WO2012137672A1

WO2012137672A1 - Pattern-forming method and pattern

Info

Publication number: WO2012137672A1
Application number: PCT/JP2012/058510
Authority: WO
Inventors: 児玉　邦彦; 児玉　憲一
Original assignee: 富士フイルム株式会社
Priority date: 2011-04-01
Filing date: 2012-03-30
Publication date: 2012-10-11
Also published as: JP2012216700A

Abstract

Provided is a pattern-forming method that is well able to form an ultrafine pattern even when applying a photo-curable composition using an inkjet method. The pattern-forming method involves applying a photo-curable composition containing a polymerisable compound and a polymerisation initiator on a base material or on a mold having a fine pattern, and exposing the photo-curable composition to light while the composition is held by the mold or base material. The viscosity of the photo-curable composition at 25° C is 12 to 100 mPa/s. The photo-curable composition is applied to the base material or to the mold having a fine pattern by being discharged in droplets, and the temperature during the discharging of the photo-curable composition is at least 28°C.

Description

Pattern forming method and pattern

The present invention relates to a pattern forming method. In particular, the present invention relates to a pattern forming method for forming a component of an electronic device. More specifically, semiconductor integrated circuits (particularly circuits), flat screens, micro electromechanical systems (MEMS), sensor elements, optical recording media such as high-density memory disks, optical components such as diffraction gratings and relief holograms, and nanodevices , Optical devices, optical films and polarizing elements for flat panel display fabrication, 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 The present invention relates to a pattern formation method by an imprint method, which is a fine pattern formation using light irradiation used for producing a DNA separation chip, a microreactor, a nanobio device, an optical waveguide, an optical filter, a photonic liquid crystal, 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 two methods: a thermal imprint method using a thermoplastic resin as a material to be processed (for example, see Non-Patent Document 1) and an optical imprint method using a curable composition (for example, see Non-Patent Document 2). Street technology has 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. 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 simultaneously forming a microstructure and a nanostructure at the same time, or by simple alignment between layers, 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, an application example for manufacturing a high-density semiconductor integrated circuit will be described first. 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 Document 1 and Patent Document 3 listed below disclose nanoimprint technology 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 example of applying the nanoimprint method to next-generation hard disk drive (HDD) fabrication will be described. 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 substrates and PDP substrates, the optical nanoimprint 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 the transparent protective film material described in Patent Document 4 and Patent Document 5, the spacer described in Patent Document 5, and the like 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.
The nanoimprint method can also be used to create an antireflection structure generally called moth eye. By forming innumerable fine irregularities made of a transparent material on the surface of the transparent molded article at a pitch equal to or less than the wavelength of light, an antireflection structure in which the refractive index of light changes in the thickness direction can be formed. Since the refractive index of such an antireflection structure continuously changes in the thickness direction, there is no refractive index interface, and theoretically it can be made non-reflective. Further, since the wavelength dependency is small and the antireflection performance against oblique light is high, the antireflection performance superior to that of the multilayer antireflection film is provided.

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 order to use nanoimprint in the industry, it is required that a good pattern is repeatedly formed.
In the photoimprinting method, a photocurable composition is applied onto a substrate or a mold having a fine pattern, and the photocurable composition is irradiated with light while the photocurable composition is sandwiched between the substrate and the mold. The mold pattern is transferred to a cured product by curing. Here, as a method for applying the photocurable composition on a substrate or a mold having a fine pattern, a method such as a spin coating method or a slit coating method is generally used.
In recent years, the inkjet method has attracted attention particularly in applications for forming ultrafine patterns with high accuracy (for example, etching resists for processing semiconductor substrates) (Patent Document 9). The ink jet method is effective in applications in which an ultrafine pattern is formed with high accuracy because the amount of the curable composition can be adjusted according to the density of the pattern. On the other hand, there has been a problem that the pattern formability is rather deteriorated if the inkjet discharge is not performed stably. Furthermore, it has been difficult to simultaneously satisfy the performance required for products such as pattern formability, dry etching resistance in substrate processing applications, and line edge roughness after dry etching.

US Pat. No. 5,772,905 US Pat. No. 5,956,216 US Pat. No. 5,259,926 JP 2005-197699 A JP 2005-301289 A Japanese Patent Laid-Open No. 2004-240241 JP 2006-310565 A JP 2008-95037 A Special table 2008-502157 gazette

An object of the present invention is to solve the above-described problems, and provides a pattern forming method capable of forming an ultrafine pattern satisfactorily even when a photocurable composition is applied using an inkjet method. For the purpose. Furthermore, it aims at providing the pattern formation method which can form the pattern which satisfy | fills these pattern formation property and the line edge roughness after dry etching simultaneously.

It is known that the suitable viscosity for ink jet ejection is about 5 to 10 mPa · s. On the other hand, those having a low viscosity generally tend to volatilize. Such volatilization is not particularly problematic in the case of ink ejection such as ink, but when the curable composition for imprinting is ejected by ink jet, the volatilization immediately after ejection becomes the pattern formability and the line edge roughness after dry etching. It turns out that it has a big influence. Under such circumstances, the present inventors have found that such a problem can be solved by discharging a photocurable composition having a viscosity of 12 to 100 mPa · s at 25 ° C. at a temperature of 28 ° C. or higher, and complete the invention. It came to.
Specifically, the above problem has been solved by the following means.

(1) A photocurable composition containing a polymerizable compound and a polymerization initiator is applied on a substrate or a mold having a fine pattern, and the photocurable composition is light sandwiched between the mold or the substrate. A pattern forming method including irradiating,
The viscosity of the photocurable composition at 25 ° C. is 12 to 100 mPa · s,
The photocurable composition is applied to a substrate or a mold having a fine pattern by discharging droplets, and the temperature at the time of discharging the photocurable composition is 28 ° C. or more. .
(2) The pattern forming method according to (1), wherein the photocurable composition is discharged by an inkjet method.
(3) The pattern forming method according to (1) or (2), wherein a temperature at the time of discharging the photocurable composition is 70 ° C. or less.
(4) The pattern forming method according to any one of (1) to (3), wherein the viscosity of the photocurable composition upon ejection is 2 mPa · s to 30 mPa · s.
(5) The pattern forming method according to any one of (1) to (3), wherein the viscosity at the time of discharging the photocurable composition is 5 mPa · s or more and less than 12 mPa · s.
(6) A polymerizable compound contained in the photocurable composition, wherein the content of the polymerizable compound having a viscosity of less than 5 mPa · s at 25 ° C. is contained in the photocurable composition. The pattern forming method according to any one of (1) to (5), wherein the pattern forming method is 30% by mass or less.
(7) The difference between the viscosity at 25 ° C. of the curable composition and the viscosity at the time of discharging the photocurable composition is 2 to 100 mPa · s, according to any one of (1) to (6) Pattern forming method.
(8) The photocurable composition contains two or more kinds of polymerizable compounds, and 25 of the polymerizable compound having the largest compounding amount and the second most polymerizable compound in the photocurable composition. 8. The pattern forming method according to any one of (1) to (7), wherein the difference in viscosity at 0 ° C. is 0.1 to 120 mPa · s.
(9) The curable composition has a viscosity at 25 ° C. of 12 mPa · s to 80 mPa · s, and has a viscosity at the time of discharge of 2 mPa · s or more and less than 12 mPa · s, any of (1) to (8) 2. The pattern forming method according to item 1.
(10) The pattern forming method according to any one of (1) to (9), wherein the photocurable composition contains a polymerizable compound having an alicyclic hydrocarbon group and / or an aromatic group.
(11) A method for manufacturing an electronic device, comprising the pattern forming method according to any one of (1) to (10).
(12) A pattern forming apparatus having means for executing the pattern forming method described in any one of (1) to (10).
(13) The pattern forming apparatus according to (12), which has a temperature control unit of the photocurable composition.

When the photocurable composition used in the present invention is used as a cured composition for imprints, it has good pattern forming properties, has few defects, and has good line edge roughness after etching when used in substrate processing applications. A curable composition for imprints can be provided.

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 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, “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 2,000 or less.
The “imprint” in the present invention preferably refers to pattern transfer with a size of 1 nm to 10 mm, and more preferably refers to pattern transfer with a size (nanoimprint) of approximately 10 nm to 100 μm. 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).

