KR20130099656A

KR20130099656A - Method of fabricating master mold for low reflection film and master mold for low reflection film using the same

Info

Publication number: KR20130099656A
Application number: KR1020120021332A
Authority: KR
Inventors: 박정호; 이종병; 신부건; 김태수; 김재진
Original assignee: 주식회사 엘지화학
Priority date: 2012-02-29
Filing date: 2012-02-29
Publication date: 2013-09-06

Abstract

The present invention relates to a method of manufacturing a master mold for a low reflection film, comprising the steps of: (a) preparing a substrate on which a hard mask layer is laminated; (b) patterning the hard mask layer using at least two nano imprint processes; And (c) patterning the substrate using the patterned hard mask layer.

Description

METHOD OF MANUFACTURING A MASTER MOLD FOR LOW REFLECTION FILM AND MASTER MOLD FOR LOW REFLECTION FILM USING THE MANUFACTURING METHOD

The present invention relates to a method for producing a low-reflection film master mold and a low-reflection film master mold using the manufacturing method, more specifically, to a low-reflection film master mold manufacturing method using two or more nano-imprint process and its production It relates to a master mold for low reflection film using the method.

Conventional image display devices such as liquid crystal displays (LCDs), plasma displays (PDPs), electroluminescent displays (ELDs), and cathode ray tube displays (CRTs) include external light sources such as outdoor sunlight or indoor lighting. The antireflective film is used to reflect the light and lower the original image visibility, and to minimize the deterioration of the visibility caused by the reflection.

In general, the antireflection film can be divided into single layer and multilayer antireflection film according to the number of layers of the antireflection film. The single layer antireflection film is generally called a low reflection film to distinguish it from the multilayer antireflection film.

The low reflection film (single layer antireflection film) is a structure in which a low refractive index layer is coated on a substrate, and in general, the low refractive layer has a destructive interference between light reflected at an interface between an air-low refractive layer and a low refractive layer-substrate. It is coated with a thickness of λ / 4 so as to cause a flat shape, but a flat shape may be used, but the flat shape has low antireflection characteristics and a narrow wavelength range exhibiting antireflection characteristics, so that the effective refractive index is changed to reduce the reflectance by external light. The film containing the dimension fine uneven | corrugated shape is used a lot.

On the other hand, as the image display device becomes larger, the surface of the low reflection film is also required, and in order to satisfy the demand, the surface of the master mold for the low reflection film for manufacturing the large reflection low reflection film is also required.

The most widely used method for large-area master mold for low reflection film is by using interference light lithography. According to this method, a two-beam interferometer is used to form a two-dimensional fine uneven shape. It is essential to pattern the two-dimensional line grating shape in two exposure processes. Using a three-beam interferometer can realize a two-dimensional nanowire grating shape in a single exposure process, but has a limitation in expanding the area where three beams overlap, which limits the pattern area. Here, the two-dimensional nano-linear lattice shape refers to a pattern formed by crossing the stripe-shaped first patterns arranged in a row with the stripe-shaped second patterns arranged in a row.

In addition, in the case of the exposure process, the height of the polymer photosensitive material pattern used as the etching mask is reduced, so that it is difficult to form a pattern having a sufficient step ratio with the photosensitive material pattern. Here, the step difference ratio of the pattern refers to the ratio of the height of the pattern to the line width of the pattern.

Specifically, in the case of forming a one-dimensional grid pattern (ie, a stripe pattern arranged in a row) by two-beam interference exposure, a reliable pattern having a high aspect ratio can be realized, whereas irradiation of two interference patterns is performed. In the case of the two-dimensional line grid pattern obtained by, the loss of aspect ratio occurs considerably, which means that the amount of light in the area where offset interference takes place should ideally be zero, but the actual amount of light has a certain amount of background intensity I ₀ . As a result, in the actual process, a small amount of exposure is carried out even in a portion where destructive interference occurs. That is, in the fabrication of the one-dimensional line grating pattern using interference exposure, the difference between the maximum light intensity I _max and the background intensity I ₀ can be given, but the substrate pattern is placed twice at a specific angle (for example, 90 ^o ). When exposing the interference pattern by exposing the two-dimensional line grid pattern, the background intensity I ₀ should be applied to the part where the light should not be irradiated _. Since the amount of light is irradiated further, after the development process, even though the area of the portion corresponding to the destructive interference is exposed by twice the background intensity I ₀ , the loss occurs in the aspect ratio of the pattern. . Therefore, efforts have been made to minimize the loss of the aspect ratio by precisely designing the optical system so that the difference between the maximum light intensity I _max and the background intensity I ₀ is large, but the pattern to be implemented is a step difference ratio in the nano pattern of 100 nm scale. Since there is a limit in establishing an interference exposure condition to minimize the loss of, there is a problem that a significant loss of the step difference ratio is inevitable.

