JP2018046182A - Method for manufacturing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a structure, which can suppress deformation of the shape of a convex-concave pattern when removing a remaining film present in a concave portion of the convex-concave pattern of a resin layer.SOLUTION: A method for manufacturing a structure is provided according to the present invention, which comprises: a transferred layer formation step of forming a transferred layer by applying a photo-curable resin composition onto a base material; a convex-concave pattern formation step of forming a resin layer having a convex-concave pattern by exposing the transferred layer to activation energy rays with a mold pressed against the transferred layer to cure the transferred layer; and an ashing step of ashing the resin layer to remove a remaining film present in a concave portion of the convex-concave pattern in the resin layer. The photo-curable resin composition comprises a photopolymerizable monomer; the monomer is 0.95 or more in average C/H ratio.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a structure.

  Patent Document 1 discloses a step of forming a concavo-convex pattern by pressing a mold against a resist layer formed of a resist for optical imprinting, and removing a residual film located in a concave portion of the concavo-convex pattern by ashing. Yes.

JP2016-54317A

  The concavo-convex pattern of the resist layer is used in a subsequent patterning process, but there is a problem in that the pattern shape may be lost in the ashing process for removing the remaining film, and the accuracy of subsequent patterning may be reduced.

  This invention is made in view of such a situation, and manufacture of the structure which can suppress the collapse of the shape of an uneven | corrugated pattern at the time of removing the residual film which exists in the recessed part of the uneven | corrugated pattern of a resin layer. A method is provided.

  According to the present invention, a transfer layer forming step of forming a transfer layer by applying a photocurable resin composition onto a substrate, and an active energy applied to the transfer layer in a state where a mold is pressed against the transfer layer. A concavo-convex pattern forming step of forming a resin layer having a concavo-convex pattern by irradiating a line to cure the transferred layer, and performing ashing on the resin layer, and the concave portion of the concavo-convex pattern in the resin layer The photocurable resin composition contains a photopolymerizable monomer, and the monomer has an average C / H ratio of 0.95 or more. A manufacturing method is provided.

  As a result of intensive studies, the inventor has made a residual film removal ashing by setting the average C / H ratio of the monomer contained in the photocurable resin composition for forming the transfer layer to 0.95 or more. It was found that the deformation of the concavo-convex pattern at the time can be greatly suppressed, and the present invention has been completed.

Hereinafter, various embodiments of the present invention will be exemplified. The embodiments described below can be combined with each other.
Preferably, an inorganic material layer forming step of forming an inorganic material layer so as to cover the resin layer and fill the concave portion after the ashing step, and an extra portion present on the resin layer of the inorganic material layer A surplus part removing process to be removed and a resin layer removing process to remove the resin layer after the surplus part removing process are provided. Preferably, the average C / H ratio is 1.00 or more. Preferably, the monomer includes an aromatic ring. Preferably, the monomer includes a plurality of aromatic rings. Preferably, any two of the plurality of aromatic rings are directly bonded. Preferably, any two of the plurality of aromatic rings are bonded via one intervening atom. Preferably, the monomer is a (meth) acrylate monomer. Preferably, the ashing is gas plasma ashing. Preferably, the concavo-convex pattern has a line and space shape, a pillar shape, or a hole shape.

(A)-(g) is sectional drawing which shows the manufacturing method of the structure of one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various characteristic items shown in the following embodiments can be combined with each other. In addition, the invention is independently established for each feature.

A structure manufacturing method according to an embodiment of the present invention includes a transferred layer forming step, a concavo-convex pattern forming step, an ashing step, an inorganic material layer forming step, a surplus portion removing step, and a resin layer removing step. .
Hereinafter, each step will be described in detail.

(1) Transferred Layer Forming Step In this step, as shown in FIG. 1A, a photocurable resin composition is applied onto the substrate 1 to form the transferred layer 2.

  The material of the substrate 1 is not particularly limited, but is preferably a transparent substrate such as a resin substrate, a quartz substrate, or a sapphire substrate, and is preferably a resin substrate from the viewpoint of flexibility. From this point of view, a quartz substrate or a sapphire substrate is preferable. Examples of the resin constituting the resin base material include one selected from the group consisting of polyethylene terephthalate, polycarbonate, polyester, polyolefin, polyimide, polysulfone, polyethersulfone, cyclic polyolefin, and polyethylene naphthalate.

