JP2010157542A - Curable composition for nanoimprint and method of forming pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition for nanoimprint having improved photo-curing properties and pattern formation properties. <P>SOLUTION: The curable composition for nanoimprint contains a polymerizable monomer (A) and a photopolymerization initiator (B), where at least one type of the polymerizable monomer (A) is a polymerizable monomer (Ax) expressed by general formula (I). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a curable composition for nanoimprint. More specifically, semiconductor integrated circuits, flat screens, micro electromechanical systems (MEMS), sensor elements, optical recording media such as optical disks and high density memory disks, optical components such as diffraction grating relief holograms, nano devices, optical devices, Optical films and polarizing elements for manufacturing flat panel displays, thin film transistors for liquid crystal displays, organic transistors, color filters, overcoat layers, pillar materials, rib materials for liquid crystal alignment, microlens arrays, immunoassay chips, DNA separation chips The present invention relates to a curable composition for nanoimprinting for forming a fine pattern using light irradiation used for production of microreactors, nanobiodevices, optical waveguides, optical filters, photonic liquid crystals, and the like.

  The nanoimprint method has been developed by developing an embossing technique that is well-known in optical disc production, and mechanically pressing a mold master (generally called a mold, stamper, or template) with a concavo-convex pattern onto a resist. This is a technology that precisely deforms and transfers fine patterns. Once the mold is made, it is economical because nanostructures and other microstructures can be easily and repeatedly molded, and it is economical, and since it is a nano-processing technology with less harmful waste and emissions, it has recently been applied to various fields. Is expected.

  The nanoimprint method includes a thermal imprint method using a thermoplastic resin as a material to be processed (for example, see Non-Patent Document 1) and a photo-imprint method using a photocurable composition (for example, see Non-Patent Document 2). Two techniques have been proposed. In the case of the thermal nanoimprint method, the mold is pressed on a polymer resin heated to a temperature higher than the glass transition temperature, and the mold is released after cooling to transfer the fine structure to the resin on the substrate. Since this method can be applied to various resin materials and glass materials, application to various fields is expected. For example, Patent Documents 1 and 2 disclose a nanoimprint method for forming a nanopattern at low cost using a thermoplastic resin.

  On the other hand, in the optical nanoimprint method in which light is irradiated through a transparent mold or a transparent substrate and the curable composition for optical nanoimprint is photocured, it is not necessary to heat the material transferred when the mold is pressed, and imprinting at room temperature is possible. It becomes possible. Recently, new developments such as a nanocasting method combining the advantages of both and a reversal imprint method for producing a three-dimensional laminated structure have been reported.

In such a nanoimprint method, the following applied technologies have been proposed.
The first technique is a case where a molded shape (pattern) itself has a function and can be applied as various nanotechnology element parts or structural members. Specific examples include various micro / nano optical elements, high-density recording media, optical films, and structural members in flat panel displays. The second technology is to build a laminated structure by simultaneous integral molding of microstructure and nanostructure and simple interlayer alignment, and apply this to the production of μ-TAS (Micro-Total Analysis System) and biochips. It is what. The third technique is used for processing a substrate by a method such as etching using the formed pattern as a mask. In this technology, high-precision alignment and high integration enable high-density semiconductor integrated circuit fabrication, liquid crystal display transistor fabrication, and magnetic media for next-generation hard disks called patterned media instead of conventional lithography technology. It can be applied to processing. In recent years, efforts have been made to put the nanoimprint method relating to these applications into practical use.

  As an application example of the nanoimprint method, first, an application example for manufacturing a high-density semiconductor integrated circuit will be described. 2. Description of the Related Art In recent years, semiconductor integrated circuits have been miniaturized and integrated, and photolithography apparatuses have been improved in accuracy as a pattern transfer technique for realizing the fine processing. However, it has become difficult to satisfy three requirements of fine pattern resolution, apparatus cost, and throughput for further miniaturization requirements. On the other hand, nanoimprint lithography (optical nanoimprint method) has been proposed as a technique for performing fine pattern formation at low cost. For example, Patent Documents 1 and 3 below disclose a nanoimprint technique in which a silicon wafer is used as a stamper and a fine structure of 25 nm or less is formed by transfer. In this application, a pattern forming property of a level of several tens of nanometers and a high etching resistance for functioning as a mask during substrate processing are required.

  An application example of the nanoimprint method to the production of the next generation hard disk drive (HDD) will be described. HDDs have a history of both high-capacity and miniaturization, with both high-performance heads and high-performance media. From the viewpoint of improving the performance of media, HDDs have increased in capacity by increasing the surface recording density. However, when the recording density is increased, so-called magnetic field spreading from the side surface of the magnetic head becomes a problem. Since the magnetic field spread does not become smaller than a certain value even if the head is made smaller, a phenomenon called sidelight occurs as a result. When side writing occurs, writing to an adjacent track occurs during recording, and already recorded data is erased. Further, due to the magnetic field spread, a phenomenon such as reading an excessive signal from an adjacent track occurs during reproduction. In order to solve such a problem, technologies such as discrete track media and bit patterned media have been proposed which are solved by filling the spaces between tracks with a nonmagnetic material and physically and magnetically separating the tracks. The application of nanoimprinting has been proposed as a method for forming a magnetic or nonmagnetic pattern in the production of these media. Also in this application, a pattern forming property of several tens of nm level and high etching resistance for functioning as a mask during substrate processing are required.

Next, an application example of the nanoimprint method to a flat display such as a liquid crystal display (LCD) or a plasma display (PDP) will be described.
With the trend toward larger and higher-definition LCD and PDP substrates, the optical nanoimprinting method has recently attracted attention as an inexpensive lithography that replaces the conventional photolithography method used in the manufacture of thin film transistors (TFTs) and electrode plates. Yes. Therefore, it has become necessary to develop a photo-curable resist that replaces the etching photoresist used in the conventional photolithography method.
Further, as a structural member such as an LCD, application of the optical nanoimprint method to a transparent protective film material described in the following Patent Documents 4 and 5 or a spacer described in the following Patent Document 5 has begun to be studied. Unlike the etching resist, such a resist for a structural member is finally left in the display, and is sometimes referred to as “permanent resist” or “permanent film”.
In addition, a spacer that defines a cell gap in a liquid crystal display is also a kind of permanent film. In conventional photolithography, a photocurable composition comprising a resin, a photopolymerizable monomer, and an initiator has been widely used. (For example, see Patent Document 6). The spacer is generally a pattern having a size of about 10 μm to 20 μm by photolithography after applying the photocurable composition after forming the color filter on the color filter substrate or after forming the protective film for the color filter. And is further heated and cured by post-baking.

In addition, microelectromechanical systems (MEMS), sensor elements, optical components such as diffraction gratings and relief holograms, nanodevices, optical devices, optical films and polarizing elements for the production of flat panel displays, thin film transistors for liquid crystal displays, organic transistors , Color filter, overcoat layer, pillar material, rib material for liquid crystal alignment, microlens array, immunoassay chip, DNA separation chip, microreactor, nanobiodevice, optical waveguide, optical filter, photonic liquid crystal, etc. Nanoimprint lithography is also useful in applications.
In these permanent film applications, the formed pattern will eventually remain in the product, so the durability of the film, mainly heat resistance, light resistance, solvent resistance, scratch resistance, high mechanical properties against external pressure, hardness, etc. And strength-related performance is required.
As described above, most of the patterns conventionally formed by the photolithography method can be formed by nanoimprinting, and attention has been paid as a technique capable of forming a fine pattern at low cost.

In these applications, it is premised that a good pattern is formed, but for thermal nanoimprinting in pattern formation, the mold is fixed to a resin composition softened by heating at a high pressure, and the resin composition is formed into a mold. Fill. On the other hand, in the optical nanoimprint method, the mold needs to be sufficiently filled with the composition even at a low pressure, and the curable composition used in the optical nanoimprint method is required to have a low viscosity. Moreover, in order to form a favorable pattern, it is also required to contain a highly curable polymerizable monomer. However, in general, in order to obtain high curability, a high viscosity compound having a plurality of polymerizable groups is often contained in the curable composition.
Thus, in order to obtain a good pattern faithful to the mold when using the optical nanoimprint method in the industry, a polymerizable monomer that simultaneously satisfies low viscosity and high curability is indispensable.

  On the other hand, Patent Document 7 discloses a photocurable composition essentially containing a fluorene monomer. Furthermore, an example using trimethylolethane trimethacrylate is described as a comparative example in the publication.

