WO2013015648A2

WO2013015648A2 - Method of manufacturing mold for nano imprint

Info

Publication number: WO2013015648A2
Application number: PCT/KR2012/006007
Authority: WO
Inventors: Kyoung Jong Yoo; Young Jae Lee; Jin Su Kim; Jun Lee
Original assignee: Lg Innotek Co., Ltd.
Priority date: 2011-07-28
Filing date: 2012-07-27
Publication date: 2013-01-31
Also published as: KR101775163B1; CN103842861B; TW201319636A; CN103842861A; WO2013015648A3; KR20130013502A

Abstract

Provided is a method of manufacturing a mold for nano imprint comprising: forming a plurality of grid patterns on a substrate; forming a metal grid pattern on the grid patterns; forming a plated layer on the metal grid pattern; and separating a mold consisting of the metal grid pattern and the plated layer from the grid pattern, which can reduce a production cost, improve the efficiency of a process, and provide the mold for nano having improved durability and reliability.

Description

METHOD OF MANUFACTURING MOLD FOR NANO IMPRINT

This application claims priority to Korean Patent Application No. 10-2011-0075191 , filed on July 28, 2011, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference.

The present invention relates to a technical field for manufacturing a mold for nano imprint.

A polarizer or a polarizing device means an optical device for drawing linearly polarized light having a specific vibration direction among non-polarized lights such as natural light. Generally, in a case where a cycle of metal line disposition is shorter than a half-wavelength of an incident electromagnetic wave, a polarized component (s wave) parallel to the metal line is reflected and a polarized component (p wave) vertical to the metal line is transmitted. When the phenomenon is used, a planar polarizer having excellent polarization efficiency, a high transmission rate and a wide view angle can be manufactured. This device is called a line grid polarizer or a wire grid polarizer.

A technology for manufacturing the aforesaid wire grid polarizer using a nano-imprinting process has been recently suggested. The nano-imprinting process is a technology for molding a nano-scale pattern in an imprint shape using a mold. This nano-imprinting process may form a grid pattern through a relatively simple process compared to a conventional photo-lithography process. Furthermore, in a case where the nano-imprinting process forms the grid pattern using a mold having a nano-scale width, a nano-scale grid pattern which cannot be implemented by the photo-lithograph process may be formed. Thus, it is advantageous that productivity is improved, and a production cost is reduced.

To form the grid pattern using the aforesaid nano-imprinting process, first of all, molds having a pattern in a desired shape should be manufactured. Among these molds, a mold manufactured using a silicon wafer or quartz has the high frequency of breakage during processing. Thus, to improve mechanical properties, a technology for manufacturing a nickel electroformed mold as disclosed in Korean Laid Open Patent Publication No. 10-2007-0072949 was suggested. FIG. 1 through FIG. 3 illustrate a process of manufacturing a mold using electroforming as disclosed in Korean Laid Open Patent Publication No. 10-2007-0072949. Referring to FIG. 1 through FIG. 3, as illustrated in FIG. 1, first of all, a grid pattern 13 is formed on a substrate 11 to manufacture a master mold. And then, a conductive seed layer 14 for electroforming is formed on the grid pattern 13. Since then, a metal layer 15 is formed on the conductive seed layer 14 using an electroforming process, thereby finally manufacturing a mold. However, the mold manufacturing method using the electroforming has the problems in that it would be difficult to form the conductive seed layer 14, and that a pore 16 is formed in an inner part of the mold during the electroforming process, thereby reducing mechanical properties and durability of the mold, and increasing the probability of breakage of the master mold during separating the manufactured mold from the grid pattern 13.

An aspect of the present invention provides a mold for nano imprint capable of reducing a production cost and improving the efficiency of a process and having improved durability and reliability, which resulted from the production of a mold implementing a fine pitch by forming a plurality of grid patterns on a substrate, forming a metal grid pattern on the grid patterns, forming a plated layer on the metal grid pattern, and separating the mold consisting of the metal grid pattern and the plated layer from the grid patterns.