In the pattern forming method of the present invention, a photocurable composition containing a polymerizable compound and a polymerization initiator is applied to a substrate or a mold having a fine pattern, and the photocurable composition is applied to the mold or the substrate. A pattern forming method including irradiating light in a sandwiched state, wherein the photocurable composition has a viscosity at 25 ° C. of 12 to 100 mPa · s, and the photocurable composition is formed by discharging droplets to form a base. It is applied to a material or a mold having a fine pattern, and the temperature at the time of discharging the photocurable composition is 28 ° C. or more.

The photocurable composition used in the present invention has a viscosity at 25 ° C. of 12 to 100 mPa · s, preferably 12 to 80 mPa · s, more preferably 15 to 50 mPa · s, and still more preferably 15 to 40 mPa · s. Particularly preferred is 15 to 30 mPa · s.
The viscosity at the time of discharging the photocurable composition is preferably 2 to 30 mPa · s, more preferably 3 to 25 mPa · s, still more preferably 3 to 20 mPa · s, and still more preferably 5 mPa · s. s to less than 15 mPa · s, particularly preferably 5 to less than 12 mPa · s. By setting it as such a range, a photocurable composition can be stably applied on the base or the mold which has a fine pattern, and a continuous pattern formation property improves. Here, the viscosity at the time of discharge refers to the viscosity of the photocurable composition at X ° C. when the temperature of the photo-curable composition at the time of discharge is adjusted (for example, heated) to be X ° C.
Further, the difference between the viscosity at 25 ° C. of the curable composition and the viscosity at the time of discharging the photocurable composition is preferably 2 to 100 mPa · s, more preferably 3 to 80 mPa · s, It is more preferably 3 to 50 mPa · s, and most preferably 5 to 20 mPa · s. By setting it as such a range, it exists in the tendency for the effect of this invention to be exhibited more effectively.
Further, the photocurable composition contains two or more kinds of polymerizable compounds, and the polymerizable compound having the largest amount and the second most polymerizable compound in the photocurable composition are at 25 ° C. The difference in viscosity is preferably 0.1 to 120 mPa · s, more preferably 1 to 100 mPa · s, still more preferably 1 to 50 mPa · s, and most preferably 1 to 20 mPa · s. preferable.

The photocurable composition is discharged at a temperature of 28 ° C. or higher. (X ° C.) is preferably 28 ° C. to 70 ° C., more preferably 30 to 60 ° C., and particularly preferably 30 to 50 ° C. By setting it as such a range, the discharge stability of a hardening composition improves, pattern formation improves, and it can suppress generation | occurrence | production of the particle | grains and air bubbles in an apparatus.

The photocurable composition used in the present invention contains a polymerizable compound (A) and a polymerization initiator (B).
The type of the polymerizable compound used in the curable composition for imprints used in the present invention is not particularly defined as long as it does not depart from the gist of the present invention. For example, it has 1 to 6 ethylenically unsaturated bond-containing groups. Polymerizable unsaturated monomer; epoxy compound, oxetane compound; vinyl ether compound; styrene derivative; propenyl ether or butenyl ether.

Polymerizable compound (A)
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 include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, N-vinylpyrrolidinone, -Acryloyloxyethyl phthalate, 2-acryloyloxy 2-hydroxyethyl phthalate, 2-acryloyloxyethyl hexahydrophthalate, 2-acryloyloxypropyl phthalate, 2-ethyl-2-butylpropanediol acrylate, 2-ethylhexyl (meta ) Acrylate, 2-ethylhexyl carbitol (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) ) Acrylate, acrylic acid dimer, benzyl (meth) acrylate, 1- or 2-naphthyl (meth) acrylate, butoxyethyl (meth) acrylate, cetyl (meth) acrylate, ethylene oxide modified (hereinafter referred to as “EO”) cresol (meth) ) Acrylate, dipropylene glycol (meth) acrylate, ethoxylated phenyl (meth) acrylate, isooctyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyl Oxyethyl (meth) acrylate, isomyristyl (meth) acrylate, lauryl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripro Lenglycol (meth) acrylate, methoxypolyethyleneglycol (meth) acrylate, methoxytriethyleneglycol (meth) acrylate, neopentylglycol benzoate (meth) acrylate, nonylphenoxypolyethyleneglycol (meth) acrylate, nonylphenoxypolypropyleneglycol (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 Recall (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, stearyl (meth) acrylate, EO-modified succinic acid (meth) acrylate, tribromophenyl (meth) acrylate, EO-modified tribromo Examples include phenyl (meth) acrylate, tridodecyl (meth) acrylate, p-isopropenylphenol, N-vinylpyrrolidone, and N-vinylcaprolactam.

Among the monofunctional polymerizable compounds containing an ethylenically unsaturated bond, it is preferable in the present invention to use a monofunctional (meth) acrylate compound from the viewpoint of photocurability. Examples of the monofunctional (meth) acrylate compound include monofunctional (meth) acrylate compounds in the monofunctional polymerizable compound containing the ethylenically unsaturated bond.

In the present invention, it is also preferable to use a polyfunctional polymerizable unsaturated monomer having two or more ethylenically unsaturated bond-containing groups as the polymerizable compound.
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, allyloxypolyethylene 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, divinylpropylene urea, o-, m-, p-xylylene di (meth) acrylate, 1,3-adamantane diacrylate norbornane dimethanol diacrylate.

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 Bifunctional (meth) such as glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, o-, m-, p-benzenedi (meth) acrylate, o-, m-, p-xylylene di (meth) acrylate Acrylate is preferably used in the present invention.

Examples of the polyfunctional polymerizable unsaturated monomer having three 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) Acrylate, 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 Trifunctional or higher functional (meth) acrylates such as (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate and pentaerythritol tetra (meth) acrylate are preferably used in the present invention.

Among the polyfunctional polymerizable unsaturated monomers having two or more ethylenically unsaturated bonds, it is preferable in the present invention to use a polyfunctional (meth) acrylate from the viewpoint of photocurability. The polyfunctional (meth) acrylate referred to here is a generic term for the bifunctional (meth) acrylate and the trifunctional or higher functional (meth) acrylate. Specific examples of the polyfunctional (meth) acrylate include those exemplified in the polyfunctional polymerizable unsaturated monomer having two ethylenically unsaturated bonds, and those having three or more ethylenically unsaturated bonds. Various polyfunctional (meth) acrylates exemplified in the functional polymerizable unsaturated monomer can be exemplified.

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 di 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 acids The glycidyl esters of

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.

Examples of 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 the cyclic compounds－Small Ring Heterocycles part3 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 Laid-Open No. 11-1000037, Japanese Patent No. 2906245, Japanese Patent No. 2926262 and the like can be synthesized.

As the polymerizable compound that can be used in the present invention, a vinyl ether compound may be used in combination. The vinyl ether compound can be appropriately selected from known ones, such as 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 are, for example, the methods described in Stephen C. Lapin, Polymers Paint, Color Journal 179 (4237), 321 (1989), 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.

Also, as the polymerizable compound that can be used in the present invention, a styrene derivative can also be employed. Examples of the styrene derivative include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-methylstyrene, and p-hydroxy. Examples include styrene.

A polymerizable compound having an aromatic group is preferred as the polymerizable compound used in the present invention. By using a polymerizable compound having an aromatic group, the line edge roughness is improved when used as an etching resist for substrate processing.

As the polymerizable monomer having an aromatic group used in the present invention, a monofunctional (meth) acrylate compound represented by the following general formula (I) or a polyfunctional (meta) represented by the following general formula (II): ) Acrylate compounds are preferred.

(In the general formula, Z represents a group containing an aromatic group, and R ¹ represents a hydrogen atom, an alkyl group or a halogen atom. However, when the polymerizable monomer (Ax) is liquid at 25 ° C., (The viscosity at 25 ° C. is 500 mPa · s or less.)
R ¹ is preferably a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom from the viewpoint of curability. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Z is preferably an aralkyl group which may have a substituent, an aryl group which may have a substituent, or a group in which these groups are bonded via a linking group. The linking group here may include a linking group containing a hetero atom, and preferably a group consisting of —CH ₂ —, —O—, —C (═O) —, —S—, and combinations thereof. It is. The aromatic group contained in Z is preferably a phenyl group or a naphthyl group. The molecular weight of Z is preferably 90 to 300, more preferably 120 to 250.