In addition, due to the above-described loss of the step difference caused by the two interference exposure processes, process constraints are realized in implementing the two-dimensional line lattice pattern of the master mold into the shape of the micro-uneven nanostructure of the moth eye structure. As a result, the antireflection property of the finally produced low reflection film is reduced. Specifically, when the step difference ratio of the pattern is small, the underlying hard mask (Al) layer cannot be sufficiently patterned, so that the reliable nano eye irregular structure of the moth eye structure cannot be transferred to the quartz substrate, and the vertical direction of the substrate This is because there is a problem in that the antireflection property is poor because the shape in which the effective refractive index gradually changes can not be realized.

Therefore, production of a master mold for producing a large area of a low reflection film having a pattern having a high step ratio is required.

The present invention is to solve the above problems, to provide a low-reflection film master mold manufacturing method that can form a large nano-pattern having a high step ratio using at least two nanoimprint process.

In addition, the present invention is to provide a master mold for a large area low reflection film having a nano pattern of high step ratio.

To this end, the present invention comprises the steps of (a) preparing a substrate on which the hard mask layer is laminated; (b) patterning the hard mask layer using at least two nano imprint processes; (c) patterning the substrate using the patterned hard mask layer and (d) patterning the patterned substrate so as to have a low reflection shape with a structure in which an effective refractive index gradually changes in an upward direction of the substrate It provides a master mold manufacturing method for a low reflection film comprising a.

In another aspect, the present invention provides a low-reflection pattern layer having a structure in which the step difference ratio of the pattern is 0.5 to 5, the pitch of the pattern is 50 nm to 500 nm, and the effective refractive index gradually changes in the upper direction of the substrate. It provides, and provides a master mold for large area low reflection films of 11 cm x 11 cm or more.

According to the method of manufacturing a master mold for a low reflection film of the present invention, since the pattern of fine unevenness can be formed without undergoing an exposure process, the master mold for a low reflection film having a large area having a high step ratio nano pattern can be easily manufactured. can do.

Moreover, when the master mold for low reflection films of this invention is used, the low reflection film excellent in the reflection prevention function can be manufactured because the step difference ratio of a pattern is high.

1 is a flow chart schematically showing the flow of a method of manufacturing a master mold for a low reflection film according to an embodiment of the present invention.
FIG. 2 is a view sequentially showing a patterning process of a hard mask layer in a method of manufacturing a master mold for low reflection film according to an embodiment of the present invention.
3 is a view sequentially showing a manufacturing method of a master mold for a low reflection film according to an embodiment of the present invention.
4 is a view showing the structure of a master mold for a low reflection film according to an embodiment of the present invention.
5 to 10 is a view showing a pattern structure in each process step of the manufacturing process of the low-reflection film master mold according to the embodiment.
11 and 12 are views showing a pattern structure of a low reflection film manufactured by the master mold for low reflection film according to the embodiment.
FIG. 13 is a graph showing reflectance according to a wavelength of a film prepared according to Examples and Comparative Examples. FIG.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

However, the following drawings are made in order to better understand the present invention, but are only one embodiment of the present invention, and the present invention is not limited thereto. Also, in the following drawings, like reference numerals refer to like elements, and it is to be understood that elements shown in the drawings may be exaggerated, reduced or omitted for clarity.

1 is a flow chart illustrating a flow of a method of manufacturing a master mold for a low reflection film according to an embodiment of the present invention, and FIG. 2 illustrates the step (b) of hard mask layer patterning (S200). 3 is a flow chart, and FIG. 3 is a view sequentially showing a method of manufacturing a master mold for a low reflection film according to an embodiment of the present invention.

1 to 3, a method of manufacturing a master mold for a low reflection film according to the present invention, (a) a substrate preparing step (S100); (b) hard mask layer patterning step (S200); And (c) substrate patterning step S300 and (d) low reflection shape patterning step S400.