According to an aspect of the present invention, there is provided a method of manufacturing a mold for nano imprint including: forming a plurality of grid patterns on a substrate; forming a metal grid pattern on the grid patterns; forming a plated layer on the metal grid pattern; and separating a mold consisting of the metal grid pattern and the plated layer from the grid patterns.

In the method of manufacturing the mold for nano imprint of the present invention, the forming of the grid patterns may include: coating the substrate with an ultraviolet curing resin to form a grid base layer; pressurizing the grid base layer using an imprint mold; and irradiating ultraviolet rays to the grid base layer to cure the grid base layer.

In the method of manufacturing the mold for nano imprint of the present invention, the forming of the grid patterns may include: coating the substrate with a heat curing resin to form a grid base layer; and pressurizing the grid base layer using the heated imprint mold to cure the grid base layer.

In the method of manufacturing the mold for nano imprint of the present invention, a width of the grid patterns may be formed in range of 20nm to 200nm.

In the method of manufacturing the mold for nano imprint of the present invention, the forming of the metal grid pattern may include depositing a metal material on the grid patterns to form a metal grid base layer, and wet-etching the metal grid base layer.

In the method of manufacturing the mold for nano imprint of the present invention, the metal material may be formed of Ni or a Ni alloy.

In the method of manufacturing the mold for nano imprint of the present invention, the metal material may be deposited on the grid patterns using at least one of a sputtering method, a chemical vapor deposition method, and an evaporation method.

In the method of manufacturing the mold for nano imprint of the present invention, the forming of the metal grid base layer may be performed by filling an entire space between the grid patterns or depositing the metal material on the grind patterns so that a predetermined space is provided.

In the method of manufacturing the mold for nano imprint of the present invention, the wet-etching process may etch the metal grid base layer formed between the grid patterns.

In the method of manufacturing the mold for nano imprint of the present invention, the wet-etching process may also etch a part of the metal grid base layer formed on the grid patterns.

In the method of manufacturing the mold for nano imprint of the present invention, a cross section of the metal grid pattern may have at least one shape of a polygon, a semicircle, and a semiellipse.

In the method of manufacturing the mold for nano imprint of the present invention, the forming of the plated layer may be performed by an eletroforming method.

In the method of manufacturing the mold for nano imprint of the present invention, the plated layer may be formed of the same materials as the metal grid pattern, for example, Ni or a Ni alloy.

According to exemplary embodiments of the present invention, the mold formed of the metal material having a fin pitch of less than 200 nm may be manufactured. In particular, the mold formed of Ni may be manufactured. Thus, it is advantageous that the mold for nano imprint having improved durability and reliability can be provided.

Furthermore, according to exemplary embodiments of the present invention, the mold for nano imprint having improved durability and reliability can be manufactured using the simple electroforming process. Thus, it is advantageous that as no separate complex process is performed, the efficiency of a manufacturing process is improved, and a product cost for the mold is reduced.

The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the drawings:

FIG. 1 through FIG. 3 are manufacturing process views briefly showing a method of manufacturing a mold according to a conventional art.

FIG. 4 is a flow chart showing a method of manufacturing a mold for nano imprint according to an exemplary embodiment of the present invention.

FIG. 5 through FIG. 12 are manufacturing process views showing a method of manufacturing a mold for nano imprint according to another exemplary embodiment of the present invention.

Exemplary embodiments according to the present invention will now be described more fully hereinafter with reference to the accompanying drawings so that the present invention can be easily practiced by those having ordinary skill in the art to which the present invention pertains. The exemplary embodiments described herein and the elements illustrated in the drawings are only one preferred exemplary embodiment of the present invention. It should be understood that there may be various equivalents and modifications which may be replaced with these embodiments and elements at the time of the filing of this application. Furthermore, regarding explaining in detail operation principles for the preferred exemplary embodiments, when it is considered that the detailed explanation about publicly known functions or elements may unnecessarily cloud the gist of the present invention, the detailed explanation is omitted. Terms which will be described later are terms defined under consideration of functions of the present invention. The meaning of each term should be interpreted based on the contents described throughout this specification. Throughout all drawings, the constitutive elements that perform similar functions and operations to each other refer to the same reference numerals.

