KR20190135756A - Method of manufacturing metal layer having nano pattern - Google Patents

Abstract

Provided is a method of manufacturing a metal layer having a nano pattern, capable of uniformly and neatly manufacturing a nano pattern to be formed on a metal layer. Here, the method of manufacturing a metal layer having a nano pattern comprises a first coating step, a second coating step, a first metal layer forming step, a first separation step, and a removal step. The first coating step is configured to coat an upper portion of a nano pattern to be formed on a polymer layer with a protective layer. The second coating step is configured to coat an upper portion of the protective layer with a seed layer of a metal material for electroplating. The first metal layer forming step is configured to form a first metal layer having a first transfer pattern corresponding to the nano pattern formed on the upper portion of the seed layer through electroplating. The first separation step is configured to separate the polymer layer from the first metal layer, the seed layer, and the protective layer. The removal step is configured to remove a residual polymer remaining on the protective layer. The protective layer protects the first metal layer to prevent the first transfer pattern from being damaged while the residual polymer is removed.

Description

Method of manufacturing metal layer having nano pattern {METHOD OF MANUFACTURING METAL LAYER HAVING NANO PATTERN}

The present invention relates to a metal layer manufacturing method having a nanopattern, and more particularly, to a metal layer manufacturing method having a nanopattern capable of uniformly and cleanly manufacturing a nanopattern formed on a metal layer.

Recently, large-area products using nano-patterns such as wire grid polarizers and super water-repellent surfaces have attracted attention as major industrial items. In order to commercialize nano products, large-scale mass production must be possible, and the most effective method is to apply a printing process using a roll-to-roll process.

In order to produce a functional film using a roll-to-roll process, it is important to manufacture a mold including a desired pattern. Particularly, in order to repeat regeneration and improve productivity, it is important to manufacture a metal mold including a metal nanopattern made of a metal having a constant rigidity.

Conventionally, cylindrical molds having a micron size pattern such as a transparent electrode pattern and a retroreflective pattern are mainly manufactured by a machining method. This method can produce a mold having a continuous pattern, regardless of the size of the cylindrical mold, and can produce a pattern on the metal surface itself has a very economic advantage. However, this method has a problem that it is difficult to produce a nanometer size pattern.

Another method is to make cylindrical molds using E-beams. In this method, an e-beam resist is applied to the surface of a metal cylindrical mold, and then a pattern is produced using an e-beam in a dedicated system. This method has a high precision of fabricating up to several tens of nanometers (nm), but the manufacturing time is very long, and the size of the cylindrical mold is limited due to the limitation of the vacuum chamber size for performing the e-beam lithography process.

As a method of manufacturing a mold having a nanopattern in an economical manner, a method of using a large-area polymer nanopattern manufactured by using nanoimprint lithography has been studied. In this method, a metal nanopattern is manufactured through an electroplating process on a polymer nanopattern manufactured by a nanoimprint lithography process. However, in the process of separating the metal layer containing the nanopattern from the polymer nanopattern through the release after electroplating, a problem arises that the polymer is buried on the surface of the metal layer, and thus a process technology for solving the problem is required.

Republic of Korea Patent Publication No. 2016-0029946 (Published March 16, 2016)

In order to solve the above problems, the technical problem to be achieved by the present invention is to provide a metal layer manufacturing method having a nano-pattern that can produce a nano-pattern formed on the metal layer uniformly and cleanly.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems that are not mentioned may be clearly understood by those skilled in the art from the following description. There will be.

In order to achieve the above technical problem, an embodiment of the present invention comprises a first coating step of coating a protective layer on top of the nanopattern formed on the polymer layer; A second coating step of coating a seed layer of a metal material for electroplating on top of the protective layer; A first metal layer forming step of forming a first metal layer having a first transfer pattern corresponding to the nanopattern on the seed layer through electroplating; A first separation step of separating the polymer layer from the first metal layer, the seed layer and the protective layer; And removing the remaining polymer remaining on the protective layer, wherein the protective layer protects the first metal layer to prevent the first transfer pattern from being damaged while the remaining polymer is removed. It provides a metal layer manufacturing method having a nano-pattern characterized.