US Pat. No. 5,772,905 US Pat. No. 5,956,216 US Pat. No. 5,259,926 JP 2005-197699 A Japanese Patent Laying-Open No. 2005-301289 Japanese Patent Laid-Open No. 2004-240241 JP 2004-346125 A S. Chou et al .: Appl. Phys. Lett. Vol. 67, 3114 (1995) M. Colbun et al,: Proc.SPIE, Vol. 3676,379 (1999)

Here, when this inventor examined about the said patent document 7 (Unexamined-Japanese-Patent No. 2004-346125), when the curable composition for optical nanoimprints containing a trimethylol propane triacrylate is used, the viscosity of that is used. From the height, it was found that it was difficult to obtain a good pattern because the mold was not sufficiently filled with the composition. Further, it was found that the trimethylolethane trimethacrylate disclosed in Patent Document 7 has low sensitivity for use as a curable composition for photo-nanoimprinting, so that its curability is poor and its productivity is problematic. .
The present invention has been accomplished in view of the above prior art, and has an object to provide a curable composition for nanoimprints having high pattern forming properties and excellent curability.

In particular, when the optical nanoimprint method is used industrially, in order to obtain a good pattern with high productivity, the viscosity is low enough to sufficiently fill a liquid curable composition into a mold under a low pressure. It is desired that the composition be a curable composition containing a highly sensitive polymerizable monomer having excellent curability.
Accordingly, the present invention provides a curable composition for nanoimprints that is used in optical nanoimprint lithography, which is excellent in fine pattern formation, which can cope with nano-order patterns well even with low pressure, as well as excellent photocurability. There is to do.

（一般式（Ｉ）中、Ｘ¹〜Ｘ³はそれぞれ独立に単結合または連結基を表す。Ｍｅはメチル基を表す。）
（２）（Ａ）重合性単量体のうち５０質量％以上が２５℃で液体の化合物である、（１に記載のナノインプリント用硬化性組成物。
（３）（Ａ）重合性単量体のうち５０質量％以上がアクリレート基を有する化合物である、（１）または（２）に記載のナノインプリント用硬化性組成物。
（４）一般式（Ｉ）のＸ¹〜Ｘ³が、それぞれ、単結合、オキシアルキレン基、−Ｏ−Ｃ（＝Ｏ）−若しくはアルキレン基、または、これらの２以上の組み合わせからなる基である、（１）〜（３）のいずれか１項に記載のナノインプリント用硬化性組成物。
（５）一般式（Ｉ）のＸ¹〜Ｘ³が、単結合である、（１）〜（３）のいずれか１項に記載のナノインプリント用硬化性組成物。
（６）一般式（Ｉ）で表される重合性単量体（Ａｘ）以外の（Ａ）重合性単量体として、エチレン性不飽和結合含有基を有する重合性単量体を含む、（１）〜（５）のいずれか１項に記載のナノインプリント用硬化性組成物。
（７）分子量２０００以上のポリマー成分の含有量が全重合性単量体の含量の３０質量％以下である（１）〜（６）のいずれか１項に記載のナノインプリント用硬化性組成物。
（８）界面活性剤および酸化防止剤から選ばれる少なくとも１種を含有する、（１）〜（７）のいずれか１項に記載のナノインプリント用硬化性組成物。
（９）（１）〜（８）のいずれか１項に記載のナノインプリント用硬化性組成物を用いることを特徴とする、パターン形成方法。
（１０）（１）〜（８）のいずれか１項に記載のナノインプリント用硬化性組成物を基材上に適用してパターン形成層を形成する工程と、
前記パターン形成層表面にモールドを圧接する工程と、
前記パターン形成層に光を照射する工程と、を含むことを特徴とするパターン形成方法。
（１１）前記モールドの圧接を１〜５気圧で行う、（１０）に記載のパターン形成方法。 As a result of intensive studies by the inventor under the above problems, it has been found that the above problems can be solved by adding a triacrylate having a specific structure. In particular, it has been found that it is important not to be tri (meth) acrylate but to be triacrylate. Specifically, it has been found that the above problems can be solved by the following means.
(1) Polymerizability comprising (A) a polymerizable monomer and (B) a photopolymerization initiator, wherein at least one of the polymerizable monomers (A) is represented by the following general formula (I) A curable composition for nanoimprinting, which is a monomer (Ax).
Formula (I)

(In the general formula (I), X ^{1 to} X ³ each independently represents a single bond or a linking group. Me represents a methyl group.)
(2) The curable composition for nanoimprints according to (1), wherein 50% by mass or more of the polymerizable monomer (A) is a liquid compound at 25 ° C.
(3) The curable composition for nanoimprints according to (1) or (2), wherein 50% by mass or more of the polymerizable monomer (A) is a compound having an acrylate group.
(4) X ^{1 to} X ^{3 in} the general formula (I) are each a single bond, an oxyalkylene group, —O—C (═O) — or an alkylene group, or a group consisting of a combination of two or more thereof. The curable composition for nanoimprints according to any one of (1) to (3).
(5) The curable composition for nanoimprints according to any one of (1) to (3), wherein X ^{1 to} X ^{3 in} the general formula (I) are single bonds.
(6) As the polymerizable monomer (A) other than the polymerizable monomer (Ax) represented by the general formula (I), a polymerizable monomer having an ethylenically unsaturated bond-containing group is included ( The curable composition for nanoimprints according to any one of 1) to (5).
(7) The curable composition for nanoimprints according to any one of (1) to (6), wherein the content of the polymer component having a molecular weight of 2000 or more is 30% by mass or less of the content of all polymerizable monomers.
(8) The curable composition for nanoimprints according to any one of (1) to (7), comprising at least one selected from a surfactant and an antioxidant.
(9) A pattern forming method comprising using the curable composition for nanoimprints according to any one of (1) to (8).
(10) A step of forming a pattern forming layer by applying the curable composition for nanoimprints according to any one of (1) to (8) on a substrate;
Pressing the mold against the surface of the pattern forming layer;
Irradiating the pattern forming layer with light. A pattern forming method comprising:
(11) The pattern forming method according to (10), wherein the pressing of the mold is performed at 1 to 5 atm.

  According to the present invention, there is provided a curable composition for nanoimprinting that is used for optical nanoimprint lithography, which is excellent in fine pattern formation, which can cope with nanometer patterns well even at low pressure, as well as excellent photocurability. can do.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

In this specification, “(meth) acrylate” means that both acrylate and methacrylate are included, but unless otherwise specified, acrylate and methacrylate are clearly distinguished in this specification. In the present specification, “monomer” and “monomer” are synonymous. The monomer in the present invention is distinguished from an oligomer and a polymer, and refers to a compound having a weight average molecular weight of 1,000 or less. In the present specification, “functional group” refers to a group involved in a polymerization reaction.
The “nanoimprint” as used in the present invention refers to pattern transfer having a size of about several nm to several μm, and is not limited to nano-order printing.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what has a substituent with what does not have a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

（一般式（Ｉ）中、Ｘ¹〜Ｘ³はそれぞれ独立に単結合または連結基を表す。Ｍｅはメチル基を表す。） [Curable composition for nanoimprinting of the present invention]
The curable composition for nanoimprinting of the present invention (hereinafter sometimes simply referred to as “the composition of the present invention”) contains at least (A) a polymerizable monomer and (B) a photopolymerization initiator. In addition, at least one of the polymerizable monomers (A) is a polymerizable monomer (Ax) represented by the following general formula (I).
Formula (I)

(In the general formula (I), X ^{1 to} X ³ each independently represents a single bond or a linking group. Me represents a methyl group.)

When X < ¹ > -X < ³ > is a coupling group, Preferably it is an organic coupling group and it is preferable that it is a C1-C50 organic coupling group. Specific examples of the organic linking group include an oxyalkylene group, —O—C (═O) —, an alkylene group, and a group composed of a combination of two or more thereof. Examples of the oxyalkylene group include an ethylene oxide group and a propylene oxide group. Examples of the alkylene group include a propylene group, a butylene group, a pentyl group, and a hexyl group. X ^{1 to} X ³ are preferably single bonds.
The compound represented by the general formula (I) is preferably in a liquid form at 25 ° C., but may not be in a liquid form.

