KR20200029976A - Transparent electrode - Google Patents

Abstract

The present invention provides a transparent electrode comprising: a seed layer provided on a substrate; a resistance control layer disposed on the seed layer; and an optical control layer disposed on the resistance control layer. The seed layer comprises: a first surface; and a second surface opposite to the first surface to face the resistance control layer. The surface roughness of the second surface may be greater than that of the first surface.

Description

Transparent electrode {TRANSPARENT ELECTRODE}

The present invention relates to a transparent electrode.

The transparent electrode is formed of a material having both electrical conductivity and light transmittance. As the high-tech information technology industry and the new and renewable energy industry are rising rapidly, interest in transparent electrode materials is increasing. In particular, as the industry in the field of using transparent electrodes such as flat panel displays and solar cells develops, a transparent electrode material that is thin, has high transmittance, and has excellent electrical conductivity is required.

The transparent electrode material is typically a transparent conductive oxide (TCO) manufactured in a thin film form. Depending on the size of the sheet resistance, TCO is used as a functional thin film, such as an antistatic film and electromagnetic shielding, and a core electrode material for flat panel displays, solar cells, touch panels, transparent transistors, flexible photoelectric devices, and transparent photoelectric devices.

Currently, transparent electrodes are essentially included in display and touch panels, as well as transparent and flexible electronic devices, solar cells, and transparent heating elements. In most cases, indium tin oxide (ITO) is currently used as a transparent electrode, but it is essential to develop a new transparent electrode that is thinner than ITO and is superior in resistance and transmittance because of the price problem and lack of flexibility of indium (In).

The problem to be solved by the present invention is to provide a transparent electrode with improved structural stability.

Another problem to be solved by the present invention is to provide a transparent electrode having high transmittance and low resistance.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The transparent electrode according to embodiments of the present invention for solving the above-described technical problems is provided on a seed layer provided on a substrate, a resistance control layer disposed on the seed layer, and on the resistance control layer. It may include an optical control layer disposed. The seed layer may have a first surface and a second surface facing the first surface and facing the resistance control layer. The surface roughness of the second surface may be greater than that of the first surface.

According to one embodiment, the first surface of the seed layer may be substantially flat. The second surface of the seed layer may have a maximum height roughness of 0.1 nm to 10 nm.

According to one embodiment, the resistance control layer may conformally cover the second surface of the seed layer.

According to one embodiment, the surface roughness of the lower surface of the resistance control layer facing the seed layer may be greater than the roughness of the upper surface of the resistance control layer.

According to one embodiment, the upper surface of the resistance control layer may be substantially flat.

According to one embodiment, the thickness of the seed layer may be 10nm to 150nm.

According to one embodiment, the seed layer may include titanium oxynitride (TiO _x N _y ). In the above formula, x is a real number equal to or greater than 0.2 and equal to or less than 1, and Y can be a real number greater than 0 and equal to or less than 1.

According to one embodiment, the seed layer is tin oxide (SnO _x ), fluorine doped tin oxide (FTO), gallium doped zinc oxide (ZnO: Ga), aluminum doped zinc oxide (ZnO: Al), titanium oxide (TiO _x ), Titanium nitride (TiN), molybdenum oxide (MoO _x ) or molybdenum sulfide (MoS _x ).

According to an embodiment, a refractive index control layer provided on the first surface of the seed layer may be further included.

According to an embodiment, the refractive index of the refractive index control layer may be greater than 2.0 and less than 4.0.

According to one embodiment, the refractive index control layer is molybdenum oxide (MoO _x ), molybdenum sulfide (MoS _x ), tungsten oxide (WO _x ), titanium oxide (TiO _x ), titanium nitride (TiN), titanium It may include oxynitride (TiON) or titanium sulfide (TiS _x ).

According to one embodiment, the resistance control layer may include silver (Ag), silver oxide (AgO _x ), aluminum (Al), or copper (Cu).

According to an embodiment, the optical control layer and the seed layer in plan view may have a larger plane shape than the resistance control layer. The whole of the resistance control layer may overlap the optical control layer and the seed layer.

According to one embodiment, the optical control layer may cover the top and side surfaces of the resistance control layer. The resistance control layer may be sealed by the seed layer and the optical control layer.

According to one embodiment, the refractive index of the optical control layer may be 1.4 to 2.5.

According to one embodiment, the optical control layer is silicon oxide (SiO _x ), aluminum oxide (AlO _x ), titanium oxide (TiO _x ), molybdenum oxide (MoO _x ), gallium doped zinc oxide (ZnO: Ga) , Aluminum doped zinc oxide (ZnO: Al), boron doped zinc oxide (ZnO: B), tin oxide (SnO _x ) or fluorine doped tin oxide (FTO).

According to an embodiment, a buffer layer disposed between the seed layer and the resistance control layer may be further included.

