KR20180135272A - Antireflective lens fabricating method having nanohole structures of enhanced mechanical stability - Google Patents

Abstract

The present invention relates to a manufacturing method for a nonreflecting lens including a nanohole structure. According to the present invention, the manufacturing method for a nonreflecting lens includes: a step of preparing a glass substrate having a curved surface or a flat surface; a step of forming a coating layer and a metal layer on the glass substrate in order; a step of forming a metal mask pattern having a nanohole structure smaller than optical wavelength on the coating layer by a dewetting phenomenon due to a surface energy difference between the coating layer and the metal layer by performing heat treatment on the metal layer at a temperature equal to or less than the melting point of the metal forming the metal layer; a step of forming the nanohole structure having the nanohole structure smaller than the optical wavelength by performing an anisotropic etching process on the coating layer by using the metal mask pattern as an etching mask; and a step of removing the metal mask pattern.

Description

TECHNICAL FIELD [0001] The present invention relates to an antireflective lens fabricating method using a nano-hole structure having enhanced mechanical strength,

The present invention relates to a method of manufacturing an anti-reflection lens having a nano-hole structure with increased mechanical strength, and more particularly, to a method of manufacturing an anti-reflection lens having a nano- And more particularly, to a method of manufacturing an anti-reflection lens which can be used for an anti-reflection lens.

Antireflection coating is a commonly used method to reduce reflection of light. It is a method of reducing reflection by depositing a material having a lower refractive index than a substrate such as a dielectric material or a polymer material on the substrate.

This anti-reflective coating has the advantage of providing the minimum reflection characteristic at a specific wavelength band by appropriately adjusting the refractive index and the optical thickness (Optical Thickness). However, it is difficult to find an appropriate material that is limited by the coating material corresponding to various substrate types , It is difficult to consider the electrical and thermal characteristics, and it is difficult to reduce the reflection in a wide spectrum, and there is a disadvantage that the reflectance varies greatly depending on the incident angle of light.

Surface texturing, which is used to reduce light reflections, is a method of reducing the reflection of light on the substrate surface by creating a regular or irregular structure or curvature on a substrate by physical etching or chemical etching.

Physical etching methods used for such surface texturing include, for example, plasma etching, photolithography, and mechanical scribing. These methods have advantages of obtaining low reflectance, but they are suitable for commercial use because of the complicated process, long process time, difficulty in mass production, and disadvantages such as requiring expensive vacuum equipment and additional equipment It has limitations. In addition, it has a problem that it is difficult to apply it to a substrate which can not be etched or is difficult to etch.

Korean Patent Publication No. 10-2014-0084860 (Jul.

Accordingly, an object of the present invention is to provide a method of manufacturing an anti-reflection lens having a nano-hole structure in which the mechanical strength is increased, which can overcome the above-mentioned problems of the related art.

It is another object of the present invention to provide a method of manufacturing an anti-reflection lens having a nano-hole structure capable of realizing an anti-reflection structure having increased mechanical strength in a glass substrate which is difficult to etch.

According to an embodiment of the present invention, there is provided a method of manufacturing an anti-reflection lens according to the present invention, comprising: preparing a glass substrate having a curved surface or a flat surface; Sequentially forming a coating layer and a metal layer on the glass substrate; A heat treatment is performed on the metal layer at a temperature equal to or lower than a melting point of the metal constituting the metal layer so that a dewetting phenomenon corresponding to a difference in surface energy between the coating layer and the metal layer Forming a metal mask pattern having a nano-hole structure of a size; Forming a nano-hole structure having a nano-hole structure smaller than a light wavelength on the glass substrate by performing an anisotropic etching process on the coating layer using the metal mask pattern as an etching mask; And removing the metal mask pattern.

The glass substrate may be an optical glass having at least one material selected from a crown series, a borosilicate series, and a flint series.

The coating layer may be formed of at least one material selected from OXIDE, NITRIDE, PHOTORESIST, and POLYMER by at least one of chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma chemical vapor deposition (PECVD) May be formed using a deposition method.

Wherein the metal layer is made of at least one metal selected from the group consisting of gold, silver, platinum, aluminum, copper, palladium, nickel, zinc, iron, tin, bronze and brass, Electron beam evaporation, electron beam evaporation, sputtering, and spin coating.

The coating layer may be deposited to a thickness of 10 to 500 nm, and the metal layer may be deposited to a thickness of 15 to 100 nm.

The size of the nano-holes constituting the nano-hole structure can be controlled by controlling the thickness of the metal layer or adjusting the temperature of the heat treatment.