ｍ¹、ｍ²、ｍ³、ｎ¹、ｎ²、ｎ³は、それぞれ、０〜１０の整数を表し、ｍ¹、ｍ²、ｍ³、ｎ¹、ｎ²およびｎ³の和は、１よりも大きい化合物であるか、該和の平均が１より大きい化合物の混合物である。
ｌ¹、ｌ²、ｌ³は、それぞれ、０〜１０の整数を表し、ｋ¹、ｋ²、ｋ³は、それぞれ、３〜６の整数を表し、ｌ¹、ｌ²およびｌ³の和は、１よりも大きい化合物であるか、該和の平均が１より大きい化合物の混合物である。 Specific examples of the polymerizable monomer (Ax) in the present invention are shown below.

m ¹ , m ² , m ³ , n ¹ , n ² , n ³ each represents an integer of 0 to 10, and the sum of m ¹ , m ² , m ³ , n ¹ , n ² and n ³ is It is a compound that is greater than 1 or a mixture of compounds that have an average of greater than 1.
l ¹ , l ² , and l ³ each represent an integer of 0 to 10, k ¹ , k ² , and k ³ each represent an integer of 3 to 6, and the sum of l ¹ , l ^2, and l ³ Is a compound greater than 1, or a mixture of compounds with an average of greater than 1.

  From the viewpoint of curability and composition viscosity, the total content of the polymerizable monomer (A) in the curable composition for nanoimprinting of the present invention is 50 to 99.5% by mass in all components except the solvent. Preferably, 70-99 mass% is more preferable, and 90-99 mass% is further more preferable. The content of the polymerizable monomer (Ax) in the present invention is preferably 1 to 100% by mass, more preferably 8 to 90% by mass in the total polymerizable monomer, from the viewpoint of composition viscosity and curability. More preferably, it is 10-80 mass%. That is, from the viewpoint of improving the composition viscosity, dry etching resistance, imprint suitability, curability and the like, a polymerizable monomer (Ax) and a polymerizable monomer (Ax) described below as necessary Are preferably used in combination with other polymerizable monomers.

-Other polymerizable monomers-
As described above, the curable composition for nanoimprinting of the present invention further comprises a polymerizable monomer as a polymerizable monomer for the purpose of improving the composition viscosity, dry etching resistance, imprintability, curability and the like. Another polymerizable monomer different from the monomer (Ax) may be contained. Examples of the other polymerizable monomer include a polymerizable unsaturated monomer having 1 to 6 ethylenically unsaturated bond-containing groups; a compound having an oxirane ring (epoxy compound); a vinyl ether compound; a styrene derivative; A compound having a fluorine atom; propenyl ether, butenyl ether and the like can be mentioned, and a polymerizable unsaturated monomer having 1 to 6 ethylenically unsaturated bond-containing groups is preferable from the viewpoint of curability.

The polymerizable unsaturated monomer having 1 to 6 ethylenically unsaturated bond-containing groups (1 to 6 functional polymerizable unsaturated monomer) will be described.
First, specific examples of the polymerizable unsaturated monomer having one ethylenically unsaturated bond-containing group (monofunctional polymerizable unsaturated monomer) include 2-acryloyloxyethyl phthalate, 2-acryloyloxy 2 -Hydroxyethyl phthalate, 2-acryloyloxyethyl hexahydrophthalate, 2-acryloyloxypropyl phthalate, 2-ethyl-2-butylpropanediol acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl carbitol (meth) Acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 4-hydroxy Butyl (medium ) Acrylate, acrylic acid dimer, benzyl (meth) acrylate, 1- or 2-naphthyl (meth) acrylate, butanediol mono (meth) acrylate, butoxyethyl (meth) acrylate, butyl (meth) acrylate, cetyl (meth) acrylate , Ethylene oxide modified (hereinafter referred to as “EO”) cresol (meth) acrylate, dipropylene glycol (meth) acrylate, ethoxylated phenyl (meth) acrylate, ethyl (meth) acrylate, isoamyl (meth) acrylate, isobutyl (meth) acrylate , Isooctyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclohentanyl (meth) acrylate, dicyclopentanyloxye (Meth) acrylate, isomyristyl (meth) acrylate, lauryl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxytriethylene glycol ( (Meth) acrylate, methyl (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolypropylene glycol (meth) acrylate, octyl (meth) acrylate, paracumylphenoxyethylene glycol (meth) ) Acrylate, epichlorohydrin (hereinafter referred to as “ECH”) modified phenoxy acrylate, phenoxyethyl (meth) ) Acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyhexaethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polypropylene glycol (meth) Acrylate, stearyl (meth) acrylate, EO-modified succinic acid (meth) acrylate, tert-butyl (meth) acrylate, tribromophenyl (meth) acrylate, EO-modified tribromophenyl (meth) acrylate, tridodecyl (meth) acrylate, p -Isopropenylphenol, styrene, α-methylstyrene, acrylonitrile are exemplified.
Among these, (meth) acrylates having an aromatic group or an alicyclic hydrocarbon group are particularly preferred from the viewpoint of dry etching resistance, such as benzyl (meth) acrylate, 1- or 2-naphthyl (meth) acrylate, 1- or 2-naphthylmethyl (meth) acrylate, 1- or 2-naphthylethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) ) Acrylate is preferably used in the present invention.

It is also preferable to use a polyfunctional polymerizable unsaturated monomer having two ethylenically unsaturated bond-containing groups as the other polymerizable monomer.
Examples of the bifunctional polymerizable unsaturated monomer having two ethylenically unsaturated bond-containing groups that can be preferably used in the present invention include diethylene glycol monoethyl ether (meth) acrylate, dimethylol dicyclopentane di (meta ) Acrylate, di (meth) acrylated isocyanurate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, EO-modified 1,6-hexanediol di (meth) acrylate, ECH modified 1,6-hexanediol di (meth) acrylate, allyloxy polyethylene glycol acrylate, 1,9-nonanediol di (meth) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di (meth) Acrylate, modified screw Enol A di (meth) acrylate, EO modified bisphenol F di (meth) acrylate, ECH modified hexahydrophthalic acid diacrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, EO modified Neopentyl glycol diacrylate, propylene oxide (hereinafter referred to as “PO”) modified neopentyl glycol diacrylate, caprolactone modified hydroxypivalate ester neopentyl glycol, stearic acid modified pentaerythritol di (meth) acrylate, ECH modified phthalic acid di ( (Meth) acrylate, poly (ethylene glycol-tetramethylene glycol) di (meth) acrylate, poly (propylene glycol-tetramethylene glycol) Di) (di) (meth) acrylate, polyester (di) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ECH modified propylene glycol di (meth) acrylate, silicone di (meth) acrylate, triethylene Glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, tripropylene glycol di (meth) acrylate, EO Modified tripropylene glycol di (meth) acrylate, triglycerol di (meth) acrylate, dipropylene glycol di (meth) acrylate, divinyl ethyl And urea and divinyl propylene urea are exemplified.

  Among these, neopentyl glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl hydroxypivalate Glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and the like are preferably used in the present invention.

  Examples of the polyfunctional polymerizable unsaturated monomer having 3 or more ethylenically unsaturated bond-containing groups include ECH-modified glycerol tri (meth) acrylate, EO-modified glycerol tri (meth) acrylate, PO-modified glycerol tri (meta) ) Acrylate, pentaerythritol triacrylate, EO modified phosphoric acid triacrylate, trimethylolpropane tri (meth) acrylate, caprolactone modified trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylol Propane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) Chryrate, dipentaerythritol hydroxypenta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol poly (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) Examples include acrylate, pentaerythritol ethoxytetra (meth) acrylate, and pentaerythritol tetra (meth) acrylate.

  Among these, EO-modified glycerol tri (meth) acrylate, PO-modified glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate and the like are preferably used in the present invention.

  Examples of the compound having an oxirane ring (epoxy compound) include polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of polyoxyalkylene glycol, and polyglycidyl ethers of aromatic polyols. Examples include teters, hydrogenated compounds of polyglycidyl ethers of aromatic polyols, urethane polyepoxy compounds, and epoxidized polybutadienes. These compounds can be used alone or in combination of two or more thereof.

  Examples of the compound having an oxirane ring (epoxy compound) that can be preferably used in the present invention include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, bromine Bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1,4-butanediol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol jig Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin; Diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of higher aliphatic alcohols; monoglycidyl ethers of polyether alcohols obtained by adding phenol, cresol, butylphenol or alkylene oxide to these; higher fatty acid Examples thereof include glycidyl esters.

  Among these, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol Diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether are preferred.

