WO2016104670A1

WO2016104670A1 - Photocurable composition for imprinting, pattern formation method, and device production method

Info

Publication number: WO2016104670A1
Application number: PCT/JP2015/086165
Authority: WO
Inventors: 北川　浩隆; 雄一郎後藤
Original assignee: 富士フイルム株式会社
Priority date: 2014-12-25
Filing date: 2015-12-25
Publication date: 2016-06-30
Also published as: TW201627431A; JPWO2016104670A1; JP6379220B2

Abstract

Provided is a photocurable composition for imprinting, said composition exhibiting good inkjet discharge accuracy that has good temporal stability. Also provided are a pattern formation method and a device production method. This photocurable composition for imprinting contains: a (meth)acrylate (A) that does not include a fluorine atom; a (meth)acrylate (B) that includes a fluorine atom and is represented by general formula (I); and a photopolymerization initiator (C). In the formula, R^f represents a C1-9 fluorine-containing alkyl group in which at least one hydrogen atom in the alkyl group is substituted with a fluorine atom; L represents a single bond, -O-, -OC(=O)-, or -C(=O)O-; R¹ represents a hydrogen atom or a methyl group; and n represents an integer from 1 to 8, or represents an integer from 3 to 8 if L is a single bond.

Description

Photo-curable composition for imprint, pattern forming method and device manufacturing method

The present invention relates to a photocurable composition for imprinting, a pattern forming method, and a device manufacturing method. More specifically, a semiconductor integrated circuit, a micro electro mechanical system (MEMS), a recording medium such as an optical disk and a magnetic disk, a light receiving element such as a solid-state imaging element, and a light emitting element such as a light emitting diode (LED) and organic electroluminescence (organic EL). , Optical devices such as liquid crystal display devices (LCD), diffraction gratings, relief holograms, optical waveguides, optical filters, optical components such as microlens arrays, thin film transistors, organic transistors, color filters, antireflection films, polarizing elements, optical films , Materials for flat panel displays such as pillars, nanobiodevices, immunoassay chips, deoxyribonucleic acid (DNA) separation chips, microreactors, photonic liquid crystals, and directed self-assembly of block copolymers (directed self-as Embly, relates imprint photocurable composition, a pattern forming method and pattern for pattern formation using the light irradiation used in the preparation of the guide pattern or the like for DSA).

The imprint method is an evolution of embossing technology known for optical disc production, and precisely uses the fine pattern of the original mold (generally called molds, stampers, and templates) on which irregular patterns are formed. Transfer technology. Once a mold is produced, it is economical because a microstructure such as a nanostructure can be easily and repeatedly molded, and in recent years, application to various fields is expected.

As an imprint method, a thermal imprint method using a thermoplastic resin as a material to be processed (see, for example, Non-Patent Document 1) and an optical imprint method using a photocurable composition (for example, Non-Patent Document 2, Non-Patent Document) Document 3) has been proposed. In the thermal imprint method, after pressing a mold onto a thermoplastic resin heated to a temperature higher than the glass transition temperature, the mold is peeled off after being cooled to a temperature lower than the glass transition temperature, thereby transferring the microstructure to the resin.

On the other hand, the light imprint method is a method of transferring a fine pattern to a photocured product by peeling the mold after light curing through a light transmissive mold or a light transmissive substrate to cure the photocurable composition. is there. Since this method enables imprinting at room temperature, it can be applied to the field of precision processing of ultrafine patterns such as the fabrication of semiconductor integrated circuits.

By the way, since the optical imprint method has a step of peeling the mold, the mold releasability has been a problem from the beginning. As an attempt to improve mold releasability, a method in which a fluorinated compound is contained in a curable composition is known (Patent Documents 1 to 6, Non-Patent Document 4).

JP 2006-114882 A International Publication WO2006 / 114958 Pamphlet JP 2008-95037 A JP 2010-258026 A JP 2010-239121 A JP 2010-45163 A

As one of the methods for applying the photocurable composition for imprint on a substrate or a mold, there is an ink jet method. The inkjet method can adjust the coating amount of the photocurable composition according to the density of the pattern, so that it can reduce uneven thickness of the remaining film and has an advantage of excellent pattern transferability in etching processing. Furthermore, compared to the spin coat method, the material utilization efficiency is high, and there are also advantages of reduction in production cost and environmental load. On the other hand, in order to form a fine pattern with high accuracy, it is required to control the landing position of a droplet discharged from an inkjet head with high accuracy.

By the way, in the inkjet method, the photocurable composition may be stored in a tank such as an inkjet cartridge for a long period of time. According to the study of the present inventor, it has been found that the photocurable composition stored in the ink jet cartridge for a long period of time may deteriorate the ink jet ejection accuracy.

Therefore, an object of the present invention is to provide a photocurable composition for imprint, a pattern forming method, and a device manufacturing method, which have good ink jet discharge accuracy and good temporal stability of the ink jet discharge accuracy.

As a result of intensive studies by the present inventors under such circumstances, the present inventors have found that the above object can be achieved by using a (meth) acrylate containing a fluorine atom, which will be described later, and have completed the present invention. The present invention provides the following.
<1> (meth) acrylate (A) containing no fluorine atom;
(Meth) acrylate (B) containing a fluorine atom;
A photopolymerization initiator (C);
A photocurable composition for imprints, which contains (meth) acrylate (B) containing a fluorine atom and is represented by the following general formula (I).

In the formula, R ^f represents a fluorine-containing alkyl group having 1 to 9 carbon atoms in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom;
L represents a single bond, —O—, —OC (═O) —, or —C (═O) O—,
R ¹ represents a hydrogen atom or a methyl group,
n represents an integer of 1 to 8, and when L is a single bond, it represents an integer of 3 to 8.
<2> The photocurable composition for imprints according to <1>, wherein the (meth) acrylate (B) containing a fluorine atom has a boiling point of 100 to 200 ° C. under a pressure of 0.67 kPa.
<3> In the general formula (I), R ^f is a fluorine-containing alkyl group having 1 to 9 carbon atoms in which 40 to 100% of hydrogen atoms of the alkyl group are substituted with fluorine atoms, <1> or <2 > The photocurable composition for imprints described in>.
<4> In the general formula (I), R ^f is a group comprising a perfluoroalkyl group having 4 to 6 carbon atoms and an alkylene group having 1 to 3 carbon atoms, and any one of <1> to <3> The photocurable composition for imprints described.
<5> The imprint according to any one of <1> to <4>, wherein the photocurable composition for imprints contains 1 to 5% by mass of a (meth) acrylate (B) containing a fluorine atom. Photocurable composition.
<6> The photocurable composition for imprints according to any one of <1> to <5>, further comprising 1 to 5% by mass of a non-polymerizable compound (D) having a polyoxyalkylene structure.
<7> The photocurable composition for imprints according to any one of <1> to <6>, wherein the viscosity is 5 to 12 mP · s at 23 ° C. and the surface tension is 27 to 33 mN / m.
<8> A step of applying the photocurable composition for imprints according to any one of <1> to <7> onto a substrate or a mold having a pattern by an inkjet method; The step of sandwiching the photocurable composition between the mold and the substrate, and the photocurable composition for imprinting are irradiated with light in a state of sandwiching the photocurable composition for imprinting between the mold and the substrate. A pattern forming method including a curing step and a mold peeling step.
<9> A device manufacturing method including a step of etching a substrate using a pattern produced by the pattern forming method according to <8> as a mask.

According to the present invention, it is possible to provide a photocurable composition for imprint, a pattern forming method, and a device manufacturing method that have good ink jet discharge accuracy and good temporal stability of ink jet discharge accuracy.

Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.

In the present specification, “to” is used in the sense of including the numerical values described before and after it as lower and upper limits.
In the present specification, “(meth) acrylate” represents acrylate and methacrylate, “(meth) acryl” represents acryl and methacryl, and “(meth) acryloyl” represents acryloyl and methacryloyl.
In the present specification, “imprint” preferably refers to pattern transfer having a size of 1 nm to 100 μm, more preferably pattern transfer having a size (nanoimprint) of 10 nm to 1 μm.
In the description of a group (atomic group) in this specification, the description which does not describe substitution and unsubstituted includes the group which has a substituent with the group which 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).
In this specification, “light” includes not only light in a wavelength region such as ultraviolet, near ultraviolet, far ultraviolet, visible, infrared, and electromagnetic waves, but also radiation. Examples of radiation include microwaves, electron beams, extreme ultraviolet rays (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 having a plurality of different wavelengths (composite light).
In this specification, solid content means the total mass of the component remove | excluding the solvent from the whole composition of the composition.

