·s, and the content of the solvent relative to the entire curable composition is greater than 5 volume % and less than 95 volume %.

[0010] Other objects or further aspects of the present invention will become apparent from the following detailed description of embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Figure 1 is a view for explaining a pattern forming method (film forming method) according to an embodiment; Figure 2 is a view for explaining the flow behavior of a droplet of a curable composition in a waiting step; Figure 3 is a view showing a comparison between a contacting step in the related art and a contacting step according to the embodiment; and Figure 4 is a view used to illustrate the reversal process. DETAILED DESCRIPTION

[0012] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the scope of the appended claims. A plurality of features are described in the embodiments, but the plurality of features are not all necessary for the present invention, and the plurality of features can be arbitrarily combined. In addition, in the accompanying drawings, the same reference numerals represent the same or similar parts, and repeated descriptions will be omitted.

[0013] In order to provide a new technology regarding a curable composition, the present inventors have discovered a curable composition and process conditions thereof that can form a substantially continuous liquid film before droplets of the curable composition discretely dropped (arranged) on a substrate merge with each other and a mold contacts the curable composition.

[0014] [Curable composition] The curable composition (A) according to one embodiment may be a curable composition for inkjet. The curable composition (A) according to this embodiment is a composition containing the following components: a component (as) as a polymerizable silicon compound, a component (b) as a photopolymerization initiator, and a component (d) as a solvent. The curable composition (A) according to this embodiment may further contain at least one of a polymerizable compound (a) and a non-polymerizable compound (c) not containing a silicon (Si) atom.

[0015] In this specification, the cured film refers to a film obtained by polymerizing a curable composition on a substrate and thereby curing it. Note that the shape of the cured film is not particularly limited, and the cured film may or may not have a pattern shape on the surface.

[0016] <Component (as): Silicon-containing polymerizable compound> The silicon compound as component (as) can be understood as a silicon-containing polymerizable compound. In this specification, the silicon-containing polymerizable compound is a compound that reacts with a polymerization factor (e.g., free radical) generated by a photopolymerization initiator (component (b)) and forms a film made of a polymer compound through a chain reaction (polymerization reaction).

[0017] An example of the silicon-containing polymerizable compound is a radical polymerizable compound. The polymerizable compound as the component (as) may be formed of only one type of polymerizable compound or may be formed of a plurality of types of polymerizable compounds.

[0018] Examples of the silicon-containing radical polymerizable compound are (meth)acrylate-based compounds, (meth)acrylamide-based compounds, vinylbenzene-based compounds, aryl ether-based compounds, vinyl ether-based compounds, and maleimide-based compounds.

[0019] The silicon-containing polymerizable compound (as) can be linear or branched. As the silicon-containing polymerizable compound, for example, the following structure can be used. An example of the polymerizable functional group in the group Q having a polymerizable functional group is a free radical polymerizable functional group. Detailed examples of free radical polymerizable functional groups are (meth) acrylate compounds, (meth) acrylamide compounds, vinyl benzene compounds, aryl ether compounds, vinyl ether compounds and maleimide compounds. The group Q having a polymerizable functional group can be a group having the above-mentioned polymerizable functional groups.

[0020]

[0021] Examples of the silicon-containing polymerizable compound (as) are the silsesquioxane skeleton shown in the following formula (1) and the silicone skeleton shown in the following formula (2). Here, in formula (1), m+n=8 (8≥m≥1), and R1 is a divalent organic group. In addition, in formula (2), A, B, R2 and R3 are independently alkyl, cycloalkyl, alkoxy, phenyl or hydroxyl groups having 1 to 6 carbon atoms (t is an integer from 1 to 3), and at least one of A and B is a polymerizable functional group.

[0022]

[0023]

[0024] Examples of the polymerizable functional groups in the groups Q, A and B having a polymerizable functional group are free radical polymerizable functional groups. Detailed examples of the free radical polymerizable functional group are (meth)acrylate compounds, (meth)acrylamide compounds, vinylbenzene compounds, aryl ether compounds, vinyl ether compounds and maleimide compounds. The group Q having a polymerizable functional group may be a group having the above-mentioned polymerizable functional groups.

[0025] The silicon-containing (meth)acrylate compound is a compound having one or more acryloyl groups or methacryloyl groups. Examples of the silicon-containing monofunctional (meth)acrylate compound having one acryloyl group or methacryloyl group are as follows, but the compound is not limited to these examples. (2-Acryloylethoxy)trimethylsilane, N-(3-Acryloyl-2-hydroxypropyl)-3-aminopropyltriethoxysilane, Acryloyloxymethyltrimethoxysilane, (Acryloyloxymethyl)phenethyltrimethoxysilane, Acryloyloxymethyltrimethylsilane, (3-Acryloxypropyl)dimethylmethoxysilane, (3-Acryloxypropyl)methylbis(trimethylsiloxy)silane, (3-Acryloxypropyl)methyldichlorosilane, (3-Acryloxypropyl)methyldiethoxysilane, (3-Acryloxypropyl)methyldimethoxysilane, (3-Acryloxypropyl)trichlorosilane, (3-Acryloxypropyl)trimethoxysilane, (3-Acryloxypropyl)tris(trimethylsiloxy)silane, Acryloxytriisopropylsilane, Acryloyloxytrimethylsilane, Methacryloxymethyltrimethoxysilane, O-(methacryloyloxyethoxy)carbamoylpropylmethyldimethoxysilane, (Methacryloxymethyl)bis(trimethylsiloxy)methylsilane, N-(3-methacryloyl-2-hydroxypropyl)-3-aminopropyltriethoxysilane, (Methacryloxymethyl)methyldimethoxysilane, (Methacryloxymethyl)methyldiethoxysilane, Methacryloyloxymethylmethyltriethoxysilane, Methacryloxypropyltrimethoxysilane, Methacryloylpropyltriisopropoxysilane, O-(methacryloyloxyethyl)-N-(triethoxysilylpropyl)carbamate, methacryloxypropylmethyldimethoxysilane, Methacryloxypropylmethyldiethoxysilane, Methacryloxypropyldimethylmethoxysilane, Methacryloxypropyl dimethylethoxysilane, (Methacryloxymethyl)dimethylethoxysilane, Methacryloxypropyltriethoxysilane, Methacryloyloxypropyl silazoline, Methacryloyloxypentamethyldisiloxane, (Methacryloxymethyl)phenyldimethylsilane, Methacryloxytrimethylsilane, Methacryloxymethyltrimethylsilane, (3-methacryloyloxy-2-hydroxypropoxypropyl)methylbis(trimethylsiloxy)silane, Methacryloyloxypropyl pentamethyldisiloxane, O-(Methacryloyloxyethyl)-3-[bis(trimethylsiloxy)methylsilyl]propylcarbamate, Methacryloxymethyltris(trimethylsiloxy)silane, Methacryloyloxyethoxytrimethylsilane, (3-methacryloyloxy-2-hydroxypropoxypropyl)methylbis(trimethylsiloxy)silane, Methacryloyloxypropyltri(vinyldimethylsiloxy)silane, Methacryloxypropyltris(trimethylsiloxy)silane, 3-Methacryloyloxypropyltriacetoxysilane, Methacryloyloxypropylmethyldichlorosilane, Methacryloyloxypropyltrichlorosilane, 3-Methacryloxypropylbis(trimethylsiloxy)methylsilane, 3-Methacryloyloxypropyldimethylsilyl chloride, O-methacryloyloxy(polyethyleneoxy)trimethylsilane, Poly(methacryloxypropylsilsesquioxane), Methacryloxypropyl heptaisobutyl-T8-silsesquioxane, and Methacryloxypropyltris(trimethylsiloxy)silane

[0026] Examples of commercially available products of the above silicon-containing monofunctional (meth)acrylic compound are as follows, but the products are not limited to these examples. SIA0160.0, SIA0180.0, SIA0182.0, SIA0184.0, SIA0186.0, SIA0190.0, SIA0194.0, SIA0196.0, SIA01 97.0, SIA0198.0, SIA0199.0, SIA0200.0, SIA0200.A1, SIA0210.0, SIA0315.0, SIA0320.0, SIM6483.0, SIM6487.5, SIM6480.76, SIM6481.2, SIM6486.1, SIM6481.1, SIM6481.46, SIM6481.43, SIM6482.0, SI M6487.4, SIM6487.35, SIM6480.8, SIM6486.9, SIM6486.8, SIM6486.5, SIM6486.4, SIM6481.3, SIM6487 .3. SIM6487.1, SIM6487.6, SIM6486.14, SIM6481.48, SIM6481.5, SIM6491.0, SIM6485.6, SIM6481.15 , SIM6487.0, SIM6481.05, SIM6485.8, SIM6481.0, SIM6487.4LI, SIM6481.16, SIM6487.8, SIM6487.6HP , SIM6487.17, SIM6486.7, SIM6487.2, SIM6486.0, SIM6486.2, SIM6487.6-06, SIM6487.6-20, SIM6485.9, SST-R8C42, SLT-3R01 and SIM6486.65 (manufactured by GELEST), and TM-0701T, FM-0711, FM-0721 and FM-0725 (manufactured by JNC). The silicon-containing (meth)acrylamide-based compound is a compound having one or more acrylamide groups or methacrylamide groups. Examples of silicon-containing monofunctional (meth)acrylamide-based compounds having one acrylamide group or methacrylamide group are as follows, but the compound is not limited to these examples. 3-Acrylamidopropyltrimethoxysilane, and 3-Acrylamidopropyltris(trimethylsiloxy)silane

[0027] Examples of commercially available products of the above-mentioned silicon-containing monofunctional (meth)acrylamide compound are as follows, but the products are not limited to these examples. SIA0146.0 and SIA0150.0 (manufactured by GELEST)

[0028] Examples of the polyfunctional (meth)acrylate-based compound having two or more acryloyl groups or methacryloyl groups are as follows, but the compound is not limited to these examples. Linear polydimethylsiloxane modified with acryloyloxypropyl groups at both ends. Linear polydimethylsiloxane modified with methacryloyloxypropyl groups at both ends. Cyclic siloxane modified with multiple acryloxypropyl groups, Cyclic siloxane modified with multiple methacryloxypropyl groups, Silsesquioxane modified with multiple acryloxypropyl groups, and Silsesquioxane modified with multiple methacryloxypropyl groups

[0029] Examples of commercially available products of the above-mentioned silicon-containing multifunctional (meth)acrylate compound are as follows, but the products are not limited to these examples. SIA0200.2, SIA0200.3, SIM6487.42, DMS-R11, DMS-R05, DMS-R22, DMS-R18, DMS-R31 (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-SK SI-20 (manufactured by East Asia Synthetics)

[0030] In addition, according to known literature (for example, "Ultraviolet curable branched siloxanes as low-k dielectrics for imprint lithography" by Ogawa et al. (https: / / doi.org / 10.1116 / 1.4770051), a linear modified polydimethylsiloxane (MA-Si-12) having methacryloxypropyl groups at both ends, an 8-membered cyclic siloxane (8-ring) modified with four methacryloxypropyl groups, and a 10-membered cyclic siloxane (10-ring) modified with five methacryloxypropyl groups can be synthesized and obtained.

