JPWO2018051961A1 - Pattern forming method and semiconductor device manufacturing method - Google Patents

Abstract

The provision of the pattern formation method which improved the filling property on the board | substrate of the curable composition for imprints, and the manufacturing method of a semiconductor element using the said pattern formation method. Forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer located on the substrate; and applying a curable composition for imprinting to the surface of the primer layer. , Pattern formation method.

Description

  The present invention relates to a pattern forming method and a semiconductor element manufacturing method.

The imprint method is a method of transferring a fine pattern to a cured product by irradiating light through a light transmissive mold or a light transmissive substrate, photocuring the curable composition for imprints, and then removing the mold. is there. Since this method enables imprinting at room temperature, it can be applied to the field of precision processing of ultrafine patterns such as the fabrication of semiconductor integrated circuits. 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.
Here, with the activation of the imprinting method, the adhesion between the substrate and the curable composition for imprinting has come to be regarded as a problem. That is, in the imprint method, after applying the curable composition for imprint on the surface of the substrate and curing the curable composition for imprint by light irradiation in a state where the mold is in contact with the surface, Although the mold is peeled off, the cured product may peel from the substrate and adhere to the mold in the step of peeling the mold. This is considered to be because the adhesion between the substrate and the cured product is lower than the adhesion between the mold and the cured product. In order to solve such a problem, use of an imprint adhesive layer that improves the adhesion between the substrate and the cured product has been studied (Patent Documents 1 to 3).

Special table 2009-503139 JP 2014-24322 A JP 2014-192178 A

However, it has been found that when the curable composition for imprints is applied to the surface of the conventional adhesive layer, the fillability of the curable composition for imprints may be inferior. In particular, when the curable composition for imprints is applied by an inkjet (IJ) method, droplets of the curable composition 22 for imprints are dropped at equal intervals on the surface of the adhesion layer 21 as shown in FIG. Then, the droplet spreads on the surface of the adhesion layer 21 to form a layered curable composition for imprint 22. However, when the wettability of the curable composition for imprints is low, the curable composition for imprints does not spread on the surface of the adhesion layer 21, and a portion where the curable composition for imprints 22 is not filled on the substrate remains. May end up. That is, improvement of the filling property on the substrate of the curable composition for imprints is required.
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is directed to a pattern forming method that improves the filling of a curable composition for imprints onto a substrate, and a semiconductor device using the pattern forming method. It aims at providing the manufacturing method of.

As a result of intensive studies by the inventor under the above problems, the above problem is solved by providing a primer layer having a high critical surface tension between the adhesion layer and the layer comprising the curable composition for imprints. I found that I could do it.
Specifically, the above problem has been solved by the following means <1>, preferably <2> to <17>.
<1> A step of forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer located on the substrate, and a step of applying the curable composition for imprints to the surface of the primer layer A pattern forming method.
<2> The primer layer is formed using a primer layer-forming composition containing a solvent, and the components constituting the adhesion layer are substantially contained in the solvent contained in the primer layer-forming composition. The pattern formation method as described in <1> which is not melt | dissolved in.
<3> The pattern forming method according to <1> or <2>, wherein the component constituting the adhesion layer does not substantially thermally diffuse into the primer layer.
<4> At least one of the components constituting the primer layer has a functional group capable of forming at least one of a hydrogen bond and an ionic interaction with the component constituting the adhesion layer, <1> to <1. 3> The pattern formation method as described in any one of 3>.
<5> At least one of the components constituting the primer layer has a functional group capable of forming a hydrogen bond with the component constituting the adhesion layer, according to any one of <1> to <3>. Pattern forming method.
<6> 95% by mass or more of the component constituting the primer layer is liquid at 25 ° C., and the contact angle on the surface of the adhesive layer at 25 ° C. after 10 seconds of dropping of the component constituting the primer layer is The pattern formation method according to any one of <1> to <5>, which is 5 ° or less.
<7> The pattern forming method according to any one of <1> to <6>, wherein the curable composition for imprints has a viscosity at 23 ° C. of 8.0 mPa · s or less.
<8> The pattern forming method according to any one of <1> to <7>, wherein the curable composition for imprints has a surface tension at 25 ° C. of 33 mN / m or more.
<9> The pattern forming method according to any one of <1> to <8>, wherein the primer layer satisfies at least one of A and B below;
A: a primer layer formed from a composition for forming a primer layer containing a component having a surface tension at 25 ° C. of 40 mN / m or more;
B: The critical surface tension of the primer layer at 25 ° C. is 46 mN / m or more.
<10> The pattern forming method according to <9>, wherein a component having a surface tension of 40 mN / m or more at 25 ° C. is contained in a component constituting the primer layer in a proportion of 20% by mass or more.
<11> The component having a surface tension at 25 ° C. of 40 mN / m or more is a compound having a polyalkylene glycol structure, and the polyalkylene glycol structure includes a compound composed of a linear alkylene group and an oxygen atom. <9> or <10> The pattern forming method according to <10>.
<12> The pattern forming method according to any one of <9> to <11>, wherein at least one of the components having a surface tension at 25 ° C. of 40 mN / m or more does not have a polymerizable group.
<13> The pattern forming method according to any one of <9> to <12>, wherein at least one of the components having a surface tension of 40 mN / m or more at 25 ° C is a liquid at 25 ° C.
The pattern as described in any one of <9>-<13> whose 95 mass% or more of the component which comprises the primer layer contained in the <14> said primer layer formation composition is a liquid at 25 degreeC. Forming method.
<15> The pattern forming method according to any one of <9> to <14>, wherein the component having a surface tension at 25 ° C. of 40 mN / m or more has a weight average molecular weight of 200 or more and less than 1000.
<16> The pattern forming method according to any one of <1> to <15>, further including a step of providing the adhesion layer on a substrate.
<17> The pattern forming method according to any one of <1> to <16>, wherein a critical surface tension of the primer layer is 5 mN / m or more higher than a critical surface tension of the adhesion layer.
<18> A method for manufacturing a semiconductor element, comprising the pattern forming method according to any one of <1> to <17>.

  According to the present invention, it is possible to provide a pattern forming method that improves the filling property of the curable composition for imprints onto a substrate, and a method for manufacturing a semiconductor element using the pattern forming method.

It is the schematic which shows each process of the pattern formation method of this invention. It is the schematic which shows the state of the wet spreading of the curable composition for imprints when the curable composition for imprints is apply | coated to the surface of a well-known adhesion layer by the inkjet method.

Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
In this specification, “(meth) acrylate” represents acrylate and methacrylate.
In this specification, “imprint” preferably refers to pattern transfer having a size of 1 nm to 10 mm, and more preferably refers to pattern transfer (nanoimprint) having a size of approximately 10 nm to 100 μm.
In the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
In this specification, “light” includes not only light in a wavelength region such as ultraviolet, near ultraviolet, far ultraviolet, visible, infrared, and electromagnetic waves, but also radiation. Examples of radiation include microwaves, electron beams, extreme ultraviolet rays (EUV), and X-rays. Laser light such as a 248 nm excimer laser, a 193 nm excimer laser, and a 172 nm excimer laser can also be used. The light may be monochromatic light (single wavelength light) that has passed through an optical filter, or may be light having a plurality of different wavelengths (composite light).
The weight average molecular weight (Mw) in the present invention refers to that measured by gel permeation chromatography (GPC) unless otherwise specified.

The pattern forming method of the present invention includes a step of forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer located on the substrate, and a curable composition for imprints on the surface of the primer layer. And a step of applying an object. With such a configuration, the curable composition for imprints can spread on the surface of the primer layer in a short time or easily, and the filling property of the curable composition for imprints on the substrate can be improved. Can be improved.
Hereinafter, the method of the present invention will be described with reference to FIG. Needless to say, the configuration of the present invention is not limited to that shown in FIG.