<Photocurable composition for imprint>
The photocurable composition for imprints of the present invention (hereinafter sometimes simply referred to as “the curable composition of the present invention”) contains a (meth) acrylate (A) containing no fluorine atom and a fluorine atom. (Meth) acrylate (B) and photopolymerization initiator (C), and (meth) acrylate (B) containing a fluorine atom is represented by general formula (I) described later. It is.
Hereinafter, “(meth) acrylate (A) containing no fluorine atom” is also referred to as “(meth) acrylate (A)”. The “(meth) acrylate (B) containing a fluorine atom” is also referred to as “fluorinated (meth) acrylate (B)”.

The curable composition of the present invention has good inkjet discharge accuracy and good temporal stability of inkjet discharge accuracy. Such an effect is estimated to be as follows.
Since the curable composition of this invention contains fluorine-containing (meth) acrylate (B), the surface tension of a composition can be lowered | hung moderately and it is excellent in inkjet discharge precision. Further, the surface energy of the cured film can be lowered, and the mold release property is excellent.
As described above, in the ink jet method, the curable composition is discharged from the nozzle head of the ink jet coating apparatus, and the curable composition is applied onto the substrate or the mold. May be stored in the tank for a long time. The curable composition of this invention contains the fluorine-containing (meth) acrylate (B) represented by general formula (I) mentioned later. Since the fluorine-containing (meth) acrylate (B) represented by the general formula (I) has a relatively high boiling point, it is difficult to volatilize. For this reason, it is considered that the curable composition of the present invention has a small fluctuation in surface tension during storage, and can improve the stability over time of the inkjet ejection accuracy.
Hereinafter, each component of the curable composition of this invention is demonstrated.

<< (Meth) acrylate (A) >>
The curable composition of the present invention contains (meth) acrylate (A).
The (meth) acrylate (A) is a (meth) acrylate containing no fluorine atom, and is not particularly limited as long as it does not depart from the gist of the present invention.
The curable composition of the present invention has a monofunctional (meth) acrylate (A1) having one (meth) acryloyloxy group and two or more (meth) acryloyloxy groups as (meth) acrylate (A). It is preferable to use a polyfunctional (meth) acrylate (A2).

<< Monofunctional (meth) acrylate (A1) >>
As the monofunctional (meth) acrylate (A1), a chain aliphatic (meth) acrylate (A1-1), a (meth) acrylate (A1-2) having an aromatic structure or an alicyclic hydrocarbon structure, a chain (Meth) acrylate (A1-3) other than aliphatic (meth) acrylate (A1-1) and (meth) acrylate (A1-2) (hereinafter referred to as (meth) acrylate (A1-3) having other structures) And a chain aliphatic (meth) acrylate (A1-1) is preferable.

In the present invention, the molecular weight of the monofunctional (meth) acrylate (A1) is preferably 160 to 350, more preferably 195 to 315, still more preferably 210 to 285, and most preferably 225 to 270. When the molecular weight is in the above range, both low viscosity and low volatility can be achieved.

In the present invention, the monofunctional (meth) acrylate (A1) preferably has a boiling point of 80 to 220 ° C., more preferably 100 to 200 ° C., and 110 to 180 ° C. under a pressure of 0.67 kPa. More preferred is 120 to 160 ° C. If the boiling point is 100 ° C. or higher under a pressure of 0.67 kPa, volatilization of the monofunctional (meth) acrylate (A1) during storage can be suppressed. If the boiling point is 200 ° C. or less under a pressure of 0.67 kPa, distillation purification can be easily performed, and a highly pure monofunctional (meth) acrylate (A1) can be produced with high productivity.

The chain aliphatic (meth) acrylate (A1-1) is preferably an ester of a linear or branched aliphatic alcohol having 8 to 20 carbon atoms and (meth) acrylic acid, and has 9 to 16 carbon atoms. More preferably, it is an ester of a linear or branched aliphatic alcohol and (meth) acrylic acid, and an ester of a linear or branched aliphatic alcohol having 10 to 14 carbon atoms and (meth) acrylic acid. More preferably, it is most preferably an ester of a linear or branched aliphatic alcohol having 12 carbon atoms and (meth) acrylic acid.
In the present invention, the “chain aliphatic (meth) acrylate” refers to a linear or branched aliphatic (meth) acrylate that does not contain an aromatic structure, an alicyclic hydrocarbon structure, and a heterocyclic structure. means.
Specific examples of the chain aliphatic (meth) acrylate (A1-1) include n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, and i-nonyl (meth) acrylate. , N-decyl (meth) acrylate, i-decyl (meth) acrylate, 2-propylheptyl (meth) acrylate, n-undecyl (meth) acrylate, n-dodecyl (meth) acrylate, 2-butyloctyl (meth) acrylate N-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, and 2-octadecyl (meth) acrylate. Among these, n-decyl acrylate, i-decyl acrylate, 2-propylheptyl acrylate, n-undecyl acrylate, n-dodecyl acrylate, 2-butyloctyl acrylate, n-tridecyl acrylate, and n-tetradecyl acrylate are more preferred. Preferably, n-undecyl acrylate, n-dodecyl acrylate, 2-butyl octyl acrylate, n-tridecyl acrylate, and n-tetradecyl acrylate are more preferable, and n-dodecyl acrylate or 2-butyl octyl acrylate is particularly preferable.

The (meth) acrylate (A1-2) having an aromatic structure or an alicyclic hydrocarbon structure is an ester of an aromatic alcohol or alicyclic alcohol having 7 to 20 carbon atoms and (meth) acrylic acid. More preferably, it is more preferably an ester of an aromatic alcohol or alicyclic alcohol having 8 to 15 carbon atoms and (meth) acrylic acid, and an aromatic alcohol or alicyclic alcohol having 9 to 13 carbon atoms (meta) Most preferably, it is an ester with acrylic acid.
Specific examples of the (meth) acrylate (A1-1) having an aromatic structure or an alicyclic hydrocarbon structure include, for example, benzyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, and a substituent on the aromatic ring. (Preferred substituents are alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, cyano groups), 1- or 2-naphthyl (meth) acrylate, 1- or 2 -Naphtylmethyl (meth) acrylate, 1- or 2-naphthylethyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate, 1-ethylcyclopentyl (meth) acrylate, 1-ethylcyclohexyl (meth) acrylate, isobornyl (Meth) acrylate, dicyclopentanyl (meth) Acrylate, dicyclopentanyl oxyethyl (meth) acrylate, adamantyl (meth) acrylate. Among these, benzyl acrylate or 2-naphthylmethyl acrylate having a linear or branched alkyl group having 3 to 6 carbon atoms on the aromatic ring is particularly preferable.

Examples of the (meth) acrylate (A1-3) having other structures include (meth) acrylates having a polar functional group or a heterocyclic structure.
Specific examples of the (meth) acrylate (A1-3) having other structures include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol ( (Meth) acrylate, dipropylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxydipropylene glycol ( (Meth) acrylate, methoxytripropylene glycol (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate 2-cyanoethyl acrylate, N, N-dimethylaminoethyl (meth) acrylate, tert-butylaminoethyl (meth) acrylate, tetramethylpiperidyl (meth) acrylate, pentamethylpiperidyl (meth) acrylate, β-carboxyethyl (meth) Acrylate, 2- (meth) acryloyloxyethyl succinic acid, (meth) acryloyloxyethyl acid phosphate, glycidyl (meth) acrylate, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, tetrahydrofurfuryl (meta ) Acrylate, 2,2-dimethyl-4- (meth) acryloyloxymethyldioxolane, 2-ethyl-2-methyl-4- (meth) acryloyloxymethyldioxolane, 2-isobutyl-2-methyl-4- ( Me ) Acryloyloxy methyl dioxolane, .gamma.-butyrolactone (meth) acrylate, and mevalonic lactone (meth) acrylate. Addition of these (meth) acrylates having a polar functional group or a heterocyclic structure may improve the adhesion between the cured product and the substrate.

The monofunctional (meth) acrylate (A1) is preferably contained in an amount of 5 to 60% by mass in the curable composition of the present invention. The lower limit is more preferably 10% by mass or more. The upper limit is more preferably 40% by mass or less, and still more preferably 30% by mass or less. When the content of the monofunctional (meth) acrylate (A1) is 10% by mass or more, the inkjet discharge accuracy and mold releasability can be improved. Moreover, when content of monofunctional (meth) acrylate (A1) shall be 40 mass% or less, the pattern excellent in film | membrane intensity | strength will be obtained. As for monofunctional (meth) acrylate (A1), only 1 type may be used and 2 or more types may be used together. When using 2 or more types, it is preferable that the total amount becomes the said range.