Specifically, the (a) preparing the substrate (S100) refers to preparing the substrate on which the hard mask layer is stacked (see FIG. 3 (a)), which is a high stage using a hard mask layer having a high etching selectivity. This is to form a difference pattern.

Here, the substrate 110 is preferably a material having excellent mechanical properties to minimize contamination and wear of the master mold due to the repeated replication process, for example, but is not limited to this, quartz, glass as a transparent material Or it may be made of plastic, it is preferable that made of quartz excellent in transmittance and excellent wear resistance mechanical properties of the wavelength range of the ultraviolet. This is to secure the transmittance during ultraviolet irradiation in inducing curing in the future using the ultraviolet curing resin when replicating the shape of the master pattern. However, when using a thermosetting resin, the master pattern does not need to be transparent, so the stainless steel (SUS) steel sheet having excellent mechanical properties, nickel (Ni), copper (Cu), magnesium (Mg), aluminum (Al), and chromium (Cr ), Tungsten (W), molybdenum (Mo), tantalum (Ta), silicon (Si), and the like, and metals, nonmetals, and metal oxides thereof may be used as substrates or the above materials may be deposited on a surface shape.

Meanwhile, the hard mask layer 120 is preferably made of a material having a high etching selectivity. For example, the hard mask layer 120 may be formed of aluminum (Al), chromium (Cr), or copper (copper). Cu), nickel (Ni), tantalum (Ta), iron (Fe), gold (Au), silver (Ag) or molybdenum (Mo).

Next, (b) hard mask layer patterning step (S200) refers to the step of patterning the hard mask layer 120 using at least two nanoimprint process (see Fig. 3 (b) to (i)), In the case of using two nanoimprint processes, the hard mask layer can be patterned into a two-dimensional nanowire lattice shape, and since the exposure layer is not subjected to the exposure process, the height of the resist layer is not reduced, thereby forming a pattern of a hard mask layer having a sufficient step ratio. To do this. In the conventional interference light lithography, the hard mask layer is patterned through two exposure processes, and the pattern of the photoresist layer used as an etch mask is reduced by more than half by one exposure process, resulting in a high step hard mask. The layer cannot be patterned. In contrast, the present invention does not reduce the height of the resist layer pattern even when the process is performed two or more times because the nanoimprint process is used.

On the other hand, when a two-dimensional linear lattice-shaped nanopattern is fabricated through two interference exposure processes, exposure is performed twice as much as background intensity I ₀ in the region corresponding to the destructive interference, thereby reducing the pattern length. Significant losses will occur in the difference.

In addition, due to the loss of the step difference ratio caused by the two interference exposures, process constraints are realized in implementing the two-dimensional line lattice shape of the master mold into the shape of the micro-uneven nanostructure of the moth eye structure. This results in a decrease in the antireflective properties of the finally produced low reflection film. Specifically, when the step difference ratio of the pattern is small, the underlying hard mask (Al) layer cannot be sufficiently patterned, so that the reliable nano eye irregular structure of the moth eye structure cannot be transferred to the quartz substrate, and the vertical direction of the substrate The antireflection property is poor because it is impossible to realize a shape in which the effective refractive index gradually changes.

Specifically, the (b) hard mask layer patterning step (S200) may include (b-1) forming a first resist layer 130 on the hard mask layer 120 (S210); (b-2) patterning the first resist layer 130 by imprinting the stamper 200 having the first patterns parallel to each other (S220); (b-3) patterning the hard mask layer 120 using the patterned first resist layer 130 (S230); (b-4) applying a second resist layer 140 on the hard mask layer 120 (S250); (b-5) patterning the second resist layer 140 by imprinting a stamper 300 having a second pattern intersecting the first pattern (S260); And (b-6) patterning the hard mask layer 120 using the patterned second resist layer 140 (S270).

In addition, the method may further include a step (S240) of removing the first resist layer 130 between the step (b-3) and the step (b-4), after the step (b-5). The method may further include removing the second resist layer 140 (S280).

Here, the step (b-1) is a step of forming a first resist layer on the hard mask layer (S210), wherein the first resist layer is made of a photocurable resin or a thermoplastic resin, which is a light of a later imprint process. In order to form a pattern by irradiation or heating (refer FIG. 3 (b)).