When the polymerizable monomer represented by formula (I) is a liquid at 25 ° C., the viscosity at 25 ° C. is preferably 2 to 500 mPa · s, more preferably 3 to 200 mPa · s, and more preferably 3 to 100 mPa · s. s is most preferred. The polymerizable monomer is liquid at 25 ° C, or even if it is solid, the melting point is preferably 60 ° C or lower, more preferably the melting point is 40 ° C or lower, and it is liquid at 25 ° C. Further preferred.
Z is preferably a group represented by —Z ¹ —Z ² . Here, Z ¹ is a single bond or a hydrocarbon group, and the hydrocarbon group may include a linking group containing a hetero atom in the chain. Z ² is an aromatic group which may have a substituent and has a molecular weight of 90 or more.
Z ¹ is preferably a single bond or an alkylene group, and the alkylene group may contain a linking group containing a hetero atom in the chain. Z ¹ is more preferably an alkylene group that does not contain a linking group containing a hetero atom in the chain, and more preferably a methylene group or an ethylene group. Examples of the linking group containing a hetero atom include —O—, —C (═O) —, —S—, and a group comprising a combination of these with an alkylene group. The hydrocarbon group preferably has 1 to 3 carbon atoms.

Z ² is also preferably a group in which two or more aromatic groups are linked directly or via a linking group. The linking group in this case is also preferably a group consisting of —CH ₂ —, —O—, —C (═O) —, —S—, and combinations thereof.

Examples of the substituent that the aromatic group of the polymerizable monomer represented by the general formula (I) may have include, for example, a halogen atom (fluorine atom, chloro atom, bromine atom, iodine). Atom), linear, branched or cyclic alkyl group, alkenyl group, alkynyl group, aryl group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, cyano group, carboxyl group, hydroxyl group, alkoxy group, aryloxy Group, alkylthio group, arylthio group, heterocyclic oxy group, acyloxy group, amino group, nitro group, hydrazino group, heterocyclic group and the like. A group further substituted with these groups is also preferred.

The addition amount of the polymerizable monomer represented by the general formula (I) in the photocurable composition is preferably 10 to 100% by mass, more preferably 20 to 100% by mass, It is particularly preferably 80 to 80% by mass.
Specific examples of the compound represented by the general formula (I) having no substituent on the aromatic ring include benzyl (meth) acrylate, phenethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 1- Or 2-naphthyl (meth) acrylate, 1- or 2-naphthylmethyl (meth) acrylate, 1- or 2-naphthylethyl (meth) acrylate, 1- or 2-naphthoxyethyl (meth) acrylate is preferable.

As the compound represented by the general formula (I), a compound having a substituent on the aromatic ring represented by the following general formula (II) is also preferable.

(In the general formula (II), R ¹ represents a hydrogen atom, an alkyl group or a halogen atom, X ¹ is a single bond or a hydrocarbon group, and the hydrocarbon group is a linking group containing a hetero atom in the chain. Y ¹ represents a substituent having a molecular weight of 15 or more, and n1 represents an integer of 1 to 3. Ar represents an aromatic linking group, preferably a phenylene group or a naphthylene group.

R ¹ has the same meaning as R ¹ in the formula, the preferred range is also the same.
X ¹ has the same meaning as Z ¹ described above, and the preferred range is also the same.
Y ¹ is a substituent having a molecular weight of 15 or more, and examples thereof include an alkyl group, an alkoxy group, an aryloxy group, an aralkyl group, an acyl group, an alkoxycarbonyl group, an alkylthio group, an arylthio group, a halogen atom, and a cyano group. These substituents may have further substituents.
When n1 is 2, X ¹ is preferably a single bond or a hydrocarbon group having 1 carbon atom.
In a particularly preferred embodiment, n1 is 1 and X ¹ is an alkylene group having 1 to 3 carbon atoms.

The compound represented by the general formula (II) is more preferably a compound represented by any one of (IV) and (V).

Compound represented by general formula (IV)

In the general formula (IV), R ¹ represents a hydrogen atom, an alkyl group or a halogen atom. X ² is a single bond or a hydrocarbon group, and the hydrocarbon group may contain a linking group containing a hetero atom in the chain. Y ² represents a substituent not having an aromatic group having a molecular weight of 15 or more, and n2 represents an integer of 1 to 3.
R ¹ has the same meaning as R ¹ in the formula, the preferred range is also the same.
When X ² is a hydrocarbon group, it is preferably a hydrocarbon group having 1 to 3 carbon atoms, preferably a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, and an unsubstituted carbon number More preferably, it is an alkylene group of 1 to 3, more preferably a methylene group or an ethylene group. By employing such a hydrocarbon group, a photocurable composition having a lower viscosity and lower volatility can be obtained.
Y ² represents a substituent having no aromatic group having a molecular weight of 15 or more, and the upper limit of the molecular weight of Y ² is preferably 150 or less. Y ² is an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group or a cyclohexyl group, a halogen atom such as a fluoro group, a chloro group or a bromo group, a methoxy group or an ethoxy group. Preferred examples include C 1-6 alkoxy groups such as cyclohexyloxy group, and cyano group.
n2 is preferably an integer of 1 to 2. When n2 is 1, the substituent Y is preferably in the para position. From the viewpoint of viscosity, when n2 is 2, X ² is preferably a single bond or a hydrocarbon group having 1 carbon atom.

From the viewpoint of achieving both low viscosity and low volatility, the molecular weight of the (meth) acrylate compound represented by the general formula (IV) is preferably 175 to 250, and more preferably 185 to 245.
Moreover, it is preferable that the viscosity in 25 degreeC of the (meth) acrylate compound represented by general formula (IV) is 50 mPa * s or less, and it is more preferable that it is 20 mPa * s or less.
The compound represented by the general formula (IV) can be preferably used as a reaction diluent.

The addition amount of the compound represented by the general formula (IV) in the photocurable composition is preferably 10% by mass or more from the viewpoint of the viscosity of the composition or the pattern accuracy after curing, and is 15% by mass or more. More preferably, it is particularly preferably 20% by mass or more. On the other hand, from the viewpoint of tackiness after curing and mechanical strength, the addition amount is preferably 95% by mass or less, more preferably 90% by mass or less, and particularly preferably 85% by mass or less.

Although the compound represented by general formula (IV) is illustrated below, it cannot be overemphasized that this invention is not limited to these. R ¹ represents a hydrogen atom, an alkyl group or a halogen atom.

Compound represented by general formula (V)

(In the general formula (V), R ¹ represents a hydrogen atom, an alkyl group or a halogen atom, X ³ is a single bond or a hydrocarbon group, and the hydrocarbon group contains a hetero atom in the chain. (Y ³ represents a substituent having an aromatic group, and n3 represents an integer of 1 to 3).
R ¹ has the same meaning as R ¹ in the formula, the preferred range is also the same.
Y ³ represents a substituent having an aromatic group. As the substituent having an aromatic group, the aromatic group is bonded to the aromatic ring of the general formula (V) through a single bond or a linking group. Is preferred. Preferred examples of the linking group include an alkylene group, a linking group having a hetero atom (preferably —O—, —S—, —C (═O) O—, or a combination thereof), and an alkylene group or — A group consisting of O— and combinations thereof is more preferred. The substituent having an aromatic group is preferably a substituent having a phenyl group. A mode in which the phenyl group is bonded through a single bond or the above linking group is preferable, and a phenyl group, a benzyl group, a phenoxy group, a benzyloxy group, and a phenylthio group are particularly preferable. The molecular weight of Y ³ is preferably 230 to 350.
n3 is preferably 1 or 2, more preferably 1.

The addition amount of the compound represented by the general formula (V) in the photocurable composition used in the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, and 30% by mass. The above is particularly preferable. On the other hand, from the viewpoint of tackiness after curing and mechanical strength, the addition amount is preferably 90% by mass or less, more preferably 80% by mass or less, and particularly preferably 70% by mass or less.

Although the compound represented by general formula (V) is illustrated below, it cannot be overemphasized that this invention is not limited to these. R ¹ represents a hydrogen atom, an alkyl group or a halogen atom.

Polyfunctional (meth) acrylate compound represented by general formula (II)

In the formula, Ar ₂ represents an n-valent linking group having an aromatic group, and preferably a linking group having a phenylene group. X ₁ and R ¹ are as defined above. n represents 1 to 3, and is preferably 1.