<Process for forming an adhesion layer on a substrate>
The pattern forming method of the present invention preferably includes a step of forming an adhesion layer on the substrate. However, this step is not necessarily essential when using a substrate in which an adhesion layer is previously formed on a prepared substrate.
In the embodiment shown in FIG. 1, the adhesion layer 12 is formed on the substrate 11. In FIG. 1, the adhesion layer 12 is formed on the surface of the substrate 11, but another layer may be formed between the substrate 11 and the adhesion layer 12. For example, the surface of the substrate 11 may be surface treated.

  The material of the substrate is not particularly defined, and the description in paragraph 0103 of JP 2010-109092 A (corresponding US application is US 2011/199592) can be referred to, and the contents thereof are incorporated herein. In addition to the above, a sapphire substrate, a silicon carbide (silicon carbide) substrate, a gallium nitride substrate, an aluminum substrate, an amorphous aluminum oxide substrate, a polycrystalline aluminum oxide substrate, and GaAsP, GaP, AlGaAs, InGaN, GaN, AlGaN, ZnSe , AlGaInP, or a substrate made of ZnO. Specific examples of materials for the glass substrate include aluminosilicate glass, aluminoborosilicate glass, and barium borosilicate glass. In the present invention, a silicon substrate is preferable.

  In the present invention, the critical surface tension at 25 ° C. of the adhesion layer is preferably 30 mN / m or more, and more preferably 40 mN / m or more. The upper limit is not particularly defined, but is, for example, 70 mN / m or less, and preferably 60 mN / m or less. The critical surface tension in the present specification is measured according to the method described in Examples described later.

  The lower limit of the thickness of the adhesion layer is preferably 0.1 nm or more, more preferably 0.5 nm or more, and further preferably 1 nm or more. The upper limit of the thickness of the adhesion layer is preferably 20 nm or less, more preferably 15 nm or less, and further preferably 10 nm or less.

The adhesion layer is usually formed by applying a composition for forming an adhesion layer on a substrate. More specifically, after applying the adhesive layer forming composition on the substrate, the solvent is volatilized (dried) by heat or light irradiation, and / or the adhesive layer is cured to form a thin film. The application method of the composition for forming an adhesion layer is not particularly defined, and the description of paragraph 0102 of JP 2010-109092 A (corresponding US application is US 2011/199592) can be referred to, and the contents thereof are described in this specification. Embedded in the book. In the present invention, a spin coating method or an ink jet method is preferable.
As the composition for forming an adhesion layer, a composition containing a component constituting the adhesion layer and a solvent is preferable.
As the component constituting the adhesion layer, a resin is preferable, a resin containing an ethylenically unsaturated group is more preferable, and an acrylic resin having an ethylenically unsaturated group in the side chain is more preferable. Specific examples of the resin as the component constituting the adhesion layer include resins contained in the composition for forming an adhesion layer described in Examples described later and paragraphs 0017 to 0057 described in JP-A-2014-24322. Resin (A) and resin (A2) are illustrated. The weight average molecular weight of the resin is preferably 3,000 to 25,000. Moreover, the component which comprises an adhesion | attachment layer may contain additives other than resin. However, the component constituting the adhesion layer in the present invention is preferably 70% by mass or more, more preferably 80% by mass or more.

At least one of the components constituting the adhesion layer has a functional group capable of forming at least one of a hydrogen bond and an ionic interaction with the component constituting the primer layer in order to ensure the stability of the primer layer. It is preferable. Examples of the functional group include a hydroxyl group, an amino group, a carbonyl group, and a carboxyl group. It is preferable that the resin has such a functional group.
With such a configuration, the adhesion layer and the primer layer are fixed by hydrogen bonding and / or interionic interaction. Therefore, it is possible to ensure the uniformity of application of the primer layer and suppress surface roughness such as aggregation. In addition, it is more effective that the components constituting the adhesion layer move to the primer layer, the imprint curable composition provided as an upper layer thereof, or a pattern that is a cured product of the imprint curable composition. Can be suppressed. As a result, a substance capable of increasing the fixing force between the pattern and the mold is less likely to be present in the vicinity of the pattern, and the mold releasability of the pattern can be improved.
In addition, the component which comprises an adhesion layer means the component contained in an adhesion layer. For example, the component remove | excluding the solvent from the said composition for contact | adherence layer formation corresponds to this. Similarly, the component constituting the primer layer refers to a component contained in the primer layer. For example, the component remove | excluding the solvent from the composition for primer layer formation mentioned later corresponds to this.

  In the present invention, it is also preferable that at least one (preferably all) of the components constituting the adhesion layer is not substantially dissolved in the solvent contained in the primer layer forming composition. With such a configuration, when the primer layer is formed, components constituting the adhesion layer are not easily taken into the primer layer, and the mold mold releasability is not deteriorated. The phrase “not substantially dissolved” means that the adhesion layer component eluted in the primer layer at the time of forming the primer layer is 10% by mass or less of the total primer layer forming component. By setting it as such a structure, the deterioration of mold release property with a mold can be suppressed effectively.

In the present invention, it is preferable that the component constituting the adhesion layer is a component that does not substantially thermally diffuse into the primer layer. After forming the primer layer on the surface of the adhesion layer, the adhesion layer may be heated together with the primer layer, etc., but when the components constituting the adhesion layer are thermally diffused in such a heating stage, as described above, In some cases, mold releasability of the pattern is deteriorated. In the present invention, this point is avoided by using a component that does not substantially thermally diffuse in the primer layer as a component constituting the adhesion layer. The phrase “not substantially thermally diffusing” means that the adhesion layer component eluted in the primer layer after forming the primer layer is 10% by mass or less of the total primer layer forming component. By setting it as such a structure, the deterioration of mold release property with a mold can be suppressed effectively.
In addition, as the heating in the present invention, the heating for drying the solvent contained in the composition for forming the primer layer when forming the primer layer or the light irradiation to the curable composition for imprinting is performed. Examples thereof include heating for increasing the reactivity of the curable composition. As heating temperature, it is 50-200 degreeC, for example, and 80-150 degreeC is preferable.

As a solvent which may be mix | blended with the composition for contact | adherence layer formation, the solvent of Paragraph 0059 of Unexamined-Japanese-Patent No. 2014-24322 is illustrated, This content is integrated in this specification.
Further, the composition for forming an adhesion layer used in the present invention preferably contains 0.001 to 2.0% by mass of components constituting the adhesion layer and 98.0 to 99.999% by mass of a solvent. It is more preferable that 0.05 to 0.5% by mass of the components constituting 99 and 99.95 to 99.5% by mass of the solvent are included.
The components and solvent constituting the adhesion layer may be included in the adhesion layer forming composition, respectively, or one or more of them may be included. When 2 or more types are included, the total amount is preferably within the above range.
As a specific example of the composition for forming an adhesion layer, a weight average molecular weight of 1,000 or more having an ethylenically unsaturated group (P) and a nonionic hydrophilic group (Q) described in JP-A-2014-24322 ( Examples include a composition for forming an underlayer film for imprinting, which comprises a (meth) acrylic resin (A) and a solvent (B), and the acid value of the resin (A) is less than 1.0 mmol / g. The contents of No. 24322 are incorporated herein.
In addition, the description of JP 2014-24322 A can be referred to for the preparation of the composition for forming an adhesion layer and the formation method of the adhesion layer using the composition for forming an adhesion layer, and the contents thereof are described in this specification. Incorporated into.