In an embodiment of the present invention, the protective layer may be made of an inorganic material including silicon (Si).

In an embodiment of the present invention, the polymer layer may be made of any one material of PMMA (polymethyl methacrylate), PC (polycarbonate), PET (polyethylene terephthalate).

In an embodiment of the present invention, the seed layer may be made of an electrically conductive material including copper (Cu).

In an embodiment of the present invention, the first metal layer may be made of nickel (Ni) or copper (Cu) material.

In the embodiment of the present invention, after the removing step, the second metal layer forming step of forming a second metal layer having a second transfer pattern corresponding to the first transfer pattern on the protective layer through the electroplating; And a second separation step of separating the second metal layer from the protective layer.

In an embodiment of the present invention, the seed layer is formed to a first thickness, and the seed layer is so that the electroplating is possible on top of the protective layer even when the protective layer is coated on the seed layer. It may be formed to a second thickness thicker than the first thickness.

In an embodiment of the present invention, the second metal layer may be made of nickel (Ni) or copper (Cu) material.

According to an embodiment of the present invention, since the protective layer is coated before coating the seed layer, the metal nanopattern under the protective layer is damaged even during dissolution in a strong acidic solution to remove residual polymer after electroplating and release. It can be avoided, through which, the resulting metal nanopattern can be formed uniformly and clean.

It is to be understood that the effects of the present invention are not limited to the above effects, and include all effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a flowchart illustrating a method of manufacturing a metal layer having a nanopattern according to a first embodiment of the present invention.
2 is a process example showing a process according to a method for manufacturing a metal layer having a nanopattern according to the first embodiment of the present invention.
3 is a photograph showing a metal layer manufactured by the method for manufacturing a metal layer having a nanopattern according to the first embodiment of the present invention.
Figure 4 is a photograph showing a microscope image after the first separation step in the metal layer manufacturing method having a nanopattern according to the first embodiment of the present invention.
5 is a photograph showing a microscope image after the removal step in the metal layer manufacturing method having a nanopattern according to the first embodiment of the present invention.
6 is a flowchart illustrating a method of manufacturing a metal layer having a nanopattern according to a second embodiment of the present invention.
7 is a process example showing a process according to a method of manufacturing a metal layer having a nanopattern according to a second embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, coupled)" with another part, it is not only "directly connected" but also "indirectly connected" with another member in between. Also includes the case where In addition, when a part is said to "include" a certain component, this means that unless otherwise stated, it may further include other components rather than excluding the other components.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms “comprise” or “have” are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating a method of manufacturing a metal layer having a nanopattern according to a first embodiment of the present invention, and FIG. 2 is a process example showing a process according to a method of manufacturing a metal layer having a nanopattern according to a first embodiment of the present invention. It is also.

As shown in FIGS. 1 and 2, the metal layer manufacturing method having the nanopattern includes a first coating step S110, a second coating step S120, a first metal layer forming step S130, and a first separation step S140. And it may include a removal step (S150).

The first coating step S110 may be a step of coating the protective layer 300 on the nanopattern 210 formed on the polymer layer 200.

The polymer layer 200 may be in the form of a film.

The nanopattern 210 of the polymer layer 200 may be formed in an inverted form of a target nanopattern to be finally obtained.

The polymer layer 200 may be made of a polymer material that can be molded by pressing while applying heat. For example, the polymer layer 200 may be made of any one material of PMMA (polymethyl methacrylate), PC (polycarbonate), and PET (polyethylene terephthalate).

The polymer layer 200 may be manufactured through various processes that are not particularly limited. For example, a silicon (Si) master pattern can be produced, and a PDMS soft stamp can be produced from the silicon master pattern through a PDMS (polydimethylsiloxane) replication process. Then, a thermal nanoimprint lithography process or an ultraviolet (UV) nanoimprint lithography process using a PDMS soft stamp is performed to invert the shape of the PDMS soft stamp on the surface of the PMMA film and to have a nano-sized pattern having the same shape as the silicon master pattern. The polymer layer 200 having the pattern 210 may be obtained.