[0031] <Component (a): Silicon-free polymerizable compound> Component (a) contains a silicon-free polymerizable compound. In the present specification, the silicon-free polymerizable compound is a compound that reacts with a polymerization factor (eg, radical) generated by a photopolymerization initiator (component (b)) and forms a film made of a polymer compound through a chain reaction (polymerization reaction).

[0032] Examples of the above-mentioned polymerizable compound are radical polymerizable compounds. The polymerizable compound as the component (a) may be formed of only one type of polymerizable compound or may be formed of a plurality of types (one or more types) of polymerizable compounds.

[0033] Examples of the radical polymerizable compound are Si-free (meth)acrylic compounds, Si-free styrene-based compounds, Si-free vinyl-based compounds, Si-free allyl compounds, Si-free fumaric acid compounds, and Si-free maleic acid compounds.

[0034] The Si-free (meth)acrylic compound is a compound having one or more acryloyl groups or methacryloyl groups. Examples of the Si-free monofunctional (meth)acrylic compound having one acryloyl group or methacryloyl group are as follows, but the compound is not limited to these examples. 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, polyethylene oxide Nonylphenyl ether (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, bornyl (meth)acrylate, 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, propyl (meth)acrylate, isopropyl (meth)acrylate , butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth) Butoxyethyl acrylate, ethoxydiglycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, diacetone (meth)acrylamide, isobutoxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, 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 cyanobenzyl (meth)acrylate.

[0035] Examples of commercially available products of the above-mentioned Si-free monofunctional (meth)acrylic compound are as follows, but the products are not limited to these examples. M101, M102, M110, M111, M113, M117, M5700, TO-1317, M120, M150 and M156 (manufactured by East Asia Synthetics) MEDOL10, MIBDOL10, CHDOL10, MMDOL30, MEDOL30, MIBDOL30, CHDOL30, LA, IBXA, 2-MTA, HPA, and Viscoat #150, #155, #158, #190, #192, #193, #220, #2000, #2100, and #2150 (manufactured by Osaka Organic Chemical Industry) Lightweight acrylates BO-A, EC-A, DMP-A, THF-A, HOP-A, HOA-MPE, HOA-MPL, PO-A, P-200A, NP-4EA, NP-8EA, epoxy esters M-600A, POB-A, and OPP-EA (manufactured by Kyoeisha Chemical) TC110S, R-564 and R-128H (manufactured by Nippon Kayaku) NK Ester 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). Examples of the silicon-free multifunctional (meth)acrylic compound having two or more acryloyl groups or methacryloyl groups are as follows, but the compound is not limited to these examples. 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-adamantanedimethanol di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(acryloyloxy)isocyanurate, bis(hydroxymethyl)tricyclodecane di(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, EO-modified 2,2-bis(4-((meth)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, phthalic di(meth)acrylate, isophthalic di(meth)acrylate or terephthalic di(meth)acrylate, and phthalic di(meth)acrylate, isophthalic di(meth)acrylate or terephthalic di(meth)acrylate.

[0036] Examples of commercially available products of the above-mentioned Si-free polyfunctional (meth)acrylic compound are as follows, but the products are not limited to these examples. 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) Lightweight acrylates 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) PET-30, TMPTA, R-604, DPHA, DPCA-20, -30, -60 and -120, HX-620, D-310 and D-330 (manufactured by Nippon Kayaku) M208, M210, M215, M220, M240, M305, M309, M310, M315, M325 and M400 (manufactured by East Asia Synthetics) VR-77, VR-60 and VR-90 (manufactured by Showa Polymer) OGSOL EA-0200 and OGSOL EA-0300 (manufactured by Osaka Gas Chemical).

[0037] Note that in the above compounds, (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 represents ethylene oxide, and EO-modified compound A represents a compound in which the (meth)acrylic acid residue and the alcohol residue of compound A are combined through a block structure of an ethylene oxide group. In addition, PO represents propylene oxide, and PO-modified compound B represents a compound in which the (meth)acrylic acid residue and the alcohol residue of compound B are combined through a block structure of a propylene oxide group.

[0038] Actual examples of the Si-free styrene-based compound are as follows, but the compound is not limited to these examples. Alkylstyrenes, such as styrene, 2,4-dimethyl-α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 2,6-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, 2,4,6-trimethylstyrene, 2,4,5-trimethylstyrene, pentamethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, 2,4-diisopropylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene; halogenated styrenes, such as fluorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene Ethylene, dibromostyrene and iodostyrene; and compounds having a styrene group as a polymerizable functional group, such as nitrostyrene, acetylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2-vinylbiphenyl, 3-vinylbiphenyl, 4-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, 4-vinyl-p-terphenyl, 1-vinylanthracene, α-methylstyrene, o-isopropenyltoluene, m-isopropenyltoluene, p-isopropenyltoluene, 2,3-dimethyl-α-methylstyrene, 3,5-dimethyl-α-methylstyrene, p-isopropyl-α-methylstyrene, α-ethylstyrene, α-chlorostyrene, divinylbenzene, diisopropylbenzene and divinylbiphenyl.

[0039] Actual examples of the Si-free vinyl-based compound are as follows, but the compound is not limited to these examples. Vinyl pyridine, vinyl pyrrolidone, vinyl carbazole, 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 vinylidene halides, such as vinylidene chloride, vinyl esters of organic carboxylic acids and their derivatives (such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and divinyl adipate) and (meth)acrylonitrile. Note that in this specification, (meth)acrylonitrile is a general term for acrylonitrile and methacrylonitrile.

[0040] Examples of the Si-free allyl compound are as follows, but the compound is not limited to these examples. Allyl acetate, allyl benzoate, diallyl adipate, diallyl terephthalate, diallyl isophthalate and diallyl phthalate.

[0041] Examples of the Si-free fumaric acid compound are as follows, but the compound is not limited to these examples. dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, di-sec-butyl fumarate, diisobutyl fumarate, di-n-butyl fumarate, di-2-ethylhexyl fumarate and dibenzyl fumarate. Examples of the Si-free maleic acid compound are as follows, but the compound is not limited to these examples. dimethyl maleate, diethyl maleate, diisopropyl maleate, di-sec-butyl maleate, diisobutyl maleate, di-n-butyl maleate, di-2-ethylhexyl maleate and dibenzyl maleate.

[0042] Other examples of the Si-free radical polymerizable compound are as follows, but the compound is not limited to these examples. 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 maleimide and derivatives thereof (e.g., N-phenylmaleimide and N-cyclohexylmaleimide). If component (a) is formed of various types of compounds having one or more polymerizable functional groups, it is preferably composed of monofunctional compounds and polyfunctional compounds. This is because, if the monofunctional compounds and polyfunctional compounds are combined, a cured film with well-balanced properties, such as high mechanical strength, high dry etching resistance and high heat resistance, can be obtained.

[0043] The film forming method according to the present embodiment may take several milliseconds to several hundred seconds until the droplets of the curable composition (A) discretely arranged on the substrate merge with each other to form a substantially continuous liquid film, so a waiting step (described later) is required. In this waiting step, the solvent (d) volatilizes, but the polymerizable compound (a) does not volatilize. Therefore, in the polymerizable compound (a) that may contain multiple types of compounds, the boiling point of all compounds at normal pressure is preferably above 250°C, more preferably above 300°C, and further preferably above 350°C. In addition, in order to obtain high dry etching resistance and high heat resistance, the cured film of the curable composition (A) preferably contains at least a compound having a cyclic structure, such as an aromatic structure, an aromatic heterocyclic structure or an alicyclic structure.

[0044] The boiling point of the polymerizable compound (a) is almost related to the molecular weight. Therefore, the molecular weight of all polymerizable compounds (a) is preferably 200 or more, more preferably 240 or more, and further preferably 250 or more. However, even when the molecular weight is 200 or less, if the boiling point is 250° C. or more, the compound can be preferably used as the polymerizable compound (a) of the present invention.

[0045] The vapor pressure of the polymerizable compound (a) at 80° C. is preferably 0.001 mmHg or less. This is because, although heating the curable composition is advantageous in accelerating volatilization of the solvent (d) (described later), volatilization of the polymerizable compound (a) needs to be suppressed during heating.

[0046] 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.

[0047] Actual examples of the polymerizable compound (component (a)) having a boiling point of 250° C. or higher are as follows, but the compound is not limited to these examples.

[0048] Dicyclopentyl acrylate (boiling point = 262°C, molecular weight = 206) Dicyclopentenyl acrylate (boiling point = 270°C, molecular weight = 204) 1,3-Cyclohexanedimethanol diacrylate (boiling point = 310°C, molecular weight = 252) 1,4-Cyclohexanedimethanol diacrylate (boiling point = 339°C, molecular weight = 252) 4-Hexylresorcinol diacrylate (boiling point = 379°C, molecular weight = 302) 6-Phenylhexane-1,2-diol diacrylate (boiling point = 381°C, molecular weight = 302) 7-phenylheptane-1,2-diol diacrylate (boiling point = 393°C, molecular weight = 316) 1,3-Bis((2-hydroxyethoxy)methyl)cyclohexane diacrylate (boiling point = 403°C, molecular weight = 340) 8-Phenyloctane-1,2-diol diacrylate (boiling point = 404°C, molecular weight = 330) 1,3-Bis((2-hydroxyethoxy)methyl)benzene diacrylate (boiling point = 408°C, molecular weight = 334) 1,4-bis((2-hydroxyethoxy)methyl)cyclohexane diacrylate (boiling point = 445°C, molecular weight = 340) 3-Phenoxybenzyl acrylate (mPhOBzA, OP = 2.54, boiling point = 367.4 ° C, 80 ° C vapor pressure = 0.0004 mmHg, molecular weight = 254.3)

[0049]

[0050] 1-Naphthyl acrylate (NaA, OP = 2.27, boiling point = 317 ° C, 80 ° C vapor pressure = 0.0422 mmHg, molecular weight = 198)

[0051]

[0052] 2-Phenylphenoxyethyl acrylate (PhPhOEA, OP = 2.57, boiling point = 364.2 ° C, 80 ° C vapor pressure = 0.0006 mmHg, molecular weight = 268.3)

[0053]

[0054] 1-Naphthylmethyl acrylate (Na1MA, OP = 2.33, boiling point = 342.1 ° C, 80 ° C vapor pressure = 0.042 mmHg, molecular weight = 212.2)

[0055]

[0056] 2-Naphthylmethyl acrylate (Na2MA, OP = 2.33, boiling point = 342.1°C, vapor pressure at 80°C = 0.042 mmHg, molecular weight = 212.2)

[0057]

[0058] 4-Cyanobenzyl acrylate (CNBzA, OP = 2.44, boiling point = 316 ° C, molecular weight = 187)

[0059]

[0060] DVBzA represented by the following formula (OP = 2.50, boiling point = 304.6°C, vapor pressure at 80°C = 0.0848 mmHg, molecular weight = 214.3)

[0061]

[0062] DPhPA represented by the following formula (OP = 2.38, boiling point = 354.5°C, vapor pressure at 80°C = 0.0022 mmHg, molecular weight = 266.3)

[0063]

[0064] PhBzA represented by the following formula (OP = 2.29, boiling point = 350.4°C, vapor pressure at 80°C = 0.0022 mmHg, molecular weight = 238.3)

[0065]