<Process for forming a primer layer having a higher critical surface tension than the above-mentioned adhesion layer on the surface of the adhesion layer>
In the present invention, a primer layer 13 having a critical surface tension higher than that of the adhesion layer is formed on the surface of the adhesion layer 12. By forming such a primer layer, the filling property onto the substrate of the curable composition for imprints can be improved.
The critical surface tension of the primer layer at 25 ° C. is preferably higher than the critical surface tension of the adhesion layer, more preferably 2 mN / m or more, more preferably 3 mN / m or more, and more preferably 5 mN / m or more. Is more preferable. The upper limit of the difference in critical surface tension between the primer layer and the adhesion layer is preferably 20 mN / m or less, more preferably 15 mN / m or less, and even more preferably 10 mN / m or less. By making it within the above range, the effect of improving the uniformity and wettability of the film when forming the primer layer is more effectively improved.

  The lower limit of the thickness of the primer layer is preferably 0.1 nm or more, more preferably 0.5 nm or more, and even more preferably 1 nm or more. The upper limit of the thickness of the primer layer is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less.

In the present invention, the primer layer is usually formed using a primer layer forming composition. The primer layer forming composition preferably contains a solvent. Specifically, after applying the primer layer forming composition to the surface of the adhesion layer, the solvent is volatilized by heat or light irradiation to form a thin film. The method for applying the composition for forming a primer layer is not particularly defined, and the description of paragraph 0102 of JP 2010-109092 A (corresponding US application is US 2011/199592) can be referred to, and the contents thereof are described in this specification. Incorporated into. In the present invention, a spin coating method or an ink jet method is preferable.
In the case of using a composition for forming an adhesion layer containing a solvent in forming the adhesion layer, the primer layer is formed by volatilizing (drying) the solvent from the composition for forming the adhesion layer and / or curing the adhesion layer. Therefore, it is preferable to apply the primer layer forming composition. By setting it as such a structure, the component which comprises a primer layer melt | dissolves in the solvent contained in the composition for contact | adherence layer formation, and it can suppress effectively that a contact | adherence layer and a primer layer mix.
In addition, the preparation of the primer layer forming composition and the method for forming the primer layer formed from the primer layer forming composition are the same as the preparation of the adhesion layer forming composition and the method for forming the adhesion layer. Can do.

In particular, the present invention includes forming a primer layer using a primer layer-forming composition containing a solvent, and the components constituting the adhesion layer are substantially contained in the solvent contained in the primer layer-forming composition. It is preferable not to dissolve. By adopting such a configuration, it is possible to more effectively suppress the deterioration of mold releasability caused by the incorporation of the adhesion layer component into the primer layer.
In the present invention, as described above, at least one (preferably all) of the components constituting the primer layer can form at least one of hydrogen bonding and ionic interaction with the component constituting the adhesion layer. It preferably has a functional group. Examples of the functional group that the component constituting the primer layer may have include a hydroxyl group, an amino group, a carbonyl group, and a carboxyl group, and a hydroxyl group is preferable.
Further, 95% by mass or more (preferably 98% by mass or more, more preferably 99% by mass or more) of the components constituting the primer layer is a liquid at 25 ° C., and 10 seconds after the dropping of the components constituting the primer layer The contact angle on the surface of the adhesion layer at 25 ° C. is preferably 5 ° or less. The contact angle is measured according to the method described in Examples described later. By setting it as such a structure, a primer layer can be formed more uniformly on an adhesion layer, and it becomes possible to make the filling property of the curable composition for imprints more uniform.

  Furthermore, it is preferable that the component which comprises a primer layer is compatible with the curable composition for imprints. Here, the compatibility means that the components constituting the primer layer are sufficiently dissolved in the curable composition for imprints, and there is no clear interface between the primer layer and the curable composition for imprints. . Thus, when the primer layer is compatible with the curable composition for imprints, a part of the curable composition for imprints diffuses into the primer layer when the curable composition for imprints is filled, and the adhesion layer It is possible to effectively suppress the occurrence of peeling defects and the like during mold release.

In the present invention, the primer layer preferably satisfies at least one of the following A and B.
A: a primer layer formed from a composition for forming a primer layer containing a component having a surface tension at 25 ° C. of 40 mN / m or more;
B: The critical surface tension of the primer layer at 25 ° C. is 46 mN / m or more.

The primer layer formed from the primer layer forming composition is usually a liquid film, but may be a solid film within the scope of the present invention.
The component having a surface tension of 40 mN / m or more at 25 ° C. in the present invention preferably has a surface tension of 40 to 70 mN / m. By adopting such a configuration, a primer layer having a high critical surface tension can be obtained. The surface tension is measured according to the method described in Examples described later.
In the present invention, the critical surface tension of the primer layer is preferably 46 mN / m or more. By setting it as such a structure, the wettability of the curable composition for imprints applied to the surface of a primer layer improves, and a fillability can be improved. The critical surface tension is measured according to the method described in Examples described later.
In the present invention, the lower limit of the critical surface tension of the primer layer formed from the primer layer forming composition is preferably 47 mN / m or more, and more preferably 48 mN / m or more. The upper limit value of the critical surface tension of the primer layer is not particularly defined, but is preferably 70 mN / m or less, may be 65 mN / m or less, and may be 60 mN / m or less.

The composition for forming a primer layer preferably contains a component having a surface tension of 40 mN / m or more at 25 ° C. in a component constituting the primer layer in a proportion of 20% by mass or more, and in a proportion of 51% by mass or more. More preferably, it is contained at a rate of 80% by mass or more, more preferably at a rate of 90% by mass or more, still more preferably at a rate of 95% by mass or more, and 99% by mass or more. Even more preferably, it is contained in a proportion.
The primer layer forming composition may contain only one type of component having a surface tension at 25 ° C. of 40 mN / m or more, or may contain two or more types. When 2 or more types are included, the total amount is preferably within the above range.

In the present invention, the component constituting the primer layer is a compound having a polyalkylene glycol structure, wherein the polyalkylene glycol structure is composed of a linear alkylene group and an oxygen atom (hereinafter referred to as “PEG etc.”). In some cases). The linear alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, still more preferably an alkylene group having 1 to 3 carbon atoms, and an alkylene group having 2 or 3 carbon atoms. Is more preferable, and an alkylene group having 2 carbon atoms is even more preferable. That is, in this invention, it is preferable that the component which comprises a primer layer contains the compound which has a polyethyleneglycol structure.
PEG or the like preferably contains 3 to 50 alkylene glycol units. PEG or the like may be a component having a surface tension at 25 ° C. of 40 mN / m or more, or a component having a surface tension at 25 ° C. of less than 40 mN / m, but a surface tension at 25 ° C. of 40 mN / m or more. Preferably it is a component.
When PEG or the like is a component having a surface tension at 25 ° C. of 40 mN / m or more, it preferably contains 3-20 alkylene glycol units, more preferably 5-17.

  When the critical surface tension of the primer layer at 25 ° C. is 46 mN / m or more, the primer layer forming composition is a polyalkylene composed of a linear alkylene group and an oxygen atom as components constituting the primer layer. It is a compound which has a glycol structure, Comprising: It is preferable that 21-50 alkylene glycol units are included, and 22-45 are more preferable.

PEG etc. may contain structures other than the polyalkylene glycol structure. However, it is preferable that PEG etc. consist of a polyalkylene glycol structure except a terminal group. That is, PEG or the like is preferably represented by (terminal group—polyalkylene glycol structure composed of a linear alkylene group and an oxygen atom—terminal group). The terminal group here is preferably a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group. 1-3 are preferable, as for carbon number of an alkyl group and the alkyl chain of an alkoxy group, 1 or 2 is more preferable, and 1 is more preferable.
Specific examples of PEG and the like include compounds used in the examples described later.