<< Polyfunctional (meth) acrylate (A2) >>
The polyfunctional (meth) acrylate (A2) is preferably an ester of an aliphatic polyhydric alcohol or an aromatic polyhydric alcohol and (meth) acrylic acid.
The polyfunctional (meth) acrylate (A2) is a (meth) acrylate having two or more (meth) acryloyloxy groups, and is not particularly limited as long as it does not depart from the gist of the present invention. More preferably, it has 2 to 6 acryloyloxy groups, more preferably 2 or 3, and most preferably 2.
The polyfunctional (meth) acrylate (A2) is a (meth) acrylate (A2-1) having an aromatic structure or an alicyclic hydrocarbon structure, and / or a chain aliphatic polyfunctional (meth) acrylate (A2). -2). The inclusion of (meth) acrylate (A2-1) having an aromatic structure or an alicyclic hydrocarbon structure is preferred because it tends to improve etching resistance. When the chain aliphatic polyfunctional (meth) acrylate (A2-2) is included, the viscosity can be reduced, and therefore, there is a tendency that the ink jet discharge property and the filling property to the uneven pattern of the mold can be improved, which is preferable.
The polyfunctional (meth) acrylate (A2) may be composed only of (meth) acrylate (A2-1) having an aromatic structure or an alicyclic hydrocarbon structure, or a chain aliphatic polyfunctional ( (Meth) acrylate (A2-2) may be used alone, or (meth) acrylate (A2-1) having an aromatic structure or an alicyclic hydrocarbon structure and a chain aliphatic polyfunctional (meth) An acrylate (A2-2) may be contained.

The molecular weight of the polyfunctional (meth) acrylate (A2) is preferably 170 to 600, more preferably 190 to 300, and still more preferably 210 to 270. When the molecular weight is in the above range, low volatility, low viscosity, and film strength can be established.
The polyfunctional (meth) acrylate (A2) preferably has a boiling point of 90 ° C. or higher under a pressure of 0.67 kPa, more preferably 100 ° C. or higher, and more preferably 110 ° C. or higher. preferable.

Specific examples of the polyfunctional (meth) acrylate (A2-1) include o-, m-, p-phenylene di (meth) acrylate, o-, m-, p-xylylene di (meth) acrylate, bisphenol A di ( (Meth) acrylate, EO-modified bisphenol A di (meth) acrylate, PO-modified bisphenol A di (meth) acrylate, EO-modified bisphenol F di (meth) acrylate, 9,9-bis [4- (2- (meth) acryloyloxy) Ethoxy) phenyl] fluorene, cyclohexanediol di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, norbornane dimethanol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 1,3-adamantanediol di (Meta) Acrelay There are exemplified.
Among these, m-xylylene diacrylate, cyclohexane dimethanol diacrylate, and tricyclodecane dimethanol diacrylate are particularly preferably used in the present invention.
Specific examples of the polyfunctional (meth) acrylate (A2-2) include ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 2- Butyl-2-ethyl-1,3-propanediol di (meth) acrylate, 1,10-decandiol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, polyethylene glycol Rudi (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, EO modified neopentyl glycol di (meta) ) Acrylate, PO-modified neopentyl glycol di (meth) acrylate, 2,2-dimethyl-3-((meth) acryloyloxy) propionic acid 2,2-dimethyl-3-((meth) acryloyloxy) propyl, 2- Hydroxy-3-acryloyloxypropyl methacrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythris Tall tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris (2- (meth) acryloyloxyethyl) isocyanurate are exemplified.
Among these, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 3-methyl-1,5-pentanediol diacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate is particularly preferably used in the present invention.

The polyfunctional (meth) acrylate (A2) is preferably contained in an amount of 40 to 89% by mass in the curable composition of the present invention. The lower limit is more preferably 50% by mass or more. The upper limit is more preferably 75% by mass or less. If content of polyfunctional (meth) acrylate (A2) is the said range, the pattern excellent in film | membrane intensity | strength will be obtained.
The mass ratio of the monofunctional (meth) acrylate (A1) to the polyfunctional (meth) acrylate (A2) is preferably 10:90 to 40:60, more preferably 15:85 to 35:55, and 20:80 to 30:70 is more preferable. By setting it as such a range, a permanent jet discharge precision, mold filling property, sclerosis | hardenability, mold release property, the intensity | strength of a cured film, and etching tolerance can be improved.
Only 1 type may be used for polyfunctional (meth) acrylate (A2), and 2 or more types may be used together. When using 2 or more types, it is preferable that the total amount becomes the said range.

<< Fluorine-containing (meth) acrylate (B) >>
The curable composition of this invention contains the fluorine-containing (meth) acrylate (B) represented by the following general formula (I).

In the formula, R ^f represents a fluorine-containing alkyl group having 1 to 9 carbon atoms in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom;
L represents a single bond, —O—, —OC (═O) —, or —C (═O) O—,
R ¹ represents a hydrogen atom or a methyl group,
n represents an integer of 1 to 8, and when L is a single bond, it represents an integer of 3 to 8.

In the general formula (I), R ^f represents a fluorine-containing alkyl group having 1 to 9 carbon atoms in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom. R ^f may be linear, branched or cyclic, but is preferably linear or branched, more preferably linear.
In the present specification, “a fluorine-containing alkyl group having 1 to 9 carbon atoms in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom” means a carbon atom having 1 to 9 carbon atoms containing a fluorine atom as a substituent. The alkyl group is not limited to the group synthesized by substituting the hydrogen atom of the alkyl group with a fluorine atom.
R ^f has more preferably 2 to 9, more preferably 4 to 9, still more preferably 5 to 8, and particularly preferably 6 to 8.
The fluorine atom substitution rate of R ^f is preferably 40 to 100%, more preferably 50 to 90%, and even more preferably 65 to 85%. According to this aspect, mold releasability can be improved. The substitution rate of fluorine atoms refers to the ratio (%) in which hydrogen atoms are substituted with fluorine atoms in alkyl groups having 1 to 9 carbon atoms.
R ^f is a fluorine-containing alkyl group comprising a perfluoroalkyl group having 4 to 6 carbon atoms and an alkylene group having 1 to 3 carbon atoms, or an ω-H-perfluoroalkyl group having 4 to 6 carbon atoms and one carbon atom. A fluorine-containing alkyl group comprising 3 to 3 alkylene groups is preferred, and a fluorine-containing alkyl group comprising 4 to 6 carbon perfluoroalkyl groups and 1 to 3 carbon alkylene groups is more preferred.
Specific examples of R ^f include CF ₃ CH ₂ —, CF ₃ CF ₂ CH ₂ —, CF ₃ (CF ₂ ) ₂ CH ₂ —, CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ —, CF ₃ (CF _{_{_{_{2) 4 CH 2 CH 2 CH}}}} 2 -, CF 3 (CF 2) 4 CH 2 -, CF 3 (CF 2) 5 CH 2 CH 2 -, CF 3 (CF 2) 5 CH 2 CH 2 CH 2 -, (CF ₃ ) ₂ CH—, (CF ₃ ) ₂ C (CH ₃ ) CH ₂ —, (CF ₃ ) ₂ CF (CF ₂ ) ₂ CH ₂ CH ₂ —, (CF ₃ ) ₂ CF (CF ₂ ) ₄ CH ₂ CH ₂ —, H (CF ₂ ) ₂ CH ₂ —, H (CF ₂ ) ₄ CH ₂ —, H (CF ₂ ) ₆ CH ₂ —, H (CF ₂ ) ₈ CH ₂ — and the like. Among these, CF ₃ (CF ₂ ) ₄ CH ₂ —, CF ₃ (CF ₂ ) ₅ CH ₂ —, CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ —, CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ CH ₂ —, H (CF ₂ ) ₆ CH ₂ — is more preferred, CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ — or CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ CH ₂ — is more preferred, and CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ — is particularly preferred.

In the general formula (I), L represents a single bond, —O—, —OC (═O) —, or —C (═O) O—, but —O— or —OC (═O )-Is more preferred, and -O- is most preferred.