According to one embodiment, the buffer layer may conformally cover the second surface of the seed layer.

According to an embodiment, the surface roughness of the top surface of the buffer layer may be equal to or less than the surface roughness of the first surface of the seed layer.

According to one embodiment, the buffer layer is nickel (Ni), chromium (Cr), nickel chromium (NiCr), silver nitride (AgN _x ), silver oxide (AgO _x ), aluminum (Al), aluminum oxide (AlO _x ) , Titanium nitride (TiN) or titanium oxynitride (TiON).

The transparent electrode according to the embodiments of the present invention for solving the above technical problems is a refractive index control layer provided on a substrate, a seed layer disposed on the refractive index control layer, a resistance control layer disposed on the seed layer, And an optical control layer disposed on the resistance control layer. The roughness of the top surface of the seed layer may be greater than the roughness of the top surface of the refractive index control layer.

In the transparent electrode according to the present invention, structural stability may be improved by using a seed layer. In addition, the resistance control layer may be thinly formed in the form of a thin film by the seed layer, and a transparent electrode having a thin, high light transmittance, and improved electrical properties may be provided. In addition, as the wettability of the resistance control layer and the seed layer is improved, the crystallinity of the resistance control layer provided on the top surface of the seed layer can be improved. Accordingly, the resistance of the resistance control layer may be lowered, and electrical characteristics of the transparent electrode may be improved.

In addition, a resistance control layer may be protected using a buffer layer, and a transparent electrode with improved stability may be provided.

1 is a perspective view illustrating a transparent electrode according to embodiments of the present invention.
2 is a cross-sectional view for describing a transparent electrode according to embodiments of the present invention.
3 to 5 are enlarged views of area A of FIG. 2.
6 is a cross-sectional view for describing a transparent electrode according to embodiments of the present invention.
7 is a cross-sectional view for describing a transparent electrode according to embodiments of the present invention.
8 to 11 are cross-sectional views illustrating a method of manufacturing a transparent electrode according to embodiments of the present invention.
12A is a photograph of experiments of the wetting characteristics of Comparative Example 1.
12B are photographs of experimenting on the wetting characteristics of Experimental Example 1.

In order to fully understand the configuration and effect of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be implemented in various forms and various changes can be made. However, through the description of the present embodiments, the present disclosure is made to be complete, and the present invention is provided to those of ordinary skill in the art to fully inform the scope of the invention. Those skilled in the art will understand that the concept of the present invention can be carried out in any suitable environment.

The terminology used herein is for describing the embodiments and is not intended to limit the present invention. In the present specification, the singular form also includes the plural form unless otherwise specified in the phrase. As used herein, 'comprises' and / or 'comprising' refers to the elements, steps, operations and / or elements mentioned above, the presence of one or more other components, steps, operations and / or elements. Or do not exclude additions.

Where a film (or layer) is referred to herein as being on another film (or layer) or substrate, it may be formed directly on another film (or layer) or substrate, or a third film (between them) Or layers) may be interposed.

 Although the terms first, second, third, etc. are used to describe various regions, films (or layers), etc. in various embodiments herein, these regions, films should not be limited by these terms. do. These terms are only used to distinguish one region or film (or layer) from another region or film (or layer). Therefore, the film quality referred to as the first film quality in one embodiment may be referred to as the second film quality in another embodiment. Each embodiment described and illustrated herein includes its complementary embodiments. Portions denoted by the same reference numerals throughout the specification denote the same components.

Terms used in the embodiments of the present invention may be interpreted as meanings commonly known to those skilled in the art unless otherwise defined.

Hereinafter, a transparent electrode according to the concept of the present invention will be described with reference to the drawings.

1 is a perspective view illustrating a transparent electrode according to embodiments of the present invention. 2 is a cross-sectional view for describing a transparent electrode according to embodiments of the present invention. 3 to 5 are enlarged views of area A of FIG. 2. 6 is a cross-sectional view for describing a transparent electrode according to embodiments of the present invention. 7 is a cross-sectional view for describing a transparent electrode according to embodiments of the present invention. 2, 6 and 7 correspond to cross-sections taken along line I-I 'in FIG. 1.

Referring to FIGS. 1 and 2, the substrate 100 may be provided. The substrate 100 may include a transparent substrate. For example, the substrate 100 may include a glass substrate, a sapphire substrate, or a transparent polymer substrate. The transparent polymer substrate may be a flexible substrate. The transparent polymer substrate may include polyimide (PI), polyethylene terephtalate (PET), or polyethylene napthalene (PEN). Alternatively, the substrate 100 may include a metal substrate such as a metal foil.