[0066] FLMA represented by the following formula (OP = 2.20, boiling point = 349.3°C, vapor pressure at 80°C = 0.0018 mmHg, molecular weight = 250.3)

[0067]

[0068] ATMA represented by the following formula (OP = 2.13, boiling point = 414.9°C, vapor pressure at 80°C = 0.0001 mmHg, molecular weight = 262.3)

[0069]

[0070] DNaMA represented by the following formula (OP = 2.00, boiling point = 489.4°C, vapor pressure at 80°C < 0.0001 mmHg, molecular weight = 338.4)

[0071]

[0072] Tricyclodecane dimethanol diacrylate (DCPDA, OP = 3.29, boiling point = 342 ° C, 80 ° C vapor pressure <0.0024 mmHg, molecular weight = 304)

[0073]

[0074] Isophthalene diacrylate (mXDA, OP = 3.20, boiling point = 336 ° C, 80 ° C vapor pressure <0.0043 mmHg, molecular weight = 246)

[0075]

[0076] 1-Phenylethane-1,2-diyl diacrylate (PhEDA, OP = 3.20, 80°C vapor pressure < 0.0057 mmHg, boiling point = 354°C, molecular weight = 246)

[0077]

[0078] 2-Phenyl-1,3-propanediol diacrylate (PhPDA, OP = 3.18, boiling point = 340 ° C, 80 ° C vapor pressure < 0.0017 mmHg, molecular weight = 260)

[0079]

[0080] VmXDA represented by the following formula (OP = 3.00, boiling point = 372.4°C, vapor pressure at 80°C = 0.0005 mmHg, molecular weight = 272.3)

[0081]

[0082] BPh44DA represented by the following formula (OP = 2.63, boiling point = 444 ° C, 80 ° C vapor pressure < 0.0001 mmHg, molecular weight = 322.3)

[0083]

[0084] BPh43DA represented by the following formula (OP = 2.63, boiling point = 439.5 ° C, 80 ° C vapor pressure < 0.0001 mmHg, molecular weight = 322.3)

[0085]

[0086] DPhEDA represented by the following formula (OP = 2.63, boiling point = 410°C, vapor pressure at 80°C < 0.0001 mmHg, molecular weight = 322.3)

[0087]

[0088] BPMDA represented by the following formula (OP = 2.68, boiling point = 465.7°C, vapor pressure at 80°C < 0.0001 mmHg, molecular weight = 364.4)

[0089]

[0090] Na13MDA represented by the following formula (OP = 2.71, boiling point = 438.8 ° C, 80 ° C vapor pressure < 0.0001 mmHg, molecular weight = 296.3)

[0091]

[0092] Relative to the combination of component (as) and component (a), component (b) (described later) and component (c) (described later), that is, the total mass of all components except solvent (d), the mixing ratio of component (as) in curable composition (A) is preferably 40% by weight or more and 99% by weight or less. The mixing ratio is more preferably 50% by weight or more and 95% by weight or less, and further preferably 60% by weight or more and 90% by weight or less. When the mixing ratio of component (as) is 40% by weight or more, the mechanical strength of the cured film of the curable composition increases. In addition, when the mixing ratio of component (as) is 99% by weight or less, the mixing ratio of components (b) and (c) can be increased to obtain characteristics such as high photopolymerization rate.

[0093] At least a portion of component (a) which may include various types of additive components may 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 constituent units represented by the following formulae (3) to (8):

[0094]

[0095] In formulae (3) to (8), the substituents R are substituents each independently containing a partial structure containing an aromatic ring, 1 is a hydrogen atom or a methyl group. In the present specification, in the constituent units represented by formulae (3) to (8), the portion 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 actually 500 or less.

[0096] 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 1000 or more, more preferably 2000 or more. The upper limit of the weight average molecular weight is not particularly determined, but is preferably, for example, 50000 or less. When the weight average molecular weight is set above the above lower limit, the boiling point can be set above 250°C, and the mechanical properties after curing can be further improved. In addition, when the weight average molecular weight is set below the above upper limit, the solubility in the solvent increases, and the fluidity of the discretely arranged droplets is maintained because the viscosity is not too high. This makes it possible to further improve the flatness of the liquid film surface. Note that the weight average molecular weight (Mw) in the present invention is a molecular weight measured by gel permeation chromatography (GPC), unless otherwise specifically stated.

[0097] Practical examples of the polymerizable functional group of the polymer are a (meth)acryloyl group, an epoxy group, an oxetanyl group, a hydroxymethyl group, a hydroxymethyl ether group, and a vinyl ether group. From the viewpoint of ease of polymerization, a (meth)acryloyl group is particularly advantageous.

[0098] When adding a polymer with a polymerizable functional group as at least a part of component (a), the mixing ratio can be freely set as long as the mixing ratio falls within the viscosity adjustment range described later. For example, the mixing ratio of the polymer relative to the total mass of all components except the solvent (d) is preferably 0.1% by weight or more and 60% by weight or less, more preferably 1% by weight or more and 50% by weight or less, and further preferably 10% by weight or more and 40% by weight or less. When the mixing ratio of the polymer with a polymerizable functional group is set to 0.1% by weight or more, heat resistance, dry etching resistance, mechanical strength and low volatility can be improved. In addition, when the mixing ratio of the polymer with a polymerizable functional group is set to 60% by weight or less, the mixing ratio can be made to fall within the upper limit adjustment range of viscosity (described later).

[0099] <Component (b): Photopolymerization Initiator> Component (b) is a photopolymerization initiator. In this specification, a photopolymerization initiator is a compound that senses light having a predetermined wavelength and generates the polymerization factor (free radical) described above. More specifically, a photopolymerization initiator is a polymerization initiator (free radical generator) that generates free radicals by light (infrared light, visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams such as electron beams, or radiation). Component (b) may be formed of only one type of photopolymerization initiator or may be formed of multiple types of photopolymerization initiators.

[0100] Examples of the radical generator are as follows, but the radical generator is not limited to these examples. 2,4,5-triaryl imidazole dimers which may have a substituent, 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, ketone and 4,4'-diaminodiphenylphenol; α-aminoaromatic ketone derivatives, such as 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propan-1-one; quinones, such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone and 2,3-dimethylanthraquinone; benzoin ether derivatives, such as benzoin methyl ether, benzoin ethyl ether, ethers and benzoin phenyl ethers; 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; acetophenone derivatives such as acetophenone, 3-methylacetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone and 2,2-dimethoxy-2-phenylacetophenone; thioxanthone derivatives such as thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone and 2-chlorothioxanthone; acylphosphine oxide derivatives such as 2,4,6-trimethylphenylacetyl ketone; formyldiphenylphosphine 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)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]- and 1-(O-acetoxime); as well as xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one.

[0101] Examples of commercially available products of the above-mentioned radical generating agent are as follows, but the products are not limited to these examples. Irgacure 184, 369, 651, 500, 819, 907, 784 and 2959, CGI-1700, -1750 and -1850, CG24-61, Darocur 1116 and 1173, TPO, LR8893 and LR8970 (manufactured by BASF), and Ubecryl P36 (manufactured by UCB).

[0102] Among the above-mentioned radical generators, component (b) is preferably an acylphosphine oxide-based polymerization initiator. Note that among the above-mentioned radical generators, the acylphosphine oxide-based polymerization initiator is as follows. Acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0103] Relative to the sum of component (a), component (b) and component (c) (described later), i.e. the total mass of all components except solvent (d), the mixing ratio of component (b) in curable composition (A) is preferably 0.1% by weight or more and 50% by weight or less. In addition, relative to the total mass of all components except solvent (d), the mixing ratio of component (b) in curable composition (A) is more preferably 0.1% by weight or more and 20% by weight or less, further preferably 1% by weight or more and 20% by weight or less. When the mixing ratio of component (b) is set to more than 0.1% by weight, the curing rate of the composition increases, so the reaction efficiency can be improved. In addition, when the mixing ratio of component (b) is set to less than 50% by weight, a cured film with certain mechanical strength can be obtained.

[0104] <Component (c): Non-polymerizable compound> In addition to the above-mentioned components (a) and (b), the curable composition (A) may also contain a non-polymerizable compound as a component (c). An example of component (c) is a compound that does not contain a polymerizable functional group such as a (meth)acryloyl group and does not have the ability to sense light having a predetermined wavelength and generate the previously described polymerization factor (free radical). Examples of non-polymerizable compounds are sensitizers, hydrogen donors, internal mold release agents, antioxidants, polymer components, and other additives. Component (c) may contain various types of the above-mentioned compounds.

[0105] The sensitizer is a compound appropriately added in order to promote the polymerization reaction and improve the reaction conversion rate. As the sensitizer, one type of compound may be used alone, or two or more types of compounds may be used in combination.

[0106] An example of a sensitizer is a sensitizing dye. The sensitizing dye is a compound that is excited by absorbing light having a specific wavelength and interacts with the photopolymerization initiator as component (b). The "interaction" mentioned here is energy transfer or electron transfer from the sensitizing dye in an excited state to the photopolymerization initiator as component (b). Actual examples of sensitizing dyes are as follows, but the sensitizing dyes are not limited to these examples. Anthracene derivatives, anthraquinone derivatives, pyrene derivatives, perylene derivatives, carbazole derivatives, benzophenone derivatives, thioxanthone derivatives, xanthone derivatives, coumarin derivatives, phenothiazine derivatives, camphorquinone derivatives, acridine dyes, thiopyranium salt dyes, merocyanine dyes, quinoline dyes, styrylquinoline dyes, ketocoumarin dyes, thioxanthene dyes, xanthene dyes, oxonol dyes, cyanine dyes, rhodamine dyes and pyrylium salt dyes.

[0107] The hydrogen donor is a compound that reacts with the initiation radical generated by the photopolymerization initiator as component (b) or the radical at the end of the polymerization growth to generate a radical having higher reactivity. When the photopolymerization initiator as component (b) is a photo radical generator, it is preferred to add the hydrogen donor.

[0108] Actual examples of the above-mentioned hydrogen donor are as follows, but the hydrogen donor is not limited to these examples. Amine compounds such as n-butylamine, di-n-butylamine, tri-n-butylphosphine, allylthiourea, s-benzylisothiourea-p-toluenesulfinate, triethylamine, diethylaminoethyl methacrylate, triethylenetetramine, 4,4'-bis(dialkylamino)benzophenone, N,N-dimethylaminoethyl benzoate, N,N-dimethylaminoisoamyl benzoate, amyl-4-dimethylaminobenzoate, triethanolamine and N-phenylglycine; and mercapto compounds such as 2-mercapto-N-phenylbenzimidazole and mercaptopropionate.

[0109] One type of hydrogen donor may be used alone, or two or more types of hydrogen donors may be used in combination. The hydrogen donor may also function as a sensitizer.

[0110] In order to reduce the interfacial bonding force between the mold and the curable composition, that is, to reduce the demoulding force in the demoulding step (described later), an internal mold release agent can be added to the curable composition. In this specification, "inside" refers to the step of arranging the curable composition before the mold release agent is pre-added to the curable composition. As an internal mold release agent, a surfactant such as a silicon-based surfactant, a fluorine-based surfactant and a hydrocarbon-based surfactant can be used. However, in the present invention, as will be described later, the addition amount of the fluorine-based surfactant is limited. Note that the internal mold release agent according to the present invention is non-polymerizable. One type of internal mold release agent can be used alone, or two or more types of internal mold release agents can be used in combination.

