KR102217047B1 - Pattern formation method and semiconductor device manufacturing method - Google Patents

Abstract

A method of forming a pattern having improved filling properties of a curable composition for imprinting on a substrate, and a method of manufacturing a semiconductor device using the pattern forming method are provided. The pattern formation method includes a step of forming a primer layer having a higher critical surface tension than the adhesion layer on a surface of an adhesion layer positioned on a substrate, and a step of applying a curable composition for imprinting on the surface of the primer layer. .

Description

Pattern formation method and semiconductor device manufacturing method

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

The imprint method is a method in which light is irradiated by passing through a light-transmitting mold or a light-transmitting substrate to photo-cure the curable composition for imprinting, and then remove the mold to transfer a fine pattern to a cured product. Since this method can be imprinted at room temperature, it can be applied to the field of precision processing of ultra-fine patterns such as fabrication of semiconductor integrated circuits. In recent years, new developments such as a nanocasting method that combines the advantages of both, a reversal imprint method for fabricating a three-dimensional laminated structure, have also been reported.

Here, with the activation of the imprint method, the adhesiveness between the substrate and the curable composition for imprinting has been problematic. That is, in the imprint method, the curable composition for imprinting is applied to the surface of the substrate, and the curable composition for imprinting is cured by light irradiation while the mold is in contact with the surface, and then the mold is peeled off. In the process, the cured product may peel from the substrate and adhere to the mold. It is considered that this is 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 this problem, it has been studied to use an imprint adhesion layer that improves adhesion between a substrate and a cured product (Patent Documents 1 to 3).

Patent Document 1: Japanese Patent Publication No. 2009-503139 Patent Document 2: Japanese Laid-Open Patent Publication No. 2014-024322 Patent Document 3: Japanese Laid-Open Patent Publication No. 2014-192178

However, it has been found that when the curable composition for imprinting is applied to the surface of the conventional adhesion layer, the filling property of the curable composition for imprinting may be inferior. In particular, when the curable composition for imprinting is applied by the inkjet (IJ) method, as shown in FIG. 2, when droplets of the curable composition for imprinting 22 are dropped on the surface of the adhesion layer 21 at equal intervals, the above The droplets diffuse to the surface of the adhesion layer 21 to form a layer-like curable composition 22 for imprinting. However, if the wettability of the curable composition for imprint is low, the curable composition for imprint does not diffuse to the surface of the adhesion layer 21, so that a portion on the substrate where the curable composition for imprint 22 is not filled may remain. . That is, improvement of the filling property of the curable composition for imprint on the substrate is required.

An object of the present invention is to provide a method for forming a pattern with improved filling properties of a curable composition for imprint on a substrate, and a method for manufacturing a semiconductor device using the pattern forming method. do.

Under the above problems, as a result of intensive examination by the present inventors, it was found that the above problems could be solved by providing a primer layer having a high critical surface tension between the adhesion layer and the layer made of the curable composition for imprinting.

Specifically, by the following means <1>, preferably by <2> to <17>, the said subject was solved.

<1> comprising a step of forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer positioned on the substrate, and applying a curable composition for imprinting on the surface of the primer layer, How to form a pattern.

<2> It includes forming the primer layer using a primer layer-forming composition containing a solvent, and the components constituting the adhesion layer are not substantially dissolved in the solvent contained in the primer layer-forming composition. The pattern formation method according to <1> which is not.

<3> The pattern formation method according to <1> or <2>, in which the component constituting the adhesion layer is not substantially thermally diffused to the primer layer.

<4> At least one of the components constituting the primer layer has a component constituting the adhesion layer and a functional group capable of forming at least one of a hydrogen bond and an interaction between ions, <1> to <3> The pattern formation method according to any one of.

<5> The pattern formation method according to any one of <1> to <3>, wherein at least one of the components constituting the primer layer has a component constituting the adhesion layer and a functional group capable of forming a hydrogen bond. .

<6> 95% by mass or more of the components constituting the primer layer are liquid at 25°C, and the contact angle of the components constituting the primer layer on the surface of the adhesion layer at 25°C 10 seconds after dropping The pattern formation method in any one of <1>-<5> which is 5 degrees or less.

<7> The pattern formation method according to any one of <1> to <6>, wherein the viscosity at 23°C of the curable composition for imprinting is 8.0 mPa·s or less.

<8> The pattern formation method according to any one of <1> to <7>, wherein the surface tension at 25°C of the curable composition for imprinting is 33 mN/m or more.

<9> The pattern formation method according to any one of <1> to <8>, wherein the primer layer satisfies at least one of the following A and B;

A: It is a primer layer formed of a composition for forming a primer layer containing a component having a surface tension of 40 mN/m or more at 25°C;

B: The critical surface tension at 25°C of the primer layer is 46 mN/m or more.

<10> The pattern formation method according to <9>, comprising a component having a surface tension of 40 mN/m or more at 25°C in a proportion of 20 mass% or more among the components constituting the primer layer.

<11> The component having a surface tension of 40 mN/m or more at 25°C is a compound having a polyalkylene glycol structure, and the polyalkylene glycol structure includes a compound consisting of a linear alkylene group and an oxygen atom. The pattern formation method according to <9> or <10> to do.

<12> The pattern formation method according to any one of <9> to <11>, wherein at least one of the components having a surface tension of 40 mN/m or more at 25°C does not have a polymerizable group.

<13> The pattern formation 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.

<14> The pattern formation method according to any one of <9> to <13>, wherein 95% by mass or more of the components constituting the primer layer contained in the primer layer-forming composition are liquid at 25°C.

<15> The pattern formation method according to any one of <9> to <14>, wherein the weight average molecular weight of the component having a surface tension of 40 mN/m or more at 25°C is 200 or more and less than 1000.

<16> The pattern formation method in any one of <1> to <15>, further including the step of providing the adhesion layer on the substrate.

<17> The pattern formation method according to any one of <1> to <16>, wherein the critical surface tension of the primer layer is 5 mN/m or more higher than the critical surface tension of the adhesion layer.

<18> A method for manufacturing a semiconductor element, including the pattern formation method in any one of <1> to <17>.

According to the present invention, it has become possible to provide a pattern forming method in which the filling property of a curable composition for imprinting onto a substrate is improved, and a method of manufacturing a semiconductor device using the pattern forming method.

1 is a schematic diagram showing each step of the pattern forming method of the present invention.
Fig. 2 is a schematic diagram showing a wet diffusion state of a curable composition for imprinting when a curable composition for imprinting is applied to the surface of a known adhesion layer by an ink jet method.

Hereinafter, the content of the present invention will be described in detail. In addition, in this specification, "~" is used for the meaning including the numerical value described before and behind it as a lower limit and an upper limit.

In this specification, "(meth)acrylate" represents an acrylate and a methacrylate.

In the present specification, "imprint" preferably refers to pattern transfer with a size of 1 nm to 10 mm, and more preferably refers to pattern transfer (nano imprint) with a size of approximately 10 nm to 100 μm.