  The photocurable resin composition contains a photopolymerizable monomer and a photopolymerization initiator, and has a property of being cured by irradiation with active energy rays.

  The monomer has an average C / H ratio of 0.95 or more. The C / H ratio is a value obtained by dividing the number of carbon atoms contained in the monomer by the number of hydrogen atoms. When the photocurable resin composition contains one type of monomer, the C / H ratio of the monomer is an average C / H ratio. On the other hand, when a photocurable resin composition contains multiple types of monomer, average C / H ratio is the value which averaged C / H ratio of each monomer by mass ratio. For example, when the photocurable resin composition contains monomer 1 having a C / H ratio of 1.1 and monomer 2 having a C / H ratio of 0.95 in a mass ratio of 3: 7, the average C / H ratio is 0. .3 × 1.1 + 0.7 × 0.95 = 0.993

  The average C / H ratio is a value that serves as a measure of ashing resistance of the resin layer 4 (shown in FIG. 1C) formed using this photocurable resin composition, and the average C / H ratio is The larger the size, the higher the ashing resistance of the resin layer 4, and even when ashing is performed on the resin layer 4, the shape of the uneven pattern 5 of the resin layer 4 is less likely to collapse, and the structure 8 ( It becomes easy to manufacture FIG. 1 (g). The upper limit of the average C / H ratio is not particularly specified, but is 1.8, for example. Specifically, the average C / H ratio is, for example, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1 .40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, the range between any two of the numerical values illustrated here It may be within.

  When the photocurable resin composition includes a plurality of types of monomers, the C / H ratio of at least one monomer may be 0.95 or more, and the C / H ratio of all types of monomers is 0.95 or more. Preferably there is. The mass ratio of the monomer having a C / H ratio of 0.95 or more in the monomer contained in the photocurable resin composition is preferably 0.5 or more, and more preferably 0.8 or more. 1 is more preferable. Specifically, this mass ratio is, for example, 0.5, 0.6, 0.7, 0.8, 0.9, or 1 and within a range between any two of the numerical values exemplified here. There may be.

  As the monomer having a C / H ratio of 0.95 or more, those containing an aromatic ring are preferred, those containing a plurality of aromatic rings are more preferred, and those containing four or more aromatic rings are more preferred. This is because 1 or 0 hydrogen atoms are bonded to each carbon atom in the aromatic ring, so that the C / H ratio tends to increase as the number of aromatic rings contained in the monomer increases. The aromatic ring may be monocyclic or polycyclic. The aromatic ring may be a hydrocarbon or may contain a hetero atom. 5-14 are preferable and, as for the number of atoms which comprise an aromatic ring, 6 is more preferable. The aromatic ring is preferably a benzene ring. The hydrogen atom bonded to the carbon atom contained in the aromatic ring is preferably unsubstituted or substituted with an oxygen atom, a carbon atom, or a nitrogen atom. The number of substitution of each aromatic ring is preferably 3 or less, and preferably 1 or 2.

  In addition, when the monomer includes a plurality of aromatic rings, any two of them are preferably bonded directly or via one intervening atom. This is because the C / H ratio tends to increase in such a case. Examples of the intervening atom include an oxygen atom, a carbon atom, and a nitrogen atom. Moreover, it is preferable that the monomer whose C / H ratio is 0.95 or more is a (meth) acrylate monomer. The (meth) acrylate monomer may be monofunctional or polyfunctional. In the present specification, (meth) acrylate means methacrylate and / or acrylate. Examples of the monomer having a C / H ratio of 0.95 or more include 1-pyrenylmethyl methacrylate, o-phenylphenol EO acrylate, m-phenoxybenzyl acrylate, and benzyl acrylate.

  A photoinitiator is a component added in order to accelerate | stimulate superposition | polymerization of a monomer, and it is preferable to contain 0.1 mass part or more with respect to 100 mass parts of said monomers. Although the upper limit of content of a photoinitiator is not prescribed | regulated in particular, For example, it is 20 mass parts with respect to 100 mass parts of said monomers.

  The photocurable resin composition is a range in which components such as a solvent, a polymerization inhibitor, a chain transfer agent, an antioxidant, a photosensitizer, a filler, and a leveling agent do not affect the properties of the photocurable resin composition. May be included.

  A photocurable resin composition can be manufactured by mixing the said component by a well-known method. The photocurable resin composition can be applied onto the substrate 1 by a method such as spin coating, spray coating, bar coating, dip coating, die coating, and slit coating to form the transferred layer 2.

