JP2009274405A - Composition for nanoimprint, pattern forming method, etching resist, and permanent film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for nanoimprint excellent in adhesiveness to a substrate, peel property of a mould, and etching resistance. <P>SOLUTION: The composition for nanoimprint is characterized by including a resin having a repeating unit (a) having a polycyclic aromatic structure represented by a general formula (1). Wherein, R<SP>1</SP>represents a hydrogen atom, an alkyl group which may be substituted, or a halogen atom; X represents a single bond or an organic linking group; and L represents a polycyclic aromatic group which may have a substituent group. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nanoimprint composition, a pattern forming method using the composition, an etching resist, and a permanent film. More specifically, semiconductor integrated circuits, flat screens, micro electro mechanical systems (MEMS), sensor elements, optical recording media such as high-density memory disks, optical components such as diffraction gratings and relief holograms, nano devices, optical devices, Optical films and polarizing elements for manufacturing flat panel displays, thin film transistors for liquid crystal displays, organic transistors, color filters, overcoat layers, pillar materials, rib materials for liquid crystal alignment, microlens arrays, immunoassay chips, DNA separation chips The present invention relates to an imprinting composition for forming a fine pattern used for producing a microreactor, nanobiodevice, optical waveguide, optical filter, 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.

  There are two types of nanoimprint methods: a thermal nanoimprint method using a thermoplastic resin as a material to be processed (for example, see Non-Patent Document 1) and an optical nanoimprint method using a photocurable composition (for example, see Non-Patent Document 2). The 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 nanoimprinting method in which light is irradiated through a transparent mold or a transparent substrate and the curable composition for optical nanoimprinting 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.

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 simultaneous integral molding of microstructure and nanostructure and simple interlayer alignment, and apply this to the production of μ-TAS (Micro-Total Analysis System) and biochips. It is what. The third technique is used for processing a substrate by a method such as etching using the formed pattern as a mask. In this technology, high-precision alignment and high integration enable high-density semiconductor integrated circuit fabrication, liquid crystal display transistor fabrication, and magnetic media for next-generation hard disks called patterned media instead of conventional lithography technology. It can be applied to processing. In recent years, efforts have been made to put the nanoimprint method relating to these applications into practical use.

  As a more specific 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 the three requirements of fine pattern resolution, apparatus cost, and throughput simultaneously for further miniaturization requirements. In contrast, an optical nanoimprint method has been proposed as a technique for forming a fine pattern at a low cost. For example, Patent Documents 1 and 3 below disclose a nanoimprint technique in which a silicon wafer is used as a stamper and a fine structure of 25 nm or less is formed by transfer. However, in recent years, in this application, a pattern forming property of several tens of nanometers and a high etching resistance for functioning as a mask (etching resist) at the time of substrate processing have been required.

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

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

  In addition, microelectromechanical systems (MEMS), sensor elements, optical components such as diffraction gratings and relief holograms, nanodevices, optical devices, optical films and polarizing elements for the production of flat panel displays, thin film transistors for liquid crystal displays, organic transistors , Color filter, overcoat layer, pillar material, rib material for liquid crystal alignment, microlens array, immunoassay chip, DNA separation chip, microreactor, nanobiodevice, optical waveguide, optical filter, photonic liquid crystal, etc. The nanoimprint method is also useful for applications.

  In these permanent film applications, the formed pattern will eventually remain in the product, so the durability of the film, mainly heat resistance, light resistance, solvent resistance, scratch resistance, high mechanical properties against external pressure, hardness, etc. And strength-related performance is required.

As described above, most of the patterns conventionally formed by the photolithography method can be formed by nanoimprinting, and attention has been paid as a technique capable of forming a fine pattern at low cost. In these applications, it is premised that a good pattern is formed. However, in the pattern formation, the releasability (mold releasability) between the mold and the nanoimprinting composition is important for the nanoimprint method. In contrast to the photolithography method in which the mask and the photosensitive composition do not contact, in the nanoimprint method, the mold and the nanoimprint composition are in contact. If a residue of the composition adheres to the mold when the mold is peeled off, there is a problem that a pattern defect occurs during subsequent imprinting. That is, the composition for nanoimprinting is required to satisfy both conflicting performances of good adhesion to a substrate such as a substrate and a support and easy releasability from a mold. For the problem of coexistence of substrate adhesion of conventional nanoimprinting compositions and improvement of mold releasability, surface treatment of the mold, specifically, a method of bonding a fluoroalkyl chain-containing silane coupling agent to the mold surface Attempts have been made so far to solve the adhesion problem by a fluorine plasma treatment of the mold, a method using a fluorine-containing resin mold, or the like. However, as described above, the compatibility between the substrate adhesion from the nanoimprint composition and the mold releasability improvement has been solved to some extent by these techniques, but the nanoimprint composition satisfies both the substrate adhesion and the mold releasability. It did not come to offer things. In recent years, since the mass production of patterns is required for practical application and industrialization of the nanoimprint method, it has also been required to satisfy both imprint durability of tens of thousands of molds. At that time, a new problem that mold releasability deteriorates after imprint processing of tens of thousands of times by the surface treatment technology of the mold itself has occurred, so that the composition for nanoimprint itself also has high mold releasability. However, it was requested again from the viewpoint of increasing productivity.
In view of such circumstances, in recent years, it has been required to satisfy all three elements of compatibility of the base material adhesion and mold releasability of the nanoimprint composition itself and improvement of etching resistance. In particular, improvement in dry etching resistance used for substrate processing is required from the viewpoint of industrial usefulness among etching resistance.

  Patent Document 1 discloses a thermal nanoimprint composition using polymethyl methacrylate. While this composition has a relatively good pattern and has some mold releasability, the substrate adhesion is not sufficient, and it is not sufficient from the viewpoint of substrate adhesion and mold releasability. Furthermore, the dry etching resistance is insufficient from the level required for mass production, and there is a problem that the pattern is greatly deteriorated during etching.

