KR101827854B1 - Passivation film and method for the same, and display apparatus having the passivation film - Google Patents

Abstract

According to the present invention, a manufacturing method of a passivation film comprises the processes of: preparing a ductile base; forming a graphene layer on the base; generating first plasma to form a buffer layer including an inorganic film on the graphene layer; and generating second plasma to form a passivation layer including an inorganic film on the buffer layer. Therefore, even if the passivation layer is formed on the buffer layer with high-energy plasma using high power, an impact due to the plasma is mitigated or offset by the buffer layer so that the graphene layer is not damaged or damage to the graphene layer is minimized. Moreover, the buffer layer close to hydrophilicity compared with the passivation layer can be formed so that binding force between the graphene layer and the buffer layer is improved. Thus, a high-density passivation layer can be formed so that an effect of preventing air and moisture penetration can be improved.

Description

[0001] The present invention relates to a passivation film, a method of manufacturing the passivation film, and a display device including the passivation film,

The present invention relates to a passivation film, a method of manufacturing the same, and a display device including the passivation film. More particularly, the present invention relates to a passivation film for preventing or minimizing damage to graphene, a method for manufacturing the passivation film, and a display device including the passivation film. .

An organic electroluminescent device (OLED), one of the display devices, has a structure in which an organic layer including a light emitting layer made of an organic light emitting material is formed between a pair of electrodes, at least one of which is transparent or translucent. That is, the organic electroluminescent device has a structure in which an anode, an organic layer including a light emitting layer, and a cathode are stacked on a substrate. In the organic electroluminescent device, when a voltage is applied between a pair of electrodes, electrons are injected into the light emitting layer from the cathode, holes are injected from the anode, and these recombine in the light emitting layer. Then, the organic light emitting material is excited by the energy generated at this time, and the light emitting layer emits light. Further, the organic layer has a characteristic of being deteriorated by water vapor or oxygen. Thus, a passivation portion is formed to cover the anode, the organic layer, and the cathode.

On the other hand, in order to develop a transparent and flexible display device, the passivation part should also be flexible and have high transmittance and stability. To this end, a passivation part is conventionally formed using graphene. A passivation portion having a graphene includes a substrate having flexible characteristics, a graphene layer formed on the substrate, and an inorganic film formed on the graphene layer. Here, since a film made of a polymer material is used as the substrate, an inorganic film is formed by using plasma energy, not thermal energy, when forming an inorganic film on the graphene layer. However, there is a problem that when the inorganic film is formed using plasma, the graphene layer is damaged by the energy.

In order to solve such a problem, there has been proposed a technique of forming an inorganic film on a polymer layer after forming a polymer layer on a graphene layer. However, in this case, since a graphene layer is formed on a substrate and then the substrate is taken out and transferred to equipment for forming a polymer layer, the process is complicated and the probability of exposure to external impurities increases, .

Korean Patent Publication No. 2013-0025168

The present invention provides a passivation film for preventing or minimizing damage to a graphene layer, a method for manufacturing the same, and a display device including the passivation film.

The present invention provides a passivation film capable of improving the density of the passivation layer, a method for manufacturing the passivation film, and a display device including the passivation film.

The present invention provides a passivation film having a simple manufacturing process, a manufacturing method thereof, and a display device including the passivation film.

A method of manufacturing a passivation film according to the present invention includes: preparing a base having flexibility; Forming a graphene layer on the base; Generating a first plasma to form a buffer layer including an inorganic film on the graphene layer; And generating a second plasma to form a passivation layer including an inorganic film on the buffer layer.

The power for generating the first plasma is lower than the power for generating the second plasma.

The power for generating the first plasma is preferably 45% to 55% of the power for generating the second plasma.

Each of the buffer layer and the passivation layer is formed of one of an oxide film and a nitride film, and the buffer layer and the passivation layer are formed of the same inorganic film.

When the buffer layer and the passivation layer are formed of an oxide film, the power for generating the first plasma is more than 0.5 kW and less than 2 kW, and the power for generating the second plasma is more than 0.9 kW and less than 4.4 kW.

When the buffer layer and the passivation layer are formed of an oxide film,

The buffer layer is formed to have a thickness of 1 nm to 2.5 nm.

When the buffer layer and the passivation layer are formed of a nitride film, the power for generating the first plasma is more than 0.5 kW and less than 4 kW, and the power for generating the second plasma is more than 0.9 kW and less than 8.8 kW.

When the buffer layer and the passivation layer are formed of an oxide film, the buffer layer is formed to have a thickness of 10 nm to 20 nm.

The buffer layer and the passivation layer are formed using any one of a plasma atomic layer deposition (PEALD) method and a plasma enhanced chemical vapor deposition (PECVD) method.

The passivation film according to the present invention comprises a flexible base; A graphene layer formed on the base; A passivation layer formed on the graphene layer and formed of a material including an inorganic material; And a buffer layer formed between the graphene layer and the passivation layer and formed of a material containing an inorganic material.