Next, the step (b-2) may be performed by patterning the first resist layer 130 by imprinting the stamper 200 having the first patterns parallel to each other on the first resist layer 130 ( S220), wherein the first pattern of the stamper is, for example, a linear grating pattern in which stripe shapes are formed in parallel to each other, and may be formed by a conventionally known technique such as dual beam interference lithography. In addition, the imprint process used in step (b-2) may be used in both the photo curing method and the thermal curing method (see Fig. 3 (c)).

Next, step (b-3) is a step (S230) of patterning the hard mask layer 120 using the patterned first resist layer 130, so that the hard mask layer has a first pattern parallel to each other. For patterning (see FIG. 3 (d)).

Next, after the step (b-3), the first resist layer 130 is removed (S240). This is to ensure that the second resist layer used in the second imprint process is uniformly applied (see FIG. 3 (e)).

Next, the step (b-4) is a step of applying the second resist layer 140 on the hard mask layer 120 (S250), the second resist layer is made of a thermoplastic resin, which is later This is for patterning by heating of the imprint process (see FIG. 3 (f)).

Next, the step (b-5) is a step of patterning the second resist layer 140 by imprinting the stamper 300 having the second pattern intersecting the first pattern (S260). The pattern is a pattern that crosses the first pattern with a slope, and more preferably, is a pattern orthogonal to the first pattern. In addition, the second pattern may be a linear lattice pattern in which stripe shapes are arranged in parallel with each other, similarly to the first pattern, as shown in FIG. 3 (g).

In addition, the step ratio between the first pattern and the second pattern may be the same, or the step ratio between the first pattern and the second pattern may be different. This is to adjust the step difference ratio between the first pattern and the second pattern so as to have a pattern having more various shapes.

Next, in step (b-6), the hard mask layer 120 is patterned by using the patterned second resist layer 140 (S270). Patterned to have two patterns, so that the hard mask layer is finally patterned to have a three-dimensional fine uneven pattern (see Fig. 3 (h)).

Next, the second resist layer 140 may be removed after the step (b-6) (S280) (see FIG. 3 (i)).

Meanwhile, the (c) substrate patterning step S300 refers to a step of patterning the substrate 110 using the hard mask layer 120 patterned in step (b). This is to easily form a pattern having a large step ratio by patterning a substrate using a hard mask layer having a high etching rate (see FIGS. 3 (j) and (k)).

On the other hand, the substrate has a two-dimensional line grid pattern through the step (c), wherein the pattern of the substrate has a step ratio of 0.5 to 5, 1 to 5, 3 to 5, 0.5 to 1.5, 1 to 2, It may be 1.5 to 2.5, 2 to 3, 2.5 to 3.5, 3 to 4, 3.5 to 4.5, 4 to 5. In addition, the pitch of the pattern may be 50 to 500 nm, 50 to 200 nm, 50 to 300 nm, 100 to 200 nm, 150 to 250 nm, 200 to 300 nm, 250 to 350 nm, 300 to 400 nm, 350 to 450 nm, 400 to 500 nm. The range of the step difference ratio and the pattern pitch described above is a factor in which the refractive index of the resin used in the production of the antireflective film, the shape of the structure, the mechanical properties of the gradient and the shape, etc. are taken into consideration in a complex manner. This value is derived considering the process margin for obtaining a gradual refractive index distribution at the refractive index of (n _D = 1.490) and the pattern pitch range is light at a short wavelength in order to have antireflection characteristics in the visible light region (400 to 700 nm). This is the value derived by (1/2) resolution (see FIG. 3 (k)).

Next, the (d) low reflection patterning step (S400) is to pattern the substrate 110 patterned in the step (c) to have a low reflection shape of the structure in which the effective refractive index gradually changes in the upper direction of the substrate The low reflection shape is not limited as long as the effective refractive index gradually changes in the upper direction of the substrate, but preferably has a moth eye shape in which the refractive index changes to an inclined shape. In addition, the spacing between the low reflection shapes is preferably limited to a size that does not scatter or diffract light in the visible region (see FIG. 3 (l)).

Meanwhile, the substrate patterned as described above may have a large area of 11 cm × 11 cm or more. This is because the nanoimprint process and the etching process are used only without using the interferometric light lithography process, so that the two-dimensional fine uneven shape can be easily patterned in a large area.

4 is a view showing the structure of a master mold for a low reflection film according to an embodiment of the present invention.

Referring to FIG. 4, the master mold 400 for a low reflection film according to the present invention includes a pattern layer 420 formed on a substrate 410.