(2) Irregular pattern forming step In this step, as shown in FIGS. 1A to 1C, the transfer layer 2 is irradiated with active energy rays E while the mold 3 is pressed against the transfer layer 2. Then, the transferred layer 2 is cured to form the resin layer 4 having the uneven pattern 5. “Active energy rays” is a general term for energy rays that can cure a photocurable resin composition, such as UV light, visible light, and electron beams.

  A reverse pattern 5 r of the concave / convex pattern 5 is formed on the mold 3. The patterns 5 and 5r are preferably concavo-convex fine shape patterns that repeat at a constant period. The period of the patterns 5 and 5r is preferably 50 nm to 20 μm, and more preferably 100 nm to 10 μm. Specifically, this period is, for example, 50 nm, 100 nm, 200 nm, 500 nm, 1 μm, 2 μm, 5 μm, 10 μm, or 20 μm, and may be within a range between any two of the numerical values exemplified here. The height of the patterns 5 and 5r is preferably 10 nm to 500 μm, and more preferably 30 nm to 10 μm. Specifically, this height is, for example, 10 nm, 30 nm, 50 nm, 100 nm, 200 nm, 500 nm, 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 50 μm, 100 μm, 200 μm, or 500 μm. Or within a range between the two.

Specific shapes of the patterns 5 and 5r include a line and space shape, a pillar shape, and a hole shape. The type of the mold 3 is not particularly limited. For example, a resin mold, a nickel mold, or the like can be used. The pressure for pressing the mold 3 against the transferred layer 2 may be any pressure that can transfer the shape of the reversal pattern 5 r to the transferred layer 2. The active energy ray E applied to the transferred layer 2 may be irradiated with an integrated light amount sufficient to sufficiently cure the transferred layer 2, and the integrated light amount is, for example, 100 to 10,000 mJ / cm ² . By being irradiated with the active energy ray E, the transferred layer 2 is cured, and the resin layer 4 having the concavo-convex pattern 5 is formed. In this embodiment, the active energy ray E is irradiated from the base material 1 side, but the active energy ray E may be irradiated from the mold 3 side.

  After irradiation with the active energy ray E, the mold 3 is removed as shown in FIG. In this state, as shown in FIG. 1C, the remaining film 7 remains in the recess 5 a of the uneven pattern 5 of the resin layer 4. If the inorganic material layer 6 shown in FIG. 1E is formed with the remaining film 7 remaining, the inorganic material layer 6 is likely to be peeled off from the substrate 1, so that the remaining film 7 needs to be reliably removed. Although the remaining film 7 can be removed by wet etching or the like, since the shape of the concavo-convex pattern 5 is likely to be lost in wet etching, ashing described below is performed in this embodiment.

(3) Ashing Step In this step, as shown in FIGS. 1C to 1D, ashing is performed on the resin layer 4 so that the resin layer 4 is present in the concave portion 5a of the concave-convex pattern 5. The remaining film 7 is removed.

  During ashing for removing the remaining film 7, the shape of the concavo-convex pattern 5 is liable to be eroded by erosion of the side surface of the convex portion 5b of the concavo-convex pattern 5, but in this embodiment, the average C / H ratio is 0. By using the photocurable resin composition containing a monomer that is .95 or more, the shape of the concavo-convex pattern 5 is minimized. The removal of the remaining film 7 is preferably performed so that the substrate 1 is exposed.

  The ashing is preferably gas plasma ashing, and more preferably oxygen gas plasma ashing.

  The ashing time may be the required processing time determined from the thickness of the remaining film 7 and the ashing rate, but ashing is performed for 5 to 15 seconds longer than the above required processing time in order to remove the remaining film 7 more reliably. It is preferable.

  Through the steps so far, as shown in FIG. 1D, a structure in which the resin layer 4 having the uneven pattern 5 is provided on the substrate 1 is obtained. This structure can be used as it is, for example, as a hydrophilic member or a water repellent member. On the other hand, in order to obtain the structure 8 (illustrated in FIG. 1G) in which the inorganic material layer 6 having the reversal pattern 5r is provided on the substrate 1 by performing the following steps on the structure. It can also be used. Instead of the steps shown below, it is also possible to fabricate the structure by removing the resin layer 4 after etching the base material 1 using the resin layer 4 having the uneven pattern 5 as a mask.