The buffer layer and the passivation layer are formed by generating plasma, and the buffer layer is formed with plasma energy lower than plasma energy at the time of forming the passivation layer.

The buffer layer is formed with a plasma energy of 45% to 55% of the plasma energy at the time of forming the passivation layer.

Each of the buffer layer and the passivation layer is one of an oxide film and a nitride film, and the buffer layer and the passivation layer are the same inorganic film.

Preferably, the power for generating the first plasma is greater than 0.5 kW and less than 4 kW, and the power for generating the second plasma is greater than 0.9 kW and less than 8.8 kW.

A display device comprising a passivation film, comprising: a substrate; And a display portion formed on the substrate, wherein the passivation film is formed to cover the substrate including the display portion.

According to the embodiment of the present invention, a low-energy plasma is generated using a low power before forming the passivation layer on the graphene layer to form a buffer layer on the graphene layer.

Therefore, even if a passivation layer is formed on the buffer layer with a high energy plasma using a high power, the impact due to the plasma is mitigated or canceled by the buffer layer, so that the graphene layer is not damaged or minimized. Further, a buffer layer close to hydrophilicity can be formed as compared with the passivation layer, and the bonding force between the graphene layer and the buffer layer is improved. Thus, a high-density passivation layer can be formed, and the effect of preventing air and moisture penetration can be improved.

1 is a conceptual view showing a passivation film according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a method of manufacturing a passivation film according to an embodiment of the present invention, and FIG. 3 is a schematic cross-
4 is a cross-sectional view of an apparatus for applying a film according to an embodiment of the present invention as a passivation film
5 is a cross-sectional view of an organic electroluminescent device according to an example of a display device
6 is a graph showing the degree of damage of the graphene layer in the passivation film formed by the method according to the comparative example and the method of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know.

The present invention relates to a passivation film for preventing permeation of oxygen and moisture from the outside and a method of manufacturing the same. More specifically, a passivation film according to an embodiment of the present invention is a translucent film having flexibility, which is applied to a flexible display device, and a method of manufacturing the passivation film.

Hereinafter, a passivation film and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG.

1 is a conceptual view showing a passivation film according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a method of manufacturing a passivation film according to an embodiment of the present invention, and FIG. 3 is a schematic cross-sectional view illustrating a method of manufacturing a passivation film.

1, a passivation film according to an embodiment of the present invention includes a base 10, a graphene layer G formed on the base 10, a buffer layer BL formed on the graphene layer G, and a buffer layer BL And a passivation layer PL formed on the passivation layer PL.

As shown in FIGS. 2 and 3, a method of manufacturing a passivation film includes the steps of providing a base 10 (S100), forming a graphene layer (G) on a base (S200 A process S300 of forming a buffer layer BL on the graphene layer G as shown in FIG. 3B, and a process of forming a passivation layer S100 (FIG. 3C) on the buffer layer BL do.

Hereinafter, each constitution and a forming method of the passivation film will be described.

The base 10 may be a light-transmissive, flexible material, more specifically a film made of a polymer. The base 10 may be, for example, a film composed of any one of polyacylate, polyethersulfone, polycarbonate, terephthalate, and polyether naphthalate.

The graphene layer G is formed on the base 10 and may be formed on a separate substrate and then transferred and coated on the base 10. That is, a graphene layer is formed by reacting a substrate with a reaction gas and heat containing a carbon source at a temperature of about 300 ° C to 2000 ° C, and the graphene layer produced by the roll-to-roll process is transferred onto the base . Thus, the graphene layer G is formed on the base 10.

It is effective that the graphene layer G is laminated in a plurality of layers. This is because the step of forming the graphene layer on the substrate is performed a plurality of times and the transferring of the graphene layer G onto the base 10 is performed a plurality of times . Of course, the graphene layer is not limited to a plurality of layers but may be formed as a single layer.

On the other hand, the conventional passivation film is manufactured by forming a passivation layer PL made of an inorganic film immediately on the graphene layer (G). For the purpose of maintaining the characteristics of the graphene layer G, the graphene layer G is formed on the graphene layer G by a vapor deposition method using a plasma so as to enable low-temperature deposition, (PL). However, since both the graphene layer G and the passivation layer PL made of an inorganic material are hydrophobic, the bonding force or adhesive force between the graphene layer G and the passivation layer PL is poor, The deposition is not performed properly or the density is low. Further, a plasma having a high energy is formed by using a high power for forming the passivation layer PL. At this time, there is a problem that the graphene layer G formed ahead by the high plasma energy is damaged.

Therefore, in the embodiment of the present invention, the buffer layer BL is formed on the graphene layer G before the passivation layer PL is formed, and the graphene layer G is formed by the high plasma energy when the passivation layer PL is formed The bonding force between the passivation layer PL and the graphene layer G is increased, and the passivation layer PL having a high density can be formed.

That is, according to the embodiment of the present invention, a plasma is formed in a range of more than 0.5 kW and less than 4 kW, a buffer layer BL is formed using the plasma, and then a plasma is formed in a range of more than 0.9 kW and less than 8.8 kW to form a passivation layer PL. .