The refractive index control layer 200 may be disposed on the substrate 100. The refractive index control layer 200 may be transparent. The thickness of the refractive index control layer 200 may be 2 nm to 100 nm. The refractive index control layer 200 may improve the transmittance of the transparent electrode 10. Specifically, the refractive index control layer 200 may include a high refractive index material. For example, the refractive index of the refractive index control layer 200 may be greater than 2.0 and less than 4.0. The refractive index control layer 200 includes molybdenum oxide (MoO _x ), molybdenum sulfide (MoS _x ), tungsten oxide (WO _x ), titanium oxide (TiO _x ), titanium nitride (TiN), titanium oxynitride (TiON) ) Or titanium sulfide (TiS _x ).

Referring to FIGS. 1, 2 and 3 together, the seed layer 300 may be disposed on the refractive index control layer 200. The seed layer 300 may have a lower surface 300b facing the substrate 100 and an upper surface 300a facing the lower surface 300b. The surface roughness of the top surface 300a of the seed layer 300 may be greater than the surface roughness of the bottom surface 300b. For example, the bottom surface 300b of the seed layer 300 may be substantially flat, and the top surface 300a of the seed layer 300 may have a maximum height roughness (R) of 0.1 nm to 10 nm. _max 1). Here, the maximum height roughness can be measured by measuring the distance between the highest floor and the lowest floor of the surface based on the average line of the surface. At this time, too high floors or too deep valleys, which can be seen as nicks or saratch, can be excluded. The top surface 300a of the seed layer 300 may have irregular protrusions 310 such as teeth, as shown in FIG. 3. Alternatively, the top surface 300a of the seed layer 300 may have hexahedral projections 310 as shown in FIG. 4. Alternatively, the top surface 300a of the seed layer 300 may have a curved shape, as shown in FIG. 5. However, the shape of the top surface 300a of the seed layer 300 of the present invention is not limited thereto, and may have various shapes capable of providing high surface roughness. The rough surface of the seed layer 300 may be formed by forming a thin film of a preliminary seed layer on the refractive index control layer 200 and then performing an etching process on the preliminary seed layer thin film. The thickness of the seed layer 300 may be 10nm to 150nm. The seed layer 300 may include titanium oxynitride (TiO _x N _y ). In this case, x may be a real number equal to or greater than 0.2, a real number equal to or less than 1, and y may be a real number greater than 0 and equal to or less than 1. When the seed layer 300 includes only titanium oxide (TiO), the refractive index of the seed layer 300 may be high, but the conductivity of the seed layer 300 may be low. When the seed layer 300 includes only titanium nitride (TiN), the conductivity of the seed layer 300 may be high, but the refractive index may be low. The seed layer 300 according to the present invention includes titanium oxynitride (TiO _x N _y ), and may have both high refractive index and conductivity. That is, the transparent electrode 10 of the present invention may not have a decrease in refractive index and conductivity due to the provision of the seed layer 300. Alternatively, the seed layer 300 includes tin oxide (SnO _x ), fluorine-doped tin oxide (FTO), gallium-doped zinc oxide (ZnO: Ga), aluminum-doped zinc oxide (ZnO: Al), titanium oxide (TiO _x ) , Titanium nitride (TiN), molybdenum oxide (MoO _x ) or molybdenum sulfide (MoS _x ).

1 and 2 show that the refractive index control layer 200 and the seed layer 300 are separate components, but the present invention is not limited thereto. 6, when the refractive index control layer 200 and the seed layer 300 are made of the same material, the seed layer 300 may have a continuous configuration with the refractive index control layer 200, and the refractive index The interface 210 between the control layer 200 and the seed layer 300 may not be visible. That is, the refractive index control layer 200 and the seed layer 300 may be provided integrally. Alternatively, when the seed layer 300 is made of a material different from the refractive index control layer 200, as shown in FIG. 2, the interface between the refractive index control layer 200 and the seed layer 300 may appear visually. You can. Hereinafter, description will be continued based on the embodiment of FIG. 2.

The resistance control layer 500 may be disposed on the seed layer 300. The resistance control layer 500 may conformally cover the top surface 300a of the seed layer 300. In this case, the shape of the top surface 300a of the seed layer 300 may be transferred to the top surface 500a of the resistance control layer 500. That is, the upper surface 500a of the resistance control layer 500 may be a rough surface. The surface roughness of the top surface 500a of the resistance control layer 500 may be equal to or less than the surface roughness of the top surface 300a of the seed layer 300. In addition, the surface roughness of the top surface 500a of the resistance control layer 500 is in contact with the top surface 300a of the seed layer 300 (or in contact with the top surface 400a of the buffer layer 400 described below). The surface roughness of the lower surface 500b of 500) may be equal to or smaller than the surface roughness. For example, the top surface 500a of the resistance control layer 500 may have a maximum height roughness (R _max 3) of 0.1 nm to 10 nm. Alternatively, as illustrated in FIG. 7, the upper surface 500a of the resistance control layer 500 may be substantially flat. The planar shape of the resistance control layer 500 may be smaller than the planar shape of the seed layer 300. For example, in plan view, all of the resistance control layer 500 may overlap the seed layer 300, and the seed layer 300 may protrude outside the resistance control layer 500. . The thickness of the resistance control layer 500 may be 6 to 15 nm. The resistance control layer 500 may be provided to reduce sheet resistance of the transparent electrode 10. For example, the resistance control layer 500 may include silver (Ag), silver oxide (AgO _x ), aluminum (Al), or copper (Cu). As the top surface 300a of the seed layer 300 has a rough surface, the resistance control layer 500 including metal may have improved adhesion to the seed layer 300. For example, the metal material of the resistance control layer 500 may have improved wet properties on the rough surface of the seed layer 300. Accordingly, the resistance control layer 500 may not be peeled off from the seed layer 300, and a transparent electrode 10 with improved structural stability may be provided. In addition, as the wetting characteristics of the resistance control layer 500 and the seed layer 300 are improved, crystallinity of the resistance control layer 500 provided on the top surface 300a of the seed layer 300 is improved. Can be. Accordingly, the resistance of the resistance control layer 500 may be lowered, and electrical characteristics of the transparent electrode 10 may be improved.