In the general formula (I), R ¹ represents a hydrogen atom or a methyl group. From the viewpoint of reactivity, R ¹ is preferably a hydrogen atom.
In the general formula (I), n represents an integer of 1 to 8, and when L is a single bond, it represents an integer of 3 to 8.
When L is —O—, —OC (═O) —, or —C (═O) O—, n is more preferably 1 to 5, and further preferably 1 to 3. When L is a single bond, n is more preferably 3 to 7, and further preferably 3 to 5. By setting n within the above range, the boiling point under a pressure of 0.67 kPa can be adjusted to 100 to 200 ° C.

The molecular weight of the fluorine-containing (meth) acrylate (B) is preferably 430 to 600, more preferably 440 to 550, and still more preferably 450 to 500. When the molecular weight is in the above range, both suppression of volatility and suitability for distillation purification can be achieved.

In the present invention, the fluorine-containing (meth) acrylate (B) preferably has a boiling point of 100 to 200 ° C., more preferably 100 to 180 ° C., and 100 to 160 ° C. under a pressure of 0.67 kPa. Further preferred. If the boiling point is 100 ° C. or higher under a pressure of 0.67 kPa, volatilization of the fluorine-containing (meth) acrylate (B) during storage can be suppressed. If the boiling point is 200 ° C. or less under a pressure of 0.67 kPa, distillation purification can be easily performed, and high-purity fluorine-containing (meth) acrylate (B) can be produced with high productivity.

Preferable specific examples of the fluorine-containing (meth) acrylate (B) include the following compounds, but are not limited to these compounds.

The fluorine-containing (meth) acrylate (B) is preferably contained in the curable composition of the present invention in an amount of 1 to 5% by mass, more preferably 1 to 3% by mass. When the content of the fluorine-containing (meth) acrylate (B) is 1% by mass or more, the releasability is further improved. Moreover, when content of fluorine-containing (meth) acrylate (B) shall be 5 mass% or less, it is excellent in pattern roughness. Only 1 type may be used for a fluorine-containing (meth) acrylate (B), and 2 or more types may be used together. When using 2 or more types, it is preferable that the total amount becomes the said range.
The content of the fluorine-containing (meth) acrylate (B) is 1 to 10% by mass with respect to the total content of the monofunctional (meth) acrylate (A1) and the polyfunctional (meth) acrylate (A2). It is preferably 1 to 7% by mass, more preferably 1 to 4% by mass. By setting it as such a range, the surface tension of a composition can be adjusted to an appropriate value.

<< Other polymerizable compounds >>
The curable composition of the present invention may contain a polymerizable compound (also referred to as other polymerizable compound) other than the (meth) acrylate (A) and the fluorine-containing (meth) acrylate (B) described above.
For example, an epoxy compound, an oxetane compound, a vinyl ether compound, a styrene derivative, a propenyl ether, a butenyl ether, and the like can be given. Specific examples include those described in JP-A 2011-231308, paragraphs 0020 to 0098, and the contents thereof are incorporated in the present specification.
Moreover, the curable composition of this invention can also be set as the composition which does not contain other polymeric compound substantially. “Substantially no other polymerizable compound” means that no other polymerizable compound is intentionally added.

<Photopolymerization initiator (C)>
The curable composition of the present invention contains a photopolymerization initiator. Any photopolymerization initiator may be used as long as it is a compound that generates an active species that polymerizes a polymerizable compound by light irradiation. As the photopolymerization initiator, a radical polymerization initiator and a cationic polymerization initiator are preferable, and a radical polymerization initiator is more preferable.

As the radical photopolymerization initiator, for example, a commercially available initiator can be used. As these examples, for example, those described in paragraph No. 0091 of JP-A-2008-105414 can be preferably used. Among these, acetophenone compounds, acylphosphine oxide compounds, and oxime ester compounds are preferred from the viewpoints of curing sensitivity and absorption characteristics. Commercially available products include Irgacure (registered trademark) 1173, Irgacure 184, Irgacure 2959, Irgacure 127, Irgacure 907, Irgacure 369, Irgacure 379, Lucyrin (registered trademark) TPO, Irgacure 819, Irgacure OXE-01, Irgacure OXE-02, Irgacure 651, Irgacure 754, etc. (above, manufactured by BASF) may be mentioned.

Although a photoinitiator may be used individually by 1 type, it is also preferable to use 2 or more types together. When using 2 or more types together, it is more preferable to use 2 or more types of radical polymerization initiators together. Specifically, Irgacure 1173 and Irgacure 907, Irgacure 1173 and Lucilin TPO, Irgacure 1173 and Irgacure 819, Irgacure 1173 and Irgacure OXE01, Irgacure 907 and Lucilin TPO, Irgacure 907 and Irgacure 819 are exemplified. With such a combination, the exposure margin can be further expanded.
A preferred ratio (mass ratio) when a photopolymerization initiator is used in combination is preferably 9: 1 to 1: 9, preferably 8: 2 to 2: 8, and 7: 3 to 3: 7. Is more preferable.

The content of the photopolymerization initiator is preferably from 0.1 to 15% by mass, more preferably from 0.5 to 10% by mass, and further preferably from 1 to 5% by mass with respect to the curable composition. . The curable composition may contain only one type of photopolymerization initiator, or may contain two or more types. When two or more types are included, the total amount is preferably within the above range. When the content of the photopolymerization initiator is 0.1% by mass or more, the sensitivity (fast curability), resolution, line edge roughness, and film strength tend to be further improved, which is preferable. Moreover, when content of a photoinitiator is 15 mass% or less, it exists in the tendency for a light transmittance, coloring property, a handleability, etc. to improve, and it is preferable.

<< Non-polymerizable compound (D) having a polyoxyalkylene structure >>
The curable composition of the present invention preferably contains a non-polymerizable compound (D) having a polyoxyalkylene structure in order to improve the releasability. Here, the non-polymerizable compound refers to a compound having no polymerizable group.
The polyoxyalkylene structure is preferably a polyoxyethylene structure, a polyoxypropylene structure, a polyoxybutylene structure, or a mixed structure thereof, more preferably a polyoxyethylene structure or a polyoxypropylene structure, and particularly preferably a polyoxypropylene structure. preferable. Moreover, it is also preferable that the branched structure has a polyhydric alcohol such as glycerin or pentaerythritol as a core.
The polyoxyalkylene structure preferably has 3 to 30 polyoxyalkylene structural units, more preferably 5 to 20, more preferably 7 to 15, It is particularly preferable to have 9 to 13.
The terminal hydroxyl group of the polyoxyalkylene structure may not be substituted, at least one may be substituted with an organic group, or all may be substituted with an organic group. The organic group is preferably an organic group having 1 to 20 carbon atoms, and may have an oxygen atom, a fluorine atom, or a silicon atom, but preferably does not have a fluorine atom or a silicon atom. The organic group is preferably linked to the polyoxyalkylene structure by an ether bond, an ester bond, or a divalent linking group. Specific examples of the organic group include a hydrocarbon group such as a methyl group, an ethyl group, a butyl group, an octyl group, a benzyl group, and a phenyl group, a fluorinated alkyl group, a fluorinated alkyl ether group, and a polysiloxane group.
The number average molecular weight of the non-polymerizable compound (D) is preferably 300 to 3000, more preferably 400 to 2000, and further preferably 500 to 1500.
Specific examples of the non-polymerizable compound (D) include polyoxyethylene (also referred to as polyethylene glycol), polyoxypropylene (also referred to as polypropylene glycol), polyoxybutylene, polyoxyethylene / polyoxypropylene (block and random), Polyoxyethylene (hereinafter abbreviated as PEG) glyceryl ether, polyoxypropylene (hereinafter abbreviated as PPG) glyceryl ether, PEG / PPG glyceryl ether, PEG bisphenol A ether, PEG trimethylolpropane ether, PEG pentaerythritol ether, PEG neopentyl glycol Ether, PEG trimethylolpropane ether, PEG methyl ether, PEG butyl ether, PEG 2-ethylhexyl ether, PEG lauryl ether PEG oleyl ether, PPG methyl ether, PPG butyl ether, PPG lauryl ether, PPG oleyl ether, PEG phenyl ether, PEG octyl phenyl ether, PEG nonyl phenyl ether, PEG naphthyl ether, PEG styrenated phenyl ether, PPG phenyl ether, PPG Octylphenyl ether, PPG nonylphenyl ether, PEG dimethyl ether, PEG dibenzyl ether, PPG dimethyl ether, PPG dibenzyl ether, PEG / PPG dimethyl ether, PEG glyceryl ether trimethyl ether, PPG glyceryl ether trimethyl ether, PEG monoacetate, PEG monolaurate , PEG monooleate, PPG monoacetate, PPG model Laurate, PPG monooleate, PEG diacetate, PEG dilaurate, PEG diolate, PPG diacetate, PPG dilaurate, PPG diolate, PEG glycerin fatty acid ester, PEG sorbitan fatty acid ester, PEG sorbitol fatty acid ester, 2,4,7,9-tetramethyl Ethylene oxide adducts such as -5-decine-4,7-diol (for example, Olphine E1004, E1010, E1020, etc. manufactured by Nissin Chemical Industry Co., Ltd., Surfynol 420, 440, 465, 485, 2502 manufactured by Air Products and Chemicals) , 2505, etc.), and fluorine-containing compounds represented by the following general formula (II).