Referring to FIG. 4, a method of manufacturing a mold for nano imprint according to the present exemplary embodiment of the invention may include: forming grid patterns on a substrate (S1); forming a metal grid pattern on the grid patterns (S3); forming a plated layer on the metal grid pattern (S5); and separating a mold consisting of the metal grid pattern and the plated layer from the grid patterns (S7).

The substrate used in the S1 step may composed of a transparent substrate. As for a material thereof, plastic and sapphire formed of various polymers such as glass, quartz, acrylic, PC, PET and the like may be used. In addition to this, various materials may be used. Meanwhile, the grid patterns are a concept including a protruding pattern and a groove formed between each protruding pattern, and a cycle means a distance between one grid pattern and an adjacent grid pattern. A process of forming a plurality of grid patterns will be hereinafter explained.

The process of forming the grid patterns may be performed by a nano-imprinting process. That is, a substrate is coated with a polymer resin to form a grid base layer.

Here, the coating with the polymer resin may be performed using one of a spin coating method, a die coating method, a roll coating method, a dip coating method, a cast method, a screen printing method, a transfer printing method and the like. More preferably, the coating may be performed by one of, but not limited to, the spin coating method, the die coating method, the roll coating method.

Meanwhile, as for a polymer resin, an ultraviolet curing resin or a heat curing resin may be used. For example, when the ultraviolet curing resin is used, after a grid base layer is formed, an imprint mold having a plurality of grooves and protruding parts is aligned on an upper part of the grid base layer. Here, the plurality of grooves and protruding parts of the imprint mold have a shape formed by being repeated in a shape in which they are spaced apart from each other at fixed interval. Furthermore, the grooves of the imprint mold correspond to a position for forming the grid patterns.

Since then, after pressurizing the grooves of the imprint mold and the grid base layer so that they come into contact with each other, photo curing is performed by irradiating ultraviolet rays. Thus, on an upper part of the substrate, the plurality of grid patterns are formed in a part corresponding to the grooves of the imprint mold. At this time, a width W of the grooves may range from 20nm to 200nm, but which is not limited to this. This is intended to form a width of the grid patterns formed in the part corresponding to the grooves in a range from 20nm to 200nm. However, this is only one example, and a width of the grooves of the imprint mold and a width of the grid patterns may be naturally selected in consideration of a width of the mold for nano imprint which will be formed later.

Meanwhile, the aforesaid exemplary embodiment shows the case in which the polymer resin that forms the grid base layer is the ultraviolet curing resin, but the heat curing resin may be also used. Thus, the grid patterns of the present invention may be formed in such a manner that heat-curing is performed by pressurizing the grid base layer using a heated imprint mold.

After the grid patterns are formed, the metal grid pattern is formed on the grid patterns (S3).

Here, the metal grid pattern is defined as the common name including a pattern formed on the upper part of the grid patterns. The forming of the metal grid pattern of the present invention may be performed as follow. First of all, the metal grid base layer is formed by depositing a metal material on the grid patterns using all deposition methods such as a sputtering method, a chemical vapor deposition method, an evaporation method and the like which have been currently developed and commercialized or can implemented according to the future development of technologies. At this time, the deposited metal material may include at least one of Ni, Al, Au, Ag, Cr, Cu or their alloys which have conductivity. It would be preferable that Ni or a Ni alloy is used. This is intended to improve the durability and release properties of a mold for nano imprint which will be formed later.

The metal grid pattern may be formed by forming the metal grid base layer, and then performing an etching process to etch a separation space between the grid patterns. Here, an etched part may be the separation space between the grid patterns, and as needed, a part of the metal grid base layer formed on the grid patterns may be also etched. Meanwhile, as for the aforesaid etching process, a wet etching process may be used. At this time, a width and a thickness of the metal grid pattern may be adjusted by adjusting wet etching times. The metal grid pattern of the present invention formed according to this may have a structure in which a fine protruding pattern is arranged at a fixed cycle.