  In the present invention, as described above, it is preferable that at least one of the components constituting the primer layer has a functional group capable of forming at least one of a hydrogen bond and an ionic interaction with the component constituting the adhesion layer. However, such a functional group is preferably contained in a component having a surface tension of 40 mN / m or more at 25 ° C. In particular, when the component having a surface tension at 25 ° C. of 40 mN / m or more is PEG or the like, one or both of the end groups form at least one of hydrogen bonds and interionic interactions with the component constituting the adhesion layer. And a functional group (preferably a hydroxyl group, amino group, carbonyl group, carboxyl group, etc., more preferably a hydroxyl group).

In the present invention, the component having a surface tension at 25 ° C. of 40 mN / m or more may be a compound other than PEG. Examples thereof include polyhydric alcohols such as glycerol, ionic polymers such as polyvinyl alcohol, polyvinyl acetamide, and polystyrene sulfonic acid.
In the present invention, the composition for forming a primer layer also includes an embodiment containing a component having a surface tension of 40 mN / m or more at 25 ° C. other than PEG, and a PEG having a surface tension at 25 ° C. of less than 40 mN / m. Is done.

  In the present invention, it is preferable that at least one (preferably all) components having a surface tension at 25 ° C. of 40 mN / m or more have no polymerizable group. By setting it as such a structure, mold mold release property can be improved more.

  In the present invention, it is preferable that at least one of the components having a surface tension at 25 ° C. of 40 mN / m or more is a liquid at 25 ° C. More preferably, 95% by mass or more (preferably 98% by mass or more, more preferably 99% by mass or more) of the components constituting the primer layer is a liquid at 25 ° C. By using the liquid, it is possible to more effectively reduce the surface roughness of the primer layer.

  In the present invention, at least one (preferably all) weight average molecular weight of a component having a surface tension at 25 ° C. of 40 mN / m or more is preferably 200 or more and less than 1000, more preferably 300 or more and less than 800. preferable. By setting it as such a structure, the compatibility of the component which comprises a primer layer, and the curable composition for imprints improves.

In addition to the above, the component constituting the primer layer may contain a polymerizable compound.
The polymerizable compound may be a monofunctional polymerizable compound or a polyfunctional polymerizable compound, preferably a polyfunctional polymerizable compound, more preferably a 2 to 4 functional polymerizable compound, or a bifunctional or 3 functional compound. More preferred are functional polymerizable compounds. Specific examples of the polymerizable compound include polymerizable compounds that may be contained in the curable composition for imprints described later.
Among the components constituting the primer layer, the upper limit of the content of the polymerizable compound is preferably 50% by mass or less, and more preferably 20% by mass or less. Moreover, 10 mass% or more is preferable when mix | blending the lower limit of content of the said polymeric compound.
The composition for primer layer formation may contain only 1 type of polymeric compounds, and may contain 2 or more types. When 2 or more types are included, the total amount is preferably within the above range.

In the present invention, the primer layer forming composition preferably contains a solvent. Application is possible by including a solvent. The solvent is preferably a solvent having any one or more of an ester group, a carbonyl group, a hydroxyl group, and an ether group. Specifically, preferred solvents include propylene glycol monomethyl ether acetate (PGMEA), ethoxyethyl propionate, cyclohexanone, 2-heptanone, γ-butyrolactone, butyl acetate, propylene glycol monomethyl ether, and ethyl lactate. Among these, PGMEA, γ-butyrolactone, and cyclohexanone are more preferable, and PGMEA is particularly preferable.
The solvent contained in the adhesive layer forming composition and the solvent contained in the primer layer forming composition are preferably different from each other.

In the present invention, the composition for forming a primer layer preferably contains 0.001 to 2.0% by mass of the components constituting the primer layer and 98.0 to 99.999% by mass of the solvent, and constitutes the primer layer. More preferably, 0.05 to 0.5% by mass of the component and 99.95 to 99.5% by mass of the solvent are contained. The component constituting the primer layer preferably contains a component having a surface tension of 40 mN / m or more at 25 ° C., and more preferably contains a component having a surface tension of 40 mN / m or more at 25 ° C. in a proportion of 99% by mass or more. preferable.
One or more components and solvents constituting the primer layer may be contained in the primer layer forming composition, respectively, or two or more of them may be contained. When 2 or more types are included, the total amount is preferably within the above range.

<The process of applying the curable composition for imprints to the surface of a primer layer>
In this invention, as shown in FIG. 1, the process of applying the curable composition 14 for imprints to the surface of the primer layer 13 is included. The method for applying the curable composition for imprints is not particularly defined, and the description in paragraph 0102 of JP 2010-109092 A (corresponding US application is US 2011/199592) can be referred to, and the contents thereof are described herein. Embedded in the book. The application is preferably performed by an inkjet method. Moreover, you may apply | coat the curable composition for imprint by multiple application | coating. In the method of disposing droplets on the surface of the primer layer by an inkjet method or the like, the amount of droplets is preferably about 1 to 20 pL, and it is preferable to dispose the droplets on the surface of the primer layer with a space between the droplets. As the droplet interval, an interval of 10 to 1000 μm is preferable. In the case of the ink jet method, the liquid drop interval is the arrangement interval of the ink jet nozzles.
Furthermore, the volume ratio of the layered curable composition for imprints 14 when applied to the primer layer 13 and the substrate is preferably 1: 1 to 500, and preferably 1:10 to 300. More preferably, it is 1:50 to 200.

<Pattern formation>
In the pattern forming method of the present invention, the curable composition for imprint is further irradiated with light in a state where the curable composition for imprint, the primer layer, and the adhesive layer are sandwiched between the substrate and the mold having the pattern. It is preferable to include the process of hardening | curing and the process of peeling a mold. Through such a process, for example, a pattern 15 is obtained as shown in FIG.
Specifically, in order to transfer a desired pattern to the layered curable composition for imprints, a mold is pressed against the surface of the layered curable composition for imprints. Thereby, the fine pattern previously formed on the pressing surface of the mold can be transferred to the layered curable composition for imprints.

The mold may be a light transmissive mold or a light non-transmissive mold. When using a light-transmitting mold, it is preferable to irradiate light from the mold side. On the other hand, when using a light-impermeable mold, it is preferable to use a light-transmitting substrate as the substrate and irradiate light from the substrate side. In the present invention, it is more preferable to use a light transmissive mold and irradiate light from the mold side.
The mold that can be used in the present invention is a mold having a pattern to be transferred. 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. Moreover, the pattern formed by the pattern formation method of this invention can also be used as a mold.
The material constituting the light-transmitting mold used in the present invention is not particularly limited, but includes a light-transmitting resin such as glass, quartz, polymethyl methacrylate (PMMA), and polycarbonate resin, a transparent metal vapor-deposited film, and polydimethylsiloxane. Examples thereof include a flexible film, a photocured film, and a metal film.
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.

  In the pattern forming method of the present invention, when imprint lithography is performed using the curable composition for imprints, the mold pressure is preferably 10 atm or less. By setting the mold pressure to 10 atm or less, the mold and the substrate are hardly deformed and the pattern accuracy tends to be improved. Further, it is preferable from the viewpoint that the apparatus can be reduced because the pressure is low. The mold pressure is preferably selected from a range in which the uniformity of mold transfer can be ensured within a range where the residual film of the curable composition for imprints on the mold convex portion is reduced.