In the notation of the group (atomic group) in the present specification, the notation that does not describe substituted or unsubstituted includes not only having no substituent but also having a substituent. For example, the term "alkyl group" includes not only an alkyl group not having a substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

In the present specification, "light" includes not only light having a wavelength in a region such as ultraviolet, near ultraviolet, far ultraviolet, visible, infrared, etc., and electromagnetic waves, but also radiation. Radiation includes microwaves, electron beams, extreme ultraviolet (EUV), and X-rays, for example. Moreover, laser light, such as a 248 nm excimer laser, a 193 nm excimer laser, and a 172 nm excimer laser, can also be used. These lights may be monochromatic light (single wavelength light) passed through an optical filter, or may be light having a plurality of different wavelengths (complex light).

The weight average molecular weight (Mw) in the present invention refers to what was measured by gel permeation chromatography (GPC) unless otherwise specified.

The pattern formation method of the present invention comprises a step of forming a primer layer having a higher critical surface tension than the adhesion layer on a surface of an adhesion layer positioned on a substrate, and applying a curable composition for imprinting to the surface of the primer layer. It characterized in that it includes a process. By setting it as such a structure, the curable composition for imprint can be diffused in a short time or easily on the surface of the primer layer, and the filling property of the curable composition for imprint on a substrate can be improved.

Hereinafter, the method of the present invention will be described with reference to FIG. 1. It goes without saying that the configuration of the present invention is not limited to FIG. 1.

<Process of forming an adhesion layer on the substrate>

It is preferable that the pattern formation method of the present invention includes a step of forming an adhesion layer on a substrate. However, in the case of using the one having the adhesion layer formed in advance on the prepared substrate, this step is not necessarily required.

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, a case in which surface treatment is applied to the surface of the substrate 11 is considered.

The material of the substrate is not particularly determined, and description of paragraph 0103 of Japanese Laid-Open Patent Publication No. 2010-109092 (corresponding US application, US2011/199592) can be referred to, and these contents are incorporated herein by reference. In addition, other than 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, GaAsP, GaP, AlGaAs, InGaN, GaN, AlGaN, ZnSe, AlGaInP Or, a substrate made of ZnO is mentioned. Moreover, as a specific material example of a glass substrate, aluminosilicate glass, aluminoborosilicate glass, and barium borosilicate glass can be mentioned. In the present invention, a silicon substrate is preferred.

In the present invention, the critical surface tension of the adhesion layer at 25°C is preferably 30 mN/m or more, and more preferably 40 mN/m or more. Although it does not specifically set about an upper limit, it is 70 mN/m or less, for example, and 60 mN/m or less is preferable. The critical surface tension in this specification is measured according to the method described in Examples to be described later.

As for the thickness of the adhesion layer, it is preferable that the lower limit is 0.1 nm or more, more preferably 0.5 nm or more, and still more preferably 1 nm or more. Moreover, as for the thickness of an adhesive layer, it is preferable that the upper limit is 20 nm or less, more preferably 15 nm or less, and still more 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 composition for forming an adhesive layer 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. As a method of applying the composition for forming an adhesive layer, it is not particularly determined, and the description of paragraph 0102 of Japanese Laid-Open Patent Publication No. 2010-109092 (corresponding US application, US2011/199592) can be referred to. Won. In the present invention, a spin coating method or an ink jet method is preferable.

As the composition for forming an adhesive layer, a composition containing a component constituting the adhesive layer and a solvent is preferable.

As a 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 ethylenic unsaturated group in the side chain is more preferable. As a specific example of the resin as a component constituting the adhesive layer, the resin contained in the composition for forming an adhesive layer described in Examples to be described later, or the resin (A) and resin described in paragraphs 0017 to 0057 of JP 2014-024322 (A2) is illustrated. As for the weight average molecular weight of resin, 3,000-25,000 are preferable. Moreover, the component constituting the adhesion 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, and more preferably 80% by mass or more is a resin.

At least one of the components constituting the adhesion layer preferably has a component constituting the primer layer and a functional group capable of forming at least one of a hydrogen bond and an interaction between ions in order to secure the stability of the primer layer. . Examples of the functional group include a hydroxyl group, an amino group, a carbonyl group, and a carboxyl group. It is preferable that the said resin has such a functional group.

By setting it as such a structure, an adhesion layer and a primer layer are fixed by hydrogen bonding and/or interaction between ions. For this reason, it becomes possible to ensure the uniformity of application of the primer layer and to suppress surface roughness such as aggregation. Further, it is possible to more effectively suppress the component constituting the adhesion layer from moving to a pattern which is a curable composition for imprinting or a cured product of the curable composition for imprinting provided as a primer layer or an upper layer thereof. As a result, it becomes difficult for a substance capable of increasing the adhesion between the pattern and the mold to exist in the vicinity of the pattern, and the mold releasability of the pattern can be improved.

In addition, the component constituting the adhesive layer refers to a component contained in the adhesive layer. For example, a component from which a solvent has been removed from the composition for forming an adhesive layer corresponds to this. Similarly, the component constituting the primer layer refers to a component contained in the primer layer. For example, a component from which a solvent has been removed from a composition for forming a primer layer to be described 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 composition for forming the primer layer. By setting it as such a structure, when forming a primer layer, the component which comprises an adhesion layer becomes difficult to mix in a primer layer, and a mold release property of a pattern does not deteriorate. In addition, substantially insoluble 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 in the total primer layer forming component. By setting it as such a structure, deterioration of releasability 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 heat-diffuse in 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 if the components constituting the adhesion layer are thermally diffused in this heating step, as described above, mold release of the pattern is formed. May worsen. In the present invention, this point is avoided by using a component that is not substantially thermally diffused in the primer layer as a component constituting the adhesion layer. In addition, the term "substantially not thermally diffused" means that the adhesion layer component eluted in the primer layer after formation of the primer layer is 10% by mass or less in the total primer layer forming component. By setting it as such a structure, deterioration of releasability with a mold can be suppressed effectively.

In addition, as the heating in the present invention, heating for drying the solvent contained in the composition for forming the primer layer when forming the primer layer, or for enhancing the reactivity of the curable composition for imprinting during irradiation with light to the curable composition for imprinting. Heating, etc. are illustrated. The heating temperature is, for example, 50 to 200°C, preferably 80 to 150°C.

As the solvent that may be blended into the composition for forming an adhesive layer, the solvent described in paragraph 0059 of JP 2014-024322 A is illustrated, and the contents are incorporated herein.

In addition, the composition for forming an adhesive layer used in the present invention preferably contains 0.001 to 2.0% by mass of components constituting the adhesive layer and 98.0 to 99.999% by mass of a solvent, and 0.05 to 0.5 components constituting the adhesive layer. It is more preferable to contain 99.5-99.95 mass% of mass% and a solvent.

Components and solvents constituting the adhesion layer may be included in the composition for forming the adhesion layer, respectively, only one type or two or more types may be included. When two or more types are included, it is preferable that the total amount falls within the above range.

As a specific example of the composition for forming an adhesion layer, a (meth)acrylic resin (A) having an ethylenically unsaturated group (P) and a nonionic hydrophilic group (Q) described in Japanese Laid-Open Patent Publication No. 2014-024322 (A) having a weight average molecular weight of 1,000 or more, and a solvent (B), wherein the resin (A) has an acid value of less than 1.0 mmol/g, an underlayer film-forming composition for imprinting, and the contents of JP 2014-024322 A are incorporated herein by reference.