(4) Inorganic material layer forming step In this step, as shown in FIGS. 1D to 1E, the inorganic material layer is formed so as to cover the resin layer 4 and fill the recess 5a after the ashing step. 6 is formed.

Although the kind of inorganic material which comprises the inorganic material layer 6 is not specifically limited, For example, a metal, an oxide, etc. are mentioned. Examples of the metal include Al, Ag, Au, and Ni. Examples of the oxide include SiO ₂ , Al ₂ O ₃ , ITO, and the like. The inorganic material layer 6 can be formed by a method such as vapor deposition, sputtering, or ion plating. Note that an arbitrary material selected from the inorganic materials described above may be used an arbitrary number of times to form a stack of a plurality of materials.

(5) Excess part removal process In this process, as shown to FIG.1 (e)-FIG.1 (f), the excess part 6a which exists on the resin layer 4 among the inorganic material layers 6 is removed.

  This step may be performed by rubbing the excess portion 6a using a polishing member such as a cloth to physically remove the excess portion 6a, or by chemical mechanical polishing (CMP).

  By removing the surplus portion 6 a, an inverted pattern 5 r of the concave / convex pattern 5 of the resin layer 4 is formed in the inorganic material layer 6.

(6) Resin layer removal process In this process, as shown in Drawing 1 (f)-Drawing 1 (g), resin layer 4 is removed after the above-mentioned excessive part removal process.

  The removal of the resin layer 4 may be performed by ashing, or may be performed by other methods (eg, wet etching). The ashing is preferably gas plasma ashing, and more preferably oxygen gas plasma ashing.

  As shown in FIG. 1G, by removing the resin layer 4, a structure 8 in which an inorganic material layer 6 having a reversal pattern 5r is formed on the substrate 1 is obtained.

  In this embodiment, since the resin layer 4 having the concavo-convex pattern 5 is formed by the imprint technique, it is easy to form the structure 8 having a large area. In addition, since the average C / H ratio of the monomers contained in the photocurable resin composition is 0.95 or more, the shape of the concavo-convex pattern 5 of the resin layer 4 is prevented from being deformed in the ashing process, so that the high dimension A structure 8 having the inorganic material layer 6 patterned with accuracy is obtained.

  Here, the use of the inorganic material layer 6 or the structure 8 is illustrated below.

Reverse pattern 5r is a line-and-space shape, when the inorganic material is SiO _2, the inorganic material layer 6 is, for example, super-hydrophilic surface, the flow path for the liquid feed can be utilized as an optical waveguide.

  When the reversal pattern 5r has a line-and-space shape and the inorganic material is Al, Ag, Au, or a dielectric, the structure 8 can be used in applications such as a polarizing plate and an OLED.

  When the inversion pattern 5r has a line and space shape and the inorganic material is a conductive inorganic compound such as ITO, the inorganic material layer 6 can be used as, for example, a transparent electrode or a transparent wiring.

  When the inversion pattern 5r has a pillar shape and the inorganic material is Au or other metal, the inorganic material layer 6 can be used as a bonding bump or a wiring, and the structure 8 can be used as a magnetic storage.

  When the reversal pattern 5r has a hole shape and the inorganic material is Ni, the structure 8 can be used as a mold.

When the reversal pattern 5r has a pillar shape and the inorganic material is TiO ₂ , the inorganic material layer 6 can be used as a photocatalytic surface.

(Sample preparation)
A monomer and a photopolymerization initiator were blended at a mass ratio shown in the Examples and Comparative Examples in Table 1 to prepare a photocurable resin composition. Details of the monomers A to T in Table 1 are as shown in Table 2.
In Example 1, the obtained photocurable resin composition was diluted with propylene glycol monomethyl ether acetate (PGMEA) to a weight solid content of 10%, and then spin-coated (4000 rpm) on a sapphire substrate. A cured resin layer was obtained. In other examples and comparative examples, 100 μL of the obtained photocurable resin composition was dropped onto a base material made of easy-adhesion-treated PET with a pipetter and subjected to easy-adhesion treatment using a roll-to-plate nanoimprint apparatus. An uncured resin layer was formed by laminating with uncoated PET.
Next, 3000 mJ / cm ^{2 was} irradiated with a high-pressure mercury lamp to cure the uncured resin layer, and after forming a pattern having a line and space shape, the PET that was not subjected to the easy adhesion treatment was peeled off.
Samples of Examples and Comparative Examples were produced through the above steps.