[0111] The fluorine-based surfactants include the following. Polyalkylene oxide (eg polyethylene oxide or polypropylene oxide) adducts of alcohols having a perfluoroalkyl group, and polyalkylene oxide (eg polyethylene oxide or polypropylene oxide) adducts of perfluoropolyethers.

[0112] Note that the fluorine-based surfactant may have a hydroxyl group, an alkoxy group, an alkyl group, an amino group, or a thiol group in a part of the molecular structure (eg, a terminal group). One example is pentaethylene glycol mono-1H,1H,2H,2H-perfluorooctyl ether.

[0113] Commercially available products may also be used as the fluorine-based surfactant. Examples of commercially available products of the fluorine-based surfactant are as follows. F-444, TF-2066, TF-2067 and TF-2068, and DEO-15 (abbreviation) (manufactured by DIC) Fluorad FC-430 and FC-431 (manufactured by Sumitomo 3M) S-382 (manufactured by AGC); EFTOP EF-122A, 122B, 122C, EF-121, EF-126, EF-127, and MF-100 (manufactured by Tochem Products) PF-636, PF-6320, PF-656, and PF-6520 (manufactured by OMNOVA Solutions) DS-401, DS-403 and DS-451 (manufactured by Daikin) 250, 251, 222F and 208G (manufactured by NEOS).

[0114] The internal mold release agent may also be a hydrocarbon surfactant. The hydrocarbon surfactant includes an alkyl alcohol-polyalkylene oxide adduct obtained by adding an alkylene oxide having 2 to 4 carbon atoms to an alkyl alcohol having 1 to 50 carbon atoms, and polyalkylene oxide.

[0115] Examples of the alkyl alcohol-polyalkylene oxide adducts are as follows. Methanol-ethylene oxide adduct, decyl alcohol-ethylene oxide adduct, lauryl alcohol-ethylene oxide adduct, hexadecanol-ethylene oxide adduct, stearyl alcohol-ethylene oxide adduct, and stearyl alcohol-ethylene oxide / propylene oxide adduct.

[0116] Note that the terminal group of the alkyl alcohol-polyalkylene oxide adduct is not limited to a hydroxyl group, which can be produced by simply adding a polyalkylene oxide to an alkyl alcohol. The hydroxyl group may also be substituted with a polar functional group such as a carboxyl group, an amino group, a pyridyl group, a thiol group, or a silanol group, or with a hydrophobic group such as an alkyl group or an alkoxy group.

[0117] Examples of the polyalkylene oxides are as follows. Polyethylene glycol, polypropylene glycol, their mono- or dimethyl ethers, mono- or dioctyl ethers, mono- or dinonyl ethers and mono- or didecyl ethers, monoadipates, monooleates, monostearates and monosuccinates.

[0118] Commercially available products may also be used as the alkyl alcohol-polyalkylene oxide adduct. Examples of commercially available products of the alkyl alcohol-polyalkylene oxide adduct are as follows. Polyoxyethylene methyl ether (methanol ethylene oxide adduct) (BLAUNON MP-400, MP-550 and MP-1000) manufactured by Aoki Oil and Fat Industries, polyoxyethylene decyl ether (decyl alcohol ethylene oxide adduct) (FINESURF D-1303, D-1305, D-1307 and D-1310) manufactured by Aoki Oil and Fat Industries, polyoxyethylene lauryl ether (lauryl alcohol ethylene oxide adduct) (BLAUNON EL-1505) manufactured by Aoki Oil and Fat Industries, polyoxyethylene cetyl ether (cetyl alcohol ethylene oxide adduct) (BLAUNON CH-305 and CH-310) manufactured by Aoki Oil and Fat Industries, polyoxyethylene stearyl ether (stearyl alcohol ethylene oxide adduct) (BLAUNON SR-705, SR-707, SR-715, SR-720, SR-730 and SR-750), randomly polymerized polyoxyethylene polyoxypropylene stearyl ether (BLAUNON SA-50 / 501000R and SA-30 / 70 2000R) manufactured by Aoki Oil & Fats Industries, polyoxyethylene methyl ether ( A760E), polyoxyethylene alkyl ether (EMULGEN series) manufactured by Kao.

[0119] Commercially available products can also be used as polyalkylene oxides. One example is an ethylene oxide / propylene oxide copolymer (Pluronic PE6400) manufactured by BASF.

[0120] Fluorine-based surfactants show excellent demolding force reduction effects and are therefore effective as internal mold release agents. Relative to the sum of components (a), (b) and (c), i.e., the total mass of all components except the solvent (d), the mixing ratio of component (c) other than the fluorine-based surfactant in the curable composition (A) is preferably 0% by weight or more and 50% by weight or less. Relative to the total mass of all components except the solvent (d), the mixing ratio of component (c) other than the fluorine-based surfactant in the curable composition (A) is more preferably 0.1% by weight or more and 50% by weight or less, and further preferably 0.1% by weight or more and 20% by weight or less. When the mixing ratio of component (c) other than the fluorine-based surfactant is set to 50% by weight or less, a cured film with a certain mechanical strength can be obtained.

[0121] <Component (d): Solvent> The curable composition (A) contains a solvent having a boiling point of 80°C or more and less than 250°C at normal pressure as component (d). Component (d) is a solvent that dissolves components (a), (b) and (c). Examples are alcohol solvents, ketone solvents, ether 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 in combination. The boiling point of component (d) at normal pressure is 80°C or more, preferably 140°C or more, and particularly preferably 150°C or more. The boiling point of component (d) at normal pressure is lower than 250°C, preferably 200°C or less. If the boiling point of component (d) at normal pressure is lower than 80°C, the volatilization rate in the waiting step described later is too high. Therefore, component (d) may volatilize before the droplets of the curable composition (A) merge with each other, so that the droplets of the curable composition (A) may not merge with each other. Furthermore, if the boiling point of component (d) at normal pressure is 250° C. or higher, volatilization of the solvent (d) may be insufficient in the waiting step described later, and thus component (d) remains in the cured product of the curable composition (A).

[0122] Examples of the alcoholic solvents are as follows. Monoalcohol solvents, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonanol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonanol, sec-tetradecanol, sec-heptadecanol, Phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, benzyl alcohol, diacetone alcohol and cresol; and polyol solvents such as ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 1,2-hexanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol and glycerol.

[0123] Examples of ketone-based solvents are as follows. 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 nonanone, cyclohexanone, methyl cyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone and fenthion. Examples of the ether solvent are as follows. Ethyl ether, isopropyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyl dioxane, 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 monomethyl ether alcohol 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, tetraethylene glycol di-n-butyl ether, 1-n-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran and 2-methyltetrahydrofuran.

[0124] Examples of the ester-based solvents are as follows. Diethyl carbonate, methyl acetate, ethyl acetate, amyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl amyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, Diethylene glycol monoethyl ether acetate, 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, isopentyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-pentyl lactate, diethyl malonate, dimethyl phthalate and diethyl phthalate.

[0125] Examples of the nitrogen-containing solvent are as follows. N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide and N-methylpyrrolidone.

[0126] Among the above solvents, ether solvents and ester solvents are favorable. Note that, from the viewpoint of good film-forming properties, ether solvents and ester solvents each having a diol structure are more favorable. Other favorable examples of the solvent are as follows. 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.

[0127] A particularly advantageous example is propylene glycol monomethyl ether acetate. Note that (ethyl)isocyanurate di(meth)acrylate is also advantageous.

[0128] A favorable solvent is a solvent having at least one of an ester structure, a ketone structure, a hydroxyl group and an ether structure. More specifically, a favorable solvent is a solvent or a solvent mixture selected from propylene glycol monomethyl ether acetate (boiling point = 146° C.), propylene glycol monomethyl ether, cyclohexanone, 2-heptanone, γ-butyrolactone and ethyl lactate.

[0129] A polymerizable compound having a boiling point of 80° C. or higher and lower than 250° C. under normal pressure can also be used as component (d). Examples of the polymerizable compound having a boiling point of 80° C. or higher and lower than 250° C. under normal pressure are as follows. 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).

[0130] When curable composition (A) is 100% by volume as a whole, the content of solvent (d) can be more than 5% by volume and less than 95% by volume, preferably more than 15% by volume and less than 85% by volume, more preferably more than 50% by volume and less than 80% by volume. In addition, the content of solvent (d) can be more than 70% by volume and less than 95% by volume, preferably more than 70% by volume and less than 85% by volume, more preferably more than 70% by volume and less than 80% by volume. If the content of solvent (d) is less than 5% by volume, it is difficult to obtain a film after solvent (d) evaporates under the condition that a substantially continuous liquid film can be obtained. On the other hand, if the content of solvent (d) is greater than 95% by volume, even if droplets are dripped closely by inkjet method, it is difficult to obtain a thick film after solvent (d) evaporates.

[0131] <Temperature when mixing the curable composition> When preparing the curable composition (A), at least components (a), (b) and (d) are mixed and dissolved under a predetermined temperature condition. More specifically, the predetermined temperature condition may be 0° C. or higher and 100° C. or lower. Note that this also applies to the case where the curable composition (A) contains component (c).

[0132] <Viscosity of Curable Composition> In the arrangement step described later, the curable composition (A) is a liquid. This is because in the arrangement step, droplets of the curable composition (A) are discretely dropped on the substrate by an inkjet method. At 23°C, the viscosity of the curable composition (A) may be 2mPa·s or more and 60mPa·s or less, preferably 3mPa·s or more and 30mPa·s or less, and more preferably 3mPa·s or more and 15mPa·s or less. If the viscosity of the curable composition (A) is less than 2mPa·s, the ejection characteristics of the droplets using the inkjet method may be unstable. In addition, if the viscosity of the curable composition (A) is greater than 60mPa·s, it is difficult to form droplets within a preferred volume range (e.g., 1.0 to 3.0pL).

[0133] The viscosity of the curable composition (A) after the solvent (d) is completely volatilized, that is, the curable composition (A) in the state where the solvent (d) is removed at 23°C can be, for example, 30 mPa·s or more and 10000 mPa·s or less. The viscosity of the composition (A) in the state where the solvent (d) is removed at 23°C can be 90 mPa·s or more and 2000 mPa·s or less, preferably 120 mPa·s or more and 1000 mPa·s or less, and more preferably 200 mPa·s or more and 500 mPa·s or less. The composition (A) in the state where the solvent (d) is removed can also be expressed as a curable composition (A'). When the viscosity of the curable composition (A') at 23°C is set to 1000 mPa·s or less, expansion and filling are quickly completed when the curable composition (A') is brought into contact with the mold. Therefore, the use of the curable composition (A) enables the imprint process to be performed with high throughput and suppresses pattern defects caused by insufficient filling. In addition, when the viscosity of the curable composition (A') at 23°C is set to 30 mPa·s or more, unnecessary flow of droplets of the curable composition (A') can be prevented. In addition, when the curable composition (A') is brought into contact with the mold, the curable composition (A') can be suppressed from flowing out from the end of the mold.