  Patent Document 7 discloses a pattern forming method using a fluorine-containing curable material in order to improve releasability from a mold. However, when a fluorine-based material is used as the nanoimprinting composition, there is a problem that the adhesion of the substrate is lowered, and the etching resistance is low, so that the pattern is greatly deteriorated during etching.

  Patent Document 8 discloses the use of a photocurable resin composition for nano-imprint using a (meth) acrylate monomer containing a cyclic structure in order to impart dry etching resistance. In addition to high dry etching resistance, the composition was not sufficient from the viewpoint of achieving both substrate adhesion and mold releasability.

US Pat. No. 5,772,905 US Pat. No. 5,956,216 US Pat. No. 5,259,926 JP 2005-197699 A Japanese Patent Laying-Open No. 2005-301289 Japanese Patent Laid-Open No. 2004-240241 JP 2006-114882 A JP 2007-186570 A S. Chou et al .: Appl. Phys. Lett. Vol. 67, 3114 (1995) M. Colbun et al,: Proc.SPIE, Vol. 3676,379 (1999)

  As described above, in order to industrially use the nanoimprint method, it is extremely important to have both the pattern forming property of the composition for nanoimprinting, particularly the compatibility between the substrate adhesion and the mold release property. Furthermore, the nanoimprinting composition is required to have film characteristics according to the application, and is required to have pattern durability, etching resistance among them, and dry etching resistance among them. However, with the conventional technology, it has been difficult to simultaneously achieve the pattern formability that can correspond to the nanometer pattern of the composition for nanoimprinting and the high film characteristics required for substrate processing applications.

  The first object of the present invention is to provide a nanoimprinting composition having excellent substrate adhesion, mold releasability and etching resistance. The second object of the present invention is to provide a pattern forming method using the nanoimprinting composition of the present invention, and to provide an etching resist and a permanent film formed by the pattern forming method.

［式中、Ｒ¹は水素原子、置換していてもよいアルキル基またはハロゲン原子を表し、Ｘは単結合または有機連結基を表し、Ｌは置換基を有していてもよい多環芳香族基を表す。］
［３］ 前記多環芳香族基がナフタレン構造を有することを特徴とする［１］または［２］に記載のナノインプリント用組成物。
［４］ 前記多環芳香族構造を有する繰り返し単位（ａ）が、下記一般式（２）で表される繰り返し単位であることを特徴とする［１］〜［３］のいずれか一項に記載のナノインプリント用組成物。

［式中、Ｒ¹は水素原子、置換していてもよいアルキル基またはハロゲン原子を表し、Ｘは単結合または有機連結基を表し、Ｒ²は有機置換基を表し、ｎは０〜６の整数を表す。］
［５］ 前記樹脂が前記多環芳香族構造を有する繰り返し単位（ａ）以外の繰り返し単位をさらに含むことを特徴とする［１］〜［４］のいずれか一項に記載のナノインプリント用組成物。
［６］ さらに溶剤を含有することを特徴とする［１］〜［５］のいずれか一項に記載のナノインプリント用組成物。
［７］ 前記多環芳香族構造を有する繰り返し単位（ａ）を含む樹脂が、溶剤を除く組成物の成分中８０質量％以上含有されていることを特徴とする［１］〜［６］のいずれか一項に記載のナノインプリント用組成物。
［８］ 前記溶剤として、エステル基、エーテル基、カルボニル基および水酸基からなる官能基群から選ばれる官能基を少なくとも１つ含有することを特徴とする［７］に記載のナノインプリント用組成物。
［９］ 前記溶剤として、少なくともプロピレングリコールモノメチルエーテルアセテート、２−ヘプタノン、シクロヘキサノン、乳酸エチル、エトキシプロピオン酸エチル、プロピレングリコールモノメチルエーテル、およびガンマブチロラクトンからなる群から選ばれる溶剤を含有することを特徴とする［７］または［８］に記載のナノインプリント用組成物。
［１０］ さらに界面活性剤を含むことを特徴とする［１］〜［９］のいずれか一項に記載のナノインプリント用組成物。
［１１］ 前記界面活性剤として、フッ素および／またはシリコーン系界面活性剤を含有することを特徴とする［１０］に記載のナノインプリント用組成物。
［１２］ ［１］〜［１１］のいずれか一項に記載のナノインプリント用組成物を用いて形成されたことを特徴とするエッチングレジストまたは永久膜。
［１３］ ［１］〜［１１］のいずれか一項に記載のナノインプリント用組成物を基材上に塗布してパターン形成層を形成する工程と、
前記パターン形成層を加熱する工程と、
前記パターン形成層にモールドを押圧する工程と、
前記モールドを押圧した前記パターン形成層を冷却する工程と、
前記モールドを剥離する工程と、
を含むことを特徴とするパターン形成方法。
［１４］ ［１３］に記載のパターン形成方法により形成されたことを特徴とするエッチングレジストまたは永久膜。 The present invention is as follows.
[1] A nanoimprinting composition comprising a resin containing a repeating unit (a) having a polycyclic aromatic structure.
[2] The nanoimprinting composition according to [1], wherein the repeating unit (a) having a polycyclic aromatic structure is represented by the following general formula (1).

[Wherein R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, X represents a single bond or an organic linking group, and L represents a polycyclic aromatic group which may have a substituent. Represents a group. ]
[3] The composition for nanoimprinting according to [1] or [2], wherein the polycyclic aromatic group has a naphthalene structure.
[4] The repeating unit (a) having a polycyclic aromatic structure is a repeating unit represented by the following general formula (2), wherein any one of [1] to [3] The composition for nanoimprint as described.