The compound represented by the general formula (II) is preferably a compound represented by the general formula (VI) or (VII).
Compound represented by general formula (VI)

(In General Formula (VI), X ⁶ is a (n6 + 1) -valent linking group, R ¹ is a hydrogen atom, an alkyl group, or a halogen atom. R ² and R ³ are each a substituent. Each of n4 and n5 is an integer of 0 to 4. n6 is 1 or 2, X ⁴ and X ⁵ are each a hydrocarbon group, and the hydrocarbon group is in the chain (It may contain a linking group containing a hetero atom.)

X ⁶ represents a single bond or a (n6 + 1) -valent linking group, preferably an alkylene group, —O—, —S—, —C (═O) O—, or a combination thereof. It is a linking group. The alkylene group is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 3 carbon atoms. An unsubstituted alkylene group is preferred.
n6 is preferably 1. When n6 is 2, a plurality of R ¹ , X ⁵ , and R ² may be the same or different.
X ⁴ and X ⁵ are each preferably an alkylene group containing no linking group, more preferably an alkylene group having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 3 carbon atoms, most preferably A methylene group.
R ¹ has the same meaning as R ¹ in the formula, the preferred range is also the same.
R ² and R ³ each represent a substituent, preferably an alkyl group, a halogen atom, an alkoxy group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a cyano group, or a nitro group. As the alkyl group, an alkyl group having 1 to 8 carbon atoms is preferable. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. As the alkoxy group, an alkoxy group having 1 to 8 carbon atoms is preferable. As the acyl group, an acyl group having 1 to 8 carbon atoms is preferable. As the acyloxy group, an acyloxy group having 1 to 8 carbon atoms is preferable. The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 1 to 8 carbon atoms.
n4 and n5 are each an integer of 0 to 4, and when n4 or n5 is 2 or more, a plurality of R ² and R ³ may be the same or different.

The compound represented by the general formula (VI) is preferably a compound represented by the following general formula (VIII).

(X ⁶ is an alkylene group, —O—, —S—, or a linking group in which a plurality of these are combined, and R ¹ is a hydrogen atom, an alkyl group, or a halogen atom, respectively.)
R ¹ has the same meaning as R ¹ in the formula, the preferred range is also the same.
When X ⁶ is an alkylene group, an alkylene group having 1 to 8 carbon atoms is preferable, and an alkylene group having 1 to 3 carbon atoms is more preferable. An unsubstituted alkylene group is preferred.
The ^{_{X 6, -CH 2 -, -}} CH 2 CH 2 -, - O -, - S- it is preferred.

The content of the compound represented by the general formula (VI) in the photocurable composition used in the present invention is not particularly limited, but from the viewpoint of the viscosity of the photocurable composition, It is preferably 1 to 100% by mass, more preferably 5 to 70% by mass, and particularly preferably 10 to 50% by mass.

Although the compound represented by general formula (VI) is illustrated below, it cannot be overemphasized that this invention is not limited to these. R ¹ in the following formula has the same meaning as R ¹ in the general formula (VI), and the preferred range is also the same, and particularly preferably a hydrogen atom.

The polymerizable monomer represented by the following general formula (VIII)

(In the formula, Ar represents an arylene group which may have a substituent, X represents a single bond or an organic linking group, R ¹ represents a hydrogen atom or a methyl group, and n represents 2 or 3. )

In the general formula, the arylene group includes a hydrocarbon-based arylene group such as a phenylene group and a naphthylene group; a heteroarylene group in which indole, carbazole and the like are linked groups, preferably a hydrocarbon-based arylene group, More preferred is a phenylene group from the viewpoint of viscosity and etching resistance. The arylene group may have a substituent, and preferred examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, a cyano group, an alkoxycarbonyl group, an amide group, and a sulfonamide group.

Examples of the organic linking group for X include an alkylene group, an arylene group, and an aralkylene group that may contain a hetero atom in the chain. Among these, an alkylene group and an oxyalkylene group are preferable, and an alkylene group is more preferable. X is particularly preferably a single bond or an alkylene group.

R ¹ is a hydrogen atom or a methyl group, preferably a hydrogen atom.
n is 2 or 3, preferably 2.

The polymerizable monomer (VIII) is preferably a polymerizable monomer represented by the following general formula (Ia) or (Ib) from the viewpoint of reducing the composition viscosity.

(Wherein X ¹ and X ² each independently represents a single bond or an alkylene group which may have a substituent having 1 to 3 carbon atoms, and R ¹ represents a hydrogen atom or a methyl group.)

In the general formula (Ia), X ¹ is preferably a single bond or a methylene group, and more preferably a methylene group from the viewpoint of viscosity reduction.
The preferable range of X ^{2 is the same as} the preferable range of X ¹ .
Wherein R ¹ is as in formula and R ¹ synonymous, and preferred ranges are also the same.

When the polymerizable monomer is a liquid at 25 ° C., it is preferable that the generation of foreign matters can be suppressed even when the addition amount is increased.

Specific examples of the polymerizable monomer represented by formula (VIII) are shown. R ¹ is as in formula and R ¹ synonymous represents a hydrogen atom or a methyl group. The present invention is not limited to these specific examples.

Although the more preferable specific example of the polymeric compound which has an aromatic group used with the photocurable composition used by this invention below is given, this invention is not limited to these.
Examples of the polymerizable compound having an aromatic group include benzyl (meth) acrylate which is unsubstituted or has a substituent on an aromatic ring, and phenethyl (meth) which is unsubstituted or has a substituent on an aromatic ring. Acrylate, unsubstituted or substituted phenoxyethyl (meth) acrylate on aromatic ring, unsubstituted or substituted 1- or 2-naphthyl (meth) acrylate on aromatic ring, unsubstituted Or 1- or 2-naphthylmethyl (meth) acrylate having a substituent on the aromatic ring, 1- or 2-naphthylethyl (meth) acrylate having no substituent or a substituent on the aromatic ring, 1- or 2-naphthoxyethyl (meth) acrylate, resorcinol di (meth) acrylate, m-xylylene di (meth) acrylate, naphthalene Meth) acrylate, ethoxylated bisphenol A diacrylate is preferred, benzyl acrylate having a substituent on the unsubstituted or an aromatic ring, 1 or 2-naphthyl methyl acrylate, m- xylylene acrylate, are more preferred.

Moreover, it is preferable to contain the polymeric compound which has at least one among a fluorine atom and a silicon atom for the purpose of improving peelability from a mold.
In the present invention, the polymerizable compound (A2) having at least one of a fluorine atom and a silicon atom has at least one fluorine atom, a silicon atom, or a group having both a fluorine atom and a silicon atom, and a polymerizable functional group. It is a compound having at least one. As the polymerizable functional group, a methacryloyl group, an epoxy group, and a vinyl ether group are preferable.

(A2) The polymerizable compound having at least one of a fluorine atom and a silicon atom may be a low molecular compound or a polymer.

(A2) when the polymerizable compound having at least one of fluorine atom and silicon atom is a polymer, a repeating unit having at least one of fluorine atom and silicon atom, and a polymerizable group in a side chain as a copolymerization component It may have a repeating unit having Further, the repeating unit having at least one of the fluorine atom and the silicon atom may have a polymerizable group at its side chain, particularly at the terminal. In this case, the skeleton of the repeating unit having at least one of the fluorine atom and the silicon atom is not particularly limited as long as it does not contradict the gist of the present invention. For example, it has a skeleton derived from an ethylenically unsaturated bond-containing group. It is preferable to have a (meth) acrylate skeleton. Moreover, the repeating unit which has a silicon atom may form the repeating unit by the silicon atom itself like a siloxane structure (for example, dimethylsiloxane structure). The weight average molecular weight is preferably from 2,000 to 100,000, more preferably from 3,000 to 70,000, and particularly preferably from 5,000 to 40,000.

Although there is no restriction | limiting in particular in content of (A2) in the curable composition for imprints of this invention, From a viewpoint of sclerosis | hardenability improvement and a viewpoint of the viscosity reduction of a composition, it is 0 in all the polymeric compounds. 0.1 to 20% by mass is preferable, 0.2 to 15% by mass is more preferable, 0.5 to 10% by mass is further preferable, and 0.5 to 5% by mass is particularly preferable.

Polymeric compound having fluorine atom The fluorine-containing group selected from a fluoroalkyl group and a fluoroalkyl ether group is preferred as the group having a fluorine atom that the polymerizable compound having a fluorine atom has.
The fluoroalkyl group is preferably a fluoroalkyl group having 2 to 20 carbon atoms, and more preferably a 4 to 8 fluoroalkyl group. Preferable fluoroalkyl groups include trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, hexafluoroisopropyl group, nonafluorobutyl group, tridecafluorohexyl group, and heptadecafluorooctyl group.