Meanwhile, a shape of the cross-section of the metal grid pattern may be formed in various structures such as a quadrangle, a triangle, a semicircle, and the like. The shape may be also formed in a triangle, a quadrangle, a sine wave and the like. That is, the metal grid pattern may be formed in a shape having a fixed cycle in one side direction regardless of the structures of the cross-section.

After the metal grid pattern is formed, the plated layer is formed on the metal grid pattern (S5). The forming of the plated layer is performed using an electroforming method. Furthermore, as for an electroformed material, the same materials as the aforesaid metal grid pattern may be used. In particular, Ni or a Ni alloy may be used.

In a case of performing electroforming using Ni, since a distance between each metal grid pattern is narrow, growth of the Ni in a horizontal direction is limited, and the Ni grows in a vertical direction. Furthermore, the growth is performed in a radial shape. Thus, when the Ni finally grows up to a fixed height, the plated layer formed on the metal grid pattern are connected to each other. Accordingly, a mold having a structure in which the metal grid pattern is formed in a lower part of the plated layer may be finally obtained.

After the plated layer is formed, the mold having the aforesaid plated layer and metal grid pattern is separated from the substrate and the grid patterns (S7), thereby being capable obtaining the mold for nano imprint.

The mold for nano imprint of the present invention manufactured by the aforesaid method may be implemented in a fine pitch of less than 200nm. In particular, in a case of manufacturing the mold for nano imprint using Ni, it is advantageous that durability and reliability are improved.

Moreover, according to the improvement of release properties of the mod for nano imprint, the possibility of breakage of the master mold (the substrate and the grid patterns) which can be generated during the separating process may be reduced. Thus, the grid patterns formed on the substrate that forms during a manufacturing process may be reutilized during the manufacturing process of the mold for nano imprint, thereby additional achieving an economical advantage such as the larger reduction in production costs.

Furthermore, according to the present invention, the mold for nano imprint having improved durability may be manufactured using the simple electroforming method, so it is provided with the effect that as no separate complex process is performed, efficiency of the manufacturing process is improved, and a production cost is reduced.

FIG. 5 through FIG. 12 are manufacturing process views showing a method of manufacturing a mold for nano imprint according to an exemplary embodiment of the present invention.

Referring FIG. 4 through FIG. 12, as illustrated in FIG. 5, a substrate 110 is coated with a polymer resin to form a grid base layer 130.

Since then, as illustrated in FIG. 6, an imprint mold 210 is arranged on an upper part of the grid base layer 130. Here, as earlier described in the explanation of FIG. 4, the imprint mold 210 have a plurality of protruding parts 211 arranged at fixed intervals and a plurality of grooves formed between each protruding part. Here, a width of the groove may range from 20nm to 200nm, but which is not limited to this as earlier described in the explanation of FIG. 4.

Furthermore, the grid patterns 131 may be formed by pressurizing the upper part of the grid base layer 130 using the imprint mold 210, as illustrated in FIG. 7, and thereafter, separating the imprint mold 210 from the grid base layer, as illustrated in FIG. 8. At this time, after pressurizing the grid base layer 130 using the imprint mold 310 and before separating the imprint mold from it, a heat curing process is performed when a material which forms the grid base layer 130 is a heat curing resin, and a photo curing process is performed by irradiating ultraviolet rays when the material is an ultraviolet curing resin.

A metal grid base layer 140 is formed by forming the grid pattern, and thereafter depositing a metal material on the grid patterns 131 as illustrated in FIG. 9. At this time, the metal grid base layer 140 may be formed so that as illustration in FIG. 9, a space between each grid pattern 131 is all filled, or non-illustrated in the drawings, but the metal grid base may have a fixed space formed between each grid pattern 131. As the fixed space is provided between each grid pattern 131, etching the metal grid base layer 140 during the wet etching process which will be processed later may be smoothly performed.