In the pattern formation method of this invention, the irradiation amount of the light irradiation in the process of irradiating light to the said curable composition for imprints should just be sufficiently larger than the minimum irradiation amount required for hardening. The amount of irradiation necessary for curing is appropriately determined by examining the consumption of unsaturated bonds of the curable composition for imprints.
In the imprint lithography applied to the present invention, the substrate temperature during light irradiation is usually room temperature, but light irradiation may be performed while heating 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 imprinting. 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.
During exposure is preferably in the range of exposure intensity of ^{1mW / cm 2 ~500mW / cm 2} .
In the pattern formation method of the present invention, after curing the layered curable composition for imprints (pattern formation layer) by light irradiation, if necessary, the step of further curing by applying heat to the cured pattern May be included. As temperature which heat-hardens the curable composition for imprints 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.

Next, the curable composition for imprints used in the present invention will be described.
The curable composition for imprints used in the present invention is not particularly defined, and known curable compositions for imprints can be used.
In the present invention, it is preferable to design the curable composition for imprints to have a low viscosity and a high surface tension in order to enable high-speed filling by utilizing capillary force.
Specifically, the viscosity at 23 ° C. of the curable composition for imprints is preferably 20.0 mPa · s or less, more preferably 15.0 mPa · s or less, and 10.0 mPa · s or less. More preferably, it is more preferably 8.0 mPa · s or less. Although it does not specifically limit as a lower limit of the said viscosity, For example, it can be 5.0 mPa * s or more.

The surface tension at 25 ° C. of the curable composition for imprints is preferably 30 mN / m or more, and more preferably 33 mN / m or more. By using the curable composition for imprints having a high surface tension, the capillary force increases, and the mold pattern can be filled with the curable composition for imprints at a high speed. The upper limit of the surface tension is not particularly limited, but is preferably 40 mN / m or less from the viewpoint of imparting inkjet suitability.
In the present invention, by using the primer layer, the capillary force is high and the filling property to the mold pattern is good, but the wettability with the adhesion layer is poor, and the wettability of the curable composition for imprint with high surface tension is improved. Significant in that it can be improved.
The surface tension at 25 ° C. of the curable composition for imprints is measured according to the method described in Examples described later.

The curable composition for imprints used in the present invention is not particularly defined in terms of its type and the like, but preferably contains a polymerizable compound and a photopolymerization initiator. Further, it may contain a sensitizer, a release agent, an antioxidant, a polymerization inhibitor, a solvent and the like.
The polymerizable compound contained in the curable composition for imprints used in the present invention may be a monofunctional polymerizable compound, a polyfunctional polymerizable compound, or a mixture of both. Moreover, it is preferable that at least a part of the polymerizable compound contained in the curable composition for imprints is liquid at 25 ° C. By including a polymerizable compound that is liquid at 25 ° C. in this way, the viscosity of the curable composition for imprints can be lowered even if the curable composition for imprints does not substantially contain a solvent, and an ink jet method. Can be applied. Here, substantially not containing a solvent means, for example, that the content of the solvent with respect to the curable composition for imprints is 5% by mass or less, and further means that it is 3% by mass or less. In particular, it means 1% by mass or less.
In addition, the curable composition for imprints used in the present invention is a polymer (preferably having a weight average molecular weight exceeding 1,000, more preferably a weight average molecular weight exceeding 2,000, and further preferably a weight average molecular weight. (10,000 or more polymers) may be substantially not contained. “Containing substantially no polymer” means, for example, that the polymer content is 0.01% by mass or less of the curable composition for imprints, preferably 0.005% by mass or less, and not contained. More preferred.

The type of the monofunctional polymerizable compound used in the curable composition for imprints is not particularly defined unless departing from the gist of the present invention.
The monofunctional polymerizable compound used in the curable composition for imprints preferably has a linear or branched hydrocarbon chain having 4 or more carbon atoms. In the present invention, only one monofunctional polymerizable compound may be contained, or two or more kinds may be contained.
The molecular weight of the monofunctional polymerizable compound used in the curable composition for imprints is preferably 100 or more, more preferably 200 or more, and further preferably 220 or more. The upper limit of the molecular weight is preferably 1,000 or less, more preferably 800 or less, further preferably 300 or less, and particularly preferably 270 or less. There exists a tendency which can suppress volatility by making the minimum value of molecular weight into 200 or more. By setting the upper limit of the molecular weight to 300 or less, the viscosity tends to be reduced.
The boiling point at 667 Pa of the monofunctional polymerizable compound used in the curable composition for imprints is preferably 85 ° C. or higher, more preferably 110 ° C. or higher, and further preferably 130 ° C. or higher. By setting the boiling point at 667 Pa to 85 ° C. or higher, volatility can be suppressed. The upper limit of the boiling point is not particularly defined, but for example, the boiling point at 667 Pa can be 200 ° C. or lower.

  The type of polymerizable group possessed by the monofunctional polymerizable compound used in the curable composition for imprints is not particularly defined, but examples include an ethylenically unsaturated bond-containing group and an epoxy group, and contains an ethylenically unsaturated bond. Groups are preferred. Examples of the ethylenically unsaturated bond-containing group include a (meth) acryl group and a vinyl group, a (meth) acryl group is more preferable, and an acrylic group is more preferable. The (meth) acryl group is preferably a (meth) acryloyloxy group.

  The type of atoms constituting the monofunctional polymerizable compound used in the curable composition for imprints is not particularly defined, but should be composed only of atoms selected from carbon atoms, oxygen atoms, hydrogen atoms and halogen atoms. Is preferable, and it is more preferably composed of only an atom selected from a carbon atom, an oxygen atom and a hydrogen atom.

The monofunctional polymerizable compound used in the curable composition for imprints preferably has a linear or branched hydrocarbon chain having 4 or more carbon atoms. The hydrocarbon chain in the present invention represents an alkyl chain, an alkenyl chain, or an alkynyl chain, preferably an alkyl chain or alkenyl chain, and more preferably an alkyl chain.
In the present invention, the alkyl chain represents an alkyl group and an alkylene group. Similarly, an alkenyl chain represents an alkenyl group and an alkenylene group, and an alkynyl chain represents an alkynyl group and an alkynylene group. Among these, a linear or branched alkyl group or an alkenyl group is more preferable, a linear or branched alkyl group is more preferable, and a linear alkylene group is more preferable.
The linear or branched hydrocarbon chain (preferably an alkyl group) has 4 or more carbon atoms, preferably 6 or more carbon atoms, more preferably 8 or more carbon atoms, still more preferably 10 or more carbon atoms, and more carbon atoms. 12 or more is particularly preferable. The upper limit value of the carbon number is not particularly defined, but can be, for example, 25 or less.
The linear or branched hydrocarbon chain may contain an ether group (—O—), but preferably does not contain an ether group from the viewpoint of improving releasability.
By using such a monofunctional polymerizable compound having a hydrocarbon chain, the elastic modulus of the cured film is reduced and the releasability is improved with a relatively small addition amount. In addition, when a monofunctional polymerizable compound having a linear or branched alkyl group is used, the interfacial energy between the mold and the cured film can be reduced, and the releasability can be further improved.
(1)-(3) can be mentioned as a preferable hydrocarbon group which the monofunctional polymerizable compound used for the curable composition for imprints has.
(1) a linear alkyl group having 8 or more carbon atoms (2) a branched alkyl group having 10 or more carbon atoms (3) an alicyclic or aromatic ring substituted by a linear or branched alkyl group having 5 or more carbon atoms