Formula (II)

In general formula (II), Rf ² and Rf ³ each independently represent a fluorine-containing alkyl group having 1 to 6 carbon atoms having two or more fluorine atoms; p1 and p2 are each independently 1 to 3 Q1 and q2 each independently represent an integer of 0 to 2, r represents an integer of 2 to 4, and s represents 6 to 20.
The preferred ranges of Rf ² and Rf ³ in the general formula (II) are the same as the preferred ranges of R ^f in the general formula (I), and the preferred ranges and specific examples of Rf ² and Rf ³ are also the same.
In general formula (II), p1 and p2 each independently represent an integer of 1 to 3, preferably 1 or 2, and more preferably 1.
q1 and q2 each independently represents an integer of 0 to 2, preferably 1 or 2, and more preferably 1.
r represents an integer of 2 to 4, preferably 2 or 3, and more preferably 2.
s represents 6 to 20, preferably 7 to 15, and more preferably 9 to 13.

Regarding the non-polymerizable compound (D), the description in paragraphs 0105 to 0106 of JP2013-036027A can be referred to, and the contents thereof are incorporated in the present specification.
The content of the non-polymerizable compound (D) is preferably 1 to 10% by mass in the total composition excluding the solvent. The lower limit is more preferably 2% by mass or more. The upper limit is more preferably 8% by mass or less, further preferably 6% by mass or less, and particularly preferably 4% by mass or less. By setting it as such a range, releasability and the surface smoothness of a pattern can be made compatible.

<< Polymerization inhibitor >>
The curable composition of the present invention preferably contains a polymerization inhibitor. The content of the polymerization inhibitor is preferably 0.001 to 0.1% by mass, more preferably 0.005 to 0.08% by mass, and still more preferably 0.001% to 0.1% by mass with respect to the mass of all polymerizable compounds. By blending an appropriate amount of a polymerization inhibitor in an amount of 01 to 0.05% by mass, a change in viscosity over time can be suppressed while maintaining high curing sensitivity. A polymerization inhibitor may be added at the time of manufacture of all the polymeric compounds, and may be added later to the hardening composition of this invention. Specific examples of the polymerization inhibitor include 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical. Specific examples of other polymerization inhibitors include those described in paragraph No. 0121 of JP2012-169462A, the contents of which are incorporated herein.

<Surfactant>
The curable composition of this invention can contain surfactant as needed. In general, a surfactant is a substance that has a hydrophobic part and a hydrophilic part in the molecule and significantly changes the properties of the interface when added in a small amount. The surfactant in the present invention is a substance that has a hydrophobic part and a hydrophilic part in the molecule and significantly reduces the surface tension of the curable composition when added in a small amount. It is a substance that reduces the surface tension of the curable composition from 40 mN / m to 30 mN / m or less with an addition amount of not more than mass%. When a surfactant is contained in the curable composition of the present invention, an effect of improving the uniformity of coating and an effect of improving the releasability can be expected.
The surfactant is preferably a nonionic surfactant, and preferably contains at least one of a fluorine-based surfactant, a Si-based surfactant, and a fluorine / Si-based surfactant, and a fluorine-based nonionic surfactant. Agents are particularly preferred. Here, the “fluorine / Si-based surfactant” refers to one having both the requirements of both a fluorine-based surfactant and a Si-based surfactant.

Fluorine-based nonionic surfactants include trade names such as Fluorard (Sumitomo 3M), MegaFuck (DIC), Surflon (AGC Seimi Chemical), Unidyne (Daikin Industries), Footage (Neos), Ftop (Mitsubishi Materials Electronics Chemicals). ), Polyflow (Kyoeisha Chemical), KP (Shin-Etsu Chemical), Troisol (Troy Chemical), PolyFox (OMNOVA), Capstone (DuPont) and the like.
The content of the surfactant is, for example, preferably 0.01 to 5% by mass, more preferably 0.1 to 4% by mass, and further preferably 1 to 3% by mass in the total composition. Only one surfactant may be used, or two or more surfactants may be used in combination. When using 2 or more types of surfactant, the total amount becomes the said range.

In the present invention, a low release force can be achieved even in an embodiment that does not substantially contain a surfactant. For example, it is preferably 0.001% by mass or less, and more preferably 0.0001% by mass or less, based on the total mass of the curable composition of the present invention.

<< Other ingredients >>
In addition to the components described above, the curable composition of the present invention includes a photosensitizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an anti-aging agent, a plasticizer, an adhesion promoter, a heat as necessary. Polymerization initiator, photobase generator, colorant, inorganic particles, elastomer particles, basic compound, photoacid generator, photoacid multiplier, chain transfer agent, antistatic agent, flow regulator, antifoaming agent, dispersant Etc. may be included. Specific examples of such components include those described in JP-A-2008-105414, paragraph numbers 0092 to 0093 and paragraph numbers 0113 to 0137, the contents of which are incorporated herein. Further, the corresponding descriptions in WO 2011/126101 pamphlet, WO 2013/051735 pamphlet, JP 2012-041521 A and JP 2013-093552 A can be referred to, and the contents thereof are incorporated in the present specification.

<< Solvent >>
The curable composition of the present invention may contain a solvent. The content of the solvent in the curable composition of the present invention is preferably 5% by mass or less, more preferably 3% by mass or less, and particularly preferably substantially no solvent. Here, substantially not containing a solvent means, for example, 1% by mass or less based on the total mass of the curable composition of the present invention. When applying the curable composition of this invention on a board | substrate by the inkjet method, since the viscosity change of the composition by volatilization of a solvent can be suppressed when there are few compounding quantities of a solvent, it is preferable.
Thus, although the curable composition of this invention does not necessarily contain a solvent, you may add arbitrarily, when adjusting the viscosity of a composition finely. Solvents that can be preferably used in the curable composition of the present invention include solvents that are generally used in photocurable compositions for imprints and photoresists, and dissolve and uniformly disperse the compounds used in the present invention. It is not particularly limited as long as it can be used and it does not react with these components. Examples of the solvent that can be used in the present invention include those described in paragraph No. 0088 of JP-A-2008-105414, the contents of which are incorporated herein.

<Method for preparing curable composition, application>
The curable composition of the present invention can be prepared by mixing the above-described components. The mixing of each component is usually performed in the range of 0 ° C to 100 ° C. Moreover, after mixing each component, it is preferable to filter with a filter, for example. Filtration may be performed in multiple stages or repeated many times. Moreover, the filtered liquid can also be refiltered.
Any filter can be used without particular limitation as long as it has been conventionally used for filtration. For example, fluorine resin such as PTFE (polytetrafluoroethylene), polyamide resin such as nylon-6 and nylon-6,6, polyolefin resin such as polyethylene and polypropylene (PP) (including high density and ultra high molecular weight), etc. Filter. Among these materials, polypropylene (including high density polypropylene) and nylon are preferable.
The pore size of the filter is suitably about 0.003 to 5.0 μm, for example. By setting it within this range, it becomes possible to reliably remove fine foreign matters such as impurities and aggregates contained in the composition while suppressing filtration clogging.
When using filters, different filters may be combined. At that time, the filtering by the first filter may be performed only once or may be performed twice or more. When filtering two or more times by combining different filters, it is preferable that the second and subsequent hole diameters are the same or smaller than the first filtering hole diameter. Moreover, you may combine the 1st filter of a different hole diameter within the range mentioned above. The pore diameter here can refer to the nominal value of the filter manufacturer. As a commercially available filter, for example, it can be selected from various filters provided by Nippon Pole Co., Ltd., Advantech Toyo Co., Ltd., Japan Entegris Co., Ltd. (formerly Japan Microlith Co., Ltd.) or KITZ Micro Filter Co., Ltd. .