[0134] <Surface Tension of Curable Composition> At 23 ° C, the surface tension of the curable composition (A) in the state where the solvent (component (d)) is removed can be 5mN / m or more and 70mN / m or less, preferably 7mN / m or more and 50mN / m or less, and more preferably 10mN / m or more and 40mN / m or less. In other words, at 23 ° C, the surface tension of the curable composition (A') can be 5mN / m or more and 70mN / m or less, more preferably 7mN / m or more and 50mN / m or less, and more preferably 10mN / m or more and 40mN / m or less. Note that when the surface tension is high, for example, 5mN / m or more, the capillary action is strong, so when the curable composition (A) and the mold are in contact with each other, the filling (expansion and filling) is completed in a short period of time. In addition, when the surface tension is 70mN / m or less, the cured film obtained by curing the curable composition has surface smoothness.

[0135] <Contact Angle of Curable Composition> The contact angle of the curable composition (A) in the state where the solvent (component (d)) is removed relative to the substrate surface and the mold surface is preferably 0° or more and 90° or less, particularly preferably 0° or more and 10° or less. In other words, the contact angle of the curable composition (A') relative to the substrate surface and the mold surface is preferably 0° or more and 90° or less, particularly preferably 0° or more and 10° or less. If the contact angle is greater than 90°, the capillary force acts in the negative direction (the direction in which the contact interface between the mold and the curable composition shrinks) in the mold pattern or in the gap between the substrate and the mold, and the mold will not be filled with the curable composition. When the contact angle is small, the capillary action is strong and the filling rate increases.

[0136] <Impurities Mixed in the Curable Composition> The curable composition (A) preferably contains as few impurities as possible. Note that impurities refer to components other than the above-mentioned components (as), (a), (b), (c) and (d). Therefore, the curable composition (A) is preferably a composition obtained by a refining step. Such a refining step is preferably filtration using a filter.

[0137] As this filtering 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 size of more than 0.001 μm and less than 5.0 μm. When filtering using a filter, it is further advantageous to filter in multiple stages, or to repeat filtering multiple times (circulation filtration). It is also possible to filter the liquid again after filtering through a filter, or to filter using a filter with different pore sizes. An example of a filter for filtering is a filter 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 the curable composition can be removed by the above-mentioned refining step. Therefore, it is possible to prevent the impurities mixed in the curable composition from causing pattern defects by forming unexpected concavo-convex objects on the cured film obtained after the curable composition is cured.

[0138] When using the curable composition (A) to manufacture a semiconductor integrated circuit, it is advantageous to avoid mixing impurities containing metal atoms (metal impurities) into the curable composition as much as possible to avoid hindering the operation of the product. The concentration of the metal impurities contained in the curable composition is preferably 10 ppm or less, more preferably 100 ppb or less.

[0139] [Substrate] In the present specification, a member on which droplets of the curable composition (A) are discretely dropped is described as a substrate.

[0140] The substrate is a substrate to be processed, and a silicon wafer can be used in one example. The substrate can have a layer to be processed on the surface. On the substrate, another layer can also be formed below the layer to be processed. When a quartz substrate is used as a substrate, a replica of the imprint mold can be manufactured. However, the substrate is not limited to a silicon wafer or a quartz substrate. The substrate can be freely selected from those known in semiconductor device substrates, such as aluminum, titanium tungsten alloy, aluminum silicon alloy, aluminum copper silicon alloy, silicon oxide and silicon nitride. Note that it is preferred to treat the surface of the substrate or the layer to be processed by surface treatments such as silane coupling treatment, silazane treatment or organic film deposition, so as to improve the adhesion to the curable composition (A). There is a practical example of an organic film to be deposited as a surface treatment, and the adhesive layer described in patent document 4 can be used.

[0141] [Pattern Formation Method and Film Formation Method] Will refer to Figure 1 To illustrate the pattern forming method according to the present embodiment. The cured film formed by the pattern forming method is preferably a film with a pattern of more than 1nm and less than 10mm in size, more preferably a film with a pattern of more than 10nm and less than 100μm in size. Generally, a film forming method for forming a film with a pattern (concave-convex structure) of nanometer size (more than 1nm and less than 100nm) by using light is called a photoimprinting method. A film forming method according to another embodiment forms a film of a curable composition in the space between the mold and the substrate. However, the curable composition can also be cured by other energies (for example, heat or electromagnetic waves). The film forming method can be performed as a method for forming a film with a pattern, that is, as a pattern forming method, and the film forming method can also be performed as a method for forming a film without a pattern (for example, a planarizing film), that is, as a planarizing film forming method.

[0142] The pattern forming method or film forming method may include, for example, a preparation step, an arrangement step, a waiting step, a contact step, a curing step, and a demolding step. The preparation step is a step of preparing the bottom layer. The arrangement step is a step of discretely arranging multiple droplets of the curable composition (A) on the bottom layer. The waiting step is a step of waiting until multiple droplets of the curable composition (A) merge with each other and the solvent (d) volatilizes. The contact step is a step of bringing the curable composition (A or A'), preferably the curable composition (A'), and the mold into contact with each other. The curing step is a step of curing the curable composition (A or A'), preferably the curable composition (A'). The demolding step is a step of separating the mold from the cured film of the curable composition (A or A'). The arrangement step is performed after the preparation step, the waiting step is performed after the arrangement step, the contact step is performed after the waiting step, the curing step is performed after the contact step, and the demolding step is performed after the curing step.

[0143] <Layout steps> In the layout step, if Figure 1 [1] schematically shows that a plurality of droplets of the curable composition (A) are discretely arranged on a substrate. A substrate on which a bottom layer is prepared or formed can be used as a substrate. In addition, the adhesion of the substrate surface to the curable composition (A) can be improved by surface treatment such as silane coupling treatment, silazane treatment or organic thin film deposition.

[0144] The inkjet method is particularly advantageous as a method for arranging a plurality of droplets of the curable composition (A) on a substrate. It is advantageous to arrange a plurality of droplets of the curable composition (A) densely on the substrate surface facing the region where the concave portions forming the mold pattern are densely present, and sparsely on the substrate surface facing the region where the concave portions forming the mold pattern are sparsely present. Therefore, the residual film (described later) of the cured film of the curable composition (A) formed on the substrate can be controlled so as to have a uniform thickness regardless of the sparseness and density of the mold pattern.

[0145] An index called average liquid film thickness is defined to specify the volume of the curable composition (A) to be arranged on the substrate. The average liquid film thickness is a value obtained by dividing the total volume of the curable composition (A) (excluding the solvent (d)) to be arranged in the arrangement step by the area of ​​the film forming region of the mold. The volume of the cured product or cured film of the curable composition (A) (excluding the solvent (d)) is the sum of the volumes of the individual droplets of the curable composition (A) after the solvent (d) volatilizes. According to this definition, even if the substrate surface is uneven, the average liquid film thickness can be specified regardless of the uneven state.

[0146] <Waiting Step> A waiting step is provided between the arrangement step and the contact step. Here, the value obtained by dividing the total volume of the plurality of droplets of the curable composition (A) dripped in a single pattern formation by the total area of ​​the region where the pattern is formed in the single pattern formation (pattern formation region) is defined as the average film thickness. In the waiting step, as Figure 1 As shown schematically in [2], the droplets of the curable composition (A) spread on the substrate. Therefore, the entire pattern forming area of ​​the substrate 1 is covered with the curable composition (A). Figure 1 [3] schematically shows that when the average film thickness is 130 nm or more, the droplets of the curable composition (A) merge with each other on the substrate to form a substantially continuous liquid film. This will be described later. When the average film thickness is 150 nm or more, the surface of the liquid film is flattened. This will also be described later. By placing droplets of the curable composition (A) having a volume of 1.0 pL or more at 130 droplets / mm 2By arranging at a density of 150 droplets / mm 2 By arranging at the above density, a liquid film with an average film thickness of 150 nm can be obtained.

[0147] Reference Figure 2 The flow behavior of the droplets of the curable composition (A) arranged on the substrate in the waiting step is explained. A plurality of droplets of the curable composition (A) are discretely arranged on the substrate, such as Figure 2 As shown in [1], each droplet gradually expands on the substrate, as Figure 2 As shown in [2]. Then, Figure 2 As shown in [3] of FIG. 1 , adjacent droplets of the curable composition (A) begin to merge with each other on the substrate to form a liquid film, and as shown in FIG. Figure 2 As shown in [4] in the above, a continuous liquid film is formed (the surface of the substrate is covered with the curable composition (A) and there is no exposed surface). Figure 2 The state of the curable composition (A) shown in [4] can be understood as a "substantially continuous liquid film".

[0148] In addition, if Figure 1 As shown schematically in FIG. [4], the solvent (d) contained in the liquid film volatilizes in the waiting step. Assuming that the total weight of the components other than the solvent (d) is 100 volume %, the residual amount of the solvent (d) in the liquid film after the waiting step is preferably 10 volume % or less. If the residual amount of the solvent (d) is greater than 10 volume %, the mechanical properties of the cured film will deteriorate.

[0149] In the waiting step, a baking step of heating the substrate and the curable composition (A) may be performed, or the atmosphere gas around the substrate may be ventilated to accelerate the volatilization of the solvent (d). Heating may be performed at a temperature of, for example, 30°C or more and 200°C or less, preferably 80°C or more and 150°C or less, particularly preferably 90°C or more and 110°C or less. The heating time may be 10 seconds or more and 600 seconds or less. The baking step may be performed by using a known heater (e.g., a hot plate or an oven).

[0150] The execution time of the waiting step can be, for example, in the range of 0.1 to 600 seconds, preferably in the range of 10 to 300 seconds. If the execution time of the waiting step is shorter than 0.1 seconds, the merging of the droplets of the curable composition (A) becomes insufficient, and therefore a substantially continuous liquid film may not be formed. If the waiting step exceeds 600 seconds, the productivity is reduced. Therefore, in order to suppress the reduction in productivity, the substrates completely processed in the arrangement step can also be sequentially moved to the waiting step, the waiting step is implemented in parallel to multiple substrates, and the substrates completely processed in the waiting step are sequentially moved to the contact step. Note that in the prior art, it is theoretically necessary to take several thousand seconds to tens of thousands of seconds before forming a substantially continuous liquid film. However, in practice, due to the influence of volatilization, the droplet expansion of the curable composition stagnates, and therefore a continuous liquid film cannot be formed.

[0151] When the solvent (d) evaporates in the waiting step, a substantially continuous liquid film of the composition containing components (as), (a), (b) and (c) (i.e., curable composition (A')) is left. Due to the amount of solvent (d) evaporated, the average film thickness of the substantially continuous liquid film of the curable composition (A) (i.e., curable composition (A')) from which the solvent (d) is removed is smaller than the liquid film. The entire pattern forming area of ​​the substrate is maintained to be covered by the substantially continuous liquid film of the curable composition (A').

[0152] <Contact Steps> In the contacting step, Figure 1 [5] schematically shows that the mold is brought into contact with a substantially continuous liquid film of the curable composition (A) (i.e., the curable composition (A')) from which the solvent (d) is removed. The contact step may include a step of changing the state in which the curable composition (A') and the mold are not in contact with each other to a state in which they are in contact with each other, and a step of maintaining the state in which they are in contact with each other. Therefore, the liquid of the curable composition (A') is filled into the concave portion of the fine pattern on the surface of the mold, and the filled liquid forms a liquid film filled in the fine pattern of the mold.