Hereinafter, the buffer layer BL will be described in more detail.

The buffer layer BL is first formed on the graphene layer G so as to be positioned between the graphene layer G and the passivation layer PL before formation of the passivation layer PL. The buffer layer BL is made of an inorganic film and is formed of the same material as the passivation layer PL formed subsequently. For example, the buffer layer BL may be formed of any one of oxide and nitride. For example, in the case of an oxide film, it may be formed of any one of aluminum oxide (Al _x O _y ), silicon oxide (SiO _x ), manganese oxide (MgO), and zinc oxide (ZnO). As another example, in the case of a nitride film, it may be formed of silicon nitride (SiN _x , SiO _x N _y ).

The buffer layer BL according to the embodiment has hydrophilicity close to that of the passivation layer PL to be subsequently deposited so that the bonding force or adhesion force between the graphene layer G and the buffer layer BL is lower than that of the conventional passivation layer Structure formed directly). The buffer layer BL may be formed by a deposition method capable of low temperature deposition such as a plasma enhanced atomic layer deposition (PEALD) method or a plasma enhanced chemical vapor deposition (CVD) method so that the characteristics of the graphene layer G can be maintained. PECVD).

Hereinafter, a method of forming the buffer layer BL will be described, and a plasma atomic layer deposition (PEALD) method will be described as an example.

The plasma atomic layer deposition (PEALD) device is a conventional device used in the relevant technical field, so it is briefly described. Although not shown, the plasma atomic layer deposition (PEALD) apparatus includes a chamber having an inner space, a stage for supporting a base 10 on which a graphene layer G is formed, a stage for positioning the substrate 10, And a first to a third gas supply unit for supplying the source gas, the reaction gas and the purge gas to the gas injection unit, respectively. The gas injection unit injects the process gas containing the reaction gas and the purge gas.

Here, a RF (Radio Frequency) power generator is connected to the gas injection portion, and the chamber and the stage are grounded.

In order to form the buffer layer (BL), a reaction gas is first supplied into the chamber through a gas injection part, and then a raw material gas is supplied to be adsorbed on the graphene layer (G). At this time, the raw material gas adsorbed on the graphene layer G reacts with the reaction gas to form a thin film, that is, a buffer layer BL. Then, a purge gas is supplied into the chamber through the gas injection unit, thereby purging the reaction gas and the source gas remaining in the chamber. When the above-described reaction gas supply, source gas supply, and purge gas supply are sequentially repeated a plurality of times, a buffer layer BL having a predetermined thickness is formed on the graphene layer G.

The buffer layer BL according to the embodiment can be formed of an oxide film or a nitride film, as described above. At this time, the reaction gas may be oxygen, nitrogen, hydrogen, ammonia, etc., alone or in combination, and the source gas may be a gas including Al, Si, Mg, and Zn. Further, the purge gas may be an inert gas such as argon gas. For example, when the buffer layer BL is to be formed of aluminum oxide, a buffer layer made of Al ₂ O ₃ , for example, aluminum oxide, can be obtained by using oxygen as a reaction gas and a raw material containing Al as a raw material gas such as triethyl aluminum BL) can be formed.

In the embodiment of the present invention, a buffer layer BL is formed by an atomic layer deposition method using a plasma. More specifically, when the reaction gas is supplied, RF power (RF voltage) is applied to the gas injection unit by an RF power generator to activate the reaction gas, thereby forming the reaction gas plasma. Thus, the buffer layer (BL) is formed on the graphene layer (G) by the reaction between the plasma resulting from the reaction gas and the source gas. Then, the plasma power source is shut off, the supply of the reactive gas is interrupted, and then the purge gas is supplied to exhaust the unreacted gas in the chamber to the outside.

At this time, the power applied to the gas injection portion is made smaller than the power applied at the time of forming the passivation layer PL to be subsequently formed, so that a low energy plasma (see FIG. 3B) is formed. More specifically, the power applied to the gas injecting portion is set to be more than 45%, less than 55% of the electric power applied when forming the passivation layer PL to be formed subsequently.

In the embodiment, a plasma is generated in a range of more than 0.9 kW and less than 8.8 kW to form a passivation layer PL and a plasma is generated in a range of more than 0.5 kW and less than 4.4 kW to form a buffer layer BL, The power at formation is more than 45%, less than 55% of the power of the formation of the passivation layer (PL).

More specifically, as described above, the buffer layer BL may be formed of an oxide or nitride, and the plasma generation power at the time of forming the oxide buffer layer BL and at the time of forming the nitride buffer layer BL is adjusted differently.