In the present invention, (A2) the polymerizable compound having a fluorine atom is preferably a polymerizable compound having a fluorine atom having a trifluoromethyl group structure. By having a trifluoromethyl group structure, the effects of the present invention are exhibited even with a small addition amount (for example, 10% by mass or less), so that compatibility with other components is improved, and line edge roughness after dry etching is improved. In addition to the improvement, the repeat pattern formability is improved.

As in the case of the fluoroalkyl group, the fluoroalkyl ether group preferably has a trifluoromethyl group, and preferably contains a perfluoroethyleneoxy group or a perfluoropropyleneoxy group. A fluoroalkyl ether unit having a trifluoromethyl group such as-(CF (CF ₃ ) CF ₂ O)-and / or a trifluoromethyl ether group having a trifluoromethyl group at the terminal is preferred.

(A2) The number of total fluorine atoms contained in the polymerizable compound having at least one of fluorine atoms and silicon atoms is preferably 6 to 60, more preferably 9 to 40, still more preferably 12 per molecule. ~ 40, particularly preferably 12-20.

(A2) The polymerizable compound having at least one of a fluorine atom and a silicon atom has a fluorine atom having a fluorine content of 20 to 60% as defined below. (A2) When the polymerizable compound having at least one of fluorine atom and silicon atom is a polymerizable compound, the fluorine content is preferably 20 to 60%, more preferably 35 to 60%. In the case where (A2) is a polymer having a polymerizable group, the fluorine content is more preferably 20 to 50%, still more preferably 20 to 40%. By adjusting the fluorine content to an appropriate range, compatibility with other components is excellent, mold contamination can be reduced, line edge roughness after dry etching is improved, and repeat pattern formation is improved. In the present specification, the fluorine content is represented by the following formula.

A preferred example of the group having a fluorine atom of the polymerizable compound having at least one of the fluorine atom and the silicon atom (A2) includes a compound having a partial structure represented by the following general formula (I). By adopting a compound having such a partial structure, the pattern forming property is excellent even when repeated pattern transfer is performed, and the temporal stability of the composition is improved.

Formula (I)

In general formula (I), n represents an integer of 1 to 8, preferably an integer of 4 to 6.

Another preferable example of the polymerizable compound having at least one of the fluorine atom and the silicon atom (A2) includes a compound having a partial structure represented by the following general formula (II). Of course, you may have both the partial structure represented by general formula (I), and the partial structure represented by general formula (II).

Formula (II)

In general formula (II), L ¹ represents a single bond or an alkylene group having 1 to 8 carbon atoms, L ² represents an alkylene group having 1 to 8 carbon atoms, m1 and m2 each represents 0 or 1, At least one of m1 and m2 is 1. m3 represents an integer of 1 to 3, p represents an integer of 1 to 8, and when m3 is 2 or more, -C _p F _{2p + 1} may be the same or different. .
L ¹ and L ² are each preferably an alkylene group having 1 to 4 carbon atoms. Further, the alkylene group may have a substituent within a range not departing from the gist of the present invention. The m3 is preferably 1 or 2. The p is preferably an integer of 4 to 6.

Specific examples of the polymerizable compound having a fluorine atom used in the photocurable composition used in the present invention will be given below, but the present invention is not limited thereto.

Examples of the polymerizable compound having a fluorine atom include trifluoroethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, (perfluorobutyl) ethyl (meth) acrylate, perfluorobutyl-hydroxypropyl (meth) acrylate, ( Monofunctional having fluorine atoms such as perfluorohexyl) ethyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, etc. A polymerizable compound is mentioned. Examples of the polymerizable compound having a fluorine atom include 2,2,3,3,4,4-hexafluoropentanedi (meth) acrylate, 2,2,3,3,4,4,5,5- A polyfunctional polymerizable compound having two or more polymerizable functional groups having a di (meth) acrylate having a fluoroalkylene group such as octafluorohexane di (meth) acrylate is also preferred.
A compound having two or more fluorine-containing groups such as a fluoroalkyl group or a fluoroalkyl ether group in one molecule can also be preferably used.
A compound having two or more fluoroalkyl groups or fluoroalkyl ether groups in one molecule is preferably a polymerizable compound represented by the following general formula (III).

(In the general formula (III), R ¹ represents a hydrogen atom, an alkyl group, a halogen atom or a cyano group, preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. .
A represents a (a1 + a2) -valent linking group, preferably a linking group having an alkylene group and / or an arylene group, and may further contain a linking group containing a hetero atom. Examples of the linking group having a hetero atom include —O—, —C (═O) O—, —S—, and —C (═O) —. These groups may have a substituent within a range not departing from the gist of the present invention, but preferably do not have a substituent. A preferably has 2 to 50 carbon atoms, and more preferably 4 to 15 carbon atoms.
a1 represents an integer of 1 to 6, preferably 1 to 3, and more preferably 1 or 2.
a2 represents an integer of 2 to 6, preferably 2 or 3, and more preferably 2.
R ² and R ³ each represent a single bond or an alkylene group having 1 to 8 carbon atoms. m1 and m2 each represents 0 or 1, and m3 represents an integer of 1 to 3. )
When a1 is 2 or more, each A may be the same or different.
When a2 is 2 or more, each R ² , R ³ , m1, m2, m3 may be the same or different.
Rf represents a fluoroalkyl group or a fluoroalkyl ether group, preferably a fluoroalkyl group having 1 to 8 carbon atoms, or a fluoroalkyl ether group having 3 to 20 carbon atoms.
When the polymerizable compound having a fluorine atom is a polymer, a polymer containing the polymerizable compound having a fluorine atom as a repeating unit is preferable.

Although the specific example of the polymeric compound which has a fluorine atom used by the photocurable composition used by this invention below is given, this invention is not limited to these. R ¹ in the following formula is each a hydrogen atom, an alkyl group, a halogen atom, or a cyano group.

(2) Polymerizable compound having a silicon atom Examples of the functional group having a silicon atom contained in the polymerizable compound having a silicon atom include a trialkylsilyl group, a chain siloxane structure, a cyclic siloxane structure, and a cage-like siloxane structure. From the viewpoint of compatibility with other components and mold releasability, a functional group having a trimethylsilyl group or a dimethylsiloxane structure is preferred.

Examples of the polymerizable compound having a silicon atom include 3-tris (trimethylsilyloxy) silylpropyl (meth) acrylate, trimethylsilylethyl (meth) acrylate, (meth) acryloxymethylbis (trimethylsiloxy) methylsilane, and (meth) acryloxymethyltris. (Trimethylsiloxy) silane, 3- (meth) acryloxypropylbis (trimethylsiloxy) methylsilane, polysiloxane having a (meth) acryloyl group at the terminal or side chain (for example, X-22-164 series manufactured by Shin-Etsu Chemical Co., Ltd., X -22-174DX, X-22-2426, X-22-2475) and the like.

In the present invention, it is also preferable that a polymerizable monomer (Ax) having a hydrogen bonding functional group and a fluorine-containing group is included as the polymerizable compound.
As the polymerizable functional group of the polymerizable monomer (Ax), radical polymerization such as CH (R ¹ ) ═CHC (═O) — (R ¹ is a hydrogen atom, an alkyl group, a halogen atom, a cyano group), etc. A cationic polymerizable group such as a functional group, an epoxy group, an oxetane group and a vinyl ether group, more preferably a (meth) acrylic group. The number of polymerizable groups contained in the polymerizable monomer (Ax) is preferably 1 or 2, more preferably 1.
The fluorine-containing group that the polymerizable monomer (Ax) has is preferably a fluorine-containing group selected from a fluoroalkyl group and a fluoroalkyl ether group, and more preferably a fluoroalkyl group.
The fluoroalkyl group is preferably a fluoroalkyl group having 2 or more carbon atoms, more preferably a fluoroalkyl group having 4 or more carbon atoms, and the upper limit is not particularly defined, but 20 or less is preferable. 8 or less is more preferable, and 6 or less is more preferable. Most preferred is a fluoroalkyl group having 4 to 6 carbon atoms. The fluoroalkyl group also includes a fluoroalkylene group in which the fluoroalkyl group is a linking group. The fluoroalkyl group is preferably a perfluoroalkyl group. Moreover, it is preferable that it is a linear fluoroalkyl group.