The pattern layer 420 has a low reflection pattern having a structure in which the effective refractive index gradually changes in an upper direction of the substrate, and preferably has a moth eye pattern. Here, the moth eye shape is a shape in which the refractive index is changed to an inclined shape, and the interval between the low reflection shapes is preferably limited to a size that does not scatter light in the visible light region.

Specifically, the pitch of the pattern is preferably 50 nm to 500 nm, 50 to 200 nm, 50 to 300 nm, 100 to 200 nm, 150 to 250 nm, 200 to 300 nm, 250 to 350 nm, 300 to 400 nm, 350 to 450 nm, 400 to 500 nm. This is because the above-mentioned range is a range suitable for minimizing the deterioration of reflection characteristics in the visible light region by diffraction and scattering in a pattern having a uniform pitch. In addition, the pattern is preferably a step ratio of 0.5 to 5, 1 to 5, 3 to 5, 0.5 to 1.5, 1 to 2, 1.5 to 2.5, 2 to 3, 2.5 to 3.5, 3 to 4, 3.5 to 4.5, 4 to 5 may be. This is because the above-described step ratio and range of pattern pitch are factors that must consider the refractive index of resin used in the production of the anti-reflection film, the shape of the structure, and the mechanical properties of the gradient and the shape. This value is derived considering the process margin for obtaining a gradual refractive index distribution at the refractive index of (n _D = 1.490) and the pattern pitch range is light at a short wavelength in order to have antireflection characteristics in the visible light region (400 to 700 nm). It is derived from the resolution (l / 2) of.

On the other hand, the master mold 400 is preferably excellent in mechanical properties to minimize the contamination and wear of the master mold due to the repeated replication process, it may be made of quartz, glass or plastic, among the wavelength of the ultraviolet region It is preferable that it is made of quartz which is excellent in permeability and excellent in wear resistance and mechanical properties. This is to secure the transmittance during ultraviolet irradiation in inducing curing in the future using the ultraviolet curing resin when replicating the shape of the master pattern. However, when using a thermosetting resin, the master pattern does not need to be transparent, so the stainless steel (SUS) steel sheet having excellent mechanical properties, nickel (Ni), copper (Cu), magnesium (Mg), aluminum (Al), and chromium (Cr ), Tungsten (W), molybdenum (Mo), tantalum (Ta), silicon (Si), and the like, and metals, nonmetals, and metal oxides thereof may be used as substrates or the above materials may be deposited on a surface shape.

On the other hand, the low-reflection film master mold 400 according to the present invention is formed with a large area of 11 cm × 11 cm or more. This is because the large area is easily formed using two nanoimprint processes.

According to the master mold for low reflection films of this invention, the low reflection film excellent in the antireflection function can be manufactured with a large area.

Hereinafter, with reference to the Example, the manufacturing method of the master mold for low reflection films and the low reflection film manufactured using the master mold are demonstrated concretely. However, the present invention is not limited to the following examples.

On the other hand, Figures 5 to 10 is a view showing a pattern structure in each process step of the manufacturing process of the master mold for low reflection film according to the embodiment described below, Figure 11 and Figure 12 is a low reflection film according to the embodiment Since it is a view showing the pattern structure of the low reflection film produced by the master mold for reference, it will be referred to when describing the embodiment.

[Example]

Preparation of the board

A 20 nm thick layer of aluminum (Al) was deposited through vacuum sputtering on the cleaned 11 cm × 11 cm quartz substrate. This aluminum (Al) layer is used as an etching mask in the etching process of a quartz substrate.

Manufacture of Stamper for Nano Imprint

The original mold was prepared by irradiating a double beam interference light of a Nd: Yag laser having a 266 nm wavelength on a photosensitive resin layer coated on an 11 cm × 11 cm glass substrate to form a line lattice pattern having a pitch of 150 nm and a line width of 75 nm. .

An ultraviolet curable urethane acrylate resin was applied on a polycarbonate substrate having a size of 11 cm × 11 cm and a thickness of 180 μm to form an ultraviolet curable resin layer. By imprinting the prepared original mold on the ultraviolet curable resin layer, the pattern of the original mold was transferred to the ultraviolet curable resin layer. Subsequently, SiO ₂ having a thickness of 10 nm was deposited on the upper portion of the pattern transferred to the ultraviolet curable resin layer by sputtering, and the surface was replaced by solution treatment with an alkoxide-based silane compound. In order to separate the pattern transferred to the original mold and the UV curable resin layer, a fluorine-based or silicon compound layer having a low surface energy was introduced on the surface of the nano-pattern, and SiO ₂ on which an alkoxide-based silane compound was previously deposited. This is to increase the durability of the surface treatment by chemical reaction with -OH functional groups on the surface of the layer. After that, the pattern transferred to the original mold and the UV curable resin layer was separated to produce a nano imprint stamper. The pattern formed on the produced stamper was a line lattice pattern with a pitch of 150 nm and a line width of 75 nm.