The protective layer 300 may be coated on the nanopattern 210 formed on the polymer layer 200.

The protective layer 300 may be formed of a material having any one or more of acid resistance and heat resistance. Preferably, the protective layer 300 may be an inorganic thin film layer, and silicon (Si) may be used as the inorganic material.

The protective layer 300 may be coated through a thin film coating process such as sputtering and e-beam evaporation.

The second coating step S120 may be a step of coating the seed layer 400 of the metal material for electroplating on the protective layer 300.

The seed layer 400 may be connected to the electrode in the electroplating process, through which the desired metal ions may be plated on the seed layer 400.

The seed layer 400 may be coated through a thin film coating process, such as sputtering and electron beam deposition. The seed layer 400 may be made of an electrically conductive material including copper (Cu).

The first metal layer forming step S130 may be a step of forming the first metal layer 500 having the first transfer pattern 510 corresponding to the nanopattern 210 on the seed layer 400 through electroplating. have.

The first metal layer forming step S130 may be performed through an electroplating process in a metal plating solution bath.

The first metal layer 500 may be formed on the seed layer 400 through an electroplating process. The first metal layer 500 may be formed of nickel (Ni), but is not necessarily limited thereto, and may be formed of copper (Cu).

The first transfer pattern 510 formed on the first metal layer 500 may be an inverted form of the nanopattern 210 formed on the polymer layer 200, and may be a target nano pattern to be finally obtained.

The first separation step S140 may be a step of separating the polymer layer 200 from the protective layer 300.

The first separation step S140 may be a step of finally obtaining the metal nanopattern by separating the polymer layer 200 through a demolding process. In other words, it may be a step of obtaining the first metal layer 500 having the first transfer pattern 510.

The removing step S150 may be a step of removing the remaining polymer 220 remaining on the protective layer 300.

In the first separation step S140, when the polymer layer 200 is separated from the protective layer 300, a portion of the polymer layer 200 may remain on the protective layer 300.

In addition, the remaining polymer 220 may have a form in which polymer film pieces (Flakes) are buried on the surface of the first transfer pattern 510 of the first metal layer 500.

In general, the polymer or polymer resist of PMMA or PC material before curing can be easily dissolved and removed by an organic solvent such as acetone and methylethylketone.

However, polymers or polymer resists cured by heat or ultraviolet light during thermal nanoimprint lithography or ultraviolet nanoimprint lithography processes are very difficult to remove by dissolving with organic solvents such as acetone, methylethylketone and the like.

Therefore, in order to remove the residual polymer 220 generated in the first metal layer 500, a removal method through dissolution in strong acid or carbonization by strong thermal energy (condensing beam, high temperature heat treatment) is required. However, when the removal method through dissolution by strong acid or carbonization by strong thermal energy is applied, the nanopattern formed of the metal material may be damaged.

In the present invention, since the protective layer 300 is coated before coating the seed layer 400, the protective layer 300 even during the dissolution process in a strong acid solution to remove the remaining polymer 220 after electroplating and release. The metal nanopatterns below can be protected from damage. That is, the protective layer 300 may protect the first metal layer 500 to prevent the first transfer pattern 510 from being damaged while the remaining polymer 220 is removed.

Hereinafter, it demonstrates concretely through an Example.

First, a PDMS soft stamp was fabricated from a 8-inch silicon master pattern having a line width of 150 nm, a line spacing of 250 nm, and a pitch of 400 nm through a PDMS replication process.

In addition, a polymer having the same nanopattern as the silicon master pattern while having a reverse shape of a pattern formed on the PDMS soft stamp on the surface of the PMMA film through a thermal nanoimprint lithography process using a PDMS soft stamp on a PMMA film substrate. (PMMA) films were produced.

The silicon thin film layer corresponding to the protective layer 300 was coated on the nanopattern of the polymer (PMMA) film through a sputtering process.