The curable composition of the present invention preferably has a viscosity of 5 to 12 mPa · s at 23 ° C. For example, the lower limit is more preferably 6 mPa · s or more. For example, the upper limit is more preferably 10 mPa · s or less, and still more preferably 8 mPa · s or less. By setting it as such a range, the inkjet discharge precision and the filling property to the uneven | corrugated pattern of a mold can be improved. In addition, the value of the viscosity in this invention is the value measured by the method as described in the Example mentioned later.
The curable composition of the present invention preferably has a surface tension of 27 to 33 mN / m at 23 ° C. For example, the lower limit is more preferably 28 mN / m or more, and even more preferably 29 mN / m or more. For example, the upper limit is more preferably 32 mN / m or less, and still more preferably 31 mN / m or less. By setting it as such a range, an inkjet discharge precision and mold release property can be improved. In addition, the value of the surface tension in this invention is a value measured by the method as described in the Example mentioned later.
Since the curable composition of the present invention is excellent in inkjet ejection accuracy, it is suitable as a photocurable composition for imprinting for inkjet coating.

<Pattern formation method>
Next, the pattern forming method of the present invention will be described. In the pattern forming method of the present invention, a pattern is formed by the photoimprint method using the curable composition of the present invention.
Below, the pattern formation method using the curable composition of this invention is described concretely. In the pattern forming method of the present invention, first, the curable composition of the present invention is applied on a substrate or a mold having a pattern. Next, the curable composition of the present invention is sandwiched between the mold and the substrate. Next, light irradiation (exposure) is performed in a state where the curable composition of the present invention is sandwiched between a mold and a base material to cure the curable composition of the present invention. Finally, the mold is peeled off. In this way, a cured product pattern is obtained.

As a method for applying the curable composition of the present invention on a substrate or a mold having a pattern, generally known application methods such as dip coating, air knife coating, curtain coating, and wire bar coating are used. By using a gravure coating method, an extrusion coating method, a spin coating method, a slit scanning method, an ink jet method, or the like, a coating film or droplets can be disposed on a substrate. In particular, the curable composition of the present invention is suitable for the ink jet method because it is excellent in ink jet ejection accuracy and has good temporal stability of the ink jet ejection accuracy. In particular, it is effective in an ink jet method using an ink jet apparatus that stores a curable composition in a container (for example, a cartridge) that is open to the atmosphere.

When sandwiching the curable composition of the present invention between a mold and a substrate, helium gas may be introduced between the mold and the substrate. By using such a method, it is possible to promote the permeation of the gaseous quartz mold and promote the disappearance of residual bubbles. Moreover, radical polymerization inhibition in exposure can be suppressed by reducing dissolved oxygen in the curable composition. Further, a condensable gas may be introduced between the mold and the substrate instead of helium. By using such a method, it is possible to further promote the disappearance of residual bubbles by utilizing the fact that the introduced condensable gas condenses and decreases in volume. The condensable gas refers to a gas that condenses due to temperature or pressure, and for example, trichlorofluoromethane, 1,1,1,3,3-pentafluoropropane, or the like can be used. Regarding the condensable gas, for example, the description in paragraph 0023 of JP-A-2004-103817 and paragraph 0003 of JP-A-2013-247883 can be referred to, and the contents thereof are incorporated in the present specification.

In exposure, the exposure illuminance is preferably in the range of 1 to 200 mW / cm ² . By making the exposure time 1 mW / cm ² or more, the exposure time can be shortened so that productivity is improved. By making the exposure time 200 mW / cm ² or less, deterioration of the properties of the cured film due to side reactions can be suppressed. It tends to be preferable. The exposure dose is desirably in the range of 5 to 1000 mJ / cm ² .
In the exposure, in order to suppress radical polymerization inhibition by oxygen, it is preferable to flow an inert gas such as nitrogen, helium, argon, carbon dioxide or the like to control the oxygen concentration in the atmosphere to 10 kPa or less. More preferably, the oxygen concentration in the atmosphere is 3 kPa or less, more preferably 1 kPa or less.

The pattern forming method of the present invention may include a step of further curing the cured pattern by applying heat, if necessary, after curing the curable composition of the present invention by light irradiation. When the curable composition of the present invention is heat-cured after light irradiation, the heating temperature is preferably 150 to 280 ° C, more preferably 200 to 250 ° C. The heating time is preferably 5 to 60 minutes, and more preferably 15 to 45 minutes.
Specific examples of the pattern forming method include those described in JP-A-2012-169462, paragraph numbers 0125 to 0136, the contents of which are incorporated herein.

The pattern forming method of the present invention can be applied to a pattern inversion method. Specifically, a resist pattern is formed on a substrate to be processed having a carbon film (SOC) by the pattern forming method of the present invention. Next, after the dyst pattern is covered with a Si-containing film (SOG), the upper part of the Si-containing film is etched back to expose the resist pattern, and the exposed resist pattern is removed by oxygen plasma or the like, A reverse pattern of the Si-containing film is formed. Further, by using the reverse pattern of the Si-containing film as an etching mask, the reverse carbon pattern is transferred to the carbon film by etching the carbon film thereunder. Finally, the substrate is etched using the carbon film to which the reverse pattern is transferred as an etching mask. As an example of such a method, reference can be made to paragraphs 0016 to 0030 of JP-A-5-267253, JP-A-2002-110510, JP-T 2006-521702, and JP-T 2010-541193. This content is incorporated herein by reference.

The pattern forming method of the present invention includes a step of applying a lower layer film composition on a substrate to form a lower layer film, a step of applying the curable composition of the present invention to the surface of the lower layer film, and a curable composition of the present invention And a step of curing the curable composition of the present invention, and a step of peeling off the mold may be included. Furthermore, after applying a lower layer film composition on a base material, you may make it apply | coat the curable composition of this invention, after hardening a part of lower layer film composition by heat or light irradiation.

The lower layer film composition includes, for example, a curable main agent. The curable main agent may be thermosetting or photocurable, and is preferably thermosetting. The molecular weight of the curable main agent is preferably 400 or more, and may be a low molecular compound or a polymer, but a polymer is preferred. The molecular weight of the curable main agent is preferably 500 or more, more preferably 1000 or more, and further preferably 3000 or more. The upper limit of the molecular weight is preferably 200000 or less, more preferably 100000 or less, and still more preferably 50000 or less. By setting the molecular weight to 400 or more, volatilization of components can be more effectively suppressed. As the curable main agent, for example, a polymer whose main component is a structural unit represented by the following general formula can be used.

In the general formula, R is an alkyl group, L ¹ and L ² are each a divalent linking group, and P is a polymerizable group. n is an integer of 0 to 3.
R is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group.
L ¹ is preferably an alkylene group, more preferably an alkylene group having 1 to 3 carbon atoms, and more preferably —CH ₂ —.
L ² is preferably a divalent linking group consisting of —CH ₂ —, —O—, —CHR (R is a substituent) —, and combinations of two or more thereof. R is preferably an OH group.
P is preferably a (meth) acryloyl group, more preferably an acryloyl group.
n is preferably an integer of 0 to 2, and more preferably 0 or 1.
Examples of commercially available products include NK Oligo EA-7140 / PGMAc (manufactured by Shin-Nakamura Chemical Co., Ltd.). Further, for example, those described in paragraph Nos. 0040 to 0056 of JP-T-2009-503139 can be cited, and the contents thereof are incorporated in the present specification.

The content of the curable main agent is preferably 30% by mass or more, more preferably 50% by mass or more, and still more preferably 70% by mass or more in all components except the solvent. Two or more curable main agents may be used, and in this case, the total amount is preferably within the above range.

The underlayer film composition preferably contains a solvent. 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 lower layer film 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. Particularly preferred from the viewpoint of coating uniformity.
The content of the solvent in the lower layer film composition is optimally adjusted depending on the viscosity of the component excluding the solvent, the coating property, and the target film thickness. From the viewpoint of improving the coating property, the content is 70% by mass in the total composition. It can be added in the above range, preferably 90% by mass or more, more preferably 95% by mass or more, and further preferably 99% by mass or more.

The lower layer film composition may contain at least one of a surfactant, a thermal polymerization initiator, a polymerization inhibitor, and a catalyst as other components. As these compounding quantities, 50 mass% or less is preferable with respect to all the components except a solvent.
As the underlayer film composition, for example, the compositions described in paragraph numbers 0017 to 0054 of JP-A-2014-192178 and paragraph numbers 0017 to 0068 of JP-A-2014-024322 can be used. The contents are incorporated herein.