  Commercially available products that can be suitably used as the glycidyl group-containing compound include UVR-6216 (manufactured by Union Carbide), glycidol, AOEX24, cyclomer A200, (manufactured by Daicel Chemical Industries, Ltd.), Epicoat 828, Epicoat 812, Epicoat 1031, Epicoat 872, Epicoat CT508 (above, manufactured by Yuka Shell Co., Ltd.), KRM-2400, KRM-2410, KRM-2408, KRM-2490, KRM-2720, KRM-2750 (above, Asahi Denka Kogyo ( Product)). These can be used alone or in combination of two or more.

  The production method of these compounds having an oxirane ring is not limited. For example, Maruzen KK Publishing, 4th edition Experimental Chemistry Course 20 Organic Synthesis II, 213, 1992, Ed. By Alfred Hasfner, The chemistry of cyclic compounds-Small Ring Heterocycles part 3 Oxiranes, John & Wiley and Sons, An Interscience Publication, New York, 1985, Yoshimura, Adhesion, Vol. 29, No. 12, 32, 1985, Yoshimura, Adhesion, Vol. 30, No. 5, 42, 1986, Yoshimura, Adhesion, Vol. 30, No. 7, 42, 1986, Japanese Patent Application Laid-Open No. 11-1000037, Japanese Patent No. 2906245, Japanese Patent No. 2926262 and the like can be synthesized.

As other polymerizable monomer used in the present invention, a vinyl ether compound may be used in combination.
As the vinyl ether compound, known compounds can be appropriately selected. For example, 2-ethylhexyl vinyl ether, butanediol-1,4-divinyl ether, diethylene glycol monovinyl ether, diethylene glycol monovinyl ether, ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,3-propanediol divinyl ether, 1,3-butanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylol Propane trivinyl ether, trimethylol ethane trivinyl ether, hexanediol divinyl ether, tetra Tylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, ethylene glycol diethylene vinyl ether, triethylene glycol diethylene vinyl ether, ethylene glycol dipropylene vinyl ether, triethylene glycol diethylene vinyl ether , Trimethylolpropane triethylene vinyl ether, trimethylolpropane diethylene vinyl ether, pentaerythritol diethylene vinyl ether, pentaerythritol triethylene vinyl ether, pentaerythritol tetraethylene vinyl ether, 1,1,1-to Scan [4- (2-vinyloxy ethoxy) phenyl] ethane, bisphenol A divinyloxyethyl carboxyethyl ether.

  These vinyl ether compounds can be obtained, for example, by the method described in Stephen C. Lapin, Polymers Paint Color Journal. 179 (4237), 321 (1988), that is, the reaction of a polyhydric alcohol or polyhydric phenol with acetylene, or They can be synthesized by the reaction of a polyhydric alcohol or polyhydric phenol and a halogenated alkyl vinyl ether, and these can be used singly or in combination of two or more.

  Moreover, a styrene derivative can also be employ | adopted as another polymerizable monomer used by this invention. Examples of styrene derivatives include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-methylstyrene, p-hydroxy. Examples include styrene.

  Trifluoroethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, (perfluorobutyl) ethyl (meth) acrylate, perfluorobutyl-hydroxypropyl (meth) for the purpose of improving mold release and coating properties Compounds having a fluorine atom such as acrylate, (perfluorohexyl) ethyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate and the like can be used in combination. .

  As another polymerizable monomer used in the present invention, propenyl ether and butenyl ether can also be used. Examples of the propenyl ether or butenyl ether include 1-dodecyl-1-propenyl ether, 1-dodecyl-1-butenyl ether, 1-butenoxymethyl-2-norbornene, 1-4-di (1-butenoxy) butane, 1,10-di (1-butenoxy) decane, 1,4-di (1-butenoxymethyl) cyclohexane, diethylene glycol di (1-butenyl) ether, 1,2,3-tri (1-butenoxy) propane, propenyl ether propylene Carbonate or the like can be suitably applied.

  Although the preferable content of the other polymerizable monomer described above varies depending on the content of the polymerizable monomer (Ax) and the like, the polymerizable monomer (A) of the present invention may have, for example, 0 to 90%. It is contained in the range of mass%, preferably 5 to 80 mass%, more preferably 10 to 50 mass%.

Next, a preferred blend form of the polymerizable monomer (Ax) and other polymerizable monomer (hereinafter, these may be collectively referred to as “polymerizable unsaturated monomer”) in the present invention will be described. .
The monofunctional polymerizable unsaturated monomer is usually used as a reactive diluent, has the effect of reducing the viscosity of the nanoimprint curable composition of the present invention, and the total amount of the polymerizable monomer (A). It is preferable that 15 mass% or more is added, 20-80 mass% is further more preferable, 25-70 mass% is more preferable, and 30-60 mass% is especially preferable.
The monomer having two unsaturated bond-containing groups (bifunctional polymerizable unsaturated monomer) is preferably 90% by mass or less, more preferably 80% by mass or less, and particularly preferably 80% by mass or less of the total polymerizable unsaturated monomer. Preferably, it is added in a range of 70% by mass or less. The ratio of the monofunctional and bifunctional polymerizable unsaturated monomer is preferably 10 to 100% by mass, more preferably 30 to 95% by mass, and particularly preferably 50 to 90% by mass of the total polymerizable unsaturated monomer. % Is added. The ratio of the polyfunctional polymerizable unsaturated monomer having 3 or more unsaturated bond-containing groups that is not the polymerizable monomer (Ax) in the present invention is preferably 80% of the total polymerizable unsaturated monomer. It is added in a range of not more than mass%, more preferably not more than 60 mass%, particularly preferably not more than 40 mass%. Since the viscosity of a composition can be lowered | hung by making the ratio of the polymerizable unsaturated monomer which has 3 or more of polymerizable unsaturated bond containing groups into 80 mass% or less, it is preferable.
In addition, the total amount of the polymerizable monomer (A) including the polymerizable monomer (Ax) in the present invention is such that the acrylate monomer (monomer having an acrylate group) is a fully polymerizable monomer from the viewpoint of productivity. It is preferable that 50% by mass or more is contained in the polymer, more preferably 70% by mass or more, and particularly preferably 90% by mass or more.
Furthermore, in the present invention, it is preferable that 50% by mass or more of the polymerizable monomer (A) containing the polymerizable monomer (Ax) is a liquid compound at 25 ° C., and 70% by mass or more is 25 ° C. It is more preferable that it is a liquid compound, and it is particularly preferable that 90% by mass or more is a liquid compound at 25 ° C. In particular, the polymerizable monomer (Ax) is preferably a liquid.

Photopolymerization initiator (B)
The nanoimprint curable composition of the present invention contains a photopolymerization initiator. As the photopolymerization initiator used in the present invention, any compound can be used as long as it is a compound that generates an active species capable of polymerizing the above polymerizable monomer by light irradiation. The photopolymerization initiator is preferably a radical polymerization initiator that generates radicals by light irradiation, or a cationic polymerization initiator that generates acids by light irradiation, more preferably a radical polymerization initiator. It is determined appropriately according to the type of the polymerizable group. That is, the photopolymerization initiator in the present invention is formulated with an activity with respect to the wavelength of the light source to be used, and generates appropriate active species according to the difference in the reaction format (for example, radical polymerization or cationic polymerization). It is necessary to use something. In the present invention, a plurality of photopolymerization initiators may be used in combination.

Content of the photoinitiator used for this invention is 0.01-15 mass% in all the compositions except a solvent, for example, Preferably it is 0.1-12 mass%, More preferably, it is 0. 2 to 7% by mass. When using 2 or more types of photoinitiators, the total amount becomes the said range.
When the content of the photopolymerization initiator is 0.01% by mass or more, the sensitivity (fast curability), resolution, line edge roughness, and coating strength tend to be improved, which is preferable. On the other hand, when the content of the photopolymerization initiator is 15% by mass or less, light transmittance, colorability, handleability and the like tend to be improved, which is preferable. Until now, various addition amounts of preferred photopolymerization initiators and / or photoacid generators have been studied for ink-jet compositions and dye- and / or pigment-containing liquid crystal display color filter compositions. A preferred photopolymerization initiator and / or photoacid generator addition amount for the curable composition for photo-nanoimprints is not reported. That is, in a system containing dyes and / or pigments, these may act as radical trapping agents, affecting the photopolymerizability and sensitivity. In consideration of this point, the amount of the photopolymerization initiator added is optimized in these applications. On the other hand, in the nanoimprint curable composition of the present invention, dyes and / or pigments are not essential components, and the optimum range of the photopolymerization initiator is in the fields of inkjet compositions, liquid crystal display color filter compositions, and the like. May be different.