In addition, for the preparation of a composition for forming an adhesive layer and a method for forming an adhesive layer using the composition for forming an adhesive layer, reference may be made to the description of Japanese Unexamined Patent Application Publication No. 2014-024322, and these contents are incorporated herein by reference. .

<Step of forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer>

In the present invention, on the surface of the adhesion layer 12, a primer layer 13 having a higher critical surface tension than the adhesion layer is formed. By forming such a primer layer, the filling property of the curable composition for imprint on the substrate can be improved.

The critical surface tension at 25°C of the primer layer 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, more preferably 5 mN/m or more. It is even more preferable. The upper limit of the difference in the 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 still more preferably 10 mN/m or less. By setting it within the above range, the effect of improving the uniformity and wettability of the film at the time of forming the primer layer is more effectively improved.

The thickness of the primer layer preferably has a lower limit of 0.1 nm or more, more preferably 0.5 nm or more, and further preferably 1 nm or more. Moreover, it is preferable that the upper limit is 20 nm or less, as for the thickness of a primer layer, it is more preferable that it is 15 nm or less, and it is still more preferable that it is 10 nm or less.

In the present invention, the primer layer is usually formed using a composition for forming a primer layer. It is preferable that the composition for forming a primer layer contains a solvent. Specifically, after applying the composition for forming a primer layer on the surface of the adhesion layer, the solvent is volatilized by heat or light irradiation to form a thin film. As a method of applying the composition for forming a primer layer, it is not particularly determined, and the description of paragraph 0102 of Japanese Laid-Open Patent Publication 2010-109092 (corresponding US application, US2011/199592) can be referred to, the contents of which are in the present specification. Won. In the present invention, a spin coating method or an ink jet method is preferable.

When forming the adhesive layer, when using a composition for forming an adhesive layer containing a solvent, the primer layer is after volatilizing (drying) the solvent from the composition for forming the adhesive layer and/or curing the adhesive layer, and then the primer It is preferably formed by applying the layer-forming composition. By setting it as such a constitution, the components constituting the primer layer are dissolved in the solvent contained in the composition for forming the adhesion layer, so that mixing of the adhesion layer and the primer layer can be effectively suppressed.

In addition, the preparation of the composition for forming a primer layer and the method of forming a primer layer formed from the composition for forming a primer layer can be carried out in the same manner as the preparation of the composition for forming an adhesive layer and the method of forming the adhesive layer.

In the present invention, in particular, it includes forming a primer layer using a primer layer-forming composition containing a solvent, and the components constituting the adhesion layer are substantially dissolved in a solvent contained in the primer layer-forming composition. It is desirable not to. By setting it as such a structure, the deterioration of mold releasability caused by mixing of the adhesion layer component with the primer layer can be suppressed more effectively.

In the present invention, also as described above, at least one (preferably all) of the components constituting the primer layer can form at least one of the components constituting the adhesion layer, hydrogen bonds, and interactions between ions. It is preferable to have a functional group that is present. Examples of the functional groups that the components constituting the primer layer may have include hydroxyl groups, amino groups, carbonyl groups, carboxyl groups, and the like, and a hydroxyl group is preferable.

In addition, 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 the dropwise addition of the components constituting the primer layer is 10 seconds. It is preferable that the contact angle on the surface of the adhesive layer at 25° C. after that is 5° or less. The contact angle is measured according to the method described in Examples to be described later. By setting it as such a structure, it becomes possible to form a primer layer more uniformly on the adhesion layer, and to make the filling property of the curable composition for imprint more uniform.

In addition, it is preferable that the component constituting the primer layer is compatible with the curable composition for imprinting. Here, compatibility means that the component constituting the primer layer is sufficiently dissolved in the curable composition for imprinting, so that no clear interface exists between the primer layer and the curable composition for imprinting. As described above, when the primer layer is compatible with the curable composition for imprint, a part of the curable composition for imprint diffuses into the primer layer when the curable composition for imprint is filled, thereby forming adhesion with the adhesion layer, such as peeling defects during release. It is possible to effectively suppress the occurrence of this.

In the present invention, it is preferable that the primer layer satisfies at least one of the following A and B.

A: It is a primer layer formed of a composition for forming a primer layer containing a component having a surface tension of 40 mN/m or more at 25°C;

B: The critical surface tension at 25°C of the primer layer is 46 mN/m or more.

The primer layer formed from the composition for forming a primer layer is usually a liquid film, but may be a solid film within the scope not departing from the spirit 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 setting it as such a structure, a primer layer with high critical surface tension is obtained. The surface tension is measured according to the method described in Examples to be described later.

Further, in the present invention, it is preferable that the critical surface tension of the primer layer is 46 mN/m or more. By setting it as such a structure, the wettability of the curable composition for imprint applied to the surface of a primer layer can be improved, and filling property can be improved. The critical surface tension is measured according to the method described in Examples to be described later.

In the present invention, the critical surface tension of the primer layer formed from the composition for forming a primer layer is preferably 47 mN/m or more, and more preferably 48 mN/m or more. The upper limit of the critical surface tension of the primer layer is not particularly determined, but is preferably 70 mN/m or less, 65 mN/m or less, and further 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 proportion of 20% by mass or more among the components constituting the primer layer, and contains 51% by mass or more. It is more preferable, it is more preferable to contain it in a ratio of 80 mass% or more, it is even more preferable to contain it in a ratio of 90 mass% or more, it is particularly preferable to contain it in a ratio of 95 mass% or more, and a ratio of 99 mass% or more It is most preferable to include as.

The composition for forming a primer layer may contain only one component or two or more components having a surface tension of 40 mN/m or more at 25°C. When two or more types are included, it is preferable that the total amount falls within the above range.

In the present invention, as a component constituting the primer layer, a compound having a polyalkylene glycol structure, and a compound in which the polyalkylene glycol structure is composed of a linear alkylene group and an oxygen atom (hereinafter referred to as "PEG etc." It is preferable to include). 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, more preferably an alkylene group having 1 to 3 carbon atoms, more preferably an alkylene group having 2 or 3 carbon atoms It is more preferred, and an alkylene group having 2 carbon atoms is particularly preferred. That is, in the present invention, it is preferable that the component constituting the primer layer contains a compound having a polyethylene glycol structure.

It is preferable that PEG etc. contain 3-50 alkylene glycol units. PEG etc. may be a component having a surface tension of 40 mN/m or more at 25°C, or a component having a surface tension of less than 40 mN/m at 25°C, but a component having a surface tension of 40 mN/m or more at 25°C. It is desirable.

When PEG or the like is a component having a surface tension of 40 mN/m or more at 25°C, it is preferable to include 3 to 20 alkylene glycol units, and more preferably 5 to 17 units.

In addition, when the critical surface tension at 25°C of the primer layer is 46 mN/m or more, the composition for forming the primer layer is a polyalkylene glycol structure composed of a linear alkylene group and an oxygen atom as a component constituting the primer layer. It is a compound having, and it is preferable to include a compound containing 21 to 50 alkylene glycol units, and more preferably a compound containing 22 to 45 units.