According to embodiments, the buffer layer 400 may be disposed between the seed layer 300 and the resistance control layer 500. The buffer layer 400 may conformally cover the top surface 300a of the seed layer 300. At this time, the top surface 400a of the buffer layer 400 may have a rough surface by transferring the shape of the top surface 300a of the seed layer 300. The surface roughness of the top surface 400a of the buffer layer 400 may be equal to or less than the surface roughness of the top surface 300a of the seed layer 300. For example, the upper surface 400a of the buffer layer 400 may have a maximum height roughness (R _max 2) of 0.1 nm to 10 nm. Accordingly, adhesion between the resistance control layer 500 including the metal and the buffer layer 400 may be improved. The surface roughness of the upper surface 400a of the buffer layer 400 may be equal to or less than the surface roughness of the lower surface 400b of the buffer layer 400 in contact with the upper surface 300a of the seed layer 300.

The buffer layer 400 may be provided to suppress the formation of islands during the deposition process of the resistance control layer 500. For example, when the resistance control layer 500 including a metal is to be formed as a thin film, the resistance control layer 500 may be formed by being dispersed in an island shape by surface energy. When the resistance control layer 500 is formed in an island shape, transmittance and electrical conductivity of the resistance control layer 500 may be lowered. When the resistance control layer 500 is formed thick to form a film, transmittance of the resistance control layer 500 may be lowered. The buffer layer 400 prevents the material of the resistance control layer 500 from being formed in an island shape, and the resistance control layer 500 can be formed in a thin film form. The resistance control layer 500 may be formed in a thin film form by the buffer layer 400, and may have high transmittance and electrical conductivity. In this case, the buffer layer 400 may have a thickness of 0.1 nm to 3.0 nm, and includes nickel (Ni), nickel chromium (NiCr), silver nitride (AgN _x ), silver oxide (AgO _x ) or aluminum (Al). can do.

Alternatively, the buffer layer 400 may be provided between the substrate 100, the seed layer 300, or the resistance control layer 500 to prevent the constituent materials from diffusing or diffusing impurities. When the substrate 100 includes a metal foil, alkali metal of the substrate 100 may be diffused toward the resistance control layer 500, and at this time, electrical characteristics of the resistance control layer 500 may be deteriorated. Alternatively, impurities from the substrate 100 or the outside may be diffused into each material layer (eg, the resistance control layer 500), and the impurities may degrade light transmittance or electrical properties of each material layer. The buffer layer 400 may prevent diffusion of old substances or impurities between each material layer, and may prevent deterioration of properties of the transparent electrode 10. At this time, the buffer layer 400 may have a thickness of 0.5nm to 5nm, titanium nitride (TiN) or titanium oxynitride (TiON), nickel (Ni), chromium (Cr), nickel chromium (NiCr) or aluminum oxide ( AlO _x ).

Alternatively, the buffer layer 400 may be provided to prevent oxidation of the resistance control layer 500. When oxygen or moisture penetrates into the transparent electrode 10 through the substrate 100, the resistance control layer 500 may be oxidized, and electrical characteristics of the resistance control layer 500 may be deteriorated. The buffer layer 400 may block oxygen or moisture toward the resistance control layer 500, or prevent the resistance control layer 500 from being oxidized because the buffer layer 400 is preferentially oxidized. In this case, although not shown, the buffer layer 400 may also be provided between the resistance control layer 500 and the optical control layer 600 described later. At this time, the buffer layer 400 may have a thickness of 1 nm to 8 nm, and may include multiple thin films of nickel (Ni), aluminum (Al), or silver (Ag) and silver oxide (AgO _x ).