The silicon thin film layer was coated with a thickness of 5 nm.

Then, a copper seed layer was coated on the silicon thin film layer.

The seed layer was coated to a thickness of 50 nm.

Subsequently, a polymer (PMMA) film having a seed layer (50 nm), a protective layer (5 nm), and a PMMA nanopattern is placed in a nickel (Ni) plating bath, and electroplated to perform a first metal layer on the seed layer. A nickel metal layer corresponding to 500 was produced.

In addition, the nickel metal layer and the PMMA film were separated through a demolding process. Here, due to the difference in surface energy, the silicon thin film layer and the copper seed layer are turned over to the metal pattern surface of the nickel metal layer, where a part of the PMMA film is buried in the silicon thin film layer and remains as impurities.

In order to remove a part of the PMMA impurities, that is, the PMMA film on the silicon thin film layer, a nickel metal layer containing PMMA impurities was immersed in a bath containing a strong acid solution for 24 hours. Nanostrip solution was used as the strong acid solution.

3 is a photograph showing a metal layer manufactured by the method for manufacturing a metal layer having a nanopattern according to the first embodiment of the present invention. Here, FIG. 3A is a photograph before removing PMMA impurities with a strong acid solution, and FIG. 3B is photographs with PMMA impurities removed with a strong acid solution.

First, as shown in (a) of FIG. 3, PMMA impurities, that is, the remaining polymer 220 are buried in many regions of the nickel metal layer, that is, the protective layer 300 coated on the first metal layer 500. Able to know.

However, as shown in (b) of FIG. 3, after immersing in a strong acid solution for 24 hours, the remaining polymer 220 is removed so that the nanopatterns of the protective layer 300 and the first metal layer 500 appear cleanly. The diffraction of the light shows that the rainbow scattered light appears widely.

And, Figure 4 is a photograph showing a microscope image after the first separation step in the metal layer manufacturing method having a nanopattern according to the first embodiment of the present invention. 4A is an optical microscope image, and FIGS. 4B and 4C are electron microscope images. FIG. 4B is an electron microscope image of some points of FIG. 4A, and FIG. 4C is an enlarged image of some points of FIG. 4A 12.5 times.

First, as shown in (a) of FIG. 4, most of the first metal layer 500 that has undergone the first separation step (S140) and has not yet undergone the removal step (S150) is formed in the residual polymer 220 having a predetermined thickness. It can be seen that the first transfer pattern 510 is unevenly observed.

4B is an electron microscope image of a portion A of FIG. 4A, which is taken at a magnification of 10.0 kV and 10.3 mm × 400. Referring to FIG. 4B, the first transfer pattern 510 and the remaining polymer 220 of the first metal layer 500 are confirmed.

Part (A) was performed by spectroscopic analysis (EDS), and the results of analyzing the composition are shown in Table 1 below.

division weight% atom% C 38.82 70.79 O 6.28 8.6 Si 2.7 2.11 Ni 17.83 6.65 Cu 34.37 11.85 Totals 100 100

As shown in Table 1, in part (A), the copper constituting the seed layer was found to be 34.37% by weight and 11.85 atomic%, the nickel constituting the first metal layer was found to be 17.83% by weight and 6.65 atomic%, and the protective layer. The resulting silicon was found to be 2.70 wt% and 2.11 atomic%. And, carbon was found to be 38.82% by weight and 70.79 atomic%, which was found to be the remaining PMMA impurity obtained from the PMMA film.

FIG. 4C is an enlargement of a portion A of FIG. 4A at a magnification of 10.0 kV and 10.3 mm × 5,000. As shown in FIG. 4C, the first metal layer 500 is shown in FIG. It is confirmed that a part of the first transfer pattern 510 formed at the top surface is covered by the remaining polymer 220.

5 is a photograph showing a microscope image after the removal step in the metal layer manufacturing method having a nanopattern according to the first embodiment of the present invention. Here, FIG. 5A is an optical microscope image, and FIGS. 5B and 5C are electron microscope images. FIG. 5B is an electron microscope image of a portion of FIG. 5A, and FIG. 5C is an image of an enlarged 125 times of a portion of FIG. 5A.