Here, the metal material deposited on the grid patterns 131 may be deposited using all deposition methods such as the sputtering method, the chemical vapor deposition method, the evaporation method and the like, which have been currently developed and commercialized or can implemented according to the future development of technologies. Furthermore, the metal material may include at least one of Ni, Al, Au, Ag, Cr, Cu and their alloys which have conductivity. As earlier described in the explanation of FIG. 4, it would be preferable that Ni or a Ni alloy is used.

As illustrated in FIG. 10, a metal grid pattern 150 may be formed by forming the metal grid base layer (140), and then etching the space A between each grid pattern 131 using the dry etching process. At this time, as earlier described in the explanation of FIG. 4, a width and a thickness of the metal grid pattern 150 may be adjusted by adjusting the dry etching times.

After the metal grid pattern 150 is formed, a plated layer 170 is formed on the metal grid pattern 150. At this time, as for a material used for forming the plated layer, the same materials as a material that forms the metal grid pattern 150 may be used. In particular, as earlier described in the explanation of FIG. 4, Ni or a Ni alloy may be used. During performing the electroforming, since a distance between each metal grid pattern 150 is narrow, growth of the plated layer in a horizontal direction is limited, and the plated layer grows in a vertical direction. Furthermore, the growth is performed in a radial shape. When the plated layer grows up to a fixed height, as illustrated in FIG. 11, the plated layer 170 with a shape in which the plated layer is connected onto the metal grid pattern 150 may be formed. Thus, a mold 300 with a structure in which the metal grid pattern 150 is formed in a lower part of the plated layer 170 may be finally obtained, which is previously described in the explanation of FIG. 4.

When forming the mold 300 on the grid patterns 131, and thereafter the separating the mold from the substrate 110 and the grid patterns 131, the mold for nano imprint 300 as illustrated in FIG. 12 may be obtained.

As previously described, in the detailed description of the invention, having described the detailed exemplary embodiments of the invention, it should be apparent that modifications and variations can be made by persons skilled without deviating from the spirit or scope of the invention. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims and their equivalents.

Claims

A method of manufacturing a mold for nano imprint comprising:

forming a plurality of grid patterns on a substrate;

forming a metal grid pattern on the grid patterns;

forming a plated layer on the metal grid pattern; and

separating a mold consisting of the metal grid pattern and the plated layer from the grid pattern.
The method of claim 1, wherein the forming of the grid patterns includes: coating the substrate with an ultraviolet curing resin to thereby form a grid base layer; pressurizing the grid base layer using an imprint mold; and irradiating ultraviolet rays to the grid base layer to thereby cure the grid base layer.
The method of claim 1, wherein the forming of the grid patterns includes: coating the substrate with a heat curing resin to thereby form the grid base layer; and pressurizing the grid base layer using a heated imprint mold to thereby cure the grid base layer.
The method of claim 1, wherein a width of the grid patterns ranges from 20nm to 200nm.
The method of claim 1, wherein the forming of the metal grid pattern includes: depositing a metal material on the grid patterns to thereby form a metal grid base layer; and wet-etching the metal grid base layer.
The method of claim 5, wherein the metal material is composed of Ni or a Ni alloy.
The method of claim 5, wherein the metal material is deposited on the grid patterns using at least one of a sputtering method, a chemical vapor deposition method, and an evaporation method.
The method of claim 5, wherein the forming of the metal grid base layer is performed by filling an entire space between the grid patterns or depositing the metal material on the grid patterns so that a predetermined space is provided.
The method of claim 5, wherein the wet etching process is performed by etching the metal grid base layer formed between the grid patterns.
The method of claim 9, wherein the wet etching process is performed by etching a part of the metal grid base layer formed on the grid patterns.
The method of claim 1, wherein a cross-section of the metal grid pattern has at least one shape of a polygon, a semicircle and a semiellipse.
The method of claim 1, wherein the forming of the plated layer is performed by an electroforming method.
The method of claim 1, wherein the plated layer is formed of the same materials as the metal grid pattern.
The method of claim 1, wherein the plated layer is formed of Ni or a Ni alloy.