As the fluoroalkyl ether group, those containing a perfluoroethyleneoxy group or a perfluoropropyleneoxy group are preferable. Those having a trifluoromethyl group structure at the terminal are preferred, and a fluoroalkyl ether unit having a trifluoromethyl group such as — (CF (CF ₃ ) CF ₂ O) — and / or a terminal of the fluoroalkyl ether group. Those having a trifluoromethyl group are preferred.
The fluoroalkyl ether group also includes a fluoroalkyl ether linking group in which the fluoroalkyl ether group is a linking group.
The fluoroalkyl ether group preferably has 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms.
More preferred examples of the fluorine-containing group include compounds having a partial structure represented by the following general formulas (I-1) and (I-2), and more preferred general formulas (II-1) and (II-2). By adopting a compound having such a partial structure, the pattern forming property is excellent and the temporal stability of the composition is good.

In the formula, X represents an alkylene group having 1 to 6 carbon atoms, which may have a substituent on the alkylene group, but preferably has no substituent. Preferable examples of the substituent on the alkylene group include an alkyl group, a fluoroalkyl group, and a substituent having a hydrogen bonding functional group described later. Rf represents a fluoroalkyl group or a fluoroalkyl ether group.
n represents an integer of 1 to 8, preferably an integer of 4 to 6.
From the viewpoint of compatibility with other components, the number of fluorine-containing groups present in the polymerizable monomer (Ax) is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. It is. The number of total fluorine atoms contained in the polymerizable monomer (Ax) is preferably 3 to 60, more preferably 5 to 20, and still more preferably 9 to 20.
The polymerizable monomer (Ax) has a fluorine content of preferably 30 to 60%, more preferably 35 to 55%, and still more preferably 35 to 50%. By making the fluorine content within an appropriate range, mold contamination can be reduced and the line edge roughness after dry etching is improved.

As the hydrogen bonding functional group, a functional group having a hydrogen atom capable of hydrogen bonding is preferable. The functional group having a hydrogen atom capable of hydrogen bonding is preferably a functional group having an OH bond or an NH bond, and —OH, —C (═O) OH, —SO ₃ H, —NH—, — _{NH 2, -NHC (O) -} , - NHC (O) O -, - NHC (O) NH -, - SO 2 NH -, - SO 2 NHC (= O) -, - SO 2 NHSO 2 - Table More preferably, —OH and —NHC (O) O— are more preferable, and —OH is most preferable.

The polymerizable monomer (Ax) having a hydrogen bondable functional group and a fluorine-containing group used in the present invention is composed of a polymerizable group and a divalent linking group (preferably composed of a carbon atom, a hydrogen atom and an oxygen atom). Group, more preferably a group consisting of —CH ₂ —, —O—, —C (═O) —, and combinations thereof), a hydrogen-bonding functional group, and a fluorine-containing group. .
The polymerizable monomer (Ax) is preferably a polymerizable monomer represented by the following general formula.

(In the above formula, R ₁ is a hydrogen atom, a halogen atom, an alkyl group or a cyano group, and Rf is a fluorine-containing group.)
R ¹ is preferably a hydrogen atom, an alkyl group or a cyano group, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.
Examples of the halogen atom for R ¹ include a fluorine atom and a chlorine atom.
Rf is preferably a perfluoroalkyl group, more preferably a perfluoroalkyl group having 4 to 6 carbon atoms.

The molecular weight of the polymerizable monomer (Ax) used in the present invention is preferably 300 to 2000, more preferably 300 to 1000, and further preferably 300 to 800. By setting the molecular weight within an appropriate range, the filling property to the mold is improved and defects can be reduced.

Specific examples of the polymerizable monomer (Ax) used in the curable composition of the present invention are listed below, but the present invention is not limited to these. R ¹ in the following formula is each a hydrogen atom, an alkyl group, a halogen atom, or a cyano group.

The content of (Ax) having a hydrogen-bonding functional group and a fluorine-containing group in the curable composition of the present invention is not particularly limited, but from the viewpoints of curability and composition viscosity, the total polymerizable monomer Among them, 0.01 to 100% by mass is preferable, 0.05 to 50% by mass is more preferable, 0.1 to 20% by mass is further preferable, 0.2 to 10% by mass is particularly preferable, and 0.2 to 6% is preferable. Mass% is particularly preferred.

The polymerizable compound preferably contains a polymerizable compound having an alicyclic hydrocarbon group and / or an aromatic group, and further includes a polymerizable compound having an alicyclic hydrocarbon group and / or an aromatic group; It preferably contains a polymerizable compound containing a silicon atom and / or fluorine. Furthermore, among all the polymerizable components contained in the photocurable composition in the present invention, a polymerizable compound having an alicyclic hydrocarbon group and / or an aromatic group and a polymerizable compound containing a silicon atom and / or fluorine. The total is preferably 30 to 100% by mass of the total polymerizable compound, more preferably 70 to 100% by mass, and still more preferably 90 to 100% by mass.
In a more preferred embodiment, the (meth) acrylate polymerizable compound containing an aromatic group (preferably a phenyl group, a naphthyl group, more preferably a naphthyl group) as the polymerizable compound is 70 to 100% by mass of the total polymerizable component. It is preferably 90 to 100% by mass, more preferably 95 to 100% by mass.
In a particularly preferred embodiment, the following polymerizable compound (1) is 0 to 80% by mass (more preferably 20 to 70% by mass) of the total polymerizable component, and the following polymerizable compound (2) is all polymerized. This is a case where it is 20 to 100% by mass (more preferably 30 to 80% by mass) of the active ingredient.
(1) A polymerizable compound having one aromatic group (preferably phenyl group, naphthyl group, more preferably naphthyl group) and (meth) acrylate group (2) Aromatic group (preferably phenyl group, naphthyl group, A polymerizable compound containing a (preferably phenyl group) and having two (meth) acrylate groups

Furthermore, the content of the polymerizable compound having a viscosity at 25 ° C. of less than 5 mPa · s in the photocurable composition is preferably 30% by mass or less, and preferably 20% by mass or less, based on the total polymerizable compound. More preferred is 10% by mass or less. By setting to the above range, stability at the time of ink jet ejection is improved, and defects can be reduced in imprint transfer.

Polymerization initiator (B)
The photocurable composition used in 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 that polymerizes the above-described 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. In the present invention, a plurality of photopolymerization initiators may be used in combination.

The content of the photopolymerization initiator used in the present invention is, for example, 0.01 to 15% by mass, preferably 0.1 to 12% by mass, and more preferably 0% in the entire composition excluding the solvent. 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.

As the radical photopolymerization initiator used in the present invention, for example, a commercially available initiator can be used. As these examples, for example, those described in paragraph No. 0091 of JP-A No. 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.
Preferred examples of the acetophenone compound include hydroxyacetophenone compounds, dialkoxyacetophenone compounds, and aminoacetophenone compounds. Irgacure® 2959 (1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, preferably available from BASF as a hydroxyacetophenone compound, Irgacure® 184 (1-hydroxycyclohexyl phenyl ketone), Irgacure® 500 (1-hydroxycyclohexyl phenyl ketone, benzophenone), Darocur® 1173 (2-hydroxy-2-methyl-1-phenyl) -1-propan-1-one).
The dialkoxyacetophenone compound is preferably Irgacure (registered trademark) 651 (2,2-dimethoxy-1,2-diphenylethane-1-one) available from BASF.
As the aminoacetophenone compound, Irgacure (registered trademark) 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1), Irgacure (registered trademark) 379 (available from BASF Corporation) is preferable. EG) (2-dimethylamino-2- (4methylbenzyl) -1- (4-morpholin-4-ylphenyl) butan-1-one, Irgacure® 907 (2-methyl-1 [4- Methylthiophenyl] -2-morpholinopropan-1-one.
As the acylphosphine oxide-based compound, preferably Irgacure (registered trademark) 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, Irgacure (registered trademark) 1800 (bis (2, 6-Dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, Lucirin TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) available from BASF, Lucirin TPO-L (2,4,6 -Trimethylbenzoylphenylethoxyphosphine oxide).
Irgacure (registered trademark) OXE01 (1,2-octanedione, 1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), Irgacure (registered trademark), preferably available from BASF as an oxime ester compound (Trademark) OXE02 (ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime)).