  As the radical photopolymerization initiator used in the present invention, acylphosphine compounds and oxime ester compounds are preferable from the viewpoints of curing sensitivity and absorption characteristics. As the photopolymerization initiator, for example, a commercially available initiator can be used. Examples of these include Irgacure® 2959 (1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, Irgacure (available from Ciba). (Registered trademark) 184 (1-hydroxycyclohexyl phenyl ketone), Irgacure (registered trademark) 500 (1-hydroxycyclohexyl phenyl ketone, benzophenone), Irgacure (registered trademark) 651 (2,2-dimethoxy-1,2-diphenylethane- 1-one), Irgacure® 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1), Irgacure® 907 (2-methyl-1 [4- Methylthiophenyl] -2-morpholinop Pan-1-one, Irgacure® 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, Irgacure® 1800 (bis (2,6-dimethoxybenzoyl) -2,4 , 4-trimethyl-pentylphosphine oxide, 1-hydroxy-cyclohexyl-phenyl-ketone), Irgacure® 1800 (bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide) , 2-hydroxy-2-methyl-1-phenyl-1-propan-1-one), Irgacure® OXE01 (1,2-octanedione, 1- [4- (phenylthio) phenyl] -2- ( O-benzoyloxime), Darocur (registered trader) Standard) 1173 (2-hydroxy-2-methyl-1-phenyl-1-propan-1-one), Darocur (R) 1116, 1398, 1174 and 1020, CGI242 (ethanone, 1- [9-ethyl-6 -(2-Methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), Lucirin TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide), Lucirin TPO available from BASF -L (2,4,6-trimethylbenzoylphenylethoxyphosphine oxide), ESACURE 1001M (1- [4-benzoylphenylsulfanyl] phenyl] -2-methyl-2- (4-methyl), available from ESACUR Nippon Siebel Hegner Phenylsulfur Honyl) propan-1-one, N-1414 Adeka optomer (registered trademark) N-1414 (carbazole phenone system), Adeka optomer (registered trademark) N-1717 (acridine system) available from Asahi Denka Co., Ltd. Adekaoptomer (registered trademark) N-1606 (triazine type), TFE-triazine (2- [2- (furan-2-yl) vinyl] -4,6-bis (trichloromethyl) -1 manufactured by Sanwa Chemical Co., Ltd.) , 3,5-triazine), TME-triazine (2- [2- (5-methylfuran-2-yl) vinyl] -4,6-bis (trichloromethyl) -1,3,5, manufactured by Sanwa Chemical Co., Ltd.) -Triazine), MP-triazine (2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine) manufactured by Sanwa Chemical, manufactured by Midori Chemical AZ-113 (2- [2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine), TAZ-108 (2- (3 , 4-dimethoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine), benzophenone, 4,4'-bisdiethylaminobenzophenone, methyl-2-benzophenone, 4-benzoyl-4'- Methyl diphenyl sulfide, 4-phenylbenzophenone, ethyl Michler's ketone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 1-chloro-4-propoxythioxanthone, 2-methylthioxanthone, thioxa Ton ammonium salt, benzoin, 4,4'-dimethoxybenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, 1,1,1-trichloroacetophenone, diethoxyacetophenone and dibenzosuberone , Methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoyldiphenyl ether, 1,4-benzoylbenzene, benzyl, 10-butyl-2-chloroacridone, [4- (methylphenylthio) Phenyl] phenylmethane), 2-ethylanthraquinone, 2,2-bis (2-chlorophenyl) 4,5,4 ′, 5′-tetrakis (3,4,5-trimethoxyphenyl) 1, 2′-biimidazole, 2,2-bis (o-chlorophenyl) 4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, tris (4-dimethylaminophenyl) methane, ethyl-4 -(Dimethylamino) benzoate, 2- (dimethylamino) ethyl benzoate, butoxyethyl-4- (dimethylamino) benzoate, and the like.

  In the present invention, “light” includes not only light having a wavelength in the ultraviolet, near-ultraviolet, far-ultraviolet, visible, infrared, etc., and electromagnetic waves but also radiation. Examples of the radiation include microwaves, electron beams, EUV, and X-rays. Laser light such as a 248 nm excimer laser, a 193 nm excimer laser, and a 172 nm excimer laser can also be used. The light may be monochromatic light (single wavelength light) that has passed through an optical filter, or may be light with a plurality of different wavelengths (composite light). The exposure can be multiple exposure, and the entire surface can be exposed after forming a pattern for the purpose of increasing the film strength and etching resistance.

  The photopolymerization initiator used in the present invention needs to be selected in a timely manner with respect to the wavelength of the light source to be used, but is preferably one that does not generate gas during mold pressurization / exposure. When the gas is generated, the mold is contaminated, so that the mold must be frequently washed, and the curable composition for nanoimprint is deformed in the mold, thereby deteriorating the transfer pattern accuracy.

  The nanoimprint curable composition of the present invention is a radical in which the polymerizable monomer (A) is a radical polymerizable monomer and the photopolymerization initiator (B) is a radical polymerization initiator that generates radicals upon light irradiation. A polymerizable composition is preferred.

(Other ingredients)
The nanoimprint curable composition of the present invention has a surface activity within a range that does not impair the effects of the present invention according to various purposes in addition to the polymerizable monomer (A) and the photopolymerization initiator (B). Other components such as an agent, an antioxidant, a solvent, and a polymer component may be included. The nanoimprint curable composition of the present invention preferably contains at least one selected from a fluorine surfactant, a silicone surfactant, a fluorine / silicone surfactant, and an antioxidant.

-Surfactant-
The nanoimprint curable composition of the present invention preferably contains a surfactant. The content of the surfactant used in the present invention is, for example, 0.001 to 5% by mass, preferably 0.002 to 4% by mass, and more preferably 0.005 to 5% in the entire composition. 3% by mass. When using 2 or more types of surfactant, the total amount becomes the said range. When the surfactant is in the range of 0.001 to 5% by mass in the composition, the effect of coating uniformity is good, and deterioration of mold transfer characteristics due to excessive surfactant is unlikely to occur.

The surfactant is preferably a nonionic surfactant. The nonionic surfactant preferably includes at least one of a fluorine-based surfactant, a silicone-based surfactant, and a fluorine / silicone-based surfactant, and includes a fluorine-based surfactant and a silicone-based surfactant. Or a fluorine / silicone surfactant, and most preferably a fluorine / silicone surfactant.
Here, the “fluorine / silicone surfactant” refers to one having both requirements of a fluorine surfactant and a silicone surfactant.
By using such a surfactant, a silicon wafer for manufacturing a semiconductor element, a glass square substrate for manufacturing a liquid crystal element, a chromium film, a molybdenum film, a molybdenum alloy film, a tantalum film, a tantalum alloy film, a silicon nitride film, Striation that occurs when the nanoimprint curable composition of the present invention is applied to a substrate on which various films are formed, such as an amorphous silicone film, an indium oxide (ITO) film doped with tin oxide, and a tin oxide film, It becomes possible to solve the problem of poor coating such as a scale-like pattern (unevenness of drying of the resist film). In addition, the fluidity of the composition of the present invention into the cavity of the mold recess is improved, the peelability between the mold and the resist is improved, the adhesion between the resist and the substrate is improved, the viscosity of the composition is decreased, etc. Is possible. In particular, the nanoimprint composition of the present invention can significantly improve the coating uniformity by adding the surfactant, and in a coating using a spin coater or a slit scan coater, good coating suitability regardless of the substrate size. Is obtained.

Examples of nonionic fluorosurfactants that can be used in the present invention include trade names Fluorard FC-430 and FC-431 (manufactured by Sumitomo 3M Co., Ltd.), trade names Surflon S-382 (Asahi Glass ( EFTOP EF-122A, 122B, 122C, EF-121, EF-126, EF-127, MF-100 (manufactured by Tochem Products), trade names PF-636, PF-6320, PF -656, PF-6520 (all OMNOVA Solutions, Inc.), trade names FT250, FT251, DFX18 (all manufactured by Neos), trade names Unidyne DS-401, DS-403, DS-451 ( (All are Daikin Industries, Ltd.), trade names Megafuk 171, 172, 173, 178K, 178A (all Dainippon Ink Chemical Kogyo Co., Ltd.).
Examples of the nonionic silicone surfactant include trade name SI-10 series (manufactured by Takemoto Yushi Co., Ltd.), MegaFac Paintad 31 (manufactured by Dainippon Ink & Chemicals, Inc.), KP -341 (manufactured by Shin-Etsu Chemical Co., Ltd.).
Examples of the fluorine / silicone surfactant include trade names X-70-090, X-70-091, X-70-092, X-70-093 (all Shin-Etsu Chemical Co., Ltd. )), And trade names Megafuk R-08 and XRB-4 (both manufactured by Dainippon Ink & Chemicals, Inc.).