[Wherein, R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, X represents a single bond or an organic linking group, R ² represents an organic substituent, and n represents 0-6. Represents an integer. ]
[5] The nanoimprint composition according to any one of [1] to [4], wherein the resin further includes a repeating unit other than the repeating unit (a) having the polycyclic aromatic structure. .
[6] The nanoimprinting composition according to any one of [1] to [5], further comprising a solvent.
[7] The resin according to [1] to [6], wherein the resin containing the repeating unit (a) having a polycyclic aromatic structure is contained in an amount of 80% by mass or more in the components of the composition excluding the solvent. The nanoimprinting composition according to any one of the above.
[8] The composition for nanoimprints according to [7], wherein the solvent contains at least one functional group selected from the group consisting of an ester group, an ether group, a carbonyl group, and a hydroxyl group.
[9] The solvent contains at least a solvent selected from the group consisting of propylene glycol monomethyl ether acetate, 2-heptanone, cyclohexanone, ethyl lactate, ethyl ethoxypropionate, propylene glycol monomethyl ether, and gamma butyrolactone. The composition for nanoimprints according to [7] or [8].
[10] The nanoimprinting composition according to any one of [1] to [9], further comprising a surfactant.
[11] The nanoimprinting composition according to [10], wherein the surfactant contains fluorine and / or a silicone-based surfactant.
[12] An etching resist or permanent film formed using the nanoimprinting composition according to any one of [1] to [11].
[13] A step of applying the nanoimprinting composition according to any one of [1] to [11] onto a substrate to form a pattern forming layer;
Heating the pattern forming layer;
Pressing the mold against the pattern forming layer;
Cooling the pattern forming layer pressing the mold;
Peeling the mold;
A pattern forming method comprising:
[14] An etching resist or a permanent film formed by the pattern forming method according to [13].

  ADVANTAGE OF THE INVENTION According to this invention, the composition for nanoimprint which can form the pattern excellent in base-material adhesiveness, mold peelability, and etching tolerance can be provided. Moreover, according to the pattern formation method of this invention using the composition for nanoimprints of this invention, the pattern excellent in base-material adhesiveness, mold peelability, and etching tolerance 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 1,000 or less. In the present specification, “functional group” refers to a group involved in a polymerization reaction.
The “nanoimprint” in the present invention refers to pattern transfer having a size of about several nm to several μm.

  In addition, in the description of the group (atomic group) in this specification, the description which does not indicate 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).

[Repeating unit (a) having a polycyclic aromatic structure]
The resin contained in the composition for nanoimprinting of the present invention has a repeating unit (a) having a polycyclic aromatic structure. Hereinafter, the repeating unit (a) having a polysensitive aromatic structure will be described.
The polycyclic aromatic structure in the present invention means a condensed polycyclic aromatic structure in which at least two or more ring structures are condensed. Therefore, the polycyclic aromatic structure does not include a ring assembly structure in which two or more single aromatic rings such as bisphenol are connected by a single bond or an organic connecting group. Further, in the present invention, “polycyclic aromatic” means not only those in which condensed rings such as naphthalene are all aromatic rings but also condensed aromatic rings and non-aromatic rings such as benzene and cyclohexane. 1,2,3,4-tetrahydronaphthalene structure etc. in which is fused.

The polycyclic aromatic structure in the present invention is preferably a 2-4 condensed ring structure, more preferably a 2-3 condensed ring structure, and particularly preferably 2 condensed ring structures.
When the nanoimprint composition does not contain the resin containing the repeating unit (a) having the polycyclic aromatic structure, that is, the condensation in which all the repeating units in the resin in the nanoimprinting composition are 1 or less. When the resin has a ring aromatic structure that is not formed, the pattern is greatly deteriorated during dry etching. That is, the dry etching resistance is low and sufficient pattern durability cannot be obtained. In addition, performance such as pattern formability, particularly mold releasability, cannot be exhibited at a sufficiently high level at the same time. The curable composition for nanoimprinting of the present invention has high dry etching resistance and good mold releasability from a pattern even when a nanometer order pattern is formed. In particular, the polycyclic aromatic structure is contained in the resin as compared with a case where the mold peelability and the etching resistance are made compatible at a certain level by using a methyl methacrylate resin alone (US Pat. No. 5,772,905). By adding the repeating unit (a), it is possible to achieve the three at the same time by further improving the base material adhesion while maintaining both mold releasability and etching resistance at a high level.

  The polycyclic aromatic structure includes, for example, hydrocarbon polycyclic aromatic structures such as naphthalene, anthracene, phenanthrene, pyrene, 1,2,3,4-tetrahydronaphthalene, indole, carbazole, quinoline, benzo Examples include heteropolycyclic aromatic structures such as isoquinoline. Moreover, the polycyclic aromatic structure which has hetero atoms other than a nitrogen atom may be sufficient. The polycyclic aromatic structure used in the present invention is preferably a hydrocarbon-based polycyclic aromatic structure, more preferably a naphthalene structure or an anthracene structure, and a naphthalene structure from the viewpoint of particularly improving substrate adhesion and mold releasability. Particularly preferred.

  The polycyclic aromatic structure may have a substituent. Examples of the substituent that the polycyclic aromatic structure of the present invention has include an alkyl group, a halogen atom, an alkoxy group, a hydroxyl group, an alkoxycarbonyl group, an acyl group, a nitro group, and a cyano group. Preferably, they are a C1-C8 alkyl group, a halogen atom, an alkoxy group, a hydroxyl group, or a cyano group, and a cyano group and a hydroxyl group are the most preferable from the viewpoint of improving dry etching resistance and substrate adhesion.