PEG and the like may contain structures other than the polyalkylene glycol structure. However, it is preferable that PEG and the like have a polyalkylene glycol structure by removing the terminal group. That is, PEG and the like are preferably represented by "terminal group-polyalkylene glycol structure composed of a linear alkylene group and oxygen atom-terminal group". The terminal group here is preferably a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group. 1 to 3 are preferable, as for the number of carbon atoms of the alkyl group and the number of carbon atoms of the alkyl chain of the alkoxy group, 1 or 2 is more preferable, and 1 is more preferable.

Specific examples of PEG and the like are exemplified by compounds used in 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 component constituting the adhesion layer and a functional group capable of forming at least one of a hydrogen bond and an interaction between ions, It is preferable that such a functional group has a component having a surface tension of 40 mN/m or more at 25°C. Particularly, when a component having a surface tension of 40 mN/m or more at 25°C is PEG or the like, one or both of the end groups can form at least one of a hydrogen bond and an interaction between ions with the component constituting the adhesion layer. It is preferably a functional group (preferably a hydroxyl group, an amino group, a carbonyl group, a carboxyl group, and the like, more preferably a hydroxyl group).

In the present invention, a component other than PEG may be used as a component having a surface tension of 40 mN/m or more at 25°C. For example, polyhydric alcohols such as glycerol, polyvinyl alcohol, polyvinyl acetamide, and ionic polymers such as polystyrene sulfonic acid are exemplified.

In addition, in the present invention, the composition for forming a primer layer comprises a component having a surface tension of 40 mN/m or more at 25°C other than PEG, and PEG having a surface tension of less than 40 mN/m at 25°C. Also illustrated.

In the present invention, it is preferable that at least one (preferably all) of the components having a surface tension of 40 mN/m or more at 25° C. does not have a polymerizable group. By setting it as such a structure, mold releasability can be improved more.

In the present invention, it is preferable that 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. Moreover, it is more preferable that 95 mass% or more (preferably 98 mass% or more, more preferably 99 mass% or more) of the component which comprises a primer layer is liquid at 25 degreeC. By using the liquid, it becomes possible to more effectively reduce the surface roughness of the primer layer.

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

In addition to the above, as a component constituting the primer layer, a polymerizable compound may be included.

As the polymerizable compound, a monofunctional polymerizable compound may be used, or a polyfunctional polymerizable compound may be used, a polyfunctional polymerizable compound is preferable, a 2-4 functional polymerizable compound is more preferable, and a bifunctional or trifunctional polymerizable compound This is more preferable. As a specific example of a polymeric compound, the polymeric compound which may be contained in the curable composition for imprint mentioned later is illustrated.

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. In addition, the lower limit of the content of the polymerizable compound is preferably 10% by mass or more when blended.

The composition for forming a primer layer may contain only one type of polymerizable compound, or may contain two or more types. When two or more types are included, it is preferable that the total amount falls within the above range.

In the present invention, it is preferable that the composition for forming a primer layer contains a solvent. Application becomes possible by including a solvent. The solvent is preferably a solvent having at least one 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 mono Methyl ether and ethyl lactate. Among these, PGMEA, γ-butyrolactone, and cyclohexanone are more preferable, and PGMEA is particularly preferable.

It is preferable that the solvent contained in the composition for forming an adhesion layer and the solvent contained in the composition for forming a primer layer are different solvents.

In the present invention, the composition for forming a primer layer preferably contains 0.001 to 2.0% by mass of the component constituting the primer layer and 98.0 to 99.999% by mass of the solvent, and 0.05 to 0.5% by mass and the component constituting the primer layer. It is more preferable to contain 99.5-99.95 mass% of a solvent. The component constituting the primer layer preferably contains a component having a surface tension of 40 mN/m or more at 25°C, and a component having a surface tension of 40 mN/m or more at 25°C in a ratio of 99% by mass or more. It is more preferable.

Components and solvents constituting the primer layer may be included in the primer layer-forming composition, respectively, only one type or two or more types. When two or more types are included, it is preferable that the total amount falls within the above range.

<Step of applying the curable composition for imprinting to the surface of the primer layer>

In the present invention, as shown in FIG. 1, a step of applying the curable composition 14 for imprinting to the surface of the primer layer 13 is included. The method of applying the curable composition for imprinting is not particularly determined, and the description of paragraph 0102 of Japanese Laid-Open Patent Publication No. 2010-109092 (corresponding US application, US2011/199592) can be referred to. do. It is preferable to perform the said application by an ink jet method. Moreover, you may apply|coat the curable composition for imprint by multiple coating. In the method of disposing droplets on the surface of the primer layer by an ink jet method or the like, the amount of droplets is preferably about 1 to 20 pL, and is preferably disposed on the surface of the primer layer at intervals of droplets. As the droplet spacing, a spacing of 10 to 1000 μm is preferable. In the case of the ink jet method, the droplet spacing is an arrangement spacing of the ink jet nozzles.

In addition, the volume ratio of the primer layer 13 and the curable composition 14 for imprinting when applied on a substrate is preferably 1:1 to 500, and more preferably 1:10 to 300. And, it is more preferably 1:50 ~ 200.

<Pattern formation>

In the pattern formation method of the present invention, the curable composition for imprinting, the primer layer, and the adhesion layer are placed between a substrate and a mold having a pattern, and light irradiated to cure the curable composition for imprinting, and the mold is peeled off. It is preferable to further include a process. By passing through such a process, for example, as shown in FIG. 1, the pattern 15 is obtained.

Specifically, in order to transfer a desired pattern to the layered curable composition for imprinting, a mold is pressure-welded to the surface of the layered curable composition for imprinting. Thereby, a fine pattern previously formed on the pressing surface of the mold can be transferred to the layer-like curable composition for imprinting.

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, in the case of using a light-opaque 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 irradiate light from the mold side using a light-transmitting mold.

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 a desired processing precision by, for example, photolithography, electron beam drawing, or the like, but in the present invention, the method for forming a mold pattern is not particularly limited. 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 light-transmitting resins such as glass, quartz, polymethyl methacrylate (PMMA), and polycarbonate resin, transparent metal vapor deposition film, and polydimethylsiloxane A flexible film such as Sein, a photocured film, a metal film, etc. are illustrated.

The non-light-transmitting mold material used in the case of using the light-transmitting substrate in the present invention is not particularly limited, but may have a predetermined strength. Specifically, ceramic materials, vapor deposition films, magnetic films, reflective films, metal substrates such as Ni, Cu, Cr, Fe, and substrates such as SiC, silicon, silicon nitride, polysilicon, silicon oxide, and amorphous silicon are exemplified. Not restricted.

In the pattern formation method of the present invention, when performing imprint lithography using the curable composition for imprinting, it is preferable to set the mold pressure to 10 atmospheres or less. By setting the mold pressure to 10 atmospheres or less, the mold or the substrate is hardly deformed, and the pattern accuracy tends to be improved. Moreover, since the pressurization is low, it is preferable from the point that there is a tendency that the apparatus can be reduced. The mold pressure is preferably selected from a range in which uniformity of mold transfer can be ensured within a range in which the residual film of the curable composition for imprinting of the mold convex portion is reduced.

In the pattern formation method of the present invention, the irradiation amount of light in the step of irradiating light to the curable composition for imprinting may be sufficiently larger than the minimum irradiation amount required for curing. The irradiation amount required for curing is appropriately determined by examining the consumption amount of unsaturated bonds of the curable composition for imprinting.