The buffer layer 400 may be at least one of the three types (inhibition of island formation of the resistance control layer 500, prevention of diffusion between material layers, and prevention of oxidation of the resistance control layer 500) according to characteristics required of the transparent electrode 10. It may be provided in one form, or may not be provided as needed.

The optical control layer 600 may be disposed on the resistance control layer 500. The optical control layer 600 may cover the resistance control layer 500 on the seed layer 300. For example, the planar shape of the optical control layer 600 may be larger than the planar shape of the resistance control layer 500. For example, in plan view, all of the resistance control layer 500 may overlap the optical control layer 600, and the optical control layer 600 is the top surface 500a of the resistance control layer 500. And side surfaces. That is, the resistance control layer 500 may be sealed by the seed layer 300 (or buffer layer 400) and the optical control layer 600. Accordingly, the resistance control layer 500 may be protected from external oxygen or moisture, and the resistance control layer 500 may be prevented from being oxidized. The optical control layer 600 may be provided to improve the light transmittance of the transparent electrode 10. For example, the refractive index of the optical control layer 600 may be 1.4 to 2.5. The optical control layer 600 may improve light transmittance of the transparent electrode 10 by using a difference in refractive index from the resistance control layer 500. The thickness of the optical control layer 600 may be 10 nm to 150 nm, silicon oxide (SiO _x ), aluminum oxide (AlO _x ), titanium oxide (TiO _x ), molybdenum oxide (MoO _x ), gallium doped zinc oxide (ZnO: Ga, GZO), aluminum doped zinc oxide (ZnO: Al, AZO), boron doped zinc oxide (ZnO: B, BZO), tin oxide (SnO _x ), fluorine doped tin oxide (SiO ₂ : F, FTO ). The optical control layer 600 may have its thickness and refractive index (or constituent material) adjusted according to the light transmittance required for the transparent electrode 10.

As described above, the transparent electrode 10 may be provided. In the present invention, the transparent electrode 10 includes material layers (refractive index control layer 200, seed layer 300, buffer layer 400, resistance control layer 500, and optical control layer) provided on the substrate 100 ( The total thickness of all 600)) may be 50 nm to 200 nm.

Structural stability of the transparent electrode 10 according to the present invention may be improved by using the seed layer 300. In addition, the resistance control layer 500 may be thinly formed in the form of a thin film by the seed layer 300, and a transparent electrode 10 having a thin, high light transmittance, and improved electrical property may be provided.

In addition, the resistance control layer 500 may be protected using the buffer layer 400, and the transparent electrode 10 with improved stability may be provided.

8 to 11 are cross-sectional views illustrating a method of manufacturing a transparent electrode according to embodiments of the present invention, and correspond to a cross section taken along line I-I 'of FIG. 1.

Referring to FIG. 8, a substrate 100 may be provided. The substrate 100 may include a transparent substrate. For example, the substrate 100 may include a glass substrate, a sapphire substrate, or a transparent polymer substrate. Alternatively, the substrate 100 may include a metal substrate such as a metal foil.

The refractive index control layer 200 may be formed on the substrate 100. For example, the refractive index control layer 200 may be formed through a deposition process such as chemical vapor deposition (CVD). The refractive index control layer 200 may be formed of 2 nm to 100 nm. The refractive index control layer 200 includes molybdenum oxide (MoO _x ), molybdenum sulfide (MoS _x ), tungsten oxide (WO _x ), titanium oxide (TiO _x ), titanium nitride (TiN), titanium oxynitride (TiON) ) Or titanium sulfide (TiS _x ).

A preliminary seed layer 320 may be formed on the refractive index control layer 200. For example, the preliminary seed layer 320 may be formed through a deposition process such as chemical vapor deposition (CVD). In embodiments, the process of forming the preliminary seed layer 320 may be continuously performed following the process of forming the refractive index control layer 200. For example, when the preliminary seed layer 320 is formed of the same material as the refractive index control layer 200, after the refractive index control layer 200 is formed, the preliminary seed layer 320 is formed using the same deposition process. You can. The preliminary seed layer 320 may be formed to a thickness of 10 nm to 150 nm. The preliminary seed layer 320 may include titanium oxynitride (TiO _x N _y ). In this case, x may be equal to or greater than 0.2, equal to or less than 1, and y greater than 0 and equal to or less than 1. Alternatively, the preliminary seed layer 320 may include tin oxide (SnO _x ), fluorine-doped tin oxide (SiO ₂ : F, FTO), gallium-doped zinc oxide (ZnO: Ga, GZO), aluminum-doped zinc oxide (ZnO: Al, AZO ), Titanium oxide (TiO _x ), titanium nitride (TiN), molybdenum oxide (MoO _x ) or molybdenum sulfide (MoS _x ).