[0153] In the waiting step, if the solvent (d) is removed from the curable composition (A) and a substantially continuous liquid film of the curable composition (A') is formed, the volume of gas entrapped between the mold and the substrate becomes small. Therefore, the spreading of the curable composition (A') in the contacting step can be completed quickly. Figure 3 A comparison (difference) between the contact step in the related art disclosed in Patent Document 1 and the like and the contact step according to the present embodiment is shown.

[0154] When the expansion and filling of the curable composition (A') are completed quickly in the contact step, the time (the time required for the contact step) for maintaining the state in which the mold is in contact with the curable composition (A') can be shortened. Since shortening the time required for the contact step will shorten the time required for pattern formation (film formation), productivity is improved. The execution time of the contact step is preferably 0.1 seconds or more and 3 seconds or less, and particularly preferably 0.1 seconds or more and 1 second or less. If the contact step is shorter than 0.1 seconds, expansion and filling become insufficient, and therefore many defects referred to as incomplete filling defects tend to occur.

[0155] When the curing step includes a light irradiation step, it is preferred to use a mold made of a light-transmitting material as the mold. Favorable examples of materials for forming the mold are glass, quartz, PMMA, light-transmitting resins (such as polycarbonate resins), transparent metal deposition films, soft films (such as polydimethylsiloxane), photocurable films, and metal films. Note that when a light-transmitting resin is used as a material for forming the mold, it is preferred to select a resin that is insoluble in the components contained in the curable composition. Quartz is suitable as a material for forming the mold because it has a small thermal expansion coefficient and small pattern distortion.

[0156] The height of the pattern formed on the mold surface can be, for example, more than 4nm and less than 200nm.Along with the pattern height of the mold reducing, it is possible to reduce the force of the mold being separated from the cured film of the curable composition, i.e. the demoulding force in the demoulding step, which makes it possible to reduce the quantity of the demoulding defects remaining in the mold due to the pattern of the curable composition being torn off. In addition, in some cases, the pattern of the curable composition is elastically deformed due to the impact during demoulding, and adjacent pattern elements contact each other and adhere to each other or destroy each other. In order to avoid these inconveniences, it is advantageous to make the height of the pattern element be less than about twice the width of the pattern element (making the aspect ratio be less than 2). On the other hand, if the height of the pattern element is too small, the processing accuracy of the substrate can be reduced.

[0157] In order to improve the releasability of the mold relative to the curable composition (A), the mold may also be subjected to a surface treatment before the contacting step. An example of such a surface treatment is to form a release agent layer by coating the mold surface with a release agent. Examples of release agents applied to the mold surface are silicone release agents, fluorine release agents, hydrocarbon release agents, polyethylene release agents, polypropylene release agents, paraffin release agents, montane release agents, and palm wax release agents. Commercially available coating release agents, such as those manufactured by Daikin, may also be appropriately used. DSX. Note that one type of releasing agent may be used alone, or two or more types of releasing agents may be used together. Among the above-mentioned releasing agents, fluorine-based and hydrocarbon-based releasing agents are particularly advantageous.

[0158] In the contacting step, when the mold is brought into contact with the curable composition (A), the pressure applied to the curable composition (A) is not particularly limited, and is, for example, 0 MPa to 100 MPa. Note that when the mold is brought into contact with the curable composition (A), the pressure applied to the curable composition (A) is preferably 0 MPa to 50 MPa, more preferably 0 MPa to 30 MPa, and further preferably 0 MPa to 20 MPa.

[0159] The contact step can be carried out in any of a normal air atmosphere, a reduced pressure atmosphere, and an inert gas atmosphere. However, a reduced pressure atmosphere or an inert gas atmosphere is advantageous because the effects of oxygen or water on the curing reaction can be prevented. Actual examples of inert gases used when the contact step is carried out in an inert gas atmosphere are nitrogen, carbon dioxide, helium, argon, various freon gases, and gas mixtures thereof. When the contact step is carried out in a specific gas atmosphere including a normal air atmosphere, a favorable pressure is 0.0001 atm or more and 10 atm or less.

[0160] <Curing Step> During the curing step, Figure 1 [6] schematically shows that the curable composition (A') is cured by irradiating with irradiation light as curing energy to form a cured film. In the curing step, for example, the curable composition (A) is irradiated with irradiation light through the mold. More specifically, the curable composition (A) filled in the fine pattern of the mold is irradiated with irradiation light through the mold. Therefore, the curable composition (A) filled in the fine pattern of the mold is cured, and a cured film having the pattern is formed.

[0161] The irradiation light is selected according to the sensitivity wavelength of the curable composition (A). More specifically, the irradiation light is appropriately selected from ultraviolet light, X-rays and electron beams, each of which has a wavelength of more than 150nm and less than 400nm. Note that the irradiation light is particularly preferably ultraviolet light. This is because many commercially available compounds as curing aids are sensitive to ultraviolet light. Examples of light sources that emit ultraviolet light are high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, deep ultraviolet lamps, carbon arc lamps, metal halide lamps, xenon lamps, KrF excimer lasers, ArF excimer lasers and F2 lasers. Note that ultra-high-pressure mercury lamps are particularly advantageous as light sources that emit ultraviolet light. One light source or multiple light sources can be used. Light can be emitted to the entire area of ​​the curable composition (A) filled in the fine pattern of the mold, or only to a portion of its area (by limiting the area). It is also possible to emit light to the entire area of ​​the substrate intermittently for multiple times, or to continuously emit light to the entire area of ​​the substrate. Furthermore, in the second irradiation process, a first region of the substrate may be irradiated with light, and a second region different from the first region of the substrate may be irradiated with light in the second irradiation process.

[0162] <Demolding Step> In the demoulding step, Figure 1 [7] schematically shows that the mold is detached from the cured film. When the mold is detached from the cured film having a pattern, a cured film having a pattern formed by inverting the fine pattern of the mold is obtained in an independent state. In this state, the cured film remains in the concave portion of the cured film having the pattern. This film is called a residual film.

[0163] The method of demoulding from the cured film having a pattern may be any method as long as the method does not physically damage the portion of the cured film having a pattern during demoulding, and various conditions and the like are not particularly limited. For example, the substrate may be fixed and the mold may be moved away from the substrate. The mold may also be fixed and the substrate may be moved away from the mold. In addition, the mold may be detached from the cured film having a pattern by moving both the mold and the substrate in completely opposite directions.

[0164] <repeat> A series of steps (manufacturing process) from the above-mentioned arrangement step to the demolding step makes it possible to obtain a cured film having a desired concavo-convex pattern shape (a pattern shape conforming to the concavo-convex shape of the mold) at a desired position.

[0165] In the above-described pattern forming method, the repetition unit (shot) from the arrangement step to the demolding step can be repeatedly performed a plurality of times on the same substrate, and thus a cured film having a plurality of desired patterns at desired positions on the substrate can be obtained.

[0166] [Planarization Film Formation Method] The following describes an example of applying the film forming method to a planarized film forming method. The planarized film forming method may include, for example, an arrangement step, a waiting step, a contact step, a curing step, and a demoulding step. The arrangement step is a step of arranging droplets of a curable composition (A) on a substrate. The waiting step may be a step of waiting until the droplets of the curable composition (A) merge with each other and the solvent (d) volatilizes. The contact step is a step of contacting the curable composition (A or A'), preferably the curable composition (A') with the mold. The curing step is a step of curing the curable composition (A or A'), preferably the curable composition (A'). The demoulding step is a step of separating the mold from the cured film of the curable composition (A or A'). In the planarized film forming method, a substrate having a height difference of about 10 to 1000nm of concavity and convexity is used as a substrate, a mold having a flat surface is used as a mold, and a cured film having a surface consistent with the flat surface of the mold is formed by a contact step, a curing step, and a demoulding step. In the arrangement step, the droplets of the curable composition (A) are densely arranged in the concave portion of the substrate and sparsely arranged on the convex portion of the substrate. The arrangement step is followed by a waiting step, followed by a contacting step, followed by a curing step, and followed by a demolding step.

[0167] [Item Manufacturing Method] The cured film with a pattern or the film formed by the pattern forming method or the film forming method can be directly used as at least part of the components of various articles. Alternatively, the cured film with a pattern formed by the pattern forming method can be temporarily used as a mask for etching or ion implantation of a substrate (a layer to be processed when the substrate has a layer to be processed). After etching or ion implantation in the substrate processing step, the mask is removed. Therefore, various articles can be manufactured.

[0168] When the cured product in the concave portion of the pattern of the cured product is removed by etching, the implementation method is not particularly limited, and conventionally known methods, such as dry etching, can be used. Conventionally known dry etching equipment can be used in this dry etching. The source gas for dry etching is appropriately selected according to the elemental composition of the cured product to be etched, and halogen-containing gases such as CF4, C2F6, C3F8, CCl2F2, CCl4, CBrF3, BCl3, PCl3, SF6 and Cl2 can be used. As the source gas, gases containing oxygen atoms such as O2, CO and CO2, inert gases such as He, N2 and Ar, and gases such as H2 and NH3 can also be used. Note that these gases can also be used in the form of gas mixtures. In this case, the photocured film needs to have high dry etching resistance so that the base substrate can be processed with high yield.

[0169] In the process of processing base substrate according to the present embodiment, the cured film of curable composition can be used as an etching mask. The curable composition from which the solvent is removed preferably contains more than 20% by weight of silicon atoms. In this case, the cured film of the curable composition can show excellent dry etching resistance for the gas of processing base substrate. The curable composition from which the solvent is removed more preferably contains more than 22% by weight of silicon atoms, and further preferably contains more than 23% by weight of silicon atoms. In an example, the silicon atom content in the curable composition from which the solvent is removed can be less than 36% by weight, but the present invention is not limited thereto. For example, if the uppermost surface of the base substrate is made of chromium (Cr), a halogen gas such as Cl2 can be used as an etching gas.

[0170] The Si atom content in the curable composition from which the solvent has been removed can be calculated, for example, by the following formula. (Calculation method of Si atom content) (Weight of component (as))×(Si atom content in component (as)) / (Weight of component (as)+Weight of component (a)+Weight of component (b)+Weight of component (c))

[0171] If the glass transition temperature of the curable composition is much higher than the temperature during demolding, the cured product exhibits a strong glass state, i.e., high mechanical strength, during demolding. Therefore, pattern collapse or damage caused by the impact of demolding hardly occurs. Therefore, when the demolding step is performed at room temperature, the glass transition temperature of the cured product is preferably 70°C or more, more preferably 100°C or more, and particularly preferably 150°C or more.

[0172] The glass transition temperature of the cured product can be measured using differential scanning calorimetry (DSC) or a dynamic viscoelasticity measuring device. For example, in the case of using DSC, a line obtained by extending the baseline of the DSC curve on the low temperature side (the portion of the DSC curve in the temperature region where neither transformation nor reaction occurs in the specimen) to the high temperature side, and a tangent drawn at the point where the gradient of the curve of the gradually changing portion of the glass transition is the largest. The extrapolated glass transition starting temperature (Tig) is obtained by the intersection of the straight line and the tangent, which can be obtained as the glass transition temperature. STA-6000 (manufactured by Perkin-Eimer) and the like can be used as the main equipment. On the other hand, in the case of using a dynamic viscoelasticity measuring device, the temperature at which the loss tangent (tan δ) of the photocured product is the largest is defined as the glass transition temperature. MCR301 (manufactured by Anton Paar) and the like can be used as the main equipment capable of measuring dynamic viscoelasticity.