The cationic photopolymerization initiator used in the present invention is preferably a sulfonium salt compound, an iodonium salt compound, an oxime sulfonate compound, and the like. 4-methylphenyl [4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) Examples include borate (Rhode PI2074), 4-methylphenyl [4-(2-methylpropyl) phenyliodonium hexafluorophosphate (IRSFACURE250 manufactured by BASF), IRGACURE PAG103, 108, 121, 203 (Ciba). .

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.

(Other ingredients)
The photocurable composition used in the present invention includes a surfactant, an antioxidant, a solvent, and the like within a range that does not impair the effects of the present invention in accordance with various purposes in addition to the above-described polymerizable compound and photopolymerization initiator. Other components such as a polymer component, a pigment, and a dye may be included. The photocurable composition used in the present invention preferably contains at least one selected from a surfactant and an antioxidant.

-Surfactant-
The photocurable composition used in 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 4% by mass 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 mold transfer characteristics are hardly deteriorated due to excessive surfactant.

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. It is more preferable to include both a Si-based surfactant or a fluorine / Si-based surfactant, and most preferable to include a fluorine / Si-based surfactant. The fluorine-based surfactant and the Si-based surfactant are preferably nonionic surfactants.
Here, the “fluorine / Si-based surfactant” refers to one having both the requirements of both a fluorine-based surfactant and a Si-based 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 curable composition for imprinting of the present invention is applied to a substrate on which various films such as an amorphous silicone film, an indium oxide (ITO) film doped with tin oxide, and a tin oxide film are formed. In addition, it is possible to solve the problem of poor application such as a scale-like pattern (unevenness of drying of the resist film). In addition, improvement of the fluidity of the photocurable composition used in the present invention into the cavity of the mold recess, improvement of peelability between the mold and the resist, improvement of adhesion between the resist and the substrate, The viscosity can be lowered. In particular, the curable composition for imprints of the present invention can significantly improve the coating uniformity by adding the surfactant, and the coating using a spin coater or slit scan coater does not depend on the substrate size. Good applicability 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 made by Daikin Industries, Ltd.) and trade names Megafuk 171, 172, 173, 178K, 178A, F780F (all Dainippon Ink Chemical Industry Co., Ltd.).
Examples of nonionic Si-based surfactants 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 / Si 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-
Further, the photocurable composition used in the present invention preferably contains a known antioxidant. The content of the antioxidant used in the present invention is, for example, 0.01 to 10% by mass, preferably 0.2 to 5% by mass, based on the polymerizable compound. When two or more kinds of antioxidants are used, the total amount is within the above 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. 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 Sumilyzer 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.

-Polymerization inhibitor-
Furthermore, the photocurable composition used in the present invention preferably contains a polymerization inhibitor. By including a polymerization inhibitor, it tends to be possible to suppress changes in viscosity, generation of foreign matter, and deterioration of pattern formation over time. The content of the polymerization inhibitor is 0.001 to 1% by mass, more preferably 0.005 to 0.5% by mass, and still more preferably 0.008 to 0.05% by mass with respect to the total polymerizable compound. %, A change in viscosity over time can be suppressed while maintaining high curing sensitivity. The polymerization inhibitor may be contained in advance in the polymerizable compound to be used, or may be further added to the composition.
Preferred polymerization inhibitors that can be used in the present invention include hydroquinone, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, tert-butylcatechol, benzoquinone, 4,4′-thiobis (3-methyl-6). -Tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt, phenothiazine, phenoxazine, 4-methoxynaphthol, 2,2,6 , 6-Tetramethylpiperidine-1-oxyl free radical, 2,2,6,6-tetramethylpiperidine, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, nitrobenzene, dimethyl And aniline. Particularly effective in the absence of oxygen, phenothiazine, 4-methoxynaphthol, 2,2,6,6-tetramethylpiperidine-1-oxyl free radical, 2,2,6,6-tetramethylpiperidine, 4- Hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical is preferred.

-solvent-
A solvent can be used for the photocurable composition used in the present invention according to various needs. 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. preferable.
The content of the solvent in the photocurable composition used in the present invention is optimally adjusted depending on the viscosity of the component excluding the solvent and the target film thickness. From the viewpoint of pattern formation, the content of the solvent is 30%. It is preferably at most 10% by mass, more preferably 10% by mass, further preferably 5% by mass, and most preferably contains substantially no solvent.

-Polymer component-
In the photocurable composition used in 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 compound is blended within the range of achieving the object of the present invention. You can also 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, still more 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 photocurable composition used in 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. The weight average molecular weight of the polymer component is preferably from 2,000 to 100,000, more preferably from 5,000 to 50,000, from the viewpoint of compatibility with the polymerizable compound. The addition amount of the polymer 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 2% by mass or less, relative to the component excluding the solvent of the composition. It is. Among the components excluding the solvent in the photocurable composition used in the present invention, if the content of the compound having a molecular weight of 2000 or more is 30% by mass or less, the pattern formability is improved. Preferably, the resin component is not included except for surfactants and trace amounts of additives.

In addition to the components described above, the photocurable composition used in the present invention may include a release agent, a silane coupling agent, an ultraviolet absorber, a light stabilizer, an anti-aging agent, a plasticizer, an adhesion promoter, and thermal polymerization. Initiators, colorants, elastomer particles, photoacid multipliers, photobase generators, basic compounds, flow regulators, antifoaming agents, dispersants and the like may be added.
In the curable composition of the present invention, the polymerizable compound preferably accounts for 90% by mass or more of the whole.

The photocurable composition used in the present invention can be prepared by mixing the above-described components. Mixing and dissolution of the curable composition is usually performed in the range of 0 ° C to 100 ° C. In addition, it is preferable that the components are mixed and then filtered, for example, with a filter having a pore size of 0.003 μm to 5.0 μm. 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 pattern forming method, first, a photocurable composition is applied onto a substrate or a mold having a fine pattern to form a pattern forming layer. Here, the step of applying the photocurable composition on a base material or a mold having a fine pattern includes the step of applying the photocurable composition to a temperature higher than 25 ° C. (X ° C.) of the photocurable composition. This is a step of discharging droplets. Examples of the method for ejecting droplets include a micro-dispensing method capable of ejecting droplets in the order of μL to nL, an ink-jet method capable of ejecting small droplets in the order of pL, and the like.

Ink Jet Device The ink jet device used in the present invention is not particularly limited, and commercially available ink jet devices can be used (for example, DMP-3000, DMP-2831 manufactured by Fujifilm Dimatics). Examples of the ink jet apparatus that can be used in the present invention include an ink supply system and a temperature sensor. The ink supply system includes, for example, an original tank containing the photocurable composition used in the present invention, a supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. Piezo-type ink jet heads can be driven so that ejection can be performed at 0.1 to 100 pl, preferably 0.5 to 20 pl. Droplets placed by ejection may be placed at intervals, or may be placed so that the droplets are coupled to each other, but from the viewpoint of making the thickness of the remaining film uniform and thin. It is preferable to be installed. The total amount of droplets varies depending on the pattern to be formed, and is adjusted so that the pattern and the remaining film have an appropriate thickness. Further, it is preferable to make the interval between the droplets non-uniform according to the density of the pattern.

Since the photocurable composition to be discharged is set to (X ° C.), it is preferable to control the temperature in any or all of the ink supply tank to the inkjet head portion. The temperature control method is not particularly limited, but for example, it is preferable to provide a plurality of temperature sensors at each piping site and perform heating control according to the ink flow rate and the environmental temperature. The temperature sensor can be provided in the vicinity of the ink supply tank and the nozzle of the inkjet head. Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside air. In order to shorten the printer start-up time required for heating or to reduce the loss of thermal energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

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, and Fe. Substrate, paper, polymer substrate such as SOG (Spin On Glass), polyester film, polycarbonate film, polyimide film, TFT array substrate, PDP electrode plate, glass or transparent plastic substrate, conductive base material such as ITO or metal, insulation There are no particular restrictions on a conductive substrate, a semiconductor production substrate such as silicon, silicon nitride, polysilicon, silicon oxide, and amorphous silicon. 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.

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, vapor deposition films, magnetic films, reflective films, metal substrates such as Ni, Cu, Cr, and Fe, and substrates such as SiC, silicon, silicon nitride, polysilicon, silicon oxide, and amorphous silicon. 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 that has been subjected to a release treatment in order to improve the peelability between the curable composition and the mold surface. Examples of such molds include those that have been treated with a silicon-based or fluorine-based silane coupling agent, such as OPTOOL DSX manufactured by Daikin Industries, Ltd., Novec EGC-1720 manufactured by Sumitomo 3M Co., Ltd. Commercially available release agents can also be suitably used.