-Antioxidant-
Furthermore, the nanoimprint curable composition of the present invention preferably contains a known antioxidant. Content of the antioxidant used for this invention is 0.01-10 mass% with respect to a polymerizable monomer, for example, Preferably it is 0.2-5 mass%. When using 2 or more types of antioxidant, the total amount becomes the said range.
The antioxidant suppresses fading caused by heat or light irradiation and fading caused by various oxidizing gases such as ozone, active oxygen, NO _x , SO _x (X is an integer). In particular, in the present invention, by adding an antioxidant, there is an advantage that coloring of a cured film can be prevented and a reduction in film thickness due to decomposition can be reduced. Examples of such antioxidants include hydrazides, hindered amine antioxidants, nitrogen-containing heterocyclic mercapto compounds, thioether antioxidants, hindered phenol antioxidants, ascorbic acids, zinc sulfate, thiocyanates, Examples include thiourea derivatives, sugars, nitrites, sulfites, thiosulfates, hydroxylamine derivatives, and the like. Among these, hindered phenol antioxidants and thioether antioxidants are particularly preferable from the viewpoint of coloring the cured film and reducing the film thickness.

  Commercially available products of the antioxidants include trade names Irganox 1010, 1035, 1076, 1222 (above, manufactured by Ciba Geigy Co., Ltd.), trade names Antigene P, 3C, FR, Sumilyzer S, and Sumilizer GA80 (Sumitomo Chemical Co., Ltd.). Product name) ADK STAB AO70, AO80, AO503 (manufactured by ADEKA Corporation) and the like. These may be used alone or in combination.

-Solvent-
In the curable composition for nanoimprints of the present invention, a solvent can be used according to various needs. In particular, a solvent is preferably contained when forming a pattern having a thickness of 500 nm or less. A preferable solvent is a solvent having a boiling point of 80 to 200 ° C. at normal pressure. Any solvent can be used as long as it can dissolve the composition, but a solvent having any one or more of an ester structure, a ketone structure, a hydroxyl group, and an ether structure is preferable. Specifically, preferred solvents are propylene glycol monomethyl ether acetate, cyclohexanone, 2-heptanone, gamma butyrolactone, propylene glycol monomethyl ether, ethyl lactate alone or a mixed solvent, and a solvent containing propylene glycol monomethyl ether acetate. Most preferable from the viewpoint of coating uniformity.
The content of the solvent in the composition of the present invention is optimally adjusted depending on the viscosity of the components excluding the solvent, coating properties, and the target film thickness, but from the viewpoint of coating properties, 99 mass% is preferable and 0-90 mass% is further more preferable. In particular, when forming a pattern having a thickness of 500 nm or less, 10 to 98 mass% is preferable, 30 to 98 mass% is more preferable, and 40 to 98 mass% is particularly preferable.

-Polymer component-
In the composition of the present invention, for the purpose of further increasing the crosslinking density, a polyfunctional oligomer having a molecular weight higher than that of the other polyfunctional polymerizable monomer may be blended within a range that achieves the object of the present invention. it can. Examples of the polyfunctional oligomer having photoradical polymerizability include various acrylate oligomers such as polyester acrylate, urethane acrylate, polyether acrylate, and epoxy acrylate. The addition amount of the oligomer component is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, further preferably 0 to 10% by mass, and most preferably 0 to 5% by mass with respect to the component excluding the solvent of the composition. %.
The curable composition for nanoimprinting of the present invention may further contain a polymer component from the viewpoint of improving dry etching resistance, imprintability, curability and the like. The polymer component is preferably a polymer having a polymerizable functional group in the side chain. As a weight average molecular weight of the said polymer component, 2000-100000 are preferable from a compatible viewpoint with a polymerizable monomer, and 5000-50000 are more preferable. The addition amount of the polymer component is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, still more preferably 0 to 10% by mass, and most preferably 2% by mass or less, relative to the component excluding the solvent of the composition. It is. When the content of the polymer component having a molecular weight of 2000 or more is 30% by mass or less in the components excluding the solvent in the composition of the present invention, the pattern forming property is improved. From the viewpoint of pattern forming property, the resin component is as small as possible. The method is preferable, and it is preferable not to include a resin component except for a surfactant and a small amount of additives.

  In addition to the above components, the nanoimprint curable composition of the present invention may include a release agent, a silane coupling agent, a polymerization inhibitor, an ultraviolet absorber, a light stabilizer, an anti-aging agent, a plasticizer, and an adhesion promoter. An agent, a thermal polymerization initiator, a colorant, elastomer particles, a photoacid growth agent, a photobase generator, a basic compound, a flow regulator, an antifoaming agent, a dispersant, and the like may be added.

The curable composition for nanoimprinting of the present invention can be prepared by mixing the above-described components. Moreover, after mixing each said component, it can also prepare as a solution by filtering with a filter with a hole diameter of 0.05 micrometer-5.0 micrometers, for example. Mixing and dissolution of the curable composition for optical nanoimprint is usually performed in a range of 0 ° C to 100 ° C. Filtration may be performed in multiple stages or repeated many times. Moreover, the filtered liquid can be refiltered. The material of the filter used for filtration may be polyethylene resin, polypropylene resin, fluorine resin, nylon resin or the like, but is not particularly limited.
In the curable composition for nanoimprints of the present invention, the viscosity of the components excluding the solvent at 25 ° C. is preferably 1 to 100 mPa · s. More preferably, it is 2-50 mPa * s, More preferably, it is 5-30 mPa * s. By setting the viscosity within an appropriate range, the rectangularity of the pattern can be improved and the remaining film can be kept low.

[Pattern formation method]
Next, the formation method of the pattern (especially fine uneven | corrugated pattern) using the curable composition for nanoimprints of this invention is demonstrated. In the pattern forming method of the present invention, a step of applying (usually coating) the curable composition for nanoimprinting of the present invention onto a substrate such as a substrate or a support to form a pattern forming layer, and the pattern forming layer A fine concavo-convex pattern can be formed by curing the composition of the present invention through a step of pressing a mold on the surface and a step of irradiating the pattern forming layer with light.
Here, the nanoimprint curable composition of the present invention is preferably further heated and cured after light irradiation. Specifically, a layer formed of the composition of the present invention (pattern forming layer) is applied (usually applied) at least on the base material and usually dried as necessary. To form a pattern receptor (with a pattern-forming layer provided on the substrate), press the mold against the surface of the pattern-receiving layer of the pattern receptor, and transfer the mold pattern. The concavo-convex pattern forming layer is cured by light irradiation. The optical imprint lithography according to the pattern forming method of the present invention can be laminated and multiple patterned, and can be used in combination with ordinary thermal imprint.

  The curable composition for nanoimprinting of the present invention can form a fine pattern with low cost and high accuracy by an optical nanoimprinting method. For this reason, what was formed using the conventional photolithographic technique can be formed with further high precision and low cost. For example, an overcoat layer used for a liquid crystal display (LCD) or the like by applying the composition of the present invention to a substrate and exposing, curing, and drying (baking) the layer made of the composition as necessary. It can also be applied as a permanent film such as an insulating film, an etching resist such as a semiconductor integrated circuit, a recording material, or a flat panel display.

  In permanent films (resist for structural members) used in liquid crystal displays (LCDs) and resists used in substrate processing of electronic materials, ions of metals or organic substances in the resist are used so as not to hinder the operation of the product. It is desirable to avoid contamination with sexual impurities as much as possible. For this reason, the concentration of the ionic impurities of the metal or organic matter in the curable composition for nanoimprints of the present invention is preferably 1000 ppm or less, desirably 10 ppm or less, more preferably 100 ppb or less.