First, as shown in (a) of FIG. 5, the remaining polymer 220 is removed from most of the first metal layers 500 that have undergone the removing step S150, so that the first transfer pattern 510 is uniformly observed. You can check it.

FIG. 5B is an electron microscope image of a portion B of FIG. 5A, taken at a magnification of 10.0 kV and 10.3 mm × 400. Referring to FIG. 5B, the first transfer pattern 510 of the first metal layer 500 and some residual polymer 220 are confirmed.

Part (B) was performed by spectroscopic analysis (EDS), the composition analysis results are shown in Table 2 below.

division weight% atom% C 6.12 20.55 O 7.89 19.9 Si 4.24 6.09 Ni 29.84 20.5 Cu 51.91 32.96 Totals 100 100

As shown in Table 2, in part (B), the copper constituting the seed layer was found to be 51.91 wt% and 32.96 atomic%, and the nickel constituting the first metal layer was found to be 29.84 wt% and 20.50 atomic%, and the protective layer. The resulting silicon was found to be 4.24 wt% and 6.09 atomic%.

Comparing the carbon content before and after the removal of the remaining polymer 220, the carbon decreased by 0.16 times from 38.82% to 6.12% by weight and decreased 0.29 times from 70.79% to 20.55% by atom.

Since carbon is a residual PMMA impurity obtained from the PMMA film, through this, it is confirmed that most of the PMMA residual impurity is dissolved by the strong acid through the removal step (S150).

On the other hand, when comparing the weight percent of the composition before and after the removal of the residual polymer 220, copper increased 1.51 times from 34.37% to 51.91% by weight, and nickel increased 1.67 times from 17.83% to 29.84% by weight. , Silicon increased 1.57 times from 2.70 wt% to 4.24 wt%. That is, copper, nickel and silicon increased relatively evenly in the range of 1.51 to 1.67 times.

And, when comparing the atomic% before and after the removal of the remaining polymer 220, copper increased 2.78 times from 11.85 atomic% to 32.96 atomic%, nickel increased 3.08 times from 6.65 atomic% to 20.50 atomic%, and silicon Silver increased 2.89 times from 2.11 atomic% to 6.09 atomic%. That is, copper, nickel and silicon increased relatively evenly in the range of 2.78 to 3.08 times.

Through this, it can be seen that not only the protective layer but also the seed layer and the first metal layer 500 are not corroded by the strong acid by the protective layer. That is, it can be assumed that the uppermost protective layer implements a protective function that prevents the first transfer pattern 510 from being corroded by the strong acid.

FIG. 5C is an enlargement of a portion B of FIG. 5A at a magnification of 10.0 kV and 10.3 mm × 50,000. As shown in FIG. 5C, the first metal layer 500 is shown in FIG. It is confirmed that the first transfer pattern 510 is formed uniformly and cleanly.

The first metal layer 500 may be wound around the circumferential surface of the roller and manufactured into a roller mold for a roll-to-roll process. Using this method, the roller mold can be easily manufactured, and a uniform and clean metal nanopattern implemented as the first transfer pattern can be provided on the circumferential surface of the roller mold.

6 is a flowchart illustrating a method of manufacturing a metal layer having a nanopattern according to a second embodiment of the present invention, and FIG. 7 is a process example showing a process according to a method of manufacturing a metal layer having a nanopattern according to a second embodiment of the present invention. It is also. In the present embodiment, a process step may be further added after the removing step, and the other configuration is the same as in the above-described first embodiment, and thus repeated content is omitted as much as possible.

6 and 7, the metal layer manufacturing method having the nanopattern includes a first coating step S110, a second coating step S120, a first metal layer forming step S130, and a first separation step S140. It may include a removing step (S150), a second metal layer forming step (S160) and a second separation step (S170).