The repeating unit (a) having a polycyclic aromatic structure is preferably a vinyl polycyclic aromatic repeating unit and / or a polycyclic aromatic substituted (meth) acrylic repeating unit. Further, the vinyl aromatic repeating unit and the aromatic substituted (meth) acrylic repeating unit are bonded via an (organic) linking group even in a structure in which the main chain portion and the polycyclic aromatic portion are directly bonded. It may be a structure.
Examples of the vinyl polycyclic aromatic repeating unit include a vinyl naphthalene repeating unit, a vinyl anthracene repeating unit, and a vinyl pyrene repeating unit. Among these, the vinyl aromatic repeating unit used in the present invention is preferably a vinyl naphthalene repeating unit.
The polycyclic aromatic substituted (meth) acrylic repeating unit is preferably a polycyclic aromatic substituted (meth) acrylic ester repeating unit or a polycyclic aromatic substituted (meth) acrylamide repeating unit. Among these, as the polycyclic aromatic substituted (meth) acrylic repeating unit used in the present invention, a naphthalene-substituted (meth) acrylic acid ester repeating unit is more preferable, and a naphthalene-substituted acrylic acid ester repeating unit is more preferable. Further, from the viewpoint of improving dry etching resistance, the polycyclic aromatic substituted (meth) acrylic repeating unit is more preferably an acrylate repeating unit.

［式中、Ｒ¹は水素原子、置換していてもよいアルキル基またはハロゲン原子を表し、Ｘは単結合または有機連結基を表し、Ｌは置換基を有していてもよい多環芳香族基を表す。］ The repeating unit (a) having a polycyclic aromatic structure is more preferably represented by the following general formula (1).

[Wherein R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, X represents a single bond or an organic linking group, and L represents a polycyclic aromatic group which may have a substituent. Represents a group. ]

In the general formula (1), R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, preferably a hydrogen atom or a methyl group.
X represents a single bond or an organic linking group. The organic linking group is preferably —COO—Y—, —CON (R ³ ) —Y—, or a combination thereof. Here, Y represents a single bond or an alkylene group having 1 to 4 carbon atoms, and R ³ represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. In the present invention, X is preferably a single bond or —COO—Y—, and most preferably —COO—Y—.

  L represents a polycyclic aromatic group which may have a substituent, and the preferred range of the polycyclic aromatic structure and the substituent is the same as in the description of the polycyclic aromatic structure.

  The repeating unit (a) having a polycyclic aromatic structure is particularly preferably a repeating unit represented by the following general formula (2).

［式中、Ｒ¹は水素原子、置換していてもよいアルキル基またはハロゲン原子を表し、Ｘは単結合または有機連結基を表し、Ｒ²は有機置換基を表し、ｎは０〜６の整数を表す。］

[Wherein, R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, X represents a single bond or an organic linking group, R ² represents an organic substituent, and n represents 0-6. Represents an integer. ]

In the general formula (2), R ¹ has the same meaning as R ¹ in the general formula (1), and the preferred range is also the same.
X is synonymous with X of General formula (1), and its preferable range is also the same.
R ² represents an organic substituent, preferably an alkyl group having 1 to 8 carbon atoms, a halogen atom, an alkoxy group, a hydroxyl group, an alkoxycarbonyl group, an acyl group, a nitro group or a cyano group, particularly preferably an alkyl group, A halogen atom, an alkoxy group, a hydroxyl group, or a cyano group, with a cyano group and a hydroxyl group being most preferred.
n is an integer of 0 to 6, preferably 0 to 4, and more preferably 0 to 3. When n is 2 or more, a plurality of R ² may be the same or different.

［式中、Ｒ¹は水素原子、置換していてもよいアルキル基またはハロゲン原子を表し、Ｒ²は有機置換基を表し、ｎは０〜６の整数を表す。］

［式中、Ｒ¹は水素原子、置換していてもよいアルキル基またはハロゲン原子を表し、Ｒ²は有機置換基を表し、ｎは０〜６の整数を表す。］ The repeating unit (a) having a polycyclic aromatic structure is more preferably a repeating unit represented by the following general formula (3) or (4).

[Wherein, R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, R ² represents an organic substituent, and n represents an integer of 0 to 6. ]

[Wherein, R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, R ² represents an organic substituent, and n represents an integer of 0 to 6. ]

In the general formula (3) and (4), R ¹ is the general formula (1) and (2) have the same meanings as R ^1, and the preferred range is also the same.
In the general formula (3) and (4), R ² has the same meaning as R ² in the general formula (2), and the preferred range is also the same.
In the general formulas (3) and (4), n has the same meaning as n in the general formula (2), and the preferred range is also the same.

  Preferred examples of the repeating unit (a) having the polycyclic aromatic structure are shown below. In the following examples, Ra represents a hydrogen atom or a methyl group.

[Resin containing a repeating unit (a) having a polycyclic aromatic structure]
Hereinafter, the resin containing the repeating unit (a) having a polycyclic aromatic structure will be described.
The composition for nanoimprinting of the present invention contains a resin containing the repeating unit (a) having the polycyclic aromatic structure. The resin containing the repeating unit (a) having a polycyclic aromatic structure may contain at least one kind of the repeating unit (a), and may be a copolymer containing two or more kinds. When the resin containing the repeating unit (a) having a polycyclic aromatic structure is a copolymer, it may be a block copolymer or a random copolymer.

  The molecular weight of the resin containing the repeating unit (a) having a polycyclic aromatic structure is preferably 3000 to 100,000, more preferably 5000 to 70000, and still more preferably 5000 to 50000 in terms of weight average molecular weight in terms of polystyrene. By adjusting the molecular weight to an appropriate range, pattern formability such as mold releasability and substrate adhesion and coating solvent solubility are improved, and the generation of foreign matters over time can be suppressed.

  The glass transition point (Tg) of the resin containing the repeating unit (a) having the polycyclic aromatic structure is preferably 40 ° C to 200 ° C, more preferably 60 ° C to 170 ° C, and still more preferably 80 ° C to 150 ° C. is there.