For example, when it is desired to form an oxide buffer layer BL of any one of aluminum oxide (Al _x O _y ), silicon oxide (SiO _x ), manganese oxide (MgO) and zinc oxide (ZnO) The plasma is generated to form the buffer layer BL. And the passivation layer PL formed later is formed using plasma formed above 0.9 kW and below 4.4 kW. Here, the power for forming the buffer layer (BL) is 45% to 55% of the power for forming the passivation layer (PL). When the buffer layer (BL) is formed with an oxide film by generating a plasma with a power exceeding 0.5 kW and less than 2 kW, the buffer layer (BL) generates plasma with a power of more than 0.9 kW and 4.4 kW to form a passivation layer ), It is possible to prevent the graphene layer (G) from being damaged by the plasma for forming the passivation. Also, when the buffer layer (BL) is formed by generating a plasma with a power of more than 0.5 kW and less than 2 kW, the graphene layer (G) is not formed or minimized.

On the other hand, when the buffer layer (BL) is formed by generating a plasma with a power of 0.5 kW or less, for example, the plasma energy may be weak and the degree of activation of the process gas may be weak. Therefore, much time is required to form the buffer layer BL with a desired thickness and density, and there is a problem that the whole process time is increased. Also, defects such as pinholes are generated in the buffer layer BL, and the buffer or buffering function is insufficient when the passivation layer PL is formed, so that the graphene layer G may be damaged. On the other hand, when the buffer layer BL is formed by generating a plasma with a power of 2 kW or more, the graphene layer G can be damaged by the reactive gas plasma, the hydrophobic property can be obtained, and the bonding force with the graphene layer becomes poor .

When forming the buffer layer BL by the plasma atomic layer deposition method, more specifically, when forming the buffer layer BL of the oxide film, the 'reaction gas supply-source gas supply-purge gas supply' cycle is performed three times or more It is preferable to set it to 12 times or less.

When the buffer layer (BL) is formed of an oxide film, the buffer layer is formed to a thickness of 1 to 2.5 nm. Thus, the buffer layer BL can be formed so as to prevent the graphene layer G from being damaged by the second plasma energy at the time of forming the passivation layer PL, or to have a buffer and a buffer function.

On the other hand, when the thickness of the buffer layer (BL) is less than 1 nm, the film density is low and the ability to prevent the damage of the graphene layer (G) by the plasma for forming the passivation may be deteriorated. On the contrary, when the thickness of the buffer layer exceeds 2.5 nm, there is a problem that the density is low and the passivation layer PL having increased roughness is formed later, thereby deteriorating the moisture barrier properties.

As another example, when a nitride buffer layer such as aluminum silicon nitride (SiN _x , SiO _x N _y ) is to be formed, a plasma is generated at a power of more than 0.5 kW and less than 4 kW to form a buffer layer. And the subsequently formed passivation layer is formed using plasma formed above 0.9 kW and below 8.8 kW. Here, the power for forming the buffer layer (BL) is 45% to 55% of the power for forming the passivation layer (PL).

When a buffer layer BL made of a nitride film is formed by generating a plasma with a power of more than 0.5 kW and less than 4.4 kW, the buffer layer BL generates a plasma with a power of more than 0.9 kW and a power of 8.8 kW to form a passivation layer PL ), It is possible to prevent the graphene layer (G) from being damaged by the plasma for forming the passivation. Also, when the buffer layer BL is formed by generating plasma with a power of more than 0.5 kW and less than 4.4 kW, the graphene layer G is not formed or minimized.

On the other hand, when the buffer layer (BL) is formed by generating a plasma with a power of 0.5 kW or less, for example, the plasma energy may be weak and the degree of activation of the process gas may be weak. Therefore, much time is required to form the buffer layer BL with a desired thickness and density, and there is a problem that the whole process time is increased. Also, defects such as pinholes are generated in the buffer layer BL, and the buffer or buffering function is insufficient when the passivation layer PL is formed, so that the graphene layer G may be damaged. On the other hand, when the buffer layer BL is formed by generating the plasma with a power of 4.4 kW or more, the graphene layer G is damaged by the reactive gas plasma and the bonding force with the graphene layer G is poor.

Further, when the buffer layer (BL) is formed of a nitride film, the buffer layer (BL) is formed to a thickness of 10 to 20 nm. Thus, the buffer layer BL can be formed so as to prevent the graphene layer G from being damaged by the second plasma energy at the time of forming the passivation layer PL, or to have a buffer and a buffer function.

On the other hand, when the thickness of the buffer layer (BL) is less than 10 nm, the film density is low and the ability to prevent damage to the graphene layer (G) by the plasma for forming the passivation may be deteriorated. On the contrary, when the thickness of the buffer layer exceeds 20 nm, the entire thickness becomes too thick, and the stress increases so that it is easy to reduce particularly when folded or bent, which hinders the application of the flexible display.

In the above description, the buffer layer is formed by the plasma atomic layer deposition (PEALD) method. However, the present invention is not limited thereto. The buffer layer BL may be formed by plasma enhanced chemical vapor deposition (PECVD). At this time, it is effective that the processing time for forming the buffer layer (BL) is less than 2 seconds.