In addition, in the imprint lithography applied to the present invention, the substrate temperature during light irradiation is usually performed at room temperature, but light irradiation may be performed while heating to increase reactivity. As a preliminary step of light irradiation, if it is placed in a vacuum state, since it is effective in preventing air bubbles from being mixed, suppressing reduction of reactivity due to oxygen mixing, and improving the adhesion between the mold and the curable composition for imprinting, light irradiation may be performed in a vacuum state. In addition, in the pattern formation method of the present invention, a preferable vacuum degree at the time of light irradiation is in the range of 10 ^-1 Pa to normal pressure.

At the time of exposure, it is preferable to set the exposure illuminance in the range of 1 mW/cm ² to 500 mW/cm ² .

In the pattern formation method of the present invention, after curing the layered curable composition for imprinting (pattern formation layer) by irradiation with light, the cured pattern may be further cured by applying heat to the cured pattern, if necessary. . 150-280 degreeC is preferable and 200-250 degreeC is more preferable as a temperature for heat-hardening the curable composition for imprint after light irradiation. Moreover, as a time to apply heat, 5 to 60 minutes are preferable, and 15 to 45 minutes are more preferable.

Next, the curable composition for imprinting used in the present invention will be described.

The curable composition for imprint used in the present invention is not particularly determined, and a known curable composition for imprint can be used.

In the present invention, in order to enable fast filling using capillary force, it is preferable to design the curable composition for imprint to have a low viscosity and a high surface tension.

Specifically, the viscosity at 23° C. of the imprint curable composition is preferably 20.0 mPa·s or less, more preferably 15.0 mPa·s or less, further preferably 10.0 mPa·s or less, and 8.0 mPa·s It is even more preferable that it is the following. 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.

Moreover, it is preferable that it is 30 mN/m or more, and, as for the surface tension at 25 degreeC of the curable composition for imprint, it is more preferable that it is 33 mN/m or more. By using the curable composition for imprinting having a high surface tension, the capillary force increases, and high-speed filling of the curable composition for imprinting to the mold pattern becomes possible. Although it does not specifically limit as the upper limit of the said surface tension, It is preferable that it is 40 mN/m or less from a 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 imprinting with high surface tension can be improved. Is high.

The surface tension at 25°C of the curable composition for imprinting is measured according to the method described in Examples described later.

The type of the curable composition for imprinting used in the present invention is not particularly defined, but it is preferable to contain a polymerizable compound and a photopolymerization initiator. Moreover, you may contain a sensitizer, a mold release agent, an antioxidant, a polymerization inhibitor, a solvent, etc.

The polymerizable compound contained in the curable composition for imprinting 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 some of the polymerizable compounds contained in the curable composition for imprint are liquid at 25°C. By including the polymerizable compound that is liquid at 25°C in this way, even if the curable composition for imprint does not contain a solvent substantially, the viscosity of the curable composition for imprint can be lowered, so that it can be applied by an ink jet method. Here, the term "substantially free of a solvent" means that the content of the solvent in the curable composition for imprinting is 5% by mass or less, further means 3% by mass or less, and particularly 1% by mass or less.

In addition, the curable composition for imprint used in the present invention is a polymer (preferably, the weight average molecular weight exceeds 1,000, more preferably the weight average molecular weight exceeds 2,000, and more preferably the weight average molecular weight is 10,000 or more. It can also be made into an aspect which does not contain a polymer) substantially. Substantially free of polymer means, for example, that the content of the polymer is 0.01% by mass or less of the curable composition for imprinting, preferably 0.005% by mass or less, and more preferably not containing it.

The kind of the monofunctional polymerizable compound used in the curable composition for imprinting is not particularly determined unless it deviates from the gist of the present invention.

It is preferable that the monofunctional polymerizable compound used for the curable composition for imprint has a C4 or more linear or branched hydrocarbon chain. In the present invention, only one type of monofunctional polymerizable compound may be included, or two or more types may be included.

The molecular weight of the monofunctional polymerizable compound used in the curable composition for imprinting is preferably 100 or more, more preferably 200 or more, and still more preferably 220 or more. As for the upper limit of a molecular weight, 1,000 or less are preferable, 800 or less are more preferable, 300 or less are more preferable, and 270 or less are especially preferable. By setting the lower limit of the molecular weight to 200 or more, there is a tendency that volatility can be suppressed. By setting the upper limit of the molecular weight to 300 or less, there is a tendency that the viscosity can be reduced.

The boiling point in 667Pa of the monofunctional polymerizable compound used in the curable composition for imprinting is preferably 85°C or higher, more preferably 110°C or higher, and still more preferably 130°C or higher. Volatility can be suppressed by making the boiling point in 667Pa 85 degreeC or more. Although it does not specifically set about the upper limit of a boiling point, the boiling point in 667 Pa can be made 200 degrees C or less, for example.

Although the kind of the polymerizable group which the monofunctional polymerizable compound used for the imprinting curable composition has is not specifically determined, an ethylenic unsaturated bond-containing group, an epoxy group, etc. are illustrated, and an ethylenically unsaturated bond-containing group is preferable. As an ethylenically unsaturated bond-containing group, a (meth)acryl group, a vinyl group, etc. are illustrated, a (meth)acryl group is more preferable, and an acrylic group is more preferable. Moreover, it is preferable that a (meth)acryl group is a (meth)acryloyloxy group.

The type of atoms constituting the monofunctional polymerizable compound used in the imprintable composition is not particularly determined, but it is preferably composed of only atoms selected from carbon atoms, oxygen atoms, hydrogen atoms and halogen atoms, and carbon atoms, oxygen It is more preferable to consist of only an atom selected from an atom and a hydrogen atom.

It is preferable that the monofunctional polymerizable compound used for the curable composition for imprint has a C4 or more linear or branched hydrocarbon chain. The hydrocarbon chain in the present invention represents an alkyl chain, an alkenyl chain, and an alkyneyl chain, and an alkyl chain and an alkenyl chain are preferable, and an alkyl chain is more preferable.

In the present invention, an 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 alkyneyl group and an alkynylene group. Among these, a linear or branched alkyl group and an alkenyl group are more preferable, a linear or branched alkyl group is more preferable, and a linear alkylene group is even 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, more preferably 10 or more carbon atoms, and particularly 12 or more carbon atoms desirable. The upper limit of the number of carbon atoms is not particularly determined, but may be, for example, 25 or less carbon atoms.

The linear or branched hydrocarbon chain may contain an ether group (-O-), but it is preferable from the viewpoint of improving the releasability that the ether group is not included.

By using the monofunctional polymerizable compound having such a hydrocarbon chain, the elastic modulus of the cured film is reduced with a relatively small amount of addition, and releasability is improved. Moreover, when a monofunctional polymerizable compound having a linear or branched alkyl group is used, the interfacial energy between the mold and the cured film is reduced, and the releasability can be further improved.

(1) to (3) are mentioned as a preferable hydrocarbon group which the monofunctional polymerizable compound used for the curable composition for imprint has.