Next, the photocurable composition is irradiated with light while being sandwiched between a substrate and a mold having a fine pattern. Thereby, the reversal pattern of a mold is transcribe | transferred to a photocurable composition, and a pattern is formed on a base material by peeling a base material and a mold. The pressure when sandwiching with a mold having a substrate and a fine pattern is preferably 10 atm or less. As a result, the mold and the substrate are hardly deformed and the pattern accuracy tends to be improved. 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 residual film of the curable composition on the mold convex portion is reduced.

The irradiation amount of light irradiation in the step of irradiating light should 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 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 bubbles from being mixed, suppressing the decrease in reactivity due to oxygen mixing, and improving the adhesion between the mold and the curable composition. May be. 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 photocurable composition used in the present invention is not particularly limited. For example, light or radiation having a wavelength in the region of high energy ionizing radiation, near ultraviolet, far ultraviolet, visible, infrared, or the like. 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).

In exposure, the exposure illuminance is preferably in the range of 1 mW / cm ² to 50 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, 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 preferably 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.

The pattern forming method of the present invention may include a step of further curing by applying heat to the cured pattern as necessary after curing the pattern forming layer by light irradiation. The heat for heat-curing the photocurable composition used in the present invention after light irradiation is preferably 150 to 280 ° C, more preferably 200 to 250 ° C. The time for applying heat is preferably 5 to 60 minutes, more preferably 15 to 45 minutes.

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.

(Preparation of curable composition)
A polymerizable compound and a polymerization initiator shown in the following table are mixed, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) is polymerizable as a polymerization inhibitor. In addition, it adjusted so that it might become 200 ppm (0.02 mass%) with respect to a compound. The adjusted composition was filtered with a 0.1 μm tetrafluoroethylene filter to obtain a curable composition. Furthermore, the curable composition was heated to the temperature at the time of discharge (X ° C.), and the viscosity was measured.

(Viscosity measurement method)
Viscosity was measured using a rotational viscometer (RE-80L, manufactured by Toki Sangyo Co., Ltd.), with a viscosity at 25 ° C of 25 ± 0.1 ° C and a viscosity at X ° C of X ° ± 0.1 ° C. did.
The rotational speed at the time of measurement is 100 rpm when 0.5 mPa · s or more and less than 5 mPa · s, 50 rpm when 5 mPa · s or more and less than 10 mPa · s, and 20 rpm when 10 mPa · s or more and less than 30 mPa · s. In the case of 30 mPa · s or more and less than 60 mPa · s, the viscosity was measured at 10 rpm, in the case of 60 mPa · s or more and less than 120 mPa · s, 5 rpm, and at 120 mPa · s or more, 1 rpm or 0.5 rpm.
The unit of viscosity in the following table is mPa · s. The compounding quantity of the compound is shown by weight ratio.

Photopolymerization initiator P1: IRGACURE 379EG (manufactured by BASF)
P2: DAROCURE1173 (manufactured by BASF)

The compositions of the photocurable compositions A1 to A12, B1, and B2 are shown below.

(Evaluation)
The following evaluation was performed about the obtained curable composition of each Example and a comparative example. The results are shown in the table below.

<Pattern formation method>
The mold has a rectangular line / space pattern (1/1) with a line width of 25 nm and a groove depth of 40 nm, and the surface of the pattern is treated with OPTOOL DSX (manufactured by Daikin Industries). The thing which is 2.5 nm was used.

Using an inkjet printer DMP-2831, manufactured by FUJIFILM Daimatics, the photocurable composition is controlled by controlling the discharge timing so as to form a square array at 100 μm intervals with a droplet volume of 1 pl per nozzle on a silicon wafer. The object was discharged. Under the present circumstances, it heated in the apparatus so that the temperature of the cured composition discharged might be set to X degreeC of the following table | surface. 10 sheets of 4 inch wafers are continuously discharged, the mold is placed on the first and tenth wafers under a reduced pressure of 0.1 atm, and exposure is performed from the mold side under a condition of 300 mJ / cm ² using a mercury lamp, After exposure, the mold was released to obtain a pattern.

<Pattern evaluation>
The pattern shape and pattern defect of the obtained pattern were observed with a scanning electron microscope and evaluated as follows.
(Shape evaluation)
A: A rectangular pattern faithful to the mold was obtained.
B: The pattern top was rounded, but the pattern height was faithful.
C: The pattern top was rounded and the pattern height was low.
(Defect assessment)
Pattern defects such as pattern peeling, cracking and crushing were observed.
a: No pattern defect was observed.
b: Defects were found in some of the region patterns, but they were less than 5% of the total pattern area.
c: Pattern defects were observed in a region of 5% or more with respect to the total pattern area.

<Line edge roughness after dry etching (LER)>
The 10th patterned substrate obtained by pattern formation evaluation is plasma dry etched with Ar / CF ₄ / O ₂ gas using a dry etcher manufactured by Hitachi High-Technology Co., Ltd. The distance from the reference line where the edge should be in the range where the edge in the longitudinal direction of the part is 5 μm was measured at 50 points by the length measuring SEM, the standard deviation was obtained, and 3σ was calculated. The smaller the value, the better the line edge roughness.

In the above table, the difference in viscosity indicates the difference (unit: mPa · s) between the viscosity at 25 ° C. of the photocurable composition and the temperature at the time of ejection.

As apparent from the above table, when the viscosity at 25 ° C. of the photocurable composition is 12 to 100 mPa · s and the discharge temperature is 28 ° C. or more, the pattern formability and the line edge roughness after dry etching are improved. It was found that an excellent pattern can be formed. Since the method of the present invention can be carried out regardless of the type of composition of the photocurable composition, there is also an advantage that the application range is wide.

Claims

Applying a photocurable composition containing a polymerizable compound and a polymerization initiator on a substrate or a mold having a fine pattern, and irradiating the photocurable composition with the mold or the substrate sandwiched between them. A pattern forming method comprising:
The viscosity of the photocurable composition at 25 ° C. is 12 to 100 mPa · s,
The photocurable composition is applied to a substrate or a mold having a fine pattern by discharging droplets, and the temperature at the time of discharging the photocurable composition is 28 ° C. or more. .
The pattern formation method of Claim 1 which discharges the said photocurable composition by the inkjet method.
The pattern formation method of Claim 1 or 2 whose temperature at the time of discharge of the said photocurable composition is 70 degrees C or less.
The pattern forming method according to any one of claims 1 to 3, wherein a viscosity at the time of discharging the photocurable composition is 2 mPa · s to 30 mPa · s.
The pattern forming method according to any one of claims 1 to 3, wherein a viscosity at the time of discharging the photocurable composition is 5 mPa · s or more and less than 12 mPa · s.
The polymerizable compound contained in the photocurable composition, the content of the polymerizable compound having a viscosity at 25 ° C. of less than 5 mPa · s is 30 mass of the total polymerizable compound contained in the photocurable composition. The pattern forming method according to claim 1, wherein the pattern forming method is 1% or less.
The pattern forming method according to any one of claims 1 to 6, wherein the difference between the viscosity of the curable composition at 25 ° C and the viscosity at the time of discharging the photocurable composition is 2 to 100 mPa · s.
The photocurable composition contains two or more kinds of polymerizable compounds, and the viscosity at 25 ° C. of the polymerizable compound having the largest blending amount and the second most polymerizable compound in the photocurable composition. The pattern forming method according to any one of claims 1 to 7, wherein the difference is 0.1 to 120 mPa · s.
The curable composition has a viscosity at 25 ° C of 12 mPa · s to 80 mPa · s, and a viscosity at the time of discharge of 2 mPa · s or more and less than 12 mPa · s. Pattern forming method.
The pattern forming method according to any one of claims 1 to 9, wherein the photocurable composition contains a polymerizable compound having an alicyclic hydrocarbon group and / or an aromatic group.
An electronic device manufacturing method comprising the pattern forming method according to any one of claims 1 to 10.
A pattern forming apparatus comprising means for executing the pattern forming method according to any one of claims 1 to 10.
The pattern formation apparatus of Claim 12 which has a temperature control part of a photocurable composition.