The resin containing the repeating unit (a) having a polycyclic aromatic structure may contain another repeating unit other than the repeating unit (a) having a polycyclic aromatic structure. Any other repeating unit can be used as long as it is copolymerizable with the repeating unit (a) having a polycyclic aromatic structure, and preferred is a styrene repeating unit or a (meth) acrylic repeating unit.
Examples of the styrene repeating unit include styrene, tert-butylstyrene, hydroxystyrene, acetoxystyrene, and methoxystyrene.
The (meth) acrylic repeating unit is preferably a repeating unit obtained from a (meth) acrylic acid ester derivative or a (meth) acrylamide derivative, and has an aromatic ring or a cyclic hydrocarbon group from the viewpoint of improving dry etching resistance (meth). Acrylic repeating units are more preferred. The (meth) acrylic repeating unit having an aromatic ring or a cyclic hydrocarbon group is preferably a (meth) acrylate having an aromatic ring such as phenyl (meth) acrylate or benzyl (meth) acrylate; cyclohexyl (meth) acrylate, adamantyl ( Examples include (meth) acrylates having a cyclic hydrocarbon group such as (meth) acrylate, tricyclodecanyl (meth) acrylate, tetracyclododecanyl (meth) acrylate, and dicyclopentanyl (meth) acrylate.

  The content of the repeating unit (a) in the resin containing the repeating unit (a) having the polycyclic aromatic structure is 10 to 100 mol%, preferably 30 to 100 mol%, more preferably in all repeating units. Is 50 to 100 mol%.

[Method for Producing Resin Containing Repeating Unit (a) Having Polycyclic Aromatic Structure]
The resin containing the repeating unit (a) having a polycyclic aromatic structure can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. Polymerization is initiated using a commercially available radical initiator (such as an azo-based initiator or peroxide) as a polymerization initiator, or a radical initiator that generates a radical upon irradiation with light when it is photopolymerizable. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred azo initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, the solution is used as it is, replaced with a desired solvent, or charged into a solvent to obtain a desired powder or solid. The polymer is recovered. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 50 to 100 ° C.

[Nanoimprinting composition containing resin containing repeating unit (a) having polycyclic aromatic structure]
Below, the composition for nanoimprint (henceforth the composition of this invention) containing resin containing the repeating unit (a) which has a polycyclic aromatic structure of this invention is demonstrated.

  The nanoimprint composition of the present invention may be a thermal nanoimprint composition or an optical nanoimprint composition, but is preferably a thermal nanoimprint composition.

(Resin component)
The composition of this invention contains resin containing the repeating unit (a) which has the said polycyclic aromatic structure.
The composition of this invention may contain other resin components other than resin containing the repeating unit (a) which has the said polycyclic aromatic structure. Examples of other resin components that may be added to the composition of the present invention include polystyrene resins, poly (meth) acrylate resins, polycycloolefin resins, and the like. (Meth) acrylate resins are preferred.

  In the case of a thermal nanoimprint composition, the content of the resin component containing the repeating unit (a) having a polycyclic aromatic structure in the composition of the present invention is preferably 80% by mass or more, more preferably in the component excluding the solvent. It is 90 mass% or more, More preferably, it is 95 mass% or more. In the case of the optical nanoimprint composition, from the viewpoint of pattern formability, 0.1 to 20% by mass is preferable in the component excluding the solvent, more preferably 1 to 15% by mass, and more preferably 1 to 10% by mass. .

(solvent)
The nanoimprinting composition of the present invention preferably uses a solvent according to various needs. In particular, when the composition of the present invention is used as a composition for thermal nanoimprinting, it is preferable to use the resin containing the repeating unit (a) having a polycyclic aromatic structure dissolved in a solvent. As the solvent, a solvent having a boiling point of 80 to 200 ° C. at normal pressure is preferably used. As the type of the solvent, any solvent that can dissolve the composition of the present invention can be used. Preferably, any one or more of an ester structure, a carbonyl structure (ketone structure), a hydroxyl group, and an ether structure are used. It is a solvent which has. Specific preferred solvents are propylene glycol monomethyl ether acetate, cyclohexanone, 2-heptanone, gamma butyrolactone, propylene glycol monomethyl ether and ethyl lactate alone or in a mixed solvent containing propylene glycol monomethyl ether acetate. A solvent is most preferable from the viewpoint of coating uniformity.

(Other ingredients)
The composition for nanoimprinting of the present invention may contain a surfactant, an antioxidant, and other components as long as the effects of the present invention are not impaired. When the composition for nanoimprinting of the present invention is a composition for optical nanoimprinting, it preferably contains a photopolymerization initiator, and a known photopolymerization initiator can be used as the photopolymerization initiator. The nanoimprinting composition of the present invention preferably contains at least one selected from the group consisting of a fluorine-based surfactant, a silicone-based surfactant, a fluorine / silicone-based surfactant, and an antioxidant.

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

  The surfactant preferably includes at least one of a fluorine-based surfactant, a silicone-based surfactant, and a fluorine / silicone-based surfactant, and includes both a fluorine-based surfactant and a silicone-based surfactant. Alternatively, it preferably contains a fluorine / silicone surfactant, and most preferably contains a fluorine / silicone surfactant. The fluorine-based surfactant and the silicone-based surfactant are preferably nonionic surfactants.

  Here, the “fluorine / silicone surfactant” refers to one having both requirements of a fluorine surfactant and a silicone surfactant.