By forming the buffer layer BL on the graphene layer G by adjusting the electric power and the plasma energy in the manner described above, the impact due to the plasma (second plasma) generated when the passivation layer PL is formed The buffer layer BL can be formed so as to be absorbed or relaxed. In addition, since the buffer layer BL is formed with a low energy plasma (first plasma) on the graphene layer G, the graphene layer G formed ahead of it is not damaged by the low energy first plasma , Is minimized. The buffer layer BL thus formed is more hydrophilic than the passivation layer PL. Therefore, when the passivation layer PL is formed directly on the graphene layer G, the buffer layer BL manufactured according to the embodiment of the present invention and the buffer layer BL formed thereon, as compared with the bonding force between the graphene layer G and the passivation layer PL, The bonding force between the graphene layers G is strong. Further, the ability to have a high bonding force with the graphene layer G is further improved.

Hereinafter, formation of the passivation layer will be described.

The passivation layer PL is formed on the buffer layer BL formed on the graphene layer G and formed of an inorganic film. For example, the passivation layer PL may be formed of any one of oxide and nitride. For example, in the case of an oxide film, it may be formed of any one of aluminum oxide (Al _x O _y ), silicon oxide (SiO _x ), manganese oxide (MgO), and zinc oxide (ZnO). As another example, in the case of a nitride film, it may be formed of silicon nitride (SiN _x , SiO _x N _y ) and is formed of the same inorganic film as the buffer layer BL.

The passivation layer PL may be formed by a plasma deposition method such as a Plasma Enhanced Atomic Layer Deposition (PEALD) method or a Plasma Enhanced Chemical Vapor Deposition (PECVD) .

At this time, the passivation layer PL is formed by the same deposition method as the method of forming the buffer layer BL. That is, the passivation layer PL is formed by the same device as the device for forming the buffer layer BL. For example, when the buffer layer BL is formed by a plasma atomic layer deposition (PEALD) device, the base on which the buffer layer BL is formed is formed in the plasma atomic layer deposition (PEALD) device as it is. In other words, after the buffer layer BL is formed, the passivation layer PL is formed in situ without leaving the chamber. Therefore, it is possible to prevent the contamination due to the outflow to the outside of the chamber, and the movement time is reduced, so that the process time is shortened.

Hereinafter, a method of forming a passivation layer PL will be described, and a passivation layer made of aluminum oxide is formed by a plasma atomic layer deposition (PEALD) method.

For example, after a reactive gas such as oxygen gas is supplied into the chamber through a gas injection unit, a source gas such as Al, for example, triethyl aluminum is supplied to the buffer layer (BL) Adsorbed. At this time, the raw material gas adsorbed on the graphene layer G reacts with the reaction gas to form a passivation layer PL made of aluminum oxide. Then, a purge gas is supplied into the chamber through the gas injection unit, thereby purging the reaction gas and the source gas remaining in the chamber. The above-described reaction gas supply, source gas supply, and purge gas supply are successively repeated a plurality of times to form a passivation layer PL having a predetermined thickness on the buffer layer BL.

In the embodiment of the present invention, a passivation layer PL is formed by a plasma-assisted atomic layer deposition method. More specifically, at the time of supplying the reaction gas, RF power (RF voltage) is applied to the gas injection unit by the RF power generator to activate the reactive gas, thereby forming the plasma of the reactive gas (second plasma). Then, the plasma power source is shut off, the supply of the reactive gas is interrupted, and then the purge gas is supplied to exhaust the unreacted gas in the chamber to the outside. Thus, the passivation layer PL is formed on the graphene layer G by the reaction between the plasma originating from the reaction gas and the raw material gas.

Here, the passivation layer PL is a thin film for preventing penetration of moisture and oxygen, and forms a passivation layer PL by using a high-energy second plasma using electric power of 0.9 kW to 8.8 kW.

More specifically, as described above, the passivation layer PL may be formed of an oxide or a nitride, and the plasma generation power at the time of forming the oxide buffer layer and at the time of forming the nitride is adjusted differently.

For example, when an oxide buffer layer of any one of aluminum oxide (Al _x O _y ), silicon oxide (SiO _x ), manganese oxide (MgO) and zinc oxide (ZnO) is to be formed, a plasma is generated at 0.9 kW to 4.4 kW Thereby forming a buffer layer. As another example, when a nitride buffer layer such as aluminum silicon nitride (SiN _x , SiO _x N _y ) is to be formed, a plasma is generated at 0.5 kW to 8.8 kW to form a buffer layer.

At this time, even if the passivation layer PL is formed using the high-energy second plasma formed at a high power of 0.9 kW to 4.4 kW (at the formation of the oxide passivation layer) or 0.5 kW to 8.8 kW (at the formation of the nitride passivation layer) Since the buffer layer BL is formed on the graphene layer G, it is possible to prevent the graphene layer G from being damaged by the second plasma. That is, when the ions of the second plasma are moved onto the buffer layer BL, the impact acts to buffer, relax or cancel the buffer layer BL so as not to transmit or minimize the impact to the graphene layer G. Therefore, it is possible to prevent or minimize the damage of the graphene layer G by the second plasma in the formation of the passivation layer PL.