(1) Straight chain alkyl group having 8 or more carbon atoms The straight chain alkyl group having 8 or more carbon atoms is preferably one having 10 or more carbon atoms, more preferably 11 or more carbon atoms, and particularly preferably 12 or more carbon atoms. Moreover, 20 or less carbon atoms are preferable, 18 or less carbon atoms are more preferable, 16 or less carbon atoms are more preferable, and 14 or less carbon atoms are especially preferable.
(2) C10 or more branched alkyl group The C10 or more branched alkyl group preferably has 10 to 20 carbon atoms, more preferably 10 to 16 carbon atoms, still more preferably 10 to 14 carbon atoms, C10-12 is particularly preferred.
(3) Alicyclic or aromatic ring substituted by a linear or branched alkyl group having 5 or more carbon atoms The linear or branched alkyl group having 5 or more carbon atoms is more preferably a linear alkylene group. The number of carbon atoms in the alkyl group is more preferably 6 or more, more preferably 7 or more, and still more preferably 8 or more. The carbon number of the alkyl group is preferably 14 or less, more preferably 12 or less, and even more preferably 10 or less.
The alicyclic or aromatic ring structure may be monocyclic or condensed, but is preferably monocyclic. In the case of a condensed ring, the number of rings is preferably 2 or 3. The ring structure is preferably a 3- to 8-membered ring, more preferably a 5-membered or 6-membered ring, and even more preferably a 6-membered ring. The ring structure is an alicyclic ring or an aromatic ring, but is preferably an aromatic ring. Specific examples of the ring structure include a cyclohexane ring, norbornane ring, isobornane ring, tricyclodecane ring, tetracyclododecane ring, adamantane ring, benzene ring, naphthalene ring, anthracene ring, and fluorene ring. Among these, the cyclohexane ring , A tricyclodecane ring, an adamantane ring and a benzene ring are more preferable, and a benzene ring is more preferable.

The monofunctional polymerizable compound used in the curable composition for imprints is preferably a compound in which a linear or branched hydrocarbon chain having 4 or more carbon atoms and a polymerizable group are bonded directly or via a linking group. A compound in which any one of the groups (1) to (3) and a polymerizable group are directly bonded is more preferable. Examples of the linking group include —O—, —C (═O) —, —CH ₂ —, or a combination thereof. The monofunctional polymerizable compound used in the present invention includes (1) a linear alkyl (meth) acrylate in which a linear alkyl group having 8 or more carbon atoms and a (meth) acryloyloxy group are directly bonded. preferable.
Examples of the monofunctional polymerizable compound used in the curable composition for imprints include the following first group and second group. However, it goes without saying that the present invention is not limited to these examples. The first group is more preferable than the second group.
First group

Second group

  The amount of the monofunctional polymerizable compound used in the curable composition for imprints is more than 5% by mass and less than 30% by mass with respect to all polymerizable compounds in the curable composition for imprints. 6 mass% or more is preferable, as for a lower limit, 8 mass% or more is more preferable, 10 mass% or more is further more preferable, and 15 mass% or more is especially preferable. Further, the upper limit is more preferably 29% by mass or less, further preferably 27% by mass or less, and particularly preferably 25% by mass or less. By making the amount of the monofunctional polymerizable compound 6% by mass or more with respect to the total polymerizable compound, the releasability can be improved, and defects and mold breakage can be suppressed during mold release. Moreover, by setting it as 29 mass% or less, Tg of the cured film of the curable composition for imprint can be made high, and etching processability, especially the wave | undulation of the pattern at the time of etching can be suppressed.

In the present invention, a monofunctional polymerizable compound other than the above monofunctional polymerizable compound may be used as long as it does not depart from the spirit of the present invention, and a monofunctional one of the polymerizable compounds described in JP-A-2014-170949 is used. Examples of the polymerizable compound are included in the present specification.
In the present invention, 90% by mass or more of all monofunctional polymerizable compounds contained in the curable composition for imprints are preferably monofunctional polymerizable compounds having the groups (1) to (3) above. More preferably, it is 95 mass% or more.

The polyfunctional polymerizable compound used in the curable composition for imprints is not particularly defined, but preferably contains at least one of an alicyclic structure and an aromatic ring structure, and has a viscosity at 25 ° C. of 150 mPa · s or less. . In the following description, such a compound may be referred to as a ring structure-containing polyfunctional polymerizable compound. In the present invention, by using a polyfunctional polymerizable compound containing a ring structure, etching process characteristics, particularly pattern disconnection after etching can be more effectively suppressed. This is presumed to be because the etching selectivity with respect to the object to be processed (for example, Si, Al, Cr, or an oxide thereof) at the time of etching is further improved.
The curable composition for imprints may contain only one type of ring structure-containing polyfunctional polymerizable compound, or may contain two or more types.

The molecular weight of the ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints is preferably 1,000 or less, more preferably 800 or less, further preferably 500 or less, and more preferably 350 or less. Preferably, 250 or less is even more preferable. There exists a tendency which can reduce a viscosity by making the upper limit of molecular weight into 1,000 or less.
The lower limit of the molecular weight is not particularly defined, but can be, for example, 200 or more.

  The number of polymerizable groups of the ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints is 2 or more, preferably 2 to 7, more preferably 2 to 4, more preferably 2 or 3. 2 is particularly preferred.

  The type of polymerizable group possessed by the ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints is not particularly defined, but examples include ethylenically unsaturated bond-containing groups and epoxy groups. Saturated bond-containing groups are preferred. Examples of the ethylenically unsaturated bond-containing group include a (meth) acryl group and a vinyl group, a (meth) acryl group is more preferable, and an acrylic group is more preferable. The (meth) acryl group is preferably a (meth) acryloyloxy group. Two or more polymerizable groups may be contained in one molecule, or two or more polymerizable groups of the same type may be contained.

  The type of atoms constituting the ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints is not particularly defined, but is composed only of atoms selected from carbon atoms, oxygen atoms, hydrogen atoms and halogen atoms. It is preferable that it is composed only of atoms selected from a carbon atom, an oxygen atom and a hydrogen atom.

The ring structure contained in the ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints may be monocyclic or condensed, but is preferably monocyclic. In the case of a condensed ring, the number of rings is preferably 2 or 3. The ring structure is preferably a 3- to 8-membered ring, more preferably a 5-membered or 6-membered ring, and even more preferably a 6-membered ring. The ring structure may be an alicyclic ring or an aromatic ring, but is preferably an aromatic ring. Specific examples of the ring structure include a cyclohexane ring, norbornane ring, isobornane ring, tricyclodecane ring, tetracyclododecane ring, adamantane ring, benzene ring, naphthalene ring, anthracene ring, and fluorene ring. Among these, the cyclohexane ring , A tricyclodecane ring, an adamantane ring and a benzene ring are more preferable, and a benzene ring is more preferable.
The number of ring structures in the ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints may be one or two or more, but preferably one or two, and one is More preferred. In the case of a condensed ring, one condensed ring is considered.
The ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints is (polymerizable group)-(single bond or divalent linking group)-(divalent group having a ring structure)-(single bond). Or a divalent linking group)-(polymerizable group). Here, as the linking group, an alkylene group is more preferable, and an alkylene group having 1 to 3 carbon atoms is more preferable.

一般式（１）において、Ｑは、脂環構造または芳香環構造を有する２価の基を表す。
Ｑにおける脂環または芳香環（環構造）の好ましい範囲は、上述と同義であり好ましい範囲も同様である。The ring structure-containing polyfunctional polymerizable compound used in the curable composition for imprints is preferably represented by the following general formula (1).

In the general formula (1), Q represents a divalent group having an alicyclic structure or an aromatic ring structure.
The preferred range of the alicyclic ring or aromatic ring (ring structure) in Q is as defined above, and the preferred range is also the same.