Referring to FIG. 9, a surface treatment process may be performed on the preliminary seed layer 320 (see FIG. 8) to form the seed layer 300. For example, the top surface 320a of the preliminary seed layer 320 (see FIG. 8) may be etched using a wet etching process. The etchant may include nitric acid, acetic acid, acetic acid, or mixtures thereof. The wet cutting process may be performed for 1 second to 180 seconds. Alternatively, the preliminary seed layer 320 may be etched using a dry etching process. For example, by performing a plasma etching process on the upper surface 320a of the preliminary seed layer 320, the upper surface 320a of the preliminary seed layer 320 may be etched. The upper surface 320a of the preliminary seed layer 320 may be etched irregularly by the etching process. A seed layer 300 having a large surface roughness of the upper surface 300a may be formed as described above. The surface roughness of the top surface 300a of the seed layer 300 may be greater than the roughness of the top surface of the top surface 320a of the preliminary seed layer 320.

Alternatively, after forming a mask pattern on the upper surface 320a of the preliminary seed layer 320, an etching process may be performed using the mask pattern as an etching mask. In this case, the etch rate of the preliminary seed layer 320 can be easily adjusted. When the preliminary seed layer 320 is etched using the mask pattern, the seed layer 300 as shown in FIGS. 4 and 5 may be formed.

The buffer layer 400 may be formed on the seed layer 300 with reference to FIG. 10. For example, the buffer layer 400 may be formed through a deposition process such as chemical vapor deposition (CVD). The buffer layer 400 may be formed to a thickness of 0.1nm to 10nm. As the thickness of the buffer layer 400 is thin, the upper surface 400a of the buffer layer 400 may be formed to have a high roughness by transferring the upper surface 300a of the seed layer 300. The buffer layer 400 may not be formed as needed.

A preliminary resistance control layer 510 may be formed on the buffer layer 400. For example, the pre-resistance control layer 510 may be formed through a deposition process such as chemical vapor deposition (CVD). At this time, as the upper surface 400a of the buffer layer 400 has a rough surface, the preliminary resistance control layer 510 may be easily formed in a thin film shape. For example, the preliminary resistance control layer 510 may be formed of metal, and the metal material may have high roughness 500a and wet characteristics of the buffer layer 400. As the wetting characteristics of the buffer layer 400 and the preliminary resistance control layer 510 are improved, the preliminary resistance control layer 510 may be grown in a thin film shape rather than an island shape on the buffer layer 400 and the preliminary resistance. The adhesion between the control layer 510 and the buffer layer 400 may be improved. In addition, as the preliminary resistance control layer 510 is grown in a thin film shape, crystallinity of the preliminary resistance control layer 510 may be improved. The preliminary resistance control layer 510 may be formed to a thickness of 6 nm to 15 nm. The preliminary resistance control layer 510 may include silver (Ag), silver oxide (AgO _x ), aluminum (Al), or copper (Cu).

Referring to FIG. 11, the preliminary resistance control layer 510 (see FIG. 10) is patterned to form the resistance control layer 500. For example, after forming a mask pattern on the preliminary resistance control layer 510, the preliminary resistance control layer 510 may be patterned using the mask pattern as an etch mask. The resistance control layer 500 may be formed to have a smaller area than the seed layer 300 or the buffer layer 400 in plan view.

The resistance control layer 500 may be formed differently from those described with reference to FIGS. 10 and 11. For example, a shadow mask may be formed on the buffer layer 400. The shadow mask may have a pattern defining an area where the resistance control layer 500 is formed later. A pre-resistance layer may be formed on the buffer layer 400 and the shadow mask. Thereafter, the shadow mask may be removed. At this time, a part of the preliminary resistance control layer formed on the shadow mask may be removed together to form the resistance control layer 500.

Referring back to FIG. 2, the optical control layer 600 may be formed on the resistance control layer 500. The optical control layer 600 may be formed through a deposition process such as chemical vapor deposition (CVD). The optical control layer 600 may be formed to a thickness of 10nm to 150nm. The optical control layer 600 includes silicon oxide (SiO _x ), aluminum oxide (AlO _x ), titanium oxide (TiO _x ), molybdenum oxide (MoO _x ), gallium doped zinc oxide (ZnO: Ga), aluminum doped zinc Oxide (ZnO: Al), boron-doped zinc oxide (ZnO: B), tin oxide (SnO _x ), or fluorine-doped tin oxide (FTO).

Through the above process, the transparent electrode 10 of the present invention can be manufactured.

According to embodiments of the present invention, each material layer of the transparent electrode may be formed using two processes, a deposition process and an etching process. Accordingly, the manufacturing method of the transparent electrode 10 can be simplified.

Comparative example  One

After depositing a small amount of a metal material (silver (Ag)) forming a resistance control layer on the top surface of the seed layer (ie, the seed layer having a flat top surface) without surface treatment, a contact angle between the top surface of the seed layer and the metal material Was measured.