Since the first coating step (S110), the second coating step (S120), the first metal layer forming step (S130), the first separation step (S140), and the removing step (S150) have been described above, a description thereof is omitted.

The second metal layer forming step S160 may include a second metal layer having a second transfer pattern 610 corresponding to the first transfer pattern 510 on the protective layer 300 through electroplating after the removing step S150. It may be a step of forming (600).

Electroplating made in the second metal layer forming step S160 may be performed in the same manner as the battery plating made in the first metal layer forming step S130.

In the present exemplary embodiment, the first transfer pattern 510 may be an inverted form of the target nano pattern to be finally obtained. That is, in the present exemplary embodiment, the silicon master pattern and the nanopattern 210 of the polymer layer 200 may be formed in the form of the target nanopattern, so that the second transfer pattern 610 may be generated in the form of the target nanopattern.

In addition, in the present embodiment, the protective layer 300 may be formed to have a first thickness, and the seed layer 400 may be formed to have a second thickness, wherein the second thickness is a thickness of the protective layer 300. It may be thicker than the first thickness.

Through this, when the electroplating in the second metal layer forming step (S160), even when the protective layer 300 is coated on the seed layer 400, the electroplating is possible on the upper portion of the protective layer 300. Can be.

The second separation step S170 may be a step of separating the second metal layer 600 from the protective layer 300. In the second separation step S170, the protective layer 300 and the second metal layer 600 may be separated through a release process.

Here, since both the protective layer 300 and the second metal layer 600 are made of a metal material, the surface of the second transfer pattern 610 formed on the second metal layer 600 after being released is clean and precise. It can have

The second metal layer 600 may be wound around the circumferential surface of the roller and manufactured into a roller mold for a roll-to-roll process. Using this method, a roller mold can be easily manufactured, and a uniform and clean metal nanopattern implemented as a second transfer pattern can be provided on the circumferential surface of the roller mold.

The above description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the invention is indicated by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the invention.

200: polymer layer
210: nanopattern
220: remaining polymer
300: protective layer
400: seed layer
500: first metal layer
510: first transfer pattern
600: second metal layer
610: second transfer pattern

Claims (8)

A first coating step of coating a protective layer on top of the nanopattern formed on the polymer layer;
A second coating step of coating a seed layer of a metal material for electroplating on top of the protective layer;
A first metal layer forming step of forming a first metal layer having a first transfer pattern corresponding to the nanopattern on the seed layer through electroplating;
A first separation step of separating the polymer layer from the first metal layer, the seed layer and the protective layer; And
Removing the remaining polymer remaining on the protective layer;
The protective layer is a metal layer manufacturing method having a nano-pattern, characterized in that for protecting the first metal layer to prevent damage to the first transfer pattern in the process of removing the remaining polymer. The method of claim 1,
The protective layer is a metal layer manufacturing method having a nano-pattern, characterized in that made of an inorganic material containing silicon (Si). The method of claim 1,
The polymer layer is a metal layer manufacturing method having a nano-pattern, characterized in that made of any one material of PMMA (polymethyl methacrylate), PC (polycarbonate), PET (polyethylene terephthalate). The method of claim 1,
The seed layer is a metal layer manufacturing method having a nano-pattern, characterized in that made of an electrically conductive material containing copper (Cu). The method of claim 1,
The first metal layer is a metal layer manufacturing method having a nano pattern, characterized in that made of nickel (Ni) or copper (Cu) material. The method of claim 1,
After the removal step,
A second metal layer forming step of forming a second metal layer having a second transfer pattern corresponding to the first transfer pattern on the protective layer through electroplating; And
And a second separation step of separating the second metal layer from the protective layer. The method of claim 6,
The protective layer is formed to a first thickness,
The seed layer has a nanopattern, characterized in that the seed layer is formed with a second thickness thicker than the first thickness so that the electroplating is possible on top of the protective layer even when the protective layer is coated on the seed layer. Metal layer manufacturing method. The method of claim 6,
The second metal layer is a metal layer manufacturing method having a nano pattern, characterized in that made of nickel (Ni) or copper (Cu) material.

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