第２群

Examples of the polyfunctional polymerizable compound used in the curable composition for imprints include the following first group and second group. However, it goes without saying that the present invention is not limited to these examples. The first group is more preferable.
First group

Second group

  The ring structure-containing polyfunctional polymerizable compound is preferably contained in an amount of 30% by mass or more, more preferably 45% by mass or more, and more preferably 50% by mass or more based on the total polymerizable compound in the curable composition for imprints. More preferably, 55 mass% or more is more preferable, 60 mass% or more may be sufficient, and 70 mass% or more may be sufficient. Moreover, it is preferable that an upper limit is less than 95 mass%, it is further more preferable that it is 90 mass% or less, and it can also be 85 mass% or less. By setting the lower limit to 30% by mass or more, the etching selectivity with respect to the object to be processed (for example, Si, Al, Cr, or an oxide thereof) is improved, and the pattern after the etching process is improved. Disconnection and the like can be suppressed.

The curable composition for imprints may contain another polyfunctional polymerizable compound other than the ring structure-containing polyfunctional polymerizable compound. These other polyfunctional polymerizable compounds may contain only 1 type, or may contain 2 or more types.
Examples of other polyfunctional polymerizable compounds used in the curable composition for imprints include polyfunctional polymerizable compounds having no ring structure among the polymerizable compounds described in JP-A No. 2014-170949, These contents are included herein. More specifically, for example, the following compounds are exemplified.

  As a compounding quantity of another polyfunctional polymerizable compound, when mix | blending, it is preferable that the quantity with respect to all the polymeric compounds in the curable composition for imprints is 5-30 mass%. Moreover, it can also be set as the structure which does not mix | blend another polyfunctional polymerizable compound substantially. “Substantially not blended” means that the amount relative to the total polymerizable compound in the curable composition for imprints is, for example, 3% by mass or less, and further 1% by mass or less.

For the photopolymerization initiator, sensitizer, mold release agent, antioxidant, polymerization inhibitor, solvent, etc., which may be incorporated into the curable composition for imprints, other than the components described in the examples described later. JP-A-2013-036027, JP-A-2014-090133, JP-A-2013-189537, and Japanese Patent Application No. 2006-037872 can be used. Regarding the blending amount and the like, the description in the above publication can be referred to.
Specific examples of the curable composition for imprints that can be used in the present invention include compositions described in Examples described later, JP2013-036027A, JP2014-090133A, and JP2013. No. 189537 and the composition described in the specification of Japanese Patent Application No. 2006-037872 are exemplified, and the contents thereof are incorporated herein. The description of the above publication can be referred to for the preparation of the curable composition for imprints and the method for forming the film (pattern forming layer), and the contents thereof are incorporated in the present specification.

<Pattern>
As described above, the pattern formed by the pattern forming method of the present invention can be used as a permanent film used for a liquid crystal display (LCD) or the like, or as an etching resist for manufacturing a semiconductor element. That is, the present invention also discloses a method for manufacturing a semiconductor element including the pattern forming method of the present invention.
In addition, a grid pattern is formed on a glass substrate of a liquid crystal display device using a pattern formed by the pattern forming method of the present invention, and polarized light having a large screen size (for example, 55 inches or more than 60 inches) with little reflection and absorption. It is possible to manufacture the plate at a low cost. For example, a polarizing plate described in JP-A-2015-132825 and WO2011-132649 can be produced. One inch is 25.4 mm.
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 inside of the container is replaced with inert nitrogen or argon. You may keep it. 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.
Specifically, the pattern formed by the pattern forming method of the present invention includes a recording medium such as a magnetic disk, a light receiving element such as a solid-state imaging element, a light emitting element such as an LED or an organic EL, and a liquid crystal display (LCD) Flat panels such as optical devices, diffraction gratings, relief holograms, optical waveguides, optical filters, microlens arrays, thin film transistors, organic transistors, color filters, antireflection films, polarizing plates, polarizing elements, optical films, pillar materials, etc. Guide for display pattern, nanobiodevice, immunoassay chip, deoxyribonucleic acid (DNA) separation chip, microreactor, photonic liquid crystal, and directed self-assembly of block copolymer (directed self-assembly, DSA) Good for making patterns It can be used well.

The pattern formed by the pattern forming method of the present invention is also useful as an etching resist (lithographic mask). When using a pattern as an etching resist, first, for example, a silicon substrate (silicon wafer or the like) on which a thin film such as SiO ₂ is formed is used as a substrate, and, for example, nano patterns are formed on the substrate by the pattern forming method of the present invention. Alternatively, a fine pattern on the order of microns is formed. In the present invention, it is particularly advantageous in that a nano-order fine pattern can be formed, and a pattern having a size of 50 nm or less, particularly 30 nm or less can be formed. The lower limit of the size of the pattern formed by the pattern forming method of the present invention is not particularly defined, but can be, for example, 1 nm or more.
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 pattern has particularly good etching resistance against dry etching. That is, the pattern formed by the pattern forming method of the present invention is preferably used as a lithography mask.

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.
The ratio of each component in Tables 2 to 4 is a mass ratio.

<Preparation of composition for forming an adhesion layer>
As shown in Table 2 below, a resin and a solvent were blended and filtered through a 0.1 μm polytetrafluoroethylene filter (PTFE filter) to prepare compositions A-1 to A-5 for forming adhesion layers.

<Preparation of composition for forming primer layer>
As shown in Table 3 below, various compounds were blended and filtered through a 0.1 μm PTFE filter to prepare primer layer forming compositions B-1 to B-12. Of the components contained in the primer layer forming composition, the component whose surface tension is measured and the solvent (propylene glycol monomethyl ether acetate) are liquid at 25 ° C.

<Preparation of curable composition for imprint>
As shown in Table 4 below, various compounds are mixed, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) as a polymerization inhibitor is polymerizable compound. It was prepared by adding 200 mass ppm (0.02 mass%) with respect to the total amount. This was filtered with a 0.1 μm PTFE filter to prepare curable compositions C-1 to C-10 for imprinting.

<Formation of adhesion layer and primer layer>
A composition for forming an adhesion layer shown in Table 5 or 6 is spin-coated on a silicon wafer, heated for 1 minute using a hot plate at 220 ° C., and the solvent is dried to form an adhesion layer having a thickness of 5 nm. did. Next, the primer layer forming composition shown in Table 5 or 6 was spin-coated on the surface of the adhesion layer, heated for 1 minute using a 100 ° C. hot plate, and the solvent was dried to form a primer layer. The film thicknesses of the adhesion layer and the primer layer were measured with an ellipsometer and an atomic force microscope.

<Measurement of weight average molecular weight>
The weight average molecular weight was measured under the following conditions.
Column type: TSKgel Super Multipore HZ-H (manufactured by Tosoh Corporation, 4.6 mm ID × 15 cm) connected in series Column developing solvent: tetrahydrofuran Column temperature: 40 ° C.
Sample concentration: 0.35% by mass
Flow rate: 0.35 mL / min Sample injection volume: 10 μL
Device name: HLC-8020GPC manufactured by Tosoh Corporation
Detector: RI (refractive index) detector Calibration curve Base resin: Polystyrene

<Measurement of critical surface tension>
The critical surface tension was measured for each of the adhesion layer and the primer layer formed above.
2 μL of a solvent having a different surface tension was dropped on the surface of the adhesion layer or the primer layer, and the contact angle θ at the time of 500 ms was measured. A linear function that approximates the above measurement result is plotted by plotting the result of the contact angle of 2 ° or more (contact angle θ) on the xy plane (x: surface tension of the solvent, y: cos θ calculated from the contact angle θ). It was calculated by the least square method, and the extrapolated value of the linear function at cos θ = 1 was defined as the critical surface tension (unit: mN / m) of the adhesion layer or the primer layer.
Solvents include water (surface tension 72.9 mN / m), glycerin (63.2), formamide (58.5), ethylene glycol (50.2), γ-butyrolactone (44.1), oleic acid (32 .2), cyclohexanone (34.1), and methyl acetate (25.0) were used.
The contact angle was measured at 25 ° C. using DMs-401 manufactured by Kyowa Interface Science Co., Ltd. The value 500 msec after the landing of the droplet was measured at n = 3, and the average value was taken as the contact angle.