  By using such a surfactant, a silicon wafer for manufacturing a semiconductor element, a glass square substrate for manufacturing a liquid crystal element, a chromium film, a molybdenum film, a molybdenum alloy film, a tantalum film, a tantalum alloy film, a silicon nitride film, The striations that occur when the nanoimprint composition of the present invention is applied on a substrate on which various films are formed, such as an amorphous silicone film, an indium oxide (ITO) film doped with tin oxide, and a tin oxide film. It is possible to solve the problem of poor coating such as patterns (unevenness of drying of resist film). In addition, the fluidity of the composition of the present invention into the cavity of the mold recess is improved, the peelability between the mold and the resist is improved, the adhesion between the resist and the substrate is improved, the viscosity of the composition is decreased, etc. Is possible. In particular, the nanoimprint composition of the present invention can significantly improve the coating uniformity by adding the surfactant, and in a coating using a spin coater or a slit scan coater, good coating suitability regardless of the substrate size. Is obtained.

  Examples of the nonionic fluorosurfactant 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). (Trade name) EFTOP EF-122A, 122B, 122C, EF-121, EF-126, EF-127, MF-100 (manufactured by Gemco), trade names PF-636, PF-6320, PF-656, PF-6520 (both OMNOVA Solutions, Inc.), trade names FT250, FT251, DFX18 (both manufactured by Neos), trade names Unidyne DS-401, DS-403, DS-451 (All are made by Daikin Industries, Ltd.), trade names Megafuk 171, 172, 173, 178K, 178A, F780F (all Dainippon Ink Chemical Industry Co., Ltd.).

  Examples of the nonionic silicone surfactant include trade name SI-10 series (manufactured by Takemoto Yushi Co., Ltd.), trade name Megafuck Paintad 31 (manufactured by Dainippon Ink & Chemicals, Inc.). And trade name KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  Examples of the fluorine / silicone surfactant include trade names X-70-090, X-70-091, X-70-092, X-70-093 (all Shin-Etsu Chemical Co., Ltd. )), And trade names Megafuk R-08 and XRB-4 (both manufactured by Dainippon Ink & Chemicals, Inc.).

[Pattern formation method]
Next, the formation method of the pattern (especially fine concavo-convex pattern) using the nanoimprinting composition of the present invention will be described. In the pattern formation method of the present invention, in the thermal nanoimprint method, a step of forming the pattern formation layer by applying the composition for nanoimprint of the present invention on a substrate or a support (base material), and heating the pattern formation layer A fine concavo-convex pattern can be formed through a step of pressing a mold against the pattern forming layer, a step of cooling the pattern forming layer pressing the mold, and a step of peeling the mold. .
In the optical nanoimprint method, the step of applying the composition for nanoimprinting of the present invention on a substrate to form a pattern forming layer, the step of pressing a mold on the surface of the pattern forming layer, and the pattern forming layer A fine concavo-convex pattern can be formed through a step of irradiating light and a step of peeling the mold.

Hereinafter, a pattern formation method (pattern transfer method) using the composition for nanoimprinting of the present invention will be specifically described.
In the pattern formation method of this invention, first, the composition of this invention is apply | coated on a base material, and a pattern formation layer is formed.

  As a coating method when the nanoimprinting composition of the present invention is coated on a substrate, generally known coating methods such as a dip coating method, an air knife coating method, a curtain coating method, a wire bar coating method, and a gravure are used. Examples thereof include a coating method, an extrusion coating method, a spin coating method, a slit scanning method, and an ink jet method. Moreover, although the film thickness of the pattern formation layer which consists of a composition of this invention changes with uses to be used, it is about 0.05 micrometer-30 micrometers. Further, the composition of the present invention may be applied by multiple coating. Furthermore, you may form other organic layers, such as a planarization layer, for example between a base material and the pattern formation layer which consists of a composition of this invention. Thereby, since the pattern formation layer and the substrate are not in direct contact with each other, it is possible to prevent adhesion of dust to the substrate, damage to the substrate and the like. In addition, the pattern formed with the composition of this invention is excellent in adhesiveness with an organic layer, even when it is a case where an organic layer is provided on a base material.

  The substrate (substrate or support) for applying the composition for nanoimprinting of the present invention can be selected depending on various applications, for example, quartz, glass, optical film, ceramic material, vapor deposition film, magnetic film, reflection Film, metal substrate such as Ni, Cu, Cr, Fe, paper, polymer substrate such as SOG (Spin On Glass), polyester film, polycarbonate film, polyimide film, TFT array substrate, PDP electrode plate, glass and transparent plastic substrate There are no particular restrictions on conductive substrates such as ITO and metals, insulating substrates, semiconductor fabrication substrates such as silicone, silicon nitride, polysilicon, silicone oxide, and amorphous silicone. Further, the shape of the substrate is not particularly limited, and may be a plate shape or a roll shape. Further, as the substrate, a light transmissive or non-light transmissive material can be selected according to the combination with the mold.

  Next, in the pattern forming method of the present invention, a mold is pressed against the surface of the pattern forming layer in order to transfer the pattern to the pattern forming layer. In the thermal nanoimprint method, a step of heating the pattern forming layer is performed. At this time, either the step of heating the pattern forming layer or the step of pressing the mold may be performed first, or may be performed simultaneously, but is preferably performed simultaneously from the viewpoint of productivity. The pattern forming layer may be heated by pressing the heating mold. The heating temperature is a temperature equal to or higher than the Tg of the resin used, and is preferably a temperature 20 to 100 ° C. higher than the Tg.

(mold)
The mold that can be used in the pattern forming method of the present invention will be described.
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. However, in the present invention, the pattern forming method on the mold is not particularly limited.

  The pattern forming method of the present invention is a pattern forming method excellent in mold releasability because the composition for nanoimprinting having the repeating unit (a) having a polycyclic aromatic structure of the present invention is used. In particular, since the mold releasability is excellent irrespective of the mold release treatment on the mold surface, the mold durability is high, and high productivity can be maintained over a long period of time.