In addition, since the passivation layer PL is formed on the buffer layer BL having improved bonding strength with the graphene layer G, the density of the passivation layer PL is higher than that of forming the passivation layer PL directly on the graphene layer G, The passivation layer PL can be formed. Therefore, the moisture and carbon permeation preventing ability of the passivation film is improved.

On the other hand, when the passivation layer PL made of an oxide film or a nitride film is formed, if the power is less than 0.9 kW, the passivation layer PL may have a low thickness or density, and the passivation function may deteriorate. Further, the plasma energy may be weak and the activation degree of the process gas may be weak. Therefore, a lot of time is consumed to form the passivation layer PL with the desired thickness and density, and the whole process time is increased. Also,

When the electric power for plasma formation in the formation of the oxide film passivation layer PL exceeds 4.4 kW or the electric power for plasma formation in the formation of the nitride film passivation layer PL exceeds 8.8 kW, the plasma energy is high, The buffer layer (BL) and the graphene layer (G) may be damaged by the plasma during the formation of the plasma (PL), and the roughness may be high, thereby deteriorating the air and moisture permeation preventive ability.

Further, when the passivation layer PL is formed of an oxide film, the passivation layer PL is formed to a thickness of 30 to 100 nm. Thus, a passivation layer having a large effect of preventing penetration of moisture and air is formed.

On the other hand, when the thickness of the passivation layer PL is less than 30 nm, the film density is low, and the penetration blocking ability of moisture and air may be deteriorated. Conversely, when the thickness of the passivation layer PL exceeds 100 nm, the roughness increases and another layer such as a barrier film, which is subsequently deposited on the passivation layer PL for OLED manufacturing, And thus acts as a factor for lowering the characteristics of the OLED.

Although the passivation layer PL is formed by the plasma atomic layer deposition (PEALD) process, the passivation layer PL may be formed by plasma enhanced chemical vapor deposition (PECVD).

The passivation film as described above can be used in a display device such as an organic light emitting display device which requires prevention of penetration of air and moisture. Such a display device will now be described with reference to FIG.

FIG. 4 is a cross-sectional view of a device for applying a film according to an embodiment of the present invention as a passivation film, and FIG. 5 is a cross-sectional view of an organic electroluminescent device according to an example of a display device.

4, a display device to which the present invention is applied includes a display portion 300 formed on a substrate 200, and a passivation film 100 formed on a substrate 200 including the display portion 300. The display unit 300 may include an organic electroluminescent device in which a first conductive layer 310, an organic layer 320, and a second conductive layer 330 are stacked on a substrate 200 as shown in FIG. 5 have. Here, the first conductive layer 310 may extend in one direction on the substrate 200, and the second conductive layer 330 may extend in the other direction crossing the first conductive layer 310. The plurality of first and second conductive layers 310 and 330 may be spaced apart from each other by a predetermined distance. An organic layer 320 is formed between the first and second conductive layers 310 and 320 in the region where the first and second conductive layers 310 and 320 intersect. In addition, the passivation film 100 may be formed to seal the entire substrate 200.

The substrate 200 may be a flexible and flexible substrate. For example, a plastic substrate such as PE, PES, PET, or PEN may be used. The substrate 200 is not limited to this, and an insulating substrate, a semiconducting substrate, or a conductive substrate may be used depending on the type of display device. That is, at least any one of a glass substrate, an Al ₂ O ₃ substrate, a SiC substrate, a ZnO substrate, a Si substrate, a GaAs substrate, a GaP substrate, a LiAl ₂ O ₃ substrate, a BN substrate, an AlN substrate, Can be used. However, when a semiconductor substrate or a conductive substrate is used, an insulator must be formed to insulate the first conductive layer 310 from the substrate 200. At this time, it is preferable to use a transparent insulator as the insulator.

The first conductive layer 320 serves as a cathode for supplying holes or an anode for supplying electrons and may be formed of a transparent or semi-transparent conductive material so that light can be emitted to the outside of the device. The first conductive layer 310 may be formed using a transparent metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). In addition to the transparent metal oxide, chemically-doped conjugated polymers including polythiophene and the like having excellent stability may be used as the first conductive layer 310. At this time, if the first conductive layer 310 functions as a cathode, it may be formed of a light-transmitting metal alloy, for example, a metal alloy having transparency to visible light such as Ca / Ag or Ca / Au. Meanwhile, the first conductive layer 310 may use a metal material having a high work function. In this case, efficiency reduction through non-emission recombination in the first conductive layer 310 can be prevented.