(1) C8 or more linear alkyl group

(2) a branched alkyl group having 10 or more carbon atoms

(3) an alicyclic or aromatic ring substituted with a linear or branched alkyl group having 5 or more carbon atoms

(1) C8 or more linear alkyl group

The straight-chain alkyl group having 8 or more carbon atoms is more preferably 10 or more carbon atoms, more preferably 11 or more carbon atoms, and particularly preferably 12 or more carbon atoms. In addition, 20 or less carbon atoms are preferable, 18 or less carbon atoms are more preferable, 16 or less carbon atoms are still more preferable, and 14 or less carbon atoms are particularly preferable.

(2) a branched alkyl group having 10 or more carbon atoms

The branched alkyl group having 10 or more carbon atoms preferably has 10 to 20 carbon atoms, more preferably 10 to 16 carbon atoms, more preferably 10 to 14 carbon atoms, and particularly preferably 10 to 12 carbon atoms.

(3) an alicyclic or aromatic ring substituted with 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 even more preferably 8 or more. The number of carbon atoms in the alkyl group is preferably 14 or less, more preferably 12 or less, and still more preferably 10 or less.

The ring structure of an alicyclic or aromatic ring may be monocyclic or condensed, but is preferably monocyclic. In the case of a condensed ring, the number of rings is preferably two or three. The ring structure is preferably a 3- to 8-membered ring, more preferably a 5- or 6-membered ring, and more preferably a 6-membered ring. Moreover, although the ring structure is an alicyclic ring or an aromatic ring, it is preferable that it is an aromatic ring. Specific examples of the ring structure include a cyclohexane ring, a noborneine ring, an isobornene ring, a tricyclodecane ring, a tetracyclododecane ring, an adamantane ring, a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring. Among these, a 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 imprint is preferably a compound in which a straight or branched hydrocarbon chain having 4 or more carbon atoms and a polymerizable group are bonded directly or through a linking group, and the above (1) to (3) A compound in which any one of the groups and a polymerizable group are directly bonded is more preferable. As a linking group, -O-, -C(=O)-, -CH ₂ -, or a combination thereof is illustrated. As the monofunctional polymerizable compound used in the present invention, (1) a linear alkyl (meth)acrylate in which a C8 or more linear alkyl group and a (meth)acryloyloxy group are directly bonded to each other is particularly preferable.

The following 1st group and 2nd group can be illustrated as a monofunctional polymeric compound used for the curable composition for imprint. However, it goes without saying that the present invention is not limited to these. Moreover, the 1st group is more preferable than the 2nd group.

Group 1

[Formula 1]

Group 2

[Formula 2]

The amount of the monofunctional polymerizable compound used in the imprint curable composition with respect to the total polymerizable compound in the imprint curable composition is more than 5% by mass and less than 30% by mass. As for the lower limit, 6 mass% or more is preferable, 8 mass% or more is more preferable, 10 mass% or more is still more preferable, and 15 mass% or more is especially preferable. Moreover, as for the upper limit, 29 mass% or less is more preferable, 27 mass% or less is more preferable, and 25 mass% or less is especially preferable. When the amount of the monofunctional polymerizable compound is 6% by mass or more with respect to the entire polymerizable compound, the releasability can be improved, and defects and mold breakage can be suppressed at the time of mold release. Moreover, by setting it as 29 mass% or less, Tg of the cured film of the curable composition for imprint can be raised, and etching processability, especially, the bending of a pattern at the time of etching can be suppressed.

In the present invention, a monofunctional polymerizable compound other than the monofunctional polymerizable compound may be used as long as it does not depart from the spirit of the present invention, and a monofunctional polymerizable compound among the polymerizable compounds described in Japanese Patent Laid-Open No. 2014-170949 Is illustrated, the contents of which are incorporated herein.

In the present invention, it is preferable that 90% by mass or more of the total monofunctional polymerizable compound contained in the curable composition for imprinting is a monofunctional polymerizable compound having groups of the above (1) to (3), and 95% by mass or more. More preferable.

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

The curable composition for imprinting may contain only one type of polyfunctional polymerizable compound containing a ring structure, or may contain two or more types.

The molecular weight of the cyclic structure-containing polyfunctional polymerizable compound used in the curable composition for imprinting is preferably 1,000 or less, more preferably 800 or less, more preferably 500 or less, even more preferably 350 or less, and particularly 250 or less. desirable. By setting the upper limit of the molecular weight to 1,000 or less, there is a tendency that the viscosity can be reduced.

Although it does not specifically set about the lower limit of molecular weight, it can be set as 200 or more, for example.

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

Although the kind of the polymerizable group which the cyclic structure-containing polyfunctional polymerizable compound used for the imprinting curable composition has is not specifically determined, an ethylenically unsaturated bond-containing group, an epoxy group, etc. are illustrated, and an ethylenically unsaturated bond-containing group is preferable. As an ethylenically unsaturated bond-containing group, a (meth)acryl group, a vinyl group, etc. are illustrated, a (meth)acryl group is more preferable, and an acrylic group is more preferable. Moreover, it is preferable that a (meth)acryl group is a (meth)acryloyloxy group. Two or more types of polymerizable groups may be included in one molecule, or two or more types of polymerizable groups of the same type may be included.

The kind of atoms constituting the cyclic structure-containing polyfunctional polymerizable compound used in the imprint curable composition is not particularly determined, but it is preferably composed of only atoms selected from carbon atoms, oxygen atoms, hydrogen atoms and halogen atoms, and carbon It is more preferable to consist of only an atom selected from an atom, an oxygen atom and a hydrogen atom.

The cyclic structure contained in the cyclic structure-containing polyfunctional polymerizable compound used in the curable composition for imprinting may be monocyclic or condensed, but is preferably monocyclic. In the case of a condensed ring, the number of rings is preferably two or three. The ring structure is preferably a 3- to 8-membered ring, more preferably a 5- or 6-membered ring, and more preferably a 6-membered ring. Moreover, although the ring structure may be an alicyclic ring or an aromatic ring may be sufficient, it is preferable that it is an aromatic ring. Specific examples of the ring structure include a cyclohexane ring, a noborneine ring, an isobornene ring, a tricyclodecane ring, a tetracyclododecane ring, an adamantane ring, a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring. Among these, a 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 imprinting may be one or two or more, but one or two is preferable, and one is more preferable. In the case of a condensed ring, the condensed ring is considered as one.

The cyclic structure-containing polyfunctional polymerizable compound used in the curable composition for imprinting is (polymerizable group)-(single bond or divalent linking group)-(divalent group having cyclic structure)-(single bond or divalent linking group)-( It is preferably represented by a polymerizable group). Here, as a linking group, an alkylene group is more preferable, and a C1-C3 alkylene group is still more preferable.

It is preferable that the ring structure-containing polyfunctional polymerizable compound used for the curable composition for imprint is represented by the following general formula (1).

[Formula 3]

In General Formula (1), Q represents a divalent group having an alicyclic structure or an aromatic ring structure.

The preferable range of the alicyclic or aromatic ring (ring structure) for Q is the same as the above, and the preferable range is also the same.

The following 1st group and 2nd group can be illustrated as a polyfunctional polymeric compound used for the curable composition for imprint. However, it goes without saying that the present invention is not limited to these. The first group is more preferable.