The underlayer film composition can be prepared by mixing the above-described components. Further, after mixing the above-mentioned components, it is preferable to filter with a filter having a pore size of 0.003 μm to 5.0 μm, for example. Filtration may be performed in multiple stages or repeated many times. Moreover, the filtered liquid can also be refiltered. What was demonstrated by preparation of the curable composition mentioned above is mentioned for a filter.

Examples of the coating method of the lower layer film composition include a dip coating method, an air knife coating method, a curtain coating method, a wire bar coating method, a gravure coating method, an extrusion coating method, a spin coating method, a slit scanning method, and an inkjet method. Is mentioned. It is preferable to dry after applying the lower layer film composition on the substrate. A preferred drying temperature is 70 ° C to 130 ° C. Preferably, further curing is performed by active energy (preferably heat and / or light). Heat curing is preferably performed at a temperature of 150 ° C. to 250 ° C. You may perform the process of drying a solvent, and the process of hardening | curing simultaneously. Thus, after apply | coating a lower layer film composition, after hardening a part of lower layer film composition by a heat | fever or light irradiation, it is preferable to apply | coat the curable composition of this invention. When such a means is employed, the lower layer film composition is also completely cured during the photocuring of the curable composition of the present invention, and the adhesion tends to be further improved.

The thickness of the lower layer film varies depending on the application to be used, but is about 0.1 nm to 100 nm, preferably 1 to 20 nm, and more preferably 2 to 10 nm. Further, the underlayer film composition may be applied by multiple coating. The obtained underlayer film is preferably as flat as possible.

The base material (substrate or support) can be selected depending on various applications, for example, quartz, glass, optical film, ceramic material, vapor deposition film, magnetic film, reflection film, metal such as Ni, Cu, Cr, Fe, etc. Base materials, polymer base materials such as paper, polyester film, polycarbonate film, polyimide film, thin film transistor (TFT) array base materials, plasma display (PDP) electrode plates, ITO (Indium Tin Oxide) and conductive base materials such as metals Insulating base materials such as glass and plastic, semiconductor manufacturing base materials such as silicon, silicon nitride, polysilicon, silicon oxide, amorphous silicon, SOG (Spin On Glass) and SOC (Spin On Carbon) are not particularly limited.

<Pattern>
As described above, the pattern formed by the pattern forming method of the present invention can be used as a permanent film used for a liquid crystal display (LCD) or the like, or as an etching resist for semiconductor processing. In addition, a grid pattern is formed on a glass substrate of a liquid crystal display device using the pattern of the present invention, and a polarizing plate having a large screen size (for example, 55 inches or more than 60 inches) with low reflection and absorption is inexpensively manufactured. Is possible. For example, a polarizing plate described in JP-A-2015-132825 and WO2011-132649 can be produced. One inch is 25.4 mm.
For example, semiconductor integrated circuits, micro electro mechanical systems (MEMS), recording media such as optical disks and magnetic disks, light receiving elements such as solid-state imaging elements, light emitting elements such as LEDs and organic EL, and optical devices such as liquid crystal display devices (LCD) Flat panel display members such as diffraction gratings, relief holograms, optical waveguides, optical filters, microlens arrays, thin film transistors, organic transistors, color filters, antireflection films, polarizing elements, optical films, pillars, etc. Preparation of nano biodevices, immunoassay chips, deoxyribonucleic acid (DNA) separation chips, microreactors, photonic liquid crystals, guide patterns for micropattern formation using self-assembly of block copolymers (directed self-assembly, DSA), etc. Liked to Can be used.
Moreover, the pattern obtained using the curable composition of the present invention also has good solvent resistance. The pattern preferably has high resistance to a solvent, but it is particularly preferable that the film thickness does not change when immersed in a solvent used in a general substrate manufacturing process, for example, an N-methylpyrrolidone solvent at 25 ° C. for 10 minutes. .
The pattern formed by the pattern forming method of the present invention is particularly useful as an etching resist. When the curable composition of the present invention is used as an etching resist, a nano-order fine pattern is formed on a substrate by the pattern forming method of the present invention. Thereafter, a desired pattern can be formed on the substrate by etching using an etching gas such as hydrogen fluoride in the case of wet etching or CF _{4 in} the case of dry etching. The curable composition of the present invention has good etching resistance against dry etching using carbon fluoride or the like.

<Device manufacturing method>
The device manufacturing method of the present invention includes the pattern forming method described above.
That is, after a pattern is formed by the above-described method, a device can be manufactured by applying a method used for manufacturing various devices.
The pattern may be included in the device as a permanent film. Further, the substrate can be etched using the pattern as an etching mask. For example, dry etching is performed using the pattern as an etching mask, and the upper layer portion of the substrate is selectively removed. A device can also be manufactured by repeating such a process on the substrate. Examples of the device include semiconductor devices such as LSI (large-scale integrated circuit) and optical devices such as liquid crystal display devices.

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 fluorinated acrylate (B-1)

With respect to a solution obtained by dissolving 100 g (0.89 mol) of potassium t-butoxy in 700 mL of t-butanol, while maintaining the internal temperature at 30 ° C. or lower in a water bath, 3,3,4,4,5,5, 6,6,7,7,8,8,8-Tridecafluoro-1-octanol (316.9 g, 0.87 mol) was added dropwise to prepare an alkoxide solution.
The previously prepared alkoxide solution was added dropwise to a mixed solution of 171.7 g (0.88 mol) of t-butyl bromoacetate and 300 mL of t-butanol while maintaining the internal temperature at 30 ° C. or lower in a water bath. After completion of the dropwise addition, the mixture was stirred at 25 ° C. for 1 hour, and then 500 mL of n-hexane and 500 mL of 0.1 mol / L hydrochloric acid water were added for liquid separation extraction. The organic layer was washed twice with 500 mL of water and then concentrated under reduced pressure to obtain intermediate (1-1) (yield 406.1 g, yield 97.6%).
To a solution obtained by mixing 382.6 g (0.80 mol) of the intermediate (1-1) and 800 mL of methanol, 154.3 g of a 28% by mass sodium methoxide solution was added, and then 23.9 g of sodium tetrahydroborate ( 0.63 mol) was added and reacted at 40 ° C. for 4 hours. After completion of the reaction, the reaction solution was slowly added to 1 L of 2 mol / L hydrochloric acid water to decompose excess sodium tetrahydroborate, followed by separation and extraction by adding 300 mL of ethyl acetate and 800 mL of n-hexane. The organic layer was washed with 1000 mL of water and then concentrated under reduced pressure. The resulting concentrate was distilled under reduced pressure to obtain 326.2 g of intermediate (1-2) (boiling point: 80 to 84 ° C./0.40 kPa, yield 99.9%).
After adding 100.3 g (0.96 mol) of triethylamine to a solution obtained by mixing 326.2 g (0.799 mol) of intermediate (1-2) and 800 mL of toluene, the internal temperature is 15 ° C. or lower in an ice bath. However, 83.2 g (0.92 mol) of acryloyl chloride was added dropwise. After the completion of the dropwise addition, the mixture was stirred for 2 hours, followed by separation / extraction by adding 800 mL of 2% by mass sodium bicarbonate water. The organic layer was washed twice with 800 mL of 1 mol / L hydrochloric acid and then with 800 mL of water, and then 38 mg of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4-HO-TEMPO) And concentrated under reduced pressure. To the obtained concentrate, 380 mg of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (4-BzO-TEMPO) benzoate was added and distilled under reduced pressure to obtain the desired fluorine-containing product. 230.0 g of acrylate (B-1) (boiling point: 107 ° C./0.67 kPa, yield: 62.3%) was obtained.