(Mold material)
The molding material that can be used in the present invention will be described. In the optical nanoimprint method using the composition of the present invention, a light transmissive material is selected for at least one of the molding material and / or the base material. In the optical imprint lithography applied to the present invention, a curable composition for nanoimprinting of the present invention is applied onto a substrate to form a pattern forming layer, and a light-transmitting mold is pressed against the surface of the mold. The pattern forming layer is cured by irradiating light from the back surface. Moreover, the curable composition for optical nanoimprint can be apply | coated on a transparent base material, a mold can be pressed, light can be irradiated from the back surface of a base material, and the curable composition for optical nanoimprint can also be hardened.

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

  The mold used in the pattern forming method of the present invention may be a mold that has been subjected to a release treatment in order to further improve the releasability between the nanoimprinting composition of the present invention and the mold surface and further enhance pattern productivity. Good. Examples of such mold release treatment include treatment with a silane coupling agent such as silicone or fluorine. In addition, for example, commercially available mold release agents such as Optool DSX manufactured by Daikin Industries, Ltd. and Novec EGC-1720 manufactured by Sumitomo 3M Co., Ltd. can be suitably used for mold release treatment. As described above, by using the mold subjected to the release treatment and further using the nanoimprint composition having high mold releasability according to the present invention, it is possible to obtain higher imprint durability of the mold.

  When nanoimprint lithography is performed using the composition of the present invention, it is usually preferable to perform the mold pressure at 0.5 to 30 MPa in the pattern forming method of the present invention. By setting the mold pressure to 30 MPa or less, the mold and the substrate are less likely to be deformed and the pattern accuracy tends to be improved. Further, since the pressure is low, the apparatus can be reduced, which is preferable. When the mold pressure is 0.5 to 30 MPa, the remaining film of the nanoimprinting composition on the mold projections is reduced, and the uniformity of mold transfer can be ensured. In the case of the photoimprint method, the mold pressure is preferably 0.1 to 1 MPa. Also in this case, if it is within the range of the mold pressure, the same tendency as in thermal nanoimprinting can be obtained, which is preferable.

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

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

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

  Further, during exposure, in order to prevent inhibition of radical polymerization by oxygen, an inert gas such as nitrogen or argon may be flowed to control the oxygen concentration to less than 100 mg / L.

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

The pattern formed by the pattern forming method of the present invention can be used as an etching resist or a permanent film, and is particularly useful as an etching resist. When the composition for nanoimprinting of the present invention is used as an etching resist, first, for example, a silicon wafer on which a thin film such as SiO ₂ is formed is used as a base material. A fine pattern of order is formed. Thereafter, a desired pattern can be formed on the substrate by etching using an etching gas such as hydrogen fluoride in the case of wet etching or CF _{4 in} the case of dry etching. The composition for nanoimprinting of the present invention has particularly good etching resistance against dry etching.

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

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

[Synthesis Example 1] Resin A-1: Synthesis of poly (1-naphthylmethyl methacrylate) 3.4 g of methyl ethyl ketone was heated to 80 ° C under a nitrogen stream. A solution prepared by dissolving 8.9 g of 1-naphthylmethyl methacrylate and 0.066 g of azobisisobutyronitrile in 31 g of methyl ethyl ketone was added dropwise thereto over 2 hours. After further reacting at 80 ° C. for 3 hours, this was poured into 500 ml of methanol, and the precipitated powder was collected by filtration and washed with methanol. The obtained powder was dried at 40 ° C. for 24 hours to obtain poly (1-naphthylmethyl methacrylate). The weight average molecular weight in terms of standard polystyrene was 30000, and the dispersity was 1.9. The structure of the repeating unit of Resin A-1 is shown below.

  Other resins A-2 to A-4 and B-1 to B-3 having the following repeating unit structures were also synthesized by using the same method as in Synthesis Example 1. Resin A-4 is a copolymer having the following two unit structures, and the copolymerization ratio is shown below.

[Example 1]
(Preparation of composition for thermal nanoimprint)
2 g of the resin A-12 was dissolved in 38 g of propylene glycol monomethyl ether acetate, and 0.01 g of a fluorosurfactant F780F (Dainippon Ink Chemical Co., Ltd.) was mixed to prepare a thermal nanoimprinting composition of Example 1. .

[Example 2]
The composition for thermal nanoimprinting of Example 2 was prepared in the same manner as in Example 1 except that the resin A-2 was used instead of the resin A-1.

[Example 3]
The composition for thermal nanoimprinting of Example 3 was prepared in the same manner as in Example 1 except that the resin A-3 was used instead of the resin A-1.

[Example 4]
The composition for thermal nanoimprinting of Example 4 was prepared in the same manner as in Example 1 except that the resin A-4 was used instead of the resin A-1.
[Example 5]
The composition for thermal nanoimprinting of Example 5 was prepared in the same manner as in Example 1 except that the surfactant was not added in Example 1.

[Comparative Example 1]
The composition for thermal nanoimprinting of Comparative Example 1 was prepared in the same manner as in Example 1 except that the resin B-1 was used instead of the resin A-1.

[Comparative Example 2]
The composition for thermal nanoimprinting of Comparative Example 2 was prepared in the same manner as in Example 1 except that the resin B-2 was used instead of the resin A-1.
[Comparative Example 3]
The composition for thermal nanoimprinting of Comparative Example 3 was prepared in the same manner as in Example 1 except that the resin B-3 was used instead of the resin A-1.

[Test Example 1]
<Dry etching resistance>
Using the nanoimprinting compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3, etching resistance was evaluated by the following method.
The nanoimprint compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were each spin-coated on a Si wafer and heated on a hot plate at 100 ° C. for 90 seconds to obtain a film with a thickness of 100 nm. After the plasma dry etching was performed on the obtained film with a gas of Ar / C ₄ F ₆ / O ₂ = 100: 4: 2 using a dry etcher (U-621) manufactured by Hitachi High-Technology Co., Ltd. for 2 minutes. The amount of remaining film was measured and the etching rate per second was calculated. The obtained etching rate was normalized so that the value of Comparative Example 1 was 1, and the results are shown in Table 1 below. A smaller value indicates better dry etching resistance.