Group 1

[Formula 4]

Group 2

[Formula 5]

The cyclic structure-containing polyfunctional polymerizable compound is preferably contained in an amount of 30% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, based on the total polymerizable compound in the curable composition for imprinting, 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 it is less than 95 mass %, as for an upper limit, it is more preferable that it is 90 mass% or less, and can also be made into 85 mass% or less. By setting the lower limit to 30% by mass or more, the etching selectivity with the object to be processed (e.g., Si, Al, Cr, or oxides thereof) during the etching process is improved, thereby suppressing disconnection of the pattern after etching processing. can do.

The curable composition for imprinting may contain a polyfunctional polymerizable compound other than the polyfunctional polymerizable compound containing the ring structure. These other polyfunctional polymerizable compounds may contain only one type, and may contain two or more types.

As other polyfunctional polymerizable compounds used in the curable composition for imprinting, among the polymerizable compounds described in Japanese Laid-Open Patent Publication No. 2014-170949, a polyfunctional polymerizable compound having no ring structure is exemplified, and these contents are included in the present specification. do. More specifically, the following compounds are illustrated, for example.

[Formula 6]

As the blending amount of the other polyfunctional polymerizable compound, when blending, it is preferable that the amount relative to the total polymerizable compound in the curable composition for imprinting is 5 to 30 mass%. Moreover, it can also be set as the structure which does not mix|blend substantially another polyfunctional polymeric compound. The term "substantially not blended" means that the amount relative to the total polymerizable compound in the curable composition for imprinting is, for example, 3% by mass or less, and further, 1% by mass or less.

For photoinitiators, sensitizers, release agents, antioxidants, polymerization inhibitors, solvents, etc. that may be blended into the curable composition for imprinting, in addition to the components described in Examples to be described later, JP 2013-036027 A and JP Patent Publications Each component described in the specification of 2014-090133, Japanese Laid-Open Patent Application 2013-189537, and Japanese Patent Application No. 2016-037872 can be used. Also, the description of the above publication can be referred to for the blending amount and the like.

As a specific example of the curable composition for imprinting that can be used in the present invention, the composition described in Examples to be described later, JP 2013-036027 A, JP 2014-090133 A, JP 2013-189537 A, Japan The compositions described in the specification of patent application 2016-037872 are exemplified, the contents of which are incorporated herein. Moreover, about the preparation of the curable composition for imprinting and the formation method of a film (pattern formation layer), the description in the above publication can be referred to, and these contents are incorporated herein by reference.

<pattern>

As described above, the pattern formed by the pattern forming method of the present invention can be used as a permanent film for use in a liquid crystal display (LCD) or the like, or as an etching resist for manufacturing a semiconductor element. That is, the present invention further discloses a method for manufacturing a semiconductor device, including the method for forming a pattern of the present invention.

In addition, a grid pattern is formed on a glass substrate of a liquid crystal display using a pattern formed by the pattern formation method of the present invention, and a polarizing plate having a large screen size (for example, 55 inches, more than 60 inches) It is possible to manufacture inexpensively. For example, a polarizing plate described in Japanese Patent Application Laid-Open No. 2015-132825 or WO2011/132649 can be manufactured. Also, 1 inch is 25.4mm.

In addition, the permanent membrane is bottled in a container such as a gallon bottle or a quart bottle after manufacture, transported, and stored.In this case, for the purpose of preventing deterioration, the container may be replaced with inert nitrogen or argon. . In the case of transportation and storage, the temperature may be room temperature, but in order to prevent the permanent film from deteriorating, the temperature may be controlled in the range of -20°C to 0°C. Of course, it is preferable to block light to a level at which the reaction does not proceed.

Specifically, the pattern formed by the pattern formation method of the present invention is a recording medium such as a magnetic disk, a light-receiving element such as a solid-state image sensor, a light-emitting element such as an LED or an organic EL, and an optical device such as a liquid crystal display (LCD). , Diffraction gratings, relief holograms, optical waveguides, optical filters, optical components such as micro lens arrays, thin film transistors, organic transistors, color filters, anti-reflection films, polarizing plates, polarizing elements, optical films, and pillar members for flat panel displays , Nano bio device, immunoassay chip, deoxyribonucleic acid (DNA) separation chip, microreactor, photonic liquid crystal, guide pattern for directed self-assembly (DSA) using self-organization of block copolymers, etc. It can be preferably used for the production of.

The pattern formed by the pattern formation method of the present invention is also useful as an etching resist (lithography mask). In the case of using a pattern as an etching resist, first, using a silicon substrate (silicon wafer, etc.) on which a thin film such as SiO ₂ is formed as a substrate, for example, according to the pattern formation method of the present invention on the substrate. It forms a fine pattern on the order of nano or micron. In the present invention, it is particularly advantageous in that a fine pattern of nano-order can be formed, and further, a pattern having a size of 50 nm or less, especially 30 nm or less can be formed. The lower limit of the size of the pattern to be formed in the pattern forming method of the present invention is not particularly determined, but may 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 is particularly good in etching resistance to dry etching. That is, the pattern formed by the pattern formation method of the present invention is preferably used as a lithography mask.

Example

Hereinafter, the present invention will be described in more detail with reference to examples. Materials, usage, ratios, treatment contents, treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the gist 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 2-4 is a mass ratio.

<Preparation of the composition for forming an adhesive layer>

As shown in Table 2 below, a resin and a solvent were blended and filtered with a 0.1 μm polytetrafluoroethylene filter (PTFE filter) to prepare compositions A-1 to A-5 for forming an adhesive layer.

<Preparation of the composition for forming a 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. Among the components contained in the composition for forming a primer layer, the component and the solvent (propylene glycol monomethyl ether acetate) whose surface tension is measured are liquid at 25°C.

<Preparation of curable composition for imprint>

As shown in Table 4 below, various compounds were mixed, and a 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (manufactured by Tokyo Kasei Co., Ltd.) was added as a polymerization inhibitor. It was added and prepared so that it might become 200 mass ppm (0.02 mass %) with respect to the total amount of a polymeric compound. This was filtered through a 0.1 μm PTFE filter to prepare curable compositions C-1 to C-10 for imprinting.

<Formation of adhesion layer and primer layer>

On the silicon wafer, the composition for forming an adhesion layer shown in Table 5 or 6 was spin-coated, heated for 1 minute using a 220°C hot plate, and the solvent was dried to form an adhesion layer having a thickness of 5 nm. Subsequently, the primer layer-forming composition shown in Table 5 or Table 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 thickness of the adhesion layer and the primer layer was measured by an ellipsometer and 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, 4.6mmID×15cm) connected in series with three columns

Development 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: Toso HLC-8020GPC

Detector: RI (refractive index) detector

Calibration curve base resin: Polystyrene

<Measurement of critical surface tension>

For the adhesion layer and primer layer formed above, the critical surface tension was measured, respectively.

On the surface of the adhesion layer or the primer layer, 2 µL of solvents having different surface tensions were respectively added dropwise, and the contact angle θ at the time of 500 ms was measured. A result of a contact angle of 2° or more (contact angle θ) is plotted on the xy plane (x: surface tension of the solvent, y: cosθ calculated from the contact angle θ), and a linear function approximating the measurement result is calculated according to the least squares method. Then, the extrapolated value of the linear function at cosθ=1 was taken as the critical surface tension (unit: mN/m) of the adhesion layer or the primer layer.