Preparation of master mold for low reflection film

(1) First Nano Imprint Process

Nanoimprint resist was applied on the prepared substrate to form a first resist layer having a thickness of 100 nm. After contacting the stamper prepared in advance on the first resist layer and heated to a temperature of 160 ℃ for 15 minutes, and pressurized to a pressure of 40 bar (primary nanoimprint process) of the stamper to the first resist layer The pattern was transferred. Thereafter, the remaining layer of the first resist layer existing in the valley of the imprinted pattern was removed by a dry etching process using O ₂ gas, and the aluminum layer portion exposed by removing the remaining layer of the first resist layer was chlorine-based (Cl ₂ , BCl). ₃ ) The aluminum layer was patterned through a dry etching process using a gas. Thereafter, the resist layer was completely removed through a dry etching process using O ₂ gas. As a result, a line lattice pattern having a pitch of 150 nm and a line width of 75 nm was formed on the aluminum layer.

FIG. 5 illustrates an aluminum pattern formed after the first nanoimprint process. Referring to FIG. 5, it can be seen that the aluminum pattern of the one-dimensional wire lattice pattern is formed after the first nanoimprint process.

(2) Secondary Nano Imprint Process

After the first nanoimprint process was completed, a nanoimprint resist was applied on the substrate to form a second resist layer having a thickness of 100 nm, and contacted the stamper in a direction orthogonal to the direction of the grid pattern formed in the first nanoimprint process. After heating to 160 ° C. for 15 minutes and pressurizing to 40 bar (second nanoimprint process), the pattern of the stamper was transferred to the second resist layer. After that, the remaining layer of the second resist layer existing in the valley of the imprinted pattern was removed through a dry etching process using O ₂ gas, and the aluminum layer portion exposed by removing the remaining layer of the second resist layer was chlorine-based (Cl ₂ , BCl). ₃ ) The aluminum layer was patterned through a dry etching process using a gas. Thereafter, the resist layer was completely removed through a dry etching process using O ₂ gas. As a result, a square two-dimensional line lattice pattern having a pitch of 150 nm and a width and length of 75 nm was formed on the aluminum layer.

FIG. 6 is a view showing an aluminum pattern formed after the second nanoimprint process. Referring to FIG. 6, it can be seen that a two-dimensional grid pattern is formed after the second nanoimprint process.

(3) substrate patterning

CF ₄ using the patterned aluminum layer as an etching mask after the second imprint process The dry etching process using gas was formed on the surface of the quartz substrate having excellent mechanical properties, and a square two-dimensional line lattice pattern having a pitch of 150 nm and a width of 75 nm was formed on the surface of the quartz substrate. Compared with the aluminum pattern, which has a high etching rate, as the etching mask, the step ratio of the pattern was 3: 1.

FIG. 7 is a view of a pattern of a substrate formed by using an aluminum layer having a two-dimensional grid pattern as an etch mask, and FIG. 8 is a view of the pattern from the side. 7 and 8, it can be seen that a two-dimensional grid pattern having a high step ratio is formed on the substrate.

(3) production of moth eye shapes

The substrate patterned through the second imprint process was dry etched using CF ₄ gas to be patterned to have a moth eye shape, thereby manufacturing a master mold for a low reflection film.

The working pressure of the chamber during the dry etching process in steps (1) to (3) was 5 to 15 mtorr, and the electric field power was 300 W.

FIG. 9 is a view of a substrate on which a moth eye pattern is formed, and FIG. 10 is a view of a substrate on which a moth eye pattern is formed. 9 and 10, a substrate (ie, a master mold) having a Morse Eye shape having a high step ratio can be confirmed.