According to the present invention, it is possible to reduce the reflectance of the lens by a nano-hole structure having a size (width or period) smaller than the wavelength of light and to increase the transmittance and to manufacture a lens with high efficiency with high mechanical strength by anti- It is possible. Also, since the lens can be manufactured easily, it is possible to mass-produce the lens.

FIG. 1 is a cross-sectional view illustrating a process of manufacturing an anti-reflection lens having a nano-hole structure according to an embodiment of the present invention,
Fig. 2 shows the structure of a metal mask pattern formed in the process of Fig. 1,
3 is a graph comparing the mechanical strengths of the nanopore structure and the nanopillar structure,
FIG. 4 is a plan view and a side view of an anti-reflection lens having a nano-hole structure formed by FIG. 1,
5 is a graph showing an improvement in transmittance of an anti-reflection lens having a nano-hole structure according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings without intending to intend to provide a thorough understanding of the present invention to a person having ordinary skill in the art to which the present invention belongs.

FIG. 1 is a process sectional view showing a process of manufacturing an anti-reflection lens having a nanohole structure according to an embodiment of the present invention in a process order.

Hereinafter, a process for fabricating an anti-reflection lens having a nano-hole structure according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1 (a), in order to manufacture an anti-reflection lens having a nano-hole structure according to an embodiment of the present invention, a glass substrate 110 is first prepared.

The glass substrate 110 may have a curved surface or a flat surface and may be an optical glass having at least one material selected from a crown series, a borosilicate series, and a flint series. More specifically, it may be composed of at least one compound of SiO _x , Ba _x O _y , Ta _x O _y , and Ti _x O _y , and may include materials which are generally difficult or impossible to etch.

Next, a coating layer 120 and a metal layer 130 are sequentially formed on the glass substrate 110, as shown in FIGS. 1 (b) and 1 (c).

The coating layer 120 may be formed by depositing at least one material selected from OXIDE, NITRIDE, PHOTORESIST, and POLYMER. The coating layer 120 may be formed using at least one deposition method selected from chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma enhanced chemical vapor deposition (PECVD), and spin coating. Since the coating layer 120 is a portion where the nano-hole structure is formed through a subsequent process, the coating layer 120 may have various thicknesses, and may be formed to a thickness of 10 to 500 nm.

The metal layer 130 may be made of at least one metal selected from the group consisting of gold, silver, platinum, aluminum, copper, palladium, nickel, zinc, iron, tin, bronze and brass or an alloy including these metals. The metal layer 130 may be deposited to a thickness of 15 to 100 nm using at least one deposition method selected from thermal deposition, electron beam deposition, sputtering, and spin coating.

The thickness of the metal layer 130 may be appropriately adjusted as necessary for a subsequent process of forming the nano-hole structure 125 using the coating layer 120.

1 (d), the metal layer 130 is heat-treated at a temperature lower than the melting point of the metal constituting the metal layer 130, A metal mask pattern 135 having a nano-hole structure of small size (width or period) is formed.

The heat treatment may be a RTA (Rapid Thermal Annealing) method or an oven or a hot plate. In addition, a laser or an electromagnetic wave irradiation method may be used. The heat treatment may be performed at a temperature within a range of approximately 100 to 1300 ° C, and a temperature below the melting point of the metal constituting the metal layer 130 is suitably selected.

The metal layer 130 is subjected to a heat treatment to cause a dewetting phenomenon in accordance with a difference in surface energy between the coating layer 120 and the metal layer 130, So that it is deformed into particles. Accordingly, a metal mask pattern 135 having a nano-hole structure made of nano-sized metal particles is formed.

The metal mask pattern 135 of the nano-hole structure is shown in Fig.

The size and shape of the metal particles constituting the metal mask pattern 135 may be varied depending on the material of the coating layer 120. The thickness of the metal layer 130 and the temperature of the heat treatment The size and shape of the nano-holes may vary.

Next, as shown in FIG. 1E, anisotropic dry etching is performed on the coating layer 120 using the metal mask pattern 135 as an etching mask to form a nano-hole structure having a nano-hole structure 125 are formed. The etching process is performed only on the coating layer 120. The glass substrate 110 functions as an etch stop film because the material is difficult or impossible to etch.

The anisotropic dry etching may be performed by, for example, plasma dry etching, reactive ion etching (RIE) etching or inductively coupled plasma (ICP) etching in which plasma is generated by RF power . In addition, it is possible to control at least one of gas type, gas composition ratio, gas atmosphere, temperature, pressure, driving voltage and time to control the etching rate during the dry etching. By controlling the nano structure, It is possible to easily obtain the desired size and aspect ratio of the image.

When the dry etching is performed, a nano-hole structure 125 having a nanoholes structure having a size (width or period) smaller than the light wavelength is formed.