(Synthesis Example 2) Synthesis of fluorinated acrylate (B-2)

3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-1-octanol 364.2 g (1.0 mol), chloroacetic acid chloride 124.2 g ( 1.1 mol), 87.0 g (1.1 mol) of pyridine was added dropwise to a mixed solution of 1000 mL of ethyl acetate while maintaining the internal temperature at 15 ° C. or lower in an ice bath. After completion of the dropwise addition, the mixture was reacted at 15 ° C. for 2 hours, and then 500 mL of water was added to perform liquid separation extraction. The organic layer was washed with 500 mL of 2% by weight aqueous sodium bicarbonate and then with 500 mL of 0.1 mol / L aqueous hydrochloric acid and then concentrated under reduced pressure to obtain 432.8 g of intermediate (2-1) (yield 98.1%). .
A mixture of 220.3 g (0.5 mol) of intermediate (2-1), 82.9 g (0.6 mol) of potassium carbonate, and 500 mL of N-methylpyrrolidone was added to 43.3 g (0.6 mol) of acrylic acid. Then, 8.3 g (0.05 mol) of potassium iodide was added and reacted at 25 ° C. for 3 hours. After completion of the reaction, 500 mL of n-heptane, 500 mL of n-hexane, and 500 mL of water were added for liquid separation extraction. The organic layer was washed twice with 500 mL of 0.1 mol / L aqueous hydrochloric acid, 22 mg of 4-HO-TEMPO was added, and the mixture was concentrated under reduced pressure. To the obtained concentrate, 220 mg of 4-BzO-TEMPO was added and distilled under reduced pressure to obtain 219.0 g of the desired fluorine-containing acrylate (B-2) (boiling point: 124 ° C./0.67 kPa, yield 92.0%). )

(Synthesis Example 3) Synthesis of fluorinated acrylate (B-3)

7,7,8,8,9,9,10,10,11,11,12,12,12-tridecafluoro-1-dodecanol 84.0 g (0.20 mol), triethylamine 24.3 g (0. 24 mol), 21.7 g (0.24 mol) of acryloyl chloride was added dropwise to a mixed solution of 500 mL of ethyl acetate while maintaining the internal temperature at 10 ° C. or lower in an ice bath. After completion of the dropwise addition, the mixture was reacted at room temperature for 2 hours, and then 500 mL of water was added to perform liquid separation extraction. The organic layer was washed with 2% by mass of sodium bicarbonate water (500 mL), 1 mol / L hydrochloric acid water (500 mL), and finally with pure water (500 mL), and 8 mg of 4-HO-TEMPO was added and concentrated under reduced pressure. To the obtained concentrate, 80 mg of 4-BzO-TEMPO was added and distilled under reduced pressure to obtain 69.8 g of the desired fluorine-containing acrylate (B-3) (boiling point: 111 ° C./0.67 kPa, yield 73.6%). )

<Preparation of photocurable composition for imprint>
Non-polymerization having a (meth) acrylate (A) containing no fluorine atom, a (meth) acrylate (B) containing a fluorine atom, a photopolymerization initiator (C), and a polyoxyalkylene structure at a mass ratio shown in Table 1 below. In addition, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) as a polymerization inhibitor is mixed with the curable composition. After adding to 200 ppm (0.02 mass%), the mixture was filtered through a 0.1 μm PTFE filter to prepare curable compositions for imprints X-1 to X-6 of the present invention.
Further, for the comparative curable compositions R-1 to R-4, the curable composition of the present invention was used except that the comparative compound (S) was used instead of the (meth) acrylate (B) containing a fluorine atom. Comparative curable compositions R-1 to R-4 were prepared in the same manner as the composition.
The surface tension and viscosity at 23 ° C. of the curable composition for imprints of the present invention and the comparative curable composition were measured. It is written together with Table 1.
The surface tension was measured by using a surface tension meter CBVP-A3 manufactured by Kyowa Interface Science Co., Ltd. at 23 ± 0.2 ° C. by immersing the lower end of the platinum plate in the measurement sample. In addition, the platinum plate used was made red by heating with an alcohol lamp before the measurement to clean the surface.
The viscosity was set to 50 rpm using an E-type rotational viscometer RE85L manufactured by Toki Sangyo Co., Ltd. and a standard cone rotor (1 ° 34 ′ × R24), and the sample cup was 23 ± 0.1. The temperature was adjusted to ° C and measured.

Details of (meth) acrylate (A), photopolymerization initiator (B), non-polymerizable compound (D), and comparative compound (S) used in Examples and Comparative Examples are as follows.

<(Meth) acrylate (A) not containing fluorine atom>
A-1: Dodecyl acrylate (Kyoeisha Chemical, light acrylate LA)
A-2: Neopentyl glycol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate NP-A)
A-3: m-xylylene bisacrylate (synthesized from α, α'-dichloro-m-xylene and acrylic acid)

<Photopolymerization initiator (C)>
C-1: Irgacure 819 (manufactured by BASF)
<Non-polymerizable compound (D) having a polyoxyalkylene structure>
D-1: Polypropylene glycol (number average molecular weight 700, manufactured by Wako Pure Chemical Industries, Ltd.)
<Comparative compound (S)>
S-1: 1H, 1H-undecafluorohexyl acrylate (manufactured by SynQuest Laboratories)
S-2: 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate (manufactured by Tokyo Chemical Industry)
S-3: 3- (perfluorohexyl) propanyl acrylate (manufactured by SynQuest Laboratories)
S-4: 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol diacrylate (manufactured by Wako Pure Chemical Industries)

<Inkjet ejection accuracy>
On a silicon wafer, a curable composition for photoimprinting adjusted to a temperature of 23 ° C. was ejected with a droplet amount of 1 pl per nozzle using an inkjet printer DMP-2831 (manufactured by Fujifilm Dimatics). It apply | coated so that a droplet might become a square array of a 100 micrometer space | interval on a silicon wafer.
A 2500 mm square of 5 mm square of the coated substrate was observed, a deviation from the square arrangement was measured, and a standard deviation σ was calculated. Inkjet ejection accuracy was evaluated as A to D as follows.
A: σ <3 μm
B: 3 μm ≦ σ <5 μm
C: 5 μm ≦ σ <10 μm
D: 10 μm ≦ σ

<Stability evaluation after storage for 3 months>
After the photoimprint curable composition was filled in a material cartridge for an inkjet printer DMP-2831, it was stored for 3 months in an environment of a temperature of 23 ° C. and a humidity of 50 ° C., and then the inkjet ejection accuracy was evaluated.

As is clear from the results in the table, the curable compositions of Examples 1 to 6 showed no deterioration in inkjet ejection accuracy before and after the aging test and showed good performance.
Also, after each curable composition was applied onto a silicon wafer by ink jetting as described above, a quartz mold (line / space = 1/1, line width 30 nm, groove depth 60 nm, line edge roughness 3.0 nm) was applied. When the quartz mold was released from the quartz mold side using a high-pressure mercury lamp from the quartz mold side and exposed to 100 mJ / cm ² , the curability of Examples 4 to 6 containing the non-polymerizable compound (D) was obtained. The composition was particularly excellent in mold releasability.
On the other hand, the curable compositions of Comparative Examples 1 to 4 significantly deteriorated the inkjet discharge accuracy after 3 months.

Claims

(Meth) acrylate (A) containing no fluorine atom;
(Meth) acrylate (B) containing a fluorine atom;
A photopolymerization initiator (C);
The photocurable composition for imprints containing the said (meth) acrylate (B) containing the fluorine atom is represented by the following general formula (I).

In the formula, R f represents a fluorine-containing alkyl group having 1 to 9 carbon atoms in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom;
L represents a single bond, —O—, —OC (═O) —, or —C (═O) O—,
R 1 represents a hydrogen atom or a methyl group,
n represents an integer of 1 to 8, and when L is a single bond, it represents an integer of 3 to 8.
The photocurable composition for imprints according to claim 1, wherein the fluorine-containing (meth) acrylate (B) has a boiling point of 100 to 200 ° C under a pressure of 0.67 kPa.
3. The general formula (I), wherein R f is a fluorine-containing alkyl group having 1 to 9 carbon atoms in which 40 to 100% of hydrogen atoms of the alkyl group are substituted with fluorine atoms. A photocurable composition for imprints.
4. The general formula (I), wherein R f is a group comprising a perfluoroalkyl group having 4 to 6 carbon atoms and an alkylene group having 1 to 3 carbon atoms. A photocurable composition for imprints.
The imprinting light according to any one of claims 1 to 4, wherein the photocurable composition for imprinting contains 1 to 5% by mass of the (meth) acrylate (B) containing the fluorine atom. Curable composition.
The photocurable composition for imprints according to any one of claims 1 to 5, further comprising 1 to 5% by mass of a non-polymerizable compound (D) having a polyoxyalkylene structure.
The photocurable composition for imprints according to any one of claims 1 to 6, having a viscosity of 5 to 12 mP · s and a surface tension of 27 to 33 mN / m at 23 ° C.
Applying the photocurable composition for imprints according to any one of claims 1 to 7 on a substrate or a mold having a pattern by an inkjet method;
Sandwiching the photocurable composition for imprints between a mold and a substrate;
Irradiating light in a state where the photocurable composition for imprints is sandwiched between a mold and a substrate, and curing the photocurable composition for imprints;
And a step of peeling the mold.
A device manufacturing method including a step of etching a base material using a pattern produced by the pattern forming method according to claim 8 as a mask.