As a solvent, water (surface tension 72.9mN/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 measurement of the contact angle was performed at 25°C using DMs-401, manufactured by Kyowa Gaimen Chemical Co., Ltd. The value after 500 msec after the droplet landing was measured as n=3, and the average value was taken as the contact angle.

<Measurement of surface tension>

The measurement of the surface tension of each composition or compound was performed at 25±0.2°C using a surface tension meter SURFACE TENS-IOMETER CBVP-A3, manufactured by Kyowa Gaimen Chemical Co., Ltd., using a glass plate. The unit was expressed in mN/m.

<viscosity>

The viscosity of the curable composition for imprinting was measured at 23±0.2°C using a RE-80L type 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.

[Table 1]

<Evaluation of surface roughness of primer layer>

For the primer layer obtained above, a square 10 μm was scanned using an atomic force microscope (AFM, manufactured by Burker AX, Dimension Icon), and the arithmetic mean surface roughness (Ra) was measured, and the following criteria Evaluated as. The results are shown in Tables 5 and 6 below.

A: Ra<0.4nm

B: 0.4nm≤Ra<1.0nm

C: 1.0nm≤Ra

<Evaluation of peeling failure>

On the surface of the primer layer obtained above, the curable composition for imprinting, which was temperature-adjusted to 25°C, was discharged at a droplet amount of 1 pL per nozzle using an inkjet printer DMP-2831 manufactured by Fujifilm Dymatics, and the primer layer It applied so that droplets might be in a square arrangement of about 100 μm intervals on the surface of, and the curable composition for imprint was made into a layer shape. 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 pressure-contacted to the layer-like curable composition for imprinting, and the curable composition for imprinting is molded. Charged in. Further, after exposing from the mold side under conditions of 300 mJ/cm ² using a high-pressure mercury lamp, the pattern was transferred to the curable composition for imprinting by peeling the mold.

The pattern transferred to the curable composition for imprinting was observed using an optical microscope (manufactured by Olympus, STM6-LM), and the peeling failure of the pattern was evaluated according to the following criteria.

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 the region of 10% or more of the pattern.

<Evaluation of fillability>

On the surface of the primer layer obtained above, the curable composition for imprinting shown in Table 4, which was temperature-adjusted at 25°C, was discharged at a droplet amount of 1pL per nozzle using an inkjet printer DMP-2831 manufactured by Fujifilm Dymatics. , The surface of the primer layer was applied so that the droplets were in a square arrangement at intervals of about 100 μm, and the curable composition for imprinting was formed into a layer shape. Next, the quartz substrate was pressure-contacted to the pattern formation layer, and the curable composition for imprinting was planarized. Further, after exposure to light was performed under the conditions of 300 mJ/cm ² using a high-pressure mercury lamp from the mold side, the quartz substrate was peeled to obtain a flat film.

The surface of the flattening film was observed using an optical microscope (STM6-LM manufactured by Olympus), and the filling property was evaluated according to the following criteria.

A: In the imprint area, an unfilled region (a region in which a cured product of the curable composition for imprint does not exist) did not occur.

B: In a partial region of the imprint area, unfilled at the boundary of the inkjet droplet was confirmed.

C: Over the entire surface of the imprint area, unfilled at the boundary of the inkjet droplet was confirmed.

D: It was confirmed that the inkjet droplets were not connected to each other and thus a region in which a flat film could not be formed.

[Table 2]

[Table 3]

[Table 4]

In Table 4, n1 is 12, and n+m+l is 7 to 13.

[Table 5]

[Table 6]

As is clear from the above 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 imprinting was excellent. On the other hand, when the critical surface tension of the primer layer is lower than that of the adhesion layer, the filling property of the curable composition for imprinting is inferior.

11 substrate
12 adhesion layer
13 primer layer
14 Curable composition for imprint
15 patterns
21 adhesion layer
22 Curable composition for imprint

Claims (19)

Forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer positioned on the substrate, and
As a pattern forming method comprising the step of applying a curable composition for imprinting on the surface of the primer layer,
A pattern formation method in which the primer layer satisfies at least one of the following A and B;
A: It is a primer layer formed of a composition for forming a primer layer containing a component having a surface tension of 40 mN/m or more at 25°C;
B: The critical surface tension at 25°C of the primer layer is 46 mN/m or more. Forming a primer layer having a higher critical surface tension than the adhesion layer on the surface of the adhesion layer positioned on the substrate, and
As a pattern forming method comprising the step of applying a curable composition for imprinting on the surface of the primer layer,
Including forming the primer layer using a composition for forming a primer layer containing a solvent,
In addition, the component constituting the adhesion layer is not substantially dissolved in the solvent contained in the composition for forming the primer layer, the pattern forming method. The method according to claim 1 or 2,
The method for forming a pattern in which the components constituting the adhesion layer are not substantially thermally diffused in the primer layer. The method according to claim 1 or 2,
At least one of the components constituting the primer layer has a component constituting the adhesion layer and a functional group capable of forming at least one of a hydrogen bond and an interaction between ions. The method according to claim 1 or 2,
At least one of the components constituting the primer layer has a component constituting the adhesion layer and a functional group capable of forming a hydrogen bond. The method according to claim 1 or 2,
95% by mass or more of the components constituting the primer layer are liquid at 25°C, and the contact angle of the components constituting the primer layer on the surface of the adhesion layer at 25°C 10 seconds after dropping is 5° The following is a pattern formation method. The method according to claim 1 or 2,
The pattern formation method, wherein the viscosity at 23°C of the curable composition for imprinting is 8.0 mPa·s or less. The method according to claim 1 or 2,
The pattern forming method, wherein the surface tension at 25°C of the curable composition for imprinting is 33 mN/m or more. delete The method according to claim 1,
A pattern formation method comprising a component having a surface tension of 40 mN/m or more at 25°C in a proportion of 20% by mass or more among the components constituting the primer layer. The method according to claim 1,
The pattern wherein the component having a surface tension of 40 mN/m or more at 25°C is a compound having a polyalkylene glycol structure, and the polyalkylene glycol structure includes a compound consisting of a linear alkylene group and an oxygen atom Formation method. The method according to claim 1,
At least one of the components having a surface tension of 40 mN/m or more at 25° C. does not have a polymerizable group. The method according to claim 1,
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 method according to claim 1,
95% by mass or more of the components constituting the primer layer contained in the primer layer-forming composition are liquid at 25°C. The method according to claim 1,
The method for forming a pattern, wherein the weight average molecular weight of the component having a surface tension of 40 mN/m or more at 25°C is 200 or more and less than 1000. The method according to claim 1 or 2,
The method of forming a pattern, further comprising a step of providing the adhesion layer on the substrate. The method according to claim 1 or 2,
The method of forming a pattern, wherein the critical surface tension of the primer layer is higher than the critical surface tension of the adhesion layer by 5 mN/m or more. A method for manufacturing a semiconductor device, comprising the method for forming a pattern according to claim 1 or 2. The method according to claim 1 or 2,
The method of forming a pattern, wherein the critical surface tension of the primer layer is 2 mN/m or more higher than the critical surface tension of the adhesion layer.

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