The organic layer 320 may be formed as a single layer of an organic light emitting layer by combining holes and electrons to generate light, and may be formed of multiple layers to obtain high light emission luminance or efficiency. That is, the organic layer 320 may include a hole transporting layer 322, a light emitting layer 324, and an electron transporting layer 326, and may further include an electron injection layer (not shown) and an electron injection layer . The light emitting layer 324 may be a light emitting material of a low molecular weight material or a high molecular weight material. Examples of the low molecular weight material include Alq ₃ (hydroxyquinoline aluminum), DPVBi (4,4-bis (2,2-diphenylethen-1-yl) can be used, and diphenyl), it is a polymer material PPV (poly (p-phenylenevinylene) ), (PTh) s (poly (thiophene) s), car Ono -PPV (Cyano-PPV), PPP (poly (p - phenylene), and poly (fluorene) s. The light emitting layer 324 may be formed of a single layer or a plurality of layers, and the light emitting layer 324 may be doped with a dopant to improve the light emitting efficiency or the color purity. For example, DPVBi host can be doped with rubrene to generate white light, and various dopants can be doped into various host materials to generate various light. The hole transport layer 322 may be formed using a low molecular material such as alpha -NPD or a polymer material such as poly (n-vinylcarbazole) PVK. The electron transport layer 326 may be formed using Alq ₃ or the like can do. The hole injection layer may be formed using copper phthalocyanine (CuPc) or the like, and the electron injection layer may be formed using LiF (lithium fluorine) or the like.

The second conductive layer 330 serves as an anode for supplying electrons or a cathode for supplying holes. That is, when the first conductive layer 310 functions as a cathode, the second conductive layer 330 functions as an anode. When the first conductive layer 320 functions as an anode, the second conductive layer 330 functions as a cathode do. The second conductive layer 330 may be formed of a transparent or semitransparent material such as Al, Ca / Ag, Ca / Sr, or the like so that light generated in the organic layer 320 may pass therethrough. Of a metal or a metal alloy.

The passivation film 100 is formed by forming a graphene layer on a base fabricated according to the present invention and then forming a buffer layer BL and a passivation layer PL on the graphene layer and forming the passivation layer PL on the display part 300. That is, the passivation film 100 is formed on the substrate 200 on which a plurality of organic electroluminescent devices are formed, and has a softness, so that the passivation film 100 can be formed to surround not only the upper surface but also the side surfaces of the organic electroluminescent device.

In addition, the present invention can be applied not only to organic electroluminescent display devices but also to various flexible display devices having an object of preventing penetration of moisture and air.

6 is an experimental result showing the degree of damage to the graphene layer of the oxide film passivation film formed by the method according to the comparative example and the embodiments of the present invention, and is an experimental result showing the Raman spectrum (2D peak) of the graphene layer. Here, it is interpreted that the closer to the red color the greater the amount of graphene exists.

The passivation layer of the comparative example and the buffer layer and the passivation layer according to the first and second embodiments were all formed of Al ₂ O ₃ which is an aluminum oxide film and were formed by a plasma atomic layer deposition (PEALD) method.

The passivation film according to the comparative example directly forms a passivation layer PL on the graphene layer G. The passivation layer PL is formed by generating a high energy plasma using 2 kW of electric power. The passivation film according to the first and second embodiments generates a low energy plasma at a low power of 1 kW on the graphene layer G to form a buffer layer BL and then a high energy And a passivation layer PL is formed on the buffer layer BL.

Here, the comparative example and the base 10 according to the first and second embodiments are all made of the same material, and the graphene layer G is all four layers, and a plasma is formed at a high power of 2 kw to form the passivation layer PL . In the first and second embodiments, the final thickness of the passivation film is the same. In the case of the first embodiment, the buffer layer BL is formed through five cycles. In the case of the second embodiment, To form a buffer layer (BL).

Referring to FIG. 6, it can be seen that the intensity of the Raman peak of graphene is increased in the first and second embodiments as compared to the first comparative example. In the first comparison, it can be confirmed that the damage of the graphene layer G is large by the high energy plasma at the time of forming the passivation layer PL. In contrast, in the first and second embodiments in which the buffer layer BL is formed, since the intensity of the Raman peak of graphene is greater than that of the comparative example, Is less damaged.

Comparing the first and second embodiments, the second embodiment in which the buffer layer (BL) is formed by repeating 10 cycles is repeated five times in the Raman peak intensity of graphene to form the buffer layer (BL) Which is larger than that of the first embodiment. That is, in the first embodiment and the second embodiment, the final thickness of the passivation film is the same, but in the case of the second embodiment in which the buffer layer (BL) is formed by repeating the cycle ten times, the cycle is repeated five times less, The damage of the graphene layer G is less than that of the first embodiment.

FIG. 7 is an experimental result showing the degree of damage to the graphene layer of the nitride film passivation film formed by the method according to the comparative example and the embodiments of the present invention, and is an experimental result showing the Raman spectrum (2D peak) of the graphene layer. Here, it is interpreted that the closer to the red color the greater the amount of graphene exists.

The passivation layer of the comparative example and the buffer layer and the passivation layer according to the first and second embodiments were both formed of SiN which is a silicon nitride film and were formed by a plasma enhanced chemical vapor deposition (PECVD) method.