Hereinafter, a pattern forming method (pattern transfer method) using the curable composition for nanoimprinting of the present invention will be specifically described.
In the pattern formation method of this invention, first, the composition of this invention is applied on a base material, and a pattern formation layer is formed.
As a method for applying the curable composition for nanoimprinting of the present invention onto a substrate, generally known coating methods such as dip coating, air knife coating, curtain coating, wire bar coating, and gravure coating are used. Method, extrusion coating method, spin coating method, slit scanning method, inkjet method and the like. Moreover, although the film thickness of the pattern formation layer which consists of a composition of this invention changes with uses to be used, it is about 0.05 micrometer-30 micrometers. Further, the composition of the present invention may be applied by multiple coating. Furthermore, you may form other organic layers, such as a planarization layer, for example between a base material and the pattern formation layer which consists of a composition of this invention. Thereby, since a pattern formation layer and a board | substrate do not contact directly, adhesion of the dust with respect to a base material, damage to a base material, etc. can be prevented. In addition, the pattern formed with the composition of this invention is excellent in adhesiveness with an organic layer, even when it is a case where an organic layer is provided on a base material.

  The substrate on which the curable composition for nanoimprinting of the present invention is applied can be selected depending on various applications, for example, quartz, glass, optical film, ceramic material, deposited film, magnetic film, reflective film, Ni, Metal substrates such as Cu, Cr and Fe, paper, SOG (Spin On Glass), polyester film, polycarbonate film, polymer film such as polyimide film, TFT array substrate, PDP electrode plate, glass and transparent plastic substrate, ITO and metal There are no particular restrictions on semiconductor substrates such as conductive substrates, insulating substrates, silicone, silicon nitride, polysilicon, silicone oxide, amorphous silicone, and the like. Further, the shape of the substrate is not particularly limited, and may be a plate shape or a roll shape. In addition, as described later, a light transmissive or non-light transmissive material can be selected as the base material depending on the combination with the mold.

Next, in the pattern forming method of the present invention, a mold is pressed against the surface of the pattern forming layer in order to transfer the pattern to the pattern forming layer. Thereby, the fine pattern previously formed on the pressing surface of the mold can be transferred to the pattern forming layer.
The molding material that can be used in the present invention will be described. In optical nanoimprint lithography using the composition of the present invention, a light transmissive material is selected as at least one of a molding material and / or a base material. In the optical imprint lithography applied to the present invention, a curable composition for nanoimprinting of the present invention is applied onto a substrate to form a pattern forming layer, and a light-transmitting mold is pressed against the surface of the mold. The pattern forming layer is cured by irradiating light from the back surface. Moreover, the curable composition for optical nanoimprint can be apply | coated on a transparent base material, a mold can be pressed, light can be irradiated from the back surface of a base material, and the curable composition for optical nanoimprint can also be hardened.
The light irradiation may be performed with the mold attached or after the mold is peeled off. In the present invention, the light irradiation is preferably performed with the mold in close contact.

As the mold that can be used in the present invention, a mold having a pattern to be transferred is used. The pattern on the mold can be formed according to the desired processing accuracy by, for example, photolithography, electron beam drawing, or the like, but the mold pattern forming method is not particularly limited in the present invention.
The light-transmitting mold material used in the present invention is not particularly limited as long as it has predetermined strength and durability. Specifically, a light transparent resin such as glass, quartz, PMMA, and polycarbonate resin, a transparent metal vapor-deposited film, a flexible film such as polydimethylsiloxane, a photocured film, and a metal film are exemplified.

  In the present invention, the non-light-transmitting mold material used when a light-transmitting substrate is used is not particularly limited as long as it has a predetermined strength. Specific examples include ceramic materials, deposited films, magnetic films, reflective films, metal substrates such as Ni, Cu, Cr, and Fe, and substrates such as SiC, silicone, silicone nitride, polysilicon, silicone oxide, and amorphous silicone. There are no particular restrictions. Further, the shape of the mold is not particularly limited, and may be either a plate mold or a roll mold. The roll mold is applied particularly when continuous transfer productivity is required.

  The mold used in the pattern forming method of the present invention may be a mold subjected to a release treatment in order to improve the peelability between the curable composition for optical nanoimprint and the mold surface. Examples of such molds include those that have been treated with a silane coupling agent such as silicone or fluorine, such as Optool DSX manufactured by Daikin Industries, Ltd. or Novec EGC-1720 manufactured by Sumitomo 3M Co., Ltd. Commercially available release agents can also be suitably used.

  When performing photoimprint lithography using the composition of the present invention, it is usually preferable to perform the mold pressure at 10 atm or less in the pattern forming method of the present invention, but in the present invention, it is performed at 1 to 5 atm. it can. In the present invention, since the mold pressure can be lowered in this way, the mold and the substrate are not easily deformed and the pattern accuracy tends to be improved. Further, since the pressure can be lowered, the apparatus can be reduced. As the mold pressure, it is preferable to select a region in which the uniformity of mold transfer can be ensured within a range in which the remaining film of the curable composition for optical nanoimprinting on the mold convex portion is reduced.

In the pattern forming method of the present invention, the irradiation amount of the light irradiation in the step of irradiating the pattern forming layer may be sufficiently larger than the irradiation amount necessary for curing. The irradiation amount necessary for curing is appropriately determined by examining the consumption of unsaturated bonds of the curable composition for optical nanoimprint and the tackiness of the cured film.
In the photoimprint lithography applied to the present invention, the substrate temperature at the time of light irradiation is usually room temperature, but the light irradiation may be performed while heating in order to increase the reactivity. As a pre-stage of light irradiation, if it is in a vacuum state, it is effective in preventing bubble mixing, suppressing the decrease in reactivity due to oxygen mixing, and improving the adhesion between the mold and the curable composition for optical nanoimprinting. It may be irradiated with light. In the pattern forming method of the present invention, the preferable degree of vacuum at the time of light irradiation is in the range of 10 ⁻¹ Pa to normal pressure.

  The light used for curing the curable composition for nanoimprints of the present invention is not particularly limited. For example, light or radiation having a wavelength in a region such as high energy ionizing radiation, near ultraviolet, far ultraviolet, visible, infrared, etc. Can be mentioned. As the high-energy ionizing radiation source, for example, an electron beam accelerated by an accelerator such as a cockcroft accelerator, a handagraaf accelerator, a linear accelerator, a betatron, or a cyclotron is industrially most conveniently and economically used. However, radiation such as γ rays, X rays, α rays, neutron rays, proton rays emitted from radioisotopes or nuclear reactors can also be used. Examples of the ultraviolet ray source include an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a carbon arc lamp, and a solar lamp. The radiation includes, for example, microwaves and EUV. Also, laser light used in semiconductor microfabrication such as LED, semiconductor laser light, or 248 nm KrF excimer laser light or 193 nm ArF excimer laser can be suitably used in the present invention. These lights may be monochromatic lights, or may be lights having different wavelengths (mixed lights).

During exposure is preferably in the range of exposure intensity of ^{1mW / cm 2 ~50mW / cm 2} . By making the exposure time 1 mW / cm ² or more, the exposure time can be shortened so that productivity is improved, and by making the exposure time 50 mW / cm ² or less, deterioration of the properties of the permanent film due to side reactions can be suppressed. It tends to be preferable. The exposure dose is desirably in the range of 5 mJ / cm ^{2 to} 1000 mJ / cm ² . If it is less than 5 mJ / cm ² , the exposure margin becomes narrow, photocuring becomes insufficient, and problems such as adhesion of unreacted substances to the mold tend to occur. On the other hand, if it exceeds 1000 mJ / cm ² , the permanent film may be deteriorated due to decomposition of the composition.
Further, during exposure, in order to prevent inhibition of radical polymerization by oxygen, an inert gas such as nitrogen or argon may be flowed to control the oxygen concentration to less than 100 mg / L.

  In the pattern formation method of this invention, after hardening a pattern formation layer by light irradiation, it may include the process of applying the heat | fever to the pattern hardened | cured as needed and further making it harden | cure. As heat which heat-hardens the composition of this invention after light irradiation, 150-280 degreeC is preferable and 200-250 degreeC is more preferable. In addition, the time for applying heat is preferably 5 to 60 minutes, and more preferably 15 to 45 minutes.