Experimental example  One

After depositing a small amount of a metal material (silver (Ag)) forming a resistance control layer on the top surface of the seed layer (ie, the seed layer having a rough top surface) subjected to surface treatment, the contact angle between the top surface of the seed layer and the metal material is determined. It was measured.

12A is a photograph of experiments of the wetting characteristics of Comparative Example 1. 12B are photographs of experimenting on the wetting characteristics of Experimental Example 1.

12A and 12B, it can be seen that Experimental Example 1 subjected to surface treatment had a smaller contact angle between the top surface of the seed layer and the metallic material than Comparative Example 1 without surface treatment. The measured contact angles of Comparative Example 1 and Experimental Example 1 are shown in Table 1 below.

Contact angle Comparative Example 1 71.64 ° Experimental Example 1 39.14 °

It can be seen that the contact angle between the metal material of Experimental Example 1 and the top surface of the seed layer is 39.14 °, and the contact angle between the metal material of Comparative Example 1 and the top surface of the seed layer is very small compared to 71.64 °. That is, it can be confirmed that the wet property between the surface of the seed layer and the metal material is improved by the surface treatment of the seed layer, and the transparent electrode according to the embodiments of the present invention has a seed layer and a resistance control layer (or buffer layer). And the resistance control layer).

Experimental example  2

After forming a seed layer using titanium oxynitride (TiON), surface treatment was performed so that the top surface of the seed layer was rough. The seed layer was formed to a thickness of 20 nm. A resistance control layer was deposited on the top surface of the seed layer. The resistance control layer was formed using silver (Ag), and was deposited for each thickness in the range of 10 nm to 15 nm. An optical control layer was formed on the top surface of the seed layer. The optical control layer was formed using gallium-doped ZnO (GZO), and was deposited with a thickness of 50 nm. Then, the sheet resistance, light transmittance and performance index (FOM) of the prepared laminate were measured. The light transmittance was measured in the visible light region (wavelength range of 380 nm to 780 nm). The performance index is a performance index reflecting sheet resistance and light transmittance, and was calculated using the following formula.

The results of measuring the sheet resistance, light transmittance and performance index of Experimental Example 2 are shown in Table 2 below.

Seed layer thickness
(nm) Thickness of resistance control layer
(nm) Thickness of optical control layer
(nm) Sheet resistance
(omh / sq.) Light transmittance
(%) Performance index 20 11 50 6.14 80.88 274.27 12 4.68 80.48 351.17 13 3.97 78.19 362.73 14 3.65 75.14 336.17 15 3.28 73.14 339.47

Experimental Example 2 using titanium oxynitride as a seed layer has an average sheet resistance of about 4.34 omh / sq., And an average light transmittance of about 78%.

Comparative example  2

A layered product was formed in the same manner as in Experimental Example 2, and the seed layer was formed using gallium-doped ZnO (GZO).

In the case of Comparative Example 2, the sheet resistance was measured to be 5.5 ohm / sq., And in order to obtain visible light transmittance of 75%, the resistance control layer had to be formed thinner than 12 nm, and accordingly the sheet resistance was 5 ohm / sq. To 6 ohm / sq.

That is, it can be seen that the surface resistance and light transmittance of Experimental Example 2 in which the seed layer was formed with titanium oxynitride were improved compared to Comparative Example 2 in which the seed layer was formed with conventional GZO, and the transparent electrode according to the Example Court of the present invention Light transmittance and sheet resistance can be improved.

Experimental example  3

It was formed in the same manner as in Experimental Example 2, but was deposited so that the thickness of the resistance control layer was 13 nm. Thereafter, the sheet resistance and light transmittance of Experimental Example 3 were measured. The light transmittance was measured in the visible light region (wavelength range of 380 nm to 780 nm).

Comparative example  3

Formed in the same manner as in Experimental Example 3, the seed layer was formed of titanium oxide (TiO ₂ ). Then, the sheet resistance and light transmittance of Comparative Example 3 were measured.

Comparative example  4

After forming a seed layer using titanium oxynitride (TiON), surface treatment was performed so that the top surface of the seed layer was rough. The seed layer was formed to a thickness of 20 nm. In the case of Comparative Example 4, the light transmittance was very low, so no meaningful measurement results were collected for use as a transparent electrode, but the light transmittance of the seed layer was measured to compare the light transmittance properties of Experimental Example 3.

The results of measuring the sheet resistance and light transmittance of Experimental Example 3, Comparative Example 3 and Comparative Example 4 are shown in Table 3 below.