The passivation film according to the comparative example directly forms the passivation layer PL on the graphene layer G. The passivation layer PL is formed by generating a high energy plasma using a power of 6 kW. The passivation film according to the first and second embodiments generates a low energy plasma at a low power of 2.8 kW on the graphene layer G to form a buffer layer BL and then a high power of 6 kw And a high-energy plasma is generated to form a passivation layer PL on the buffer layer BL.

Here, the comparative example and the base 10 according to the first and second embodiments are all made of the same material, and the graphene layer G is all four layers, and the plasma is formed at a power of 6 kW to form the passivation layer PL . In the first and second embodiments, the final thickness of the passivation film is the same. In the case of the first embodiment, the buffer layer is formed by reacting for 1 second. In the case of the second embodiment, BL).

Referring to FIG. 7, it can be seen that the intensity of the Raman peak of graphene is increased in the first and second embodiments as compared to the first comparative example. In the first comparison, it can be confirmed that the damage of the graphene layer G is large by the high energy plasma at the time of forming the passivation layer PL. In contrast, in the first and second embodiments in which the buffer layer BL is formed, since the intensity of the Raman peak of graphene is greater than that of the comparative example, Is less damaged.

Comparing the first embodiment with the second embodiment, it can be seen that the peak is decreased only in the case of the second embodiment as compared with the first embodiment. It is preferable that the buffer layer and the passivation layer are formed in less than 2 seconds by plasma enhanced chemical vapor deposition (PECVD), and more preferably less than 1 second.

As described above, in the embodiment of the present invention, a low-energy plasma is generated by using low electric power before forming the passivation layer on the graphene layer to form a buffer layer on the graphene layer.

Therefore, even if a passivation layer is formed on the buffer layer with a high energy plasma using a high power, the impact due to the plasma is mitigated or canceled by the buffer layer, so that the graphene layer is not damaged or minimized. Further, a buffer layer close to hydrophilicity can be formed as compared with the passivation layer, and the bonding force between the graphene layer and the buffer layer is improved. Thus, a high-density passivation layer can be formed, and the effect of preventing air and moisture penetration can be improved.

10: Base G: Graphene layer
BL: buffer layer PL: passivation layer
100: passivation film 200: substrate
300:

Claims (15)

Preparing a base having ductility;
Forming a graphene layer on the base;
Generating a first plasma to form a buffer layer including an inorganic film on the graphene layer; And
Generating a second plasma to form a passivation layer including an inorganic film on the buffer layer;
/ RTI >
Wherein the power for generating the first plasma is lower than the power for generating the second plasma. delete The method according to claim 1,
Wherein the power for generating the first plasma is 45% to 55% of the power for generating the second plasma. The method of claim 3,
Each of the buffer layer and the passivation layer is formed of one of an oxide film and a nitride film,
Wherein the buffer layer and the passivation layer are formed of the same inorganic film. The method of claim 4,
When the buffer layer and the passivation layer are formed of an oxide film,
Wherein the power for generating the first plasma is greater than 0.5 kW and less than 2 kW and the power for generating the second plasma is greater than 0.9 kW and less than 4.4 kW. The method of claim 5,
When the buffer layer and the passivation layer are formed of an oxide film,
Wherein the buffer layer is formed to have a thickness of 1 nm to 2.5 nm. The method of claim 4,
When the buffer layer and the passivation layer are formed of a nitride film,
Wherein the power for generating the first plasma is greater than 0.5 kW and less than 4 kW and the power for generating the second plasma is greater than 0.9 kW and less than 8.8 kW. The method of claim 7,
When the buffer layer and the passivation layer are formed of a nitride film,
Wherein the buffer layer is formed to a thickness of 10 nm to 20 nm. The method according to any one of claims 1 to 7,
Wherein the buffer layer and the passivation layer are formed using one of a plasma atomic layer deposition (PEALD) method and a plasma enhanced chemical vapor deposition (PECVD) method. A flexible base;
A graphene layer formed on the base;
A passivation layer formed on the graphene layer and formed of a material including an inorganic material; And
A buffer layer formed between the graphene layer and the passivation layer and formed of a material containing an inorganic material;
/ RTI >
Wherein the buffer layer and the passivation layer are formed by generating plasma, and the buffer layer is formed with a plasma energy lower than plasma energy at the time of forming the passivation layer. delete The method of claim 10,
Wherein the buffer layer is formed with a plasma energy of 45% to 55% of plasma energy at the time of forming the passivation layer. The method of claim 12,
Wherein each of the buffer layer and the passivation layer is one of an oxide film and a nitride film,
Wherein the buffer layer and the passivation layer are the same inorganic film. 14. The method of claim 13,
Wherein the power for generating the plasma for forming the buffer layer is greater than 0.5 kW and less than 4 kW and the power for generating the plasma for forming the passivation layer is greater than 0.9 kW and less than 8.8 kW. 10. A display device comprising a passivation film according to any one of claims 10 to 12,
Board; And
A display formed on the substrate;
Lt; / RTI >
Wherein the passivation film covers the substrate including the display portion.

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