[0173] Articles are, for example, circuit elements, optical elements, MEMS, recording elements, sensors or molds. Examples of circuit elements are volatile or non-volatile semiconductor memories, such as DRAM, SRAM, flash memory and MRAM, and semiconductor elements, such as LSI, CCD, image sensors and FPGA. Examples of optical elements are microlenses, light guides, waveguides, anti-reflection films, diffraction gratings, polarizers, color filters, light emitting elements, displays and solar cells. Examples of MEMS are DMDs, microchannels and electromechanical transducers. Examples of recording elements are optical disks (such as CDs and DVDs), magnetic disks, magneto-optical disks and magnetic heads. Examples of sensors are magnetic sensors, optical sensors and gyro sensors. Examples of molds are molds for imprinting.

[0174] In addition, a known photolithography step, such as imprint lithography or extreme ultraviolet exposure technology (EUV), can be performed on the planarization film formed by the planarization film forming method. A spin-on glass (SOG) film and / or a silicon oxide layer can also be stacked, and a photolithography step can be performed by applying a curable composition thereon. Therefore, a device such as a semiconductor device can be manufactured. An apparatus including the device can also be formed, such as an electronic device such as a display, a camera or a medical device. The example of the device is LSI, system LSI, DRAM, SDRAM, RDRAM, D-RDRAM and NAND flash memory.

[0175] [Reversal process] The curable composition (A) can be used in a reverse process (reverse pattern forming method) for forming a reverse pattern. The reverse process may include the following steps. A reverse pattern forming step of arranging a curable composition (A) to fill the concave portions of the first film having a pattern including concave portions and convex portions, and curing the curable composition to form a second film including a reverse layer filled in the concave portions. An excess inversion layer removal step of removing a portion of the second film (excess inversion layer) to expose the convex portion. An etching step of patterning (etching) the first film using the inversion layer remaining in the recessed portion as a mask, thereby forming a reverse pattern formed of the patterned first film. The inversion process is advantageous in the processing of the layer to be processed. When the layer to be processed is processed, a first film having a pattern including concave portions and convex portions is formed on the layer to be processed, and then a reverse pattern is formed, and the layer to be processed is etched using the reverse pattern as a mask, thereby processing the layer to be processed. Therefore, the inversion process of processing the layer to be processed may include the following steps. A pattern forming step of forming a first film having a pattern including concave portions and convex portions on the layer to be processed. A reversal layer forming step of arranging a curable composition (A) to fill the concave portions of the first film having a pattern including concave portions and convex portions, and curing the curable composition to form a second film including a reversal layer filled in the concave portions. An excess inversion layer removal step of removing a portion of the second film (excess inversion layer) to expose the convex portion. An etching step of patterning (etching) the first film using the inversion layer remaining in the recessed portion as a mask, thereby forming a reverse pattern formed of the patterned first film. A processing step of processing the layer to be processed using the inversion layer as a mask. The following will refer to Figure 4 An example of a reverse process for processing the layer to be processed is described in detail.

[0176] <Pattern Formation Step> In the pattern forming step, the processing from the arrangement step to the demolding step in the above-mentioned pattern forming method is performed on the layer to be processed 10 using a curable composition (B) that does not contain an inorganic element such as a silicon atom, thereby forming a cured film 20 that is a first film having a pattern including concave portions 21 and convex portions 22. As the curable composition (B), for example, a curable composition described in Japanese Patent Laid-Open No. 2016-162862 can be used, but the present invention is not limited thereto.

[0177] <Inversion layer formation step> In the inversion layer forming step, a curable composition (A) is arranged on a cured film 20, which is a first film having a pattern including a concave portion 21 and a convex portion 22, to fill the inversion layer 21, and the curable composition (A) is cured, thereby forming a second film 30 including the inversion layer 21 filled in the concave portion 21. In addition to the inversion layer 21, the second film 30 may also include an excess inversion layer 32. The curing of the curable composition (A) can be performed by, for example, irradiating the curable composition (A) with light (serving as curing energy) or heating the curable composition (A). The light serving as curing energy can be appropriately selected from, for example, ultraviolet light, X-rays, or electron beams having a wavelength of 150 nm or more and 400 nm or less, particularly preferably ultraviolet light. Heating is performed at a temperature of, for example, 30° C. or more and 400° C. or less, preferably 80° C. or more and 250° C. or less, particularly preferably 90° C. or more and 220° C. or less. The heating time can be 10 seconds or more and 600 seconds or less. The baking step may be performed using known heating means, such as a hot plate or an oven.

[0178] <Excess inversion layer removal step> As described above, in the inversion layer forming step, the excess inversion layer 32 can be formed as a part of the inversion layer 30 even on the convex portion 22 of the cured film 20 as the first film. In the inversion layer forming step, the excess inversion layer 32 as a part of the second film 30 is removed to expose the convex portion 22.

[0179] The method for removing the excess inversion layer 32 is not particularly limited, and for example, dry etching may be used. A known dry etching apparatus may be used for dry etching. The source gas for dry etching is appropriately selected according to the elemental composition of the inversion layer, and fluorocarbon gases such as CF4, CHF4, C2F6, C3F8, C4F8, C5F8, C4F6, CCl2F2, and CBrF3, or halogen gases such as CCl4, BCl3, PCl3, SF6, and Cl2 may be used. Note that these gases may also be used as a gas mixture.

[0180] <Etching Step> In the etching step, the cured film 20 as the first film is patterned (etched) using the reverse layer 31 remaining in the recess 21 as a processing mask, thereby forming a reverse pattern 23 formed of the patterned cured film 20. The etching step may be continued, for example, until the surface of the substrate 10 to be processed is exposed. If an intermediate transfer layer (C) not containing an inorganic element such as silicon atoms, such as spin-on carbon (SOC), is formed between the surface of the substrate 10 to be processed and the cured film 20 as the first film, the intermediate transfer layer may also be etched.

[0181] With the above steps, a reverse pattern 23 can be formed in which the concave and convex portions of the cured film 20 as the first film are reversed. The detailed method of etching is not particularly limited, and for example, dry etching can be used. A known dry etching device can be used for dry etching. The source gas for dry etching is appropriately selected according to the element composition of the cured film 20, and a gas containing oxygen atoms such as O2, CO and CO2, an inert gas such as He, N2 and Ar, or a gas such as N2, H2 and NH3 can be used. Note that these gases can also be used as a gas mixture.

[0182] The inversion layer 31 made of the curable composition (A) as a silicon-containing polymerizable compound exhibits high resistance to plasma formed using the above-mentioned gas. However, the cured film 20 and the intermediate transfer layer (C) not containing silicon atoms have low plasma resistance. Therefore, the reverse pattern 23 can be easily formed in which the pattern of the cured film 20 before the inversion layer formation step is reversed.

[0183] <Processing steps> In the processing step, the reverse pattern 23 is used as a processing mask to etch the layer to be processed of the substrate 10 to be processed, thereby processing the layer to be processed. Alternatively, in the processing step, ion implantation can be performed on the layer to be processed using the reverse pattern 23 as a processing mask. The etching of the layer to be processed can be performed under the same conditions as the etching of the excess reverse layer described above, or can be performed under different conditions suitable for etching the layer to be processed. After the processing of the layer to be processed, the reverse pattern 23 as a processing mask can be removed.

[0184] [Example] More practical examples will be described to supplement the above-described embodiments.

[0185] <Conditions for obtaining a substantially continuous liquid film> A plurality of droplets of a curable composition (A) having a surface tension of 33mN / m, a viscosity of 30mPa·s and a volume of 1pL are dripped (arranged) on a flat substrate in a square array at predetermined intervals. The behavior of each droplet of the curable composition (A) extending on the substrate is calculated by numerical calculation based on the Navier-Stokes equation, which undergoes a thin film approximation method (lubrication theory) using a free surface. The following table 1 shows the liquid film thickness of the central part of the dripping position (the thickest part of the liquid film on the substrate) and the liquid film thickness of the central part of the square formed by four droplets arranged in a square (the thinnest part of the liquid film on the substrate) after 300 seconds of dripping from the droplet of the curable composition (A). Note that it is assumed that the contact angle of the droplet of the curable composition (A) relative to the substrate is 0°, and the volatilization of the solvent (d) during 300 seconds from the dripping of the droplet of the curable composition (A) can be ignored.

[0186] Table 1

[0187] Referring to Table 1, in Examples 1 to 5 where the average film thickness was 130 nm or more, it was found that the entire area of ​​the substrate was covered with the curable composition (A). In addition, in Examples 1 to 3 where the average film thickness was 150 nm or more, it was found that a flat liquid film was formed in which the difference between the thickness of the thickest part and the thickness of the thinnest part was substantially 0 nm.

[0188] <Controllability test of average film thickness> The droplet volume and the array spacing of the curable composition (A) can be changed, but as mentioned above, even in the area where the liquid film thickness is the smallest, the liquid film thickness before the solvent (d) evaporates is 130nm. Calculate the thickness of the liquid film remaining after the solvent (d) evaporates from the state of obtaining a substantially continuous liquid film. Assuming that the minimum array spacing of the droplets of the curable composition (A) dropped onto the substrate is 35μm, calculate the maximum thickness before contact with the mold. As mentioned above, the minimum value of the liquid film thickness before the solvent (d) evaporates to obtain a substantially continuous liquid film is calculated to be 130nm. Therefore, the minimum value of the liquid film thickness before contact with the mold can be calculated by the main component concentration (volume %) × 130nm. Here, the main component concentration (volume %) is the value obtained by subtracting the volume % of the solvent (d) from 100 volume %. The case where the droplet volume of the curable composition (A) was 1.0 pL is shown in Table 2 below, and the case where the droplet volume of the curable composition (A) was 3.0 pL is shown in Table 3 below.

[0189] Table 2 Average residual film thickness in the case where the droplet volume of the curable composition (A) is 1.0 pL Example 6 Example 7 Example 8 Example 9 Example 10 Embodiment 11 Main component concentration (volume %) 5 10 15 20 25 30 Maximum film thickness (nm) 41 82 122 163 205 245 Minimum film thickness (nm) 7 13 20 26 33 39

[0190] Table 3 Average residual film thickness in the case where the droplet volume of the curable composition (A) is 3.0 pL Example 6 Example 7 Example 8 Example 9 Example 10 Embodiment 11 Main component concentration (volume %) 5 10 15 20 25 30 Maximum film thickness (nm) 123 245 366 490 615 735 Minimum film thickness (nm) 7 13 20 26 33 39

[0191] In one example, in the photolithography step for manufacturing semiconductor devices, the film thickness required for the pattern forming method and the planarized film forming method is 30 nm or more and 200 nm or less. As shown in Tables 2 and 3, if the main component concentration is 10% by volume or more, a thick film with a thickness of 200 nm or more can be obtained. If the main component concentration is 20% by volume or less, a film with a thickness of 30 nm or less can be formed. Therefore, it is particularly preferred that the main component concentration of the curable composition (A) is 10% by volume or more and 20% by volume or less, that is, the content of the solvent (d) is 80% by volume or more and 90% by volume or less. On the other hand, if the film thickness is 200 nm or more, the content of the solvent (d) can be 5% by volume or more and 80% by volume or less. Therefore, according to the application purpose, the content of the solvent (d) of the present invention can be adjusted within the range of 5% by volume or more and 90% by volume or less.