  As described above, the pattern formed by the pattern forming method of the present invention can be used as a permanent film (resist for a structural member) used in a liquid crystal display (LCD) or the like. In addition, the permanent film is bottled in a container such as a gallon bottle or a coated bottle after manufacture, and is transported and stored. In this case, in order to prevent deterioration, the container is filled with inert nitrogen or argon. It may be replaced. Further, at the time of transportation and storage, the temperature may be normal temperature, but the temperature may be controlled in the range of −20 ° C. to 0 ° C. in order to prevent the permanent film from being altered. Of course, it is preferable to shield from light so that the reaction does not proceed.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Synthesis Example 1]
-Synthesis of Compound I-1A-
15.4 g of trimethylolethane was dissolved in 250 ml of acetone, and 77.7 g of triethylamine was added thereto. Under ice cooling, 58 g of acrylic acid chloride was added dropwise over 30 minutes, and then reacted at room temperature for 2 hours. Water was added to the reaction solution, which was then extracted with ethyl acetate, and the organic phase was washed with water, dried and concentrated to obtain a crude product. This was purified by column chromatography to obtain 16 g of Compound I-1A. Compound I-1A was liquid at 25 ° C., and its viscosity at 25 ° C. was 23 mPa · s.
¹ H-NMR (CDCL ₃ ): δ1.1 (s, 3H), δ4.2 (s, 6H), δ5.9 (d, 3H), δ6.1 (dd, 3H), δ6.4 (d , 3H)

Ｉ−２ＡおよびＩ−３Ａは、それぞれ、ｎ¹＋ｎ²＋ｎ³及び、ｌ¹＋ｌ²＋ｌ³の値が平均３となる化合物の混合物である。

I-2A and I-3A are mixtures of compounds that average n ¹ + n ² + n ³ and l ¹ + l ² + l ³ , respectively.

[Preparation of curable composition for nanoimprint]
In the polymerizable monomer shown in the following table, photopolymerization initiator P-1 (2% by mass), surfactant W-1 (0.1% by mass), surfactant W-2 (0.04% by mass) ) And antioxidants A-1 and A-2 (each 1% by mass) were added to prepare a curable composition for nanoimprinting. Here, the numerical value in the parenthesis of each component has shown the compounding quantity (mass%) with respect to all the polymerizable monomers (10g).

<Other polymerizable monomers>
R1: benzyl acrylate (Biscoat # 160: manufactured by Osaka Organic Chemical Co., Ltd.)
R2: Trimethylolpropane triacrylate (Aronix M-309: manufactured by Toagosei Co., Ltd.)
R3: Trimethylolethane trimethacrylate R4: Trimethylolpropane trimethacrylate (TPMT: Shin-Nakamura Kogyo Co., Ltd.)

<Photopolymerization initiator>
P-1: 2,4,6-trimethylbenzoyl-ethoxyphenyl-phosphine oxide (Lucirin TPO-L: manufactured by BASF)

<Surfactant>
W-1: Fluorosurfactant (manufactured by Tochem Products Co., Ltd .: Fluorosurfactant)
W-2: Silicone surfactant (manufactured by Dainippon Ink and Chemicals, Inc .: MegaFuck Paint 31)

<Antioxidant>
A-1: Sumilizer GA80 (manufactured by Sumitomo Chemical Co., Ltd.)
A-2: ADK STAB AO503 (manufactured by ADEKA Corporation)

(Evaluation 1)
The following evaluation was performed about the obtained composition. The results are shown in the table below.

<Pattern formability>
The compositions of Example 1 and Comparative Example 1 were each dissolved in propylene glycol monomethyl ether acetate to prepare a 20% by mass solution. This was spin-coated on a silicon substrate so that the film thickness when the coating film was photocured without placing a mold was 200 nm, and baked on a hot plate at 80 ° C. for 30 seconds to obtain a coating film. The obtained coating film was placed in a nanoimprint apparatus with a mold having a pattern surface made of quartz having a 200 nm line / space pattern and a groove depth of 200 nm made of quartz as a material. The inside of the apparatus was evacuated and then purged with nitrogen to replace the inside of the apparatus with nitrogen. The mold was pressure-bonded to the substrate at 25 ° C. and a pressure of 1.5 atm, and exposed to this from the back surface of the mold under the condition of 100 mJ / cm ^2. After exposure, the mold was released to obtain a pattern. The obtained pattern was observed with SEM, and the pattern shape and curability were evaluated according to the following criteria.

(Pattern shape)
A: A rectangular pattern faithful to the mold pattern.
B: The pattern top was rounded.
C: The pattern top was rounded and the pattern height was insufficient.

(Curable)
Each of the compositions of Example 1 and Comparative Example 1 was spin-coated on a glass substrate, and it was confirmed whether it was tack-free after exposure under the condition of 100 mJ / cm ² .
○: Tack-free ×: Not tack-free

(Evaluation 2)
The following evaluation was performed about the obtained composition. The results are shown in the table below.

<Pattern formability>
The compositions of Examples 2 to 4 and Comparative Examples 2 to 4 were each spin-coated on a silicon substrate. The obtained coating film was placed in a nanoimprint apparatus with a mold having a pattern surface made of quartz having a 200 nm line / space pattern and a groove depth of 200 nm made of quartz as a material. The inside of the apparatus was evacuated and then purged with nitrogen to replace the inside of the apparatus with nitrogen. The mold was pressure-bonded to the substrate at 25 ° C. and a pressure of 0.1 MPa, exposed to this from the back surface of the mold at 100 mJ / cm ² , and after exposure, the mold was released to obtain a pattern. In the comparative example, those that were not cured under the condition of 100 mJ / cm ² were exposed under the condition of 1 J / cm ² , and the pattern was formed in the same manner as in the examples.
The obtained pattern was observed with SEM, and the pattern shape and curability were evaluated in the same manner as in Evaluation 1.

Among the above, regarding pattern formation, Comparative Examples 3 and 4 were not cured under the condition of 100 mJ / cm ² , and thus were exposed under the condition of 1 J / cm ² .

(Evaluation 3)
The composition of Examples 1 to 4 was evaluated using the same method as in Evaluation 2 except that the pressure for pressing the mold to the substrate was 0.5 MPa and 1 MPa. The rectangular pattern faithful to the mold pattern at any pressure was gotten.

As is apparent from the above table, it can be seen that the pattern produced using the composition of the present invention is excellent in pattern formability and good curability. On the other hand, the pattern formed using the composition of the comparative example was found to be poor in pattern formation for those having good curability, and poor in curability for those having good pattern formation.
As described above, by using the composition of the present invention, it is possible to exhibit good fine pattern formability at any pressure from a conventional high pressure to a low pressure, and to achieve both excellent photocurability.

Claims (12)

A polymerizable monomer comprising (A) a polymerizable monomer and (B) a photopolymerization initiator, wherein at least one of the (A) polymerizable monomer is represented by the following general formula (I) A curable composition for nanoimprinting, which is (Ax).
Formula (I)

(In the general formula (I), X ^{1 to} X ³ each independently represents a single bond or a linking group. Me represents a methyl group.) The curable composition for nanoimprints according to claim 1, wherein 50% by mass or more of the polymerizable monomer (A) is a compound that is liquid at 25 ° C. (A) The curable composition for nanoimprints according to claim 1 or 2, wherein 50% by mass or more of the polymerizable monomer is a compound having an acrylate group. X ^{1 to} X ^{3 in} the general formula (I) are each a single bond, an oxyalkylene group, —O—C (═O) — or an alkylene group, or a group composed of a combination of two or more thereof. Item 4. The curable composition for nanoimprints according to any one of Items 1 to 3. The curable composition for nanoimprints according to any one of claims 1 to ³ , wherein X ^{1 to} X ^{3 in} the general formula (I) are single bonds. The polymerizable monomer (A) other than the polymerizable monomer (Ax) represented by the general formula (I) includes a polymerizable monomer having an ethylenically unsaturated bond-containing group. 6. The curable composition for nanoimprints according to any one of 5 above. The curable composition for nanoimprints according to any one of claims 1 to 6, wherein the content of a polymer component having a molecular weight of 2000 or more is 30% by mass or less of the content of all polymerizable monomers. The curable composition for nanoimprints according to any one of claims 1 to 7, comprising at least one selected from a surfactant and an antioxidant. A pattern forming method using the curable composition for nanoimprints according to claim 1. Applying the curable composition for nanoimprints according to any one of claims 1 to 8 on a substrate to form a pattern forming layer;
Pressing the mold against the surface of the pattern forming layer;
Irradiating the pattern forming layer with light. A pattern forming method comprising: The pattern forming method according to claim 10, wherein the pressing of the mold is performed at 1 to 5 atm. The pattern formation method according to claim 10 or 11, wherein the light irradiation is performed at an exposure amount of 5 mJ / cm ^{2 to} 1000 mJ / cm ² .