Preparation of Low Reflective Film

After the urethane acrylate resin for UV curing was applied to a 60 mm thickness on the low-reflection film master mold prepared by the above-described method, a base film based on PMMA was laminated. Thereafter, ultraviolet ray was transferred to transfer the pattern of the master mold, and then the base film on which the pattern was transferred was separated from the master mold. As a result, a low reflection film was engraved with a moth eye shape having a pitch of 150 nm, a height of 200 nm, and a step difference ratio of 1.2.

FIG. 11 is a view of the pattern structure of the low reflection film manufactured by the master mold for the low reflection film according to the embodiment, and FIG. 12 is a view of the pattern structure of the low reflection film viewed from a special perspective. 11 and 12, it can be seen that the low-reflection film engraved in the Morse Eye shape having a high step ratio.

Comparative example

A 1.78 mm thick PMMA (refractive index of 1.490) purchased from iComponent was used as the substrate.

Experimental Example

Films according to Examples and Comparative Examples were measured for reflectance according to a wavelength range of 350 to 800 nm using a Solidspec-3700 transmission-reflection spectrum measuring apparatus manufactured by Shimadzu. In order to obtain only the reflectivity of the surface on which the MOS eye pattern was formed, black tape was attached to the back side of the film to exclude reflections occurring at the back side of the film, that is, the PMMA substrate surface and the air layer interface. The measurement results are shown in FIG. 13.

Referring to FIG. 13, an excellent antireflection property of the film according to the example was significantly lower than the Fresnel reflection according to the refractive index difference of the film according to the comparative example to 0.5% or less in the entire wavelength range, and excellent anti-reflective property was observed.

110 substrate
120 Hard Mask Layer
130 first resist layer
140 second resist layer
200 Stamper with first pattern
300 Stamper with a second pattern
Master mold for 400 low reflection film
410 substrate
420 pattern layer

Claims

(a) preparing a substrate on which a hard mask layer is stacked;
(b) patterning the hard mask layer using at least two nano imprint processes; And
(c) patterning the substrate using the patterned hard mask layer and
(d) etching the patterned substrate and patterning the patterned substrate to have a low reflection shape having a structure in which an effective refractive index gradually changes in an upward direction of the substrate.

The method according to claim 1,
The low reflection shape formed in the step (d) is a moth eye shape (moth eye) master mold manufacturing method for a low reflection film.

The method of claim 1, wherein the step (b)
(b-1) forming a first resist layer on the hard mask layer;
(b-2) patterning the first resist layer by imprinting a stamper having a first pattern parallel to each other;
(b-3) patterning the hard mask layer using the patterned first resist layer;
(b-4) applying a second resist layer on the hard mask layer;
(b-5) patterning the second resist layer by imprinting a stamper having a second pattern intersecting the first pattern; And
(b-6) patterning the hard mask layer using the patterned second resist layer.

The method of claim 3, further comprising removing the first resist layer or the second resist layer between the step (b-3) and the step (b-4) and after the step (b-5). Master mold manufacturing method for low reflection film.

The method of claim 3, wherein the first pattern and the second pattern are orthogonal to each other.

The method of claim 3, wherein the first pattern and the second pattern intersect with an inclination.

The method of manufacturing a master mold for low reflection film according to claim 3, wherein the step ratio between the first pattern and the second pattern is the same.

The method of manufacturing a master mold for low reflection film according to claim 3, wherein the step ratio between the first pattern and the second pattern is different from each other.

The method of claim 1, wherein the hard mask layer is aluminum (Al), chromium (Cr), copper (Cu), nickel (Ni), tantalum (Ta), iron (Fe), gold (Au), silver (Ag) or A method for producing a master mold for low reflection film, consisting of one or more selected from the group consisting of molybdenum (Mo).

The method of claim 1, wherein the substrate is 11 cm x 11 cm or more of the large-area low-reflection film master mold manufacturing method.

The method of claim 1, wherein the substrate patterned in the step (c) is a method of manufacturing a master mold for low reflection film comprising a two-dimensional line lattice pattern of the pattern is 0.5 ~ 5, the pitch of the pattern is 50 ~ 500nm. .

Master mold for low reflection film prepared according to claim 1.

For a large-area low reflection film comprising a low reflection pattern layer having a structure having a step difference ratio of 0.5 to 5 and an effective refractive index gradually changing in the upper direction of the substrate having a pitch of 0.5 to 5 nm. Master mold.

The master mold for low reflection film according to claim 13, wherein the low reflection shape is a moth eye shape.

The low reflection film manufactured using the master mold for low reflection films of Claim 12 or 13.