<Board adhesion test>
With reference to JIS K 5600-5-6 (cross-cut method), the substrate adhesion of the nanoimprint compositions of Examples 1 to 5 and Comparative Examples 1 to 3 was evaluated. The nanoimprint compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were each spin-coated on a Si wafer and heated on a hot plate at 100 ° C. for 90 seconds to obtain a film with a thickness of 100 nm. A 10 × 10 square grid cut pattern of 1 mm × 1 mm was formed on this film. Tape was applied to the lattice pattern and the tape was peeled off at an angle of 60 degrees. The number of squares where pattern peeling was observed visually was measured and evaluated as follows. The results are shown in Table 1 below. The smaller the number of cells in which pattern peeling is observed, the better the substrate adhesion.
A: The number of cells where peeling was observed was 0 to less than 5 B: The number of cells where peeling was observed was 5 or more and less than 20 C: The number of cells where peeling was observed was 20 or more and less than 50 D: The number of squares where peeling was observed was 50 or more

<Evaluation of mold releasability>
Patterns were formed using the nanoimprint compositions of Examples 1 to 5 and Comparative Examples 1 to 3 according to the pattern forming method of the present invention.
The nanoimprint compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were each spin-coated on a Si wafer and heated on a hot plate at 100 ° C. for 90 seconds to obtain a film with a thickness of 100 nm. A nickel mold having a 100 nm line / space pattern, a groove depth of 100 nm and a fluorine-treated pattern surface was placed on the mold, and the mold was pressure-contacted at a pressure of 10 MPa while being heated to 150 ° C. After cooling, the mold was released to obtain a pattern. Whether or not the composition component was adhered to the mold used for pattern formation was observed with a scanning electron microscope or an optical microscope, and mold releasability was evaluated as follows. The results are shown in Table 1 below.
A: Adherence of the composition to the mold was not recognized at all.
B: Slight adhesion of the composition was observed on the mold.
C: Adhesion of the mold composition was clearly observed.

From Table 1, Examples 1 to 5 using the composition for nanoimprinting of the present invention containing a resin containing a repeating unit (a) having a polycyclic aromatic structure are composed of repeating units having only one aromatic ring. The composition of Comparative Example 1 containing a resin, the composition of Comparative Example 2 containing a polymethyl methacrylate resin, and the composition of Comparative Example 3 containing a resin containing a repeating unit having a polycyclic structure other than aromatic In comparison, it was found that dry etching resistance and substrate adhesion were improved. It was also found that high mold releasability could be achieved at the same time.
Furthermore, when Example 1 and Example 5 were compared, it was found that mold releasability was improved regardless of the presence or absence of the addition of a fluorosurfactant. That is, the good mold releasability of the composition of the present invention was not obtained simply by adding a fluorosurfactant, but because it contains a resin containing a repeating unit (a) having a polycyclic aromatic structure. It was found that it was obtained.

Claims (14)

  A nanoimprinting composition comprising a resin containing a repeating unit (a) having a polycyclic aromatic structure. The composition for nanoimprinting according to claim 1, wherein the repeating unit (a) having the polycyclic aromatic structure is represented by the following general formula (1).

[Wherein R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, X represents a single bond or an organic linking group, and L represents a polycyclic aromatic group which may have a substituent. Represents a group. ]   The composition for nanoimprinting according to claim 1 or 2, wherein the polycyclic aromatic group has a naphthalene structure. The composition for nanoimprint according to any one of claims 1 to 3, wherein the repeating unit (a) having a polycyclic aromatic structure is a repeating unit represented by the following general formula (2). object.

[Wherein, R ¹ represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, X represents a single bond or an organic linking group, R ² represents an organic substituent, and n represents 0-6. Represents an integer. ]   The nanoimprinting composition according to any one of claims 1 to 4, wherein the resin further includes a repeating unit other than the repeating unit (a) having the polycyclic aromatic structure.   Furthermore, a solvent is contained, The composition for nanoimprints as described in any one of Claims 1-5 characterized by the above-mentioned.   Resin containing the repeating unit (a) which has the said polycyclic aromatic structure is contained 80 mass% or more in the component of the composition except a solvent, The any one of Claims 1-6 characterized by the above-mentioned. The composition for nanoimprint as described.   The composition for nanoimprinting according to claim 6 or 7, comprising a solvent having at least one functional group selected from the group consisting of an ester group, an ether group, a carbonyl group and a hydroxyl group as the solvent.   The solvent is selected from the group consisting of propylene glycol monomethyl ether acetate, 2-heptanone, cyclohexanone, ethyl lactate, ethyl ethoxypropionate, propylene glycol monomethyl ether, gamma butyrolactone, and combinations of two or more thereof. Item 9. The nanoimprinting composition according to any one of Items 6 to 8.   Furthermore, surfactant is included, The composition for nanoimprints as described in any one of Claims 1-9 characterized by the above-mentioned.   The composition for nanoimprinting according to claim 10, comprising fluorine and / or a silicone-based surfactant as the surfactant.   The etching resist or permanent film formed using the composition for nanoimprints as described in any one of Claims 1-11. The process of apply | coating the composition for nanoimprints as described in any one of Claims 1-11 on a base material, and forming a pattern formation layer,
Heating the pattern forming layer;
Pressing the mold against the pattern forming layer;
Cooling the pattern forming layer pressing the mold;
Peeling the mold;
A pattern forming method comprising:   An etching resist or a permanent film formed by the pattern forming method according to claim 13.