<Measurement of surface tension>
The surface tension of each composition or compound was measured at 25 ± 0.2 ° C. using a surface tension meter SURFACE TENS-IOMETER CBVP-A3 manufactured by Kyowa Interface Science Co., Ltd. using a glass plate. The unit is expressed in mN / m.

<Viscosity>
The viscosity of the curable composition for imprints was measured at 23 ± 0.2 ° C. using a RE-80L rotational viscometer manufactured by Toki Sangyo Co., Ltd.
The rotational speed at the time of measurement was as shown in Table 1 below according to the viscosity.

<Evaluation of surface roughness of primer layer>
About the primer layer obtained above, an atomic force microscope (AFM, manufactured by Bruker AXS, Dimension Icon) was used to scan a 10 μm square to measure arithmetic average surface roughness (Ra). Evaluation based on the criteria. The results are shown in Tables 5 and 6 below.
A: Ra <0.4 nm
B: 0.4 nm ≦ Ra <1.0 nm
C: 1.0 nm ≦ Ra

<Evaluation of peeling failure>
On the surface of the primer layer obtained above, a curable composition for imprints adjusted to a temperature of 25 ° C. was used with a droplet amount of 1 pL per nozzle using an inkjet printer DMP-2831, manufactured by Fuji Film Daimatics. The curable composition for imprinting was layered by discharging and applying the droplets on the surface of the primer layer so as to form a square array with a spacing of about 100 μm. Next, a quartz mold (rectangular line / space pattern (1/1), line width 60 nm, groove depth 100 nm, line edge roughness 3.5 nm) is pressed against the layered curable composition for imprints, and imprinting is performed. The mold was filled with the curable composition. Further, using a high-pressure mercury lamp from the mold side, after exposure under conditions of 300 mJ / cm ² , the pattern was transferred to the curable composition for imprints by peeling the mold.
About the pattern transcribe | transferred to the said curable composition for imprints, it observed using the optical microscope (The Olympus make, STM6-LM), and the peeling defect of the pattern was evaluated on the following references | standards.
A: No peeling failure was observed in the entire pattern.
B: A peeling failure was observed in an area of less than 10% of the pattern.
C: A peeling failure was observed in an area of 10% or more of the pattern.

<Evaluation of fillability>
On the surface of the primer layer obtained above, the curable composition for imprints shown in Table 4 whose temperature was adjusted to 25 ° C. was 1 pL per nozzle using an inkjet printer DMP-2831 manufactured by Fuji Film Dimatics. The curable composition for imprinting was layered by discharging in the amount of droplets and applying the droplets on the surface of the primer layer so that the droplets were arranged in a square array at intervals of about 100 μm. Next, a quartz substrate was pressed against the pattern forming layer, and the curable composition for imprinting was flattened. Further, using a high-pressure mercury lamp from the mold side, exposure was performed at 300 mJ / cm ² , and then the quartz substrate was peeled off to obtain a flat film.
The flat film surface was observed with an optical microscope (Olympus STM6-LM), and the filling property was evaluated according to the following criteria.
A: In the imprint area, an unfilled region (a region where no cured product of the curable composition for imprints was present) was not generated.
B: In a part of the imprint area, unfilling at the inkjet droplet boundary was confirmed.
C: Unfilled ink jet droplet boundary was confirmed over the entire imprint area.
D: A region where inkjet droplets were not connected to each other and a flat film could not be formed was confirmed.

上記表４において、ｎ１は１２であり、ｎ＋ｍ＋ｌは７〜１３である。

In the said Table 4, n1 is 12 and n + m + 1 is 7-13.

  As apparent from Tables 5 and 6, when the critical surface tension of the primer layer was higher than that of the adhesion layer, the filling property of the curable composition for imprints was excellent. On the other hand, when the critical surface tension of the primer layer was lower than that of the adhesion layer, the filling property of the curable composition for imprinting was inferior.

11 substrate 12 adhesion layer 13 primer layer 14 curable composition for imprint 15 pattern 21 adhesion layer 22 curable composition for imprint

Claims (18)

Forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer located on the substrate;
Applying a curable composition for imprints to the surface of the primer layer. Forming the primer layer using a composition for forming a primer layer containing a solvent,
Furthermore, the component which comprises the said contact | adherence layer is a pattern formation method of Claim 1 which does not melt | dissolve substantially in the solvent contained in the composition for primer layer formation. The pattern forming method according to claim 1, wherein the component constituting the adhesion layer does not substantially thermally diffuse into the primer layer. The at least 1 sort (s) of the component which comprises the said primer layer has a functional group which can form at least 1 of a hydrogen bond and an ion interaction with the component which comprises the said contact | adherence layer. 2. The pattern forming method according to item 1. The pattern formation method of any one of Claims 1-3 in which at least 1 sort (s) of the component which comprises the said primer layer has a functional group which can form a hydrogen bond with the component which comprises the said contact | adherence layer. 95% by mass or more of the component constituting the primer layer is a liquid at 25 ° C., and the contact angle on the surface of the adhesion layer at 25 ° C. after 10 seconds of dropping of the component constituting the primer layer is 5 ° or less. The pattern formation method of any one of Claims 1-5 which are these. The pattern formation method of any one of Claims 1-6 whose viscosity in 23 degreeC of the said curable composition for imprints is 8.0 mPa * s or less. The pattern formation method of any one of Claims 1-7 whose surface tension in 25 degreeC of the said curable composition for imprints is 33 mN / m or more. The pattern forming method according to any one of claims 1 to 8, wherein the primer layer satisfies at least one of A and B below;
A: a primer layer formed from a composition for forming a primer layer containing a component having a surface tension at 25 ° C. of 40 mN / m or more;
B: The critical surface tension of the primer layer at 25 ° C. is 46 mN / m or more. The pattern formation method of Claim 9 which contains the component whose surface tension in 25 degreeC is 40 mN / m or more in the ratio which is 20 mass% or more in the component which comprises a primer layer. The component having a surface tension at 25 ° C of 40 mN / m or more is a compound having a polyalkylene glycol structure, wherein the polyalkylene glycol structure includes a compound composed of a linear alkylene group and an oxygen atom. The pattern forming method according to 9 or 10. The pattern formation method according to any one of claims 9 to 11, wherein at least one of the components having a surface tension at 25 ° C of 40 mN / m or more does not have a polymerizable group. The pattern formation method according to any one of claims 9 to 12, wherein at least one of the components having a surface tension at 25 ° C of 40 mN / m or more is a liquid at 25 ° C. The pattern formation method of any one of Claims 9-13 whose 95 mass% or more of the component which comprises the primer layer contained in the said composition for primer layer formation is a liquid in 25 degreeC. The pattern formation method of any one of Claims 9-14 whose weight average molecular weights of the component whose surface tension in 25 degreeC is 40 mN / m or more are 200-1000. Furthermore, the pattern formation method of any one of Claims 1-15 including the process of providing the said contact | adherence layer on a board | substrate. The pattern formation method according to claim 1, wherein a critical surface tension of the primer layer is 5 mN / m or more higher than a critical surface tension of the adhesion layer. The manufacturing method of a semiconductor element containing the pattern formation method of any one of Claims 1-17.

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