Seed layer material Thickness of resistance control layer
(nm) Thickness of optical control layer
(nm) Sheet resistance
(omh / sq.) Light transmittance
(%) Comparative Example 3 TiO ₂ 13 50 8.21 71.50 Experimental Example 3 TiON 13 50 3.97 78.19 Comparative Example 4 TiN Not forming Not forming 10.36

In the case of Comparative Example 3 in which the seed layer contains only titanium oxide, the refractive index of the seed layer may be high, but the conductivity of the seed layer may be low. Experimental Example 3 using titanium oxynitride as a seed layer It was confirmed that the sheet resistance was measured to be very low compared to Comparative Example 3 in which a seed layer was formed using titanium oxide. In Comparative Example 4, in which the seed layer contains only titanium nitride, the conductivity of the seed layer may be high, but the refractive index may be low. It can be seen that Experimental Example 3 using titanium oxynitride as a seed layer has a very high light transmittance compared to Comparative Example 4 using titanium nitride as a seed layer. Experimental Example 3, while maintaining a high transmittance of 75% or more, it can be seen that exhibits a low sheet resistance, the seed layer of the transparent electrode according to the present invention may include a titanium oxynitride, both refractive index and conductivity.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains can implement the present invention in other specific forms without changing its technical spirit or essential features. You will understand that there is. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

This patent was supported by the Ministry of Trade, Industry and Energy's Energy Technology Evaluation Institute (KETEP) project. [grant number 20163010012560]

10: transparent electrode
100: substrate 200: refractive index control layer
300: seed layer 400: buffer layer
500: resistance control layer 600: optical control layer

Claims (20)

A seed layer provided on the substrate;
A resistance control layer disposed on the seed layer; And
It includes an optical control layer disposed on the resistance control layer,
The seed layer has a first surface and a second surface facing the first surface and facing the resistance control layer,
A transparent electrode having a surface roughness of the second surface greater than that of the first surface. According to claim 1,
The first surface of the seed layer is substantially flat,
The second surface of the seed layer is a transparent electrode having a maximum height roughness of 0.1nm to 10nm. According to claim 1,
The resistance control layer is a transparent electrode that conformally covers the second surface of the seed layer. According to claim 1,
A transparent electrode having a surface roughness of a lower surface of the resistance control layer facing the seed layer greater than a roughness of an upper surface of the resistance control layer. The method of claim 4,
The upper surface of the resistance control layer is a substantially flat transparent electrode. According to claim 1,
The seed layer has a thickness of 10nm to 150nm transparent electrode. According to claim 1,
The seed layer includes titanium oxynitride (TiO _x N _y ),
In the above formula, x is a real number equal to or greater than 0.2 and equal to or less than 1, and Y is a real electrode greater than 0 and equal to or less than 1. According to claim 1,
A transparent electrode further comprising a refractive index control layer provided on the first surface of the seed layer. The method of claim 8,
The refractive index of the refractive index control layer is greater than 2.0 and less than 4.0 transparent electrode. The method of claim 8,
The refractive index control layer is molybdenum oxide (MoO _x ), molybdenum sulfide (MoS _x ), tungsten oxide (WO _x ), titanium oxide (TiO _x ), titanium nitride (TiN), titanium oxynitride (TiON), or A transparent electrode comprising titanium sulfide (TiS _x ). According to claim 1,
The resistance control layer is a transparent electrode including silver (Ag), silver oxide (AgO _x ), aluminum (Al), or copper (Cu). According to claim 1,
The planar view of the optical control layer and the seed layer has a larger planar shape than the resistance control layer,
All of the resistance control layer is a transparent electrode that overlaps the optical control layer and the seed layer. According to claim 1,
The optical control layer covers the top and side surfaces of the resistance control layer,
The resistance control layer is a transparent electrode sealed by the seed layer and the optical control layer. According to claim 1,
The optical control layer has a refractive index of 1.4 to 2.5. According to claim 1,
The optical control layer is silicon oxide (SiO _x ), aluminum oxide (AlO _x ), titanium oxide (TiO _x ), molybdenum oxide (MoO _x ), gallium doped zinc oxide (ZnO: Ga), aluminum doped zinc oxide ( Transparent electrode comprising ZnO: Al), boron-doped zinc oxide (ZnO: B), tin oxide (SnO _x ) or fluorine-doped tin oxide (FTO). According to claim 1,
A transparent electrode further comprising a buffer layer interposed between the seed layer and the resistance control layer. The method of claim 16,
The buffer layer is a transparent electrode that conformally covers the second surface of the seed layer. The method of claim 16,
A transparent electrode having a surface roughness of the upper surface of the buffer layer equal to or smaller than a surface roughness of the first surface of the seed layer. The method of claim 16,
The buffer layer is nickel (Ni), chromium (Cr), nickel chromium (NiCr), silver nitride (AgN _x ), silver oxide (AgO _x ), aluminum (Al), aluminum oxide (AlO _x ), titanium nitride (TiN) Or a transparent electrode containing titanium oxynitride (TiON). A refractive index control layer provided on the substrate;
A seed layer disposed on the refractive index control layer;
A resistance control layer disposed on the seed layer; And
An optical control layer disposed on the resistance control layer,
The roughness of the top surface of the seed layer is greater than the roughness of the top surface of the refractive index control layer.

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