[0192] <Evaluation of inkjet ejection and filling properties> According to the following Table 4, the curable composition (A) was mixed so that the total weight of the components (as), (a), (b) and (d) was 100 wt%. In addition, the viscosity of the curable composition (A) and the curable composition (A) mixed without the component (d) was measured at 23°C. The Si atom content and Tg after curing of the curable composition when the component (d) was removed were calculated and measured by the above method, and the results are shown in Table 5. The abbreviations in Table 4 are as follows.

[0193] "ingredient(s)" SIM6487.6: AC-SQ TA-100: Silsesquioxane derivative with acrylate groups (manufactured by East Asia Synthetics) MAC-SQ TM-100: Silsesquioxane derivative with methacrylate groups (manufactured by East Asia Synthetic) AC-SQ SI-20: Silsesquioxane derivative with acrylate groups (manufactured by East Asia Synthetics) MAC-SQ SI-20: Silsesquioxane derivative with methacrylate groups (manufactured by East Asia Synthetic) MA-Si-12: Methacrylate-introduced linear dimethylsiloxane derivative (synthetic product) 8-Ring: Cyclic siloxane derivative introduced by acrylate (synthetic product) 10-Ring: Cyclic siloxane derivative introduced by acrylate (synthetic product)

[0194] "ingredient (a)" Viscoat #150: Tetrahydrofurfuryl acrylate (manufactured by Osaka Organic Chemical Industry) Viscoat #160: Benzyl acrylate (manufactured by Osaka Organic Chemical Industry) Viscoat #200: Cyclic trimethylolpropane formal acrylate (manufactured by Osaka Organic Chemical Industry) Viscoat#295: Trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry) DCP-A: Dihydroxymethyl tricyclodecane diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.)

[0195] “ingredient (b)” Omnirad 819: Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (manufactured by IGM Resin)

[0196] “ingredient (d)” PGMEA: Propylene glycol monomethyl ether acetate (manufactured by Kanto Chemical) DEG: Diethylene glycol (manufactured by Kishida Chemical) NMP: N-methylpyrrolidone (manufactured by Kishida Chemical) <Evaluation of inkjet ejection> For the inkjet ejection evaluation, a commercially available industrial materials printer DMP-2850 (manufactured by Fujifilm) was used. Examples 12 to 32 and Comparative Examples 4 to 8 obtained in Table 4 were filled into a 1-pL ink cartridge, the ejection state was observed by an internal ejection observation camera, and evaluated based on the following criteria.

[0197] (Evaluation Criteria) AAA: At flight speeds above 11 m / s, no distortion was observed at all. AA: At flight speeds above 11 m / s, very slight distortion of no practical effect is observed. A: At flight speeds above 10 m / s, very slight distortion of no practical effect is observed. B: Ejection not performed.

[0198] <Evaluation of filling properties> Under the condition that the liquid film thickness before the solvent (d) evaporates is 130 nm, each curable composition (A) of Examples 12 to 32 and Comparative Examples 4 to 8 is discretely dropped (arranged) on a silicon substrate, the time taken to form a substantially continuous liquid film is measured, and the filling property is evaluated based on the following judgment criteria.

[0199] (Evaluation Criteria) AAA: A substantially continuous liquid film is formed in less than 100 seconds. AA: A substantially continuous liquid film is formed within a time period of 100 seconds or more and less than 200 seconds. A: A substantially continuous liquid film is formed within 200 seconds or more and less than 300 seconds. B: Even after a lapse of 300 seconds, a substantially continuous liquid film was not formed.

[0200] <Evaluation of pattern collapse> Based on the following determination criteria, patterns obtained by performing a layout step, a waiting step, a contact step, a curing step and a demolding step on the curable compositions (A) of Examples 12 to 32 and Comparative Examples 4 to 8 using a silicon oxide mold were observed and evaluated, wherein a line and space (L / S) pattern with a depth of 50 nm and a width of 20 nm was formed in the entire area.

[0201] (Evaluation Criteria) AAA: Pattern collapse was observed in an area less than 0.1% of the pattern formation area. AA: Pattern collapse was observed in an area less than 1% of the pattern formation area. A: Pattern collapse was observed in an area less than 10% of the pattern formation area. B: Pattern collapse is observed in 10% or more of the pattern formation area.

[0202] <Evaluation of dry etching resistance> The cured films obtained above were exposed to oxygen plasma in a dry etching apparatus, and the weight change of each remaining film was measured and evaluated based on the following judgment criteria.

[0203] (Evaluation Criteria) AAA: The weight of the remaining cured film is 49% or more of the weight before etching. AA: The weight of the remaining cured film is 47% or more of the weight before etching. A: The weight of the remaining cured film is 43% or more of the weight before etching. B: The weight of the remaining cured film is less than 43% of the weight before etching.

[0204] Table 6 shows the evaluation results. It was found that if the viscosity of the curable composition at 23°C is 2 mPa·s or more and 60 mPa·s or less, IJ discharge is excellent, and the viscosity is preferably 5 mPa·s or more and 30 mPa·s or less, and more preferably 5 mPa·s or more and 15 mPa·s or less. It was found that if the viscosity at 23°C when the solvent is removed is 30 mPa·s or more and 10000 mPa·s or less, filling properties are excellent, and the viscosity is preferably 90 mPa·s or more and 2000 mPa·s or less, and more preferably 120 mPa·s or more and 1000 mPa·s or less.

[0205] If the glass transition temperature of the cured curable composition is 150°C or more, pattern collapse is observed in an area less than 0.1% of the pattern forming area. If the glass transition temperature is 100°C or more and less than 150°C, pattern collapse is observed in an area less than 1% of the pattern forming area. If the glass transition temperature is 70°C or more and less than 100°C, pattern collapse is observed in an area less than 10% of the pattern forming area. If the glass transition temperature is less than 70°C, pattern collapse is observed in an area more than 10% of the pattern forming area. In all cases, the extent is very slight.

[0206] If the Si atom content of the curable composition is 23% or more when the solvent is removed, the weight of the remaining cured film is 49% or more of the weight before etching. If the Si atom content is 22% or more, 47% or more of the film remains in the form of a cured film. If the Si atom content is 20% or more, 43% or more of the film remains in the form of a cured film.

[0207] Table 4

[0208] Table 5

[0209] Table 6

[0210] This application claims priority from Japanese Patent Application No. 2022-095226 filed on June 13, 2022 and Japanese Patent Application No. 2023-092681 filed on June 5, 2023, which are hereby incorporated by reference herein.

[0211] The present invention is not limited to the above-described embodiments, and various changes and modifications may be made within the spirit and scope of the present invention. Therefore, in order to apprise the public of the scope of the present invention, the following claims are made.

Claims

1. A curable composition comprising a polymerizable compound, a photopolymerization initiator and a solvent, characterized in that: The polymerizable compound includes a polymerizable silicon compound, The curable composition has a viscosity of 2 mPa·s or more and 60 mPa·s or less at 23° C., The curable composition in a state where the solvent is removed has a viscosity of 30 mPa·s or more and 10000 mPa·s or less at 23° C., and The content of the solvent is 5 volume % or more and 95 volume % or less based on the entire curable composition.

2. The curable composition according to claim 1, characterized in that The content of the solvent is 70% by volume or more and 95% by volume or less based on the entire curable composition.

3. The curable composition according to claim 1, characterized in that The curable composition in a state where the solvent is removed contains 20% by weight or more of silicon atoms.

4. The curable composition according to claim 1, characterized in that The glass transition temperature of a cured product obtained by curing the curable composition in a state where the solvent is removed is 70° C. or higher.

5. The curable composition according to claim 1, characterized in that The silicon compound has a silsesquioxane skeleton.

6. The curable composition according to claim 1, characterized in that The silicon compound has a cyclic siloxane skeleton.

7. A method for forming a reverse pattern, characterized in that: The method includes: a step of arranging the curable composition described in any one of claims 1 to 5 to fill the concave portions of the first film having concave portions and convex portions and curing the curable composition to form a second film including an inversion layer filled in the concave portions; a step of removing a portion of the second film to expose the protrusion; and The step of patterning the first film using the inversion layer remaining in the concave portion as a mask, thereby forming a reverse pattern formed by the patterned first film.

8. A film forming method for forming a film of a curable composition in a space between a mold and a substrate, characterized in that: The method includes: an arranging step of discretely arranging a plurality of droplets of the curable composition described in claim 1 on a substrate; a waiting step of waiting until the plurality of liquid droplets discretely arranged on the substrate merge with their respective adjacent liquid droplets to form a continuous liquid film on the substrate, the solvent contained in the liquid film volatilizes, and the content of the solvent relative to the entire liquid film becomes 10 volume % or less; and The contacting step is to bring the mold and the liquid film on the substrate into contact with each other after the waiting step.

9. The film forming method according to claim 8, characterized in that In the waiting step, the substrate is heated at 30° C. or higher and 200° C. or lower for 10 seconds or higher and 600 seconds or lower.

10. The film forming method according to claim 8, characterized in that In the arranging step, droplets of the curable composition each having a volume of 1.0 pL or more are arranged at a rate of 130 droplets / mm 2 The above density is arranged on the substrate.

11. The film forming method according to claim 8, characterized in that The average liquid film thickness, which is a value obtained by dividing the volume of the curable composition remaining after the waiting step by the area of ​​the film formation region, is 20 nm or less.

12. The film forming method according to claim 8, characterized in that The mold includes a pattern, bringing the pattern of the mold and the liquid film on the substrate into contact with each other in the contacting step, and The film forming method further includes a curing step of curing the liquid film after the contacting step, thereby forming a cured film having a pattern corresponding to the mold pattern.

13. The film forming method according to claim 8, characterized in that The mold comprises a flat surface, bringing the flat surface of the mold and the liquid film on the substrate into contact with each other in the contacting step, and The film forming method further includes a curing step of curing the liquid film after the contacting step, thereby forming a cured film having a surface conforming to the flat surface of the mold.

14. A film forming method for forming a film of a curable composition in a space between a mold and a substrate, characterized in that: The method includes: an arranging step of discretely arranging a plurality of droplets of the curable composition described in claim 1 on a substrate; a waiting step of waiting until a plurality of liquid droplets discretely arranged on the substrate merge with respective adjacent liquid droplets to form a continuous liquid film on the substrate, and the solvent contained in the liquid film volatilizes; and a contacting step of bringing the mold and the liquid film on the substrate into contact with each other after the waiting step, In the waiting step, the substrate is heated at a temperature of 30° C. to 200° C. for a period of 10 seconds to 600 seconds.

15. The film forming method according to claim 8, characterized in that In the arranging step, the plurality of liquid droplets are discretely arranged on the substrate by using an inkjet method.

16. A method for manufacturing an article, characterized in that: The method includes: A step of forming a film of the curable composition on the substrate by using the film forming method according to any one of claims 8 to 15; a step of processing the substrate on which the film is formed in the forming step; and The step of manufacturing an article from a processed substrate.

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