The size (width or cycle) of the nano-holes constituting the nano-hole structure 125 may be controlled by adjusting the thickness of the metal layer 130 or adjusting the nano-hole size of the metal mask pattern 135 by controlling the temperature of the heat- Can be adjusted.

In the present invention, a nano-hole structure 125 having a nano-hole structure is formed using the coating layer 120. In the case of forming the nanostructure on the glass substrate 110 for the anti-reflection effect, if it is not supported by the mechanical strength, the nanostructure is easily damaged when it is used, resulting in a durability problem. In order to improve the durability and the mechanical strength, the nanostructure of the present invention has a nano-hole structure.

Since the nanohole structure is superior in mechanical strength to a nanopillar structure, when a lens is formed using a glass substrate which is difficult or impossible to etch, the nano-hole structure 125 having anti- When formed on the surface of the substrate, it is advantageous in that it can manufacture a lens having a long life and excellent durability because of its excellent mechanical strength.

3 is a graph comparing the hardness of the nano-hole structure and the nanopillar structure.

As shown in FIG. 3, it can be seen that the nanohole structure is 2.5 times harder than the nanopillar structure, although it is weaker than the strength of a bare glass having no nanostructure . Accordingly, when the nano-hole structure 125 is formed on the surface of the glass substrate, it is possible to manufacture an anti-reflection lens having excellent mechanical strength.

After the formation of the nano-hole structure 125, as shown in FIG. 1F, the metal mask pattern 135 is removed through isotropic wet etching to complete the non-reflective lens having the nano-hole structure 125 .

4A and 4B are a plan view and a side view of an anti-reflection lens having the nano-hole structure 125. FIG. 4A is a plan view of an anti-reflection lens having a nano-hole structure 125 formed using a metal mask pattern And Fig. 4 (b) is a side view (b).

4, when the nanoholes structure 125 is formed on the surface of the glass substrate 110, the nanostructure 125 acts as an effective refractive index layer, So that the transmittance is improved. As a result, it is possible to process at a relatively low cost compared with the non-reflective coating, to have improved mechanical properties and durability, and to use various materials.

5 is a graph showing the transmittance improvement of an anti-reflection lens having the nano structure 125 of the present invention.

As shown in FIG. 5, the transmittance of the non-reflective lens (a) having the nano-hole structure 125 of the present invention is improved as compared with the TAF lens (b) having no nano-hole structure.

3 and 5, the non-reflective lens having the nano-hole structure according to the present invention has excellent mechanical strength, can increase the transmittance, and has excellent resistance to external scratches Able to know.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to reduce the reflectance of the lens by a nano-hole structure having a size (width or period) smaller than the wavelength of light and to increase the transmittance, This is possible. Also, since the lens can be manufactured easily, it is possible to mass-produce the lens.

The foregoing description of the embodiments is merely illustrative of the present invention with reference to the drawings for a more thorough understanding of the present invention, and thus should not be construed as limiting the present invention. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the basic principles of the present invention.

110; Glass substrate 120: coating layer
130: metal layer 125: nano-hole structure
135: Metal mask pattern

Claims (6)

Preparing a glass substrate having a curved surface or a flat surface;
Sequentially forming a coating layer and a metal layer on the glass substrate;
A heat treatment is performed on the metal layer at a temperature equal to or lower than a melting point of the metal constituting the metal layer so that a dewetting phenomenon corresponding to a difference in surface energy between the coating layer and the metal layer Forming a metal mask pattern having a nano-hole structure of a size;
Forming a nano-hole structure having a nano-hole structure smaller than a light wavelength on the glass substrate by performing an anisotropic etching process on the coating layer using the metal mask pattern as an etching mask;
And removing the metal mask pattern from the metal mask pattern. The method according to claim 1,
Wherein the glass substrate is an optical glass having at least one material selected from the group consisting of a crown series, a borosilicate series, and a flint series. The method according to claim 1,
The coating layer may be formed of at least one material selected from OXIDE, NITRIDE, PHOTORESIST, and POLYMER by at least one of chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma chemical vapor deposition (PECVD) Wherein the first electrode is formed using a deposition method. The method according to claim 1,
Wherein the metal layer is made of at least one metal selected from gold, silver, platinum, aluminum, copper, palladium, nickel, zinc, iron, tin, bronze, and brass,
Wherein the metal layer is formed using at least one deposition method selected from thermal deposition, electron beam deposition, sputtering, and spin coating. The method according to claim 1,
Wherein the coating layer is deposited to a thickness of 10 to 500 nm, and the metal layer is deposited to a thickness of 15 to 100 nm. The method of claim 5,
Wherein the size of the nano-holes constituting the nano-hole structure is controlled by controlling the thickness of the metal layer or adjusting the temperature of the heat treatment.

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