(Resin layer thickness before ashing)
Next, using the F20 film thickness measurement system manufactured by Filmetrics, the base material is set to PET or sapphire, the resin component is set to a refractive index of 1.45 to 1.60, and the resin layer thickness of the sample before ashing treatment Was measured. The measurement results are shown in Table 1.

(Ashing process)
Using a SAMCO Plabma Dry Cleaner (Samco PC-300), the sample was ashed in RIE mode at a pressure of 10 Pa, an oxygen flow rate of 12 sccm, an electrode output of 250 W, and a processing time of 60 seconds.

(Thickness of resin layer after ashing)
Next, the resin layer thickness of the sample after the ashing treatment was measured under the same conditions as the “resin layer thickness before the ashing treatment”. The measurement results are shown in Table 1. Further, the ashing rate was calculated according to the following formula.
Ashing rate = {(resin layer thickness before ashing treatment) − (resin layer thickness after ashing treatment)} / ashing treatment time

(Discussion)
As shown in Table 1, in all examples where the average C / H ratio was 0.95 or more, the ashing rate was a low value of 2.0 nm / second or less. On the other hand, in all the comparative examples having an average C / H ratio of less than 0.95, the ashing rate was a high value of 2.2 nm / second or more. When the ashing rate is high, the side surface of the convex portion of the concave / convex pattern is eroded during ashing for removing the remaining film present in the concave portion of the concave / convex pattern in the above-mentioned “(3) ashing step”. Since the shape of the pattern tends to collapse, the larger the ashing rate, the more easily the shape of the convex portion of the concave-convex pattern collapses. Further, as the ashing rate is increased, the surface roughness of the ashed surface is increased and the shape of the convex portion of the concavo-convex pattern is likely to be broken. For this reason, the result of Table 1 that the ashing rate was low in all the examples indicates that the shape of the convex part of the concavo-convex pattern in the ashing process is difficult to collapse in all the examples.

  From the above results, it was demonstrated that the use of a photocurable resin composition containing a monomer having an average C / H ratio of 0.95 or more can prevent the shape of the concavo-convex pattern from being deformed in the ashing process.

1: Base material 2: Transfer target layer 3: Mold 4: Resin layer 5: Concave and convex pattern 5 a: Concave and convex pattern concave part 5 b: Concave and convex pattern convex part 5 r: Concave and convex pattern inversion pattern 6: Inorganic material layer 6 a: Inorganic material layer Excess part 7: Residual film 8: Structure E: Active energy ray

Claims (10)

A transferred layer forming step of forming a transferred layer by applying a photocurable resin composition on a substrate;
A concavo-convex pattern forming step of forming a resin layer having a concavo-convex pattern by irradiating the transferred layer with active energy rays in a state where a mold is pressed against the transferred layer, and curing the transferred layer;
Ashing the resin layer, and comprising an ashing step of removing a residual film present in the concave portion of the concavo-convex pattern in the resin layer,
The photocurable resin composition contains a photopolymerizable monomer,
The manufacturing method of a structure whose average C / H ratio of the said monomer is 0.95 or more. An inorganic material layer forming step of forming an inorganic material layer so as to cover the resin layer and fill the concave portion after the ashing step;
A surplus part removing step of removing a surplus part existing on the resin layer in the inorganic material layer;
The manufacturing method of the structure of Claim 1 provided with the resin layer removal process of removing the said resin layer after the said excessive part removal process.   The manufacturing method of the structure according to claim 1 or 2, wherein the average C / H ratio is 1.00 or more.   The method for producing a structure according to any one of claims 1 to 3, wherein the monomer includes an aromatic ring.   The method for producing a structure according to any one of claims 1 to 4, wherein the monomer includes a plurality of aromatic rings.   The method for producing a structure according to claim 5, wherein any two of the plurality of aromatic rings are directly bonded.   The method for producing a structure according to claim 5 or 6, wherein any two of the plurality of aromatic rings are bonded via one intervening atom.   The method for producing a structure according to any one of claims 1 to 7, wherein the monomer is a (meth) acrylate monomer.   The method of manufacturing a structure according to any one of claims 1 to 8, wherein the ashing is gas plasma ashing.   The said uneven | corrugated pattern is a manufacturing method of the structure as described in any one of Claims 1-9 which is a line and space shape, a pillar shape, or a hole shape.