KR20050060372A - Apparatus and method for manufacturing transparent electrode of organic electroluminescence device - Google Patents

Abstract

The present invention is to minimize the damage occurring on the surface of the substrate or the organic EL layer during the deposition of the transparent electrode of the organic electroluminescent device and to improve the interfacial properties with the transparent electrode, the present invention, filling the inert gas in the chamber and the transparent electrode After applying a voltage to the formation target, particles of the target are deposited on the substrate using the mask while voltage is applied to a mask having a plurality of slits or holes.

Description

Transparent electrode manufacturing method and apparatus for organic electroluminescent device {APPARATUS AND METHOD FOR MANUFACTURING TRANSPARENT ELECTRODE OF ORGANIC ELECTROLUMINESCENCE DEVICE}

The present invention relates to an organic electroluminescent device, and more particularly to a method and apparatus for manufacturing a transparent electrode of the organic electroluminescent device.

Electroluminescence devices (hereinafter referred to as ELDs) have attracted attention as next-generation flat panel display devices because they have characteristics such as wide viewing angle, high aperture ratio, and high chromaticity. In particular, the organic ELD is based on the principle that when electrons are injected into the organic light emitting layer formed between the hole injection electrode and the electron injection electrode, light is generated when the electrons and holes are paired and then disappear. It is possible to drive.

The organic ELD is divided into a passive electroluminescent device (passivation ELD) and an active electroluminescent device (active matrix ELD) according to the driving method. The passive electroluminescent element is composed of a transparent electrode on a transparent substrate, an organic EL layer on the transparent electrode, and a cathode electrode on the organic EL layer. An active electroluminescent device includes scan lines and data lines defining a pixel region on a substrate, a switching device electrically connected to the scan lines and data lines and controlling the electroluminescent device, And a transparent electrode formed in a pixel region on the substrate, an organic EL layer on the transparent electrode, and a metal electrode on the organic EL layer. Unlike passive electroluminescent devices, active electroluminescent devices further include switching devices, which are thin film transistors.

Active electroluminescent devices are classified into a top-emission method and a bottom emission method. Since the top-emission type active electroluminescent device emits light toward the metal common electrode in the organic EL layer, unlike the bottom-emission type active electroluminescent device, The metal common electrode should be thinly formed for efficient light transmission.

Conventionally, a sputtering deposition method is used to form a transparent electrode, by filling an argon gas into a vacuum chamber and applying a voltage to an ITO target to ionize the argon gas, and then using target particles that are released while the ionized argon collides with the target. To form a transparent electrode. However, when the transparent electrode is deposited, the particles emitted from the target have too much energy, thereby damaging the surface of the substrate or the organic EL layer. This causes problems such as deterioration of the surface roughness of the substrate and the organic EL layer, the density of the transparent electrode, the interfacial properties, and the like.

The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to minimize damage occurring on the surface of a substrate or an organic EL layer during the deposition of a transparent electrode and to improve an interface property with the transparent electrode. To provide a method and apparatus for manufacturing a transparent electrode.

In order to achieve the above object, the present invention provides a method for manufacturing a transparent electrode, comprising: placing a substrate having an organic material layer in a chamber and filling an inert gas; Applying a voltage to a target for forming a transparent electrode; Depositing the target particles onto the substrate using a mask having a plurality of slits or holes.

In the step of applying a voltage to the target for forming the transparent electrode, a DC or RF voltage is applied, and in the step of depositing the target particles, a DC or AC voltage is applied to the mask.

An apparatus for manufacturing a transparent electrode of the present invention includes a plate disposed at a position facing a substrate in a vacuum chamber; A target for forming a transparent electrode disposed on the plate; A mask disposed between the substrate and the target for forming a transparent electrode and having a plurality of slots or holes; It includes a power supply for supplying a voltage to the mask.

The target for forming the transparent electrode is made of an ITO-based material, and the slit or hole has a size of 10 Å-1 cm.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention in which the above objects can be specifically realized are described with reference to the accompanying drawings. In describing the present embodiment, the same name and the same reference numerals are used for the same configuration and additional description thereof will be omitted below.

Referring to the manufacturing method of the organic electroluminescent device is as follows. 1A to 1F are views showing a method of manufacturing an organic electroluminescent device (ELD) of the present invention. As shown in FIG. 1A, the thin film transistor 42 is formed on the glass substrate 41. The thin film transistor 42 includes source / drain regions, a channel region, a gate insulating layer, and a gate electrode.

Afterwards, an interlayer insulating layer 43 is formed on the gate insulating layer and the gate electrode. In addition, contact holes are formed by selectively etching the interlayer insulating layer 43 and the gate insulating layer so that a predetermined portion of the upper surface of the source / drain region is exposed, and a metal material is filled in the contact holes to fill the source / drain region. And electrode lines 44 electrically connected to each other are formed. An insulating layer 45 may be further formed on the interlayer insulating layer 43 and the electrode lines 44.

As shown in FIG. 1B, an insulating material is deposited on the interlayer insulating layer 43 and the electrode lines 44 by a spin coating method to deposit the planarization insulating layer 46, and the planarization insulating layer 46 is pre- It is cured through a pre-bake process. The planarization insulating layer 46 is selectively removed to form the via hole 47 so that the electrode line 44 connected to the drain region of the thin film transistor 42 is exposed.

As illustrated in FIG. 1C, a metal material for forming the pixel electrode 48 is deposited on the entire surface of the via hole 47 and the planarization insulating layer 46. In this case, in the case of a bottom-emission EL device, the metal material layer is formed of a transparent material such as indium-tin-oxide (ITO), and on the contrary, is a top-emission EL device. In this case, the metal material layer is formed of a metal material having high reflectance and work function. A method of depositing the pixel electrode 48 using ITO in the case of the EL device of the bottom emission type will be described in detail below.

Thereafter, the metal material layer is selectively removed to form the pixel electrode 48 in the pixel region. The pixel electrode 48 deposited in the via hole 47 of the planarization insulating layer 46 is connected to the electrode line 44 under the via hole 47.

As shown in FIG. 1D, after depositing an insulating material on the entire surface of the pixel electrode 48 and the planarization insulating film 46, the insulating material layer is selectively removed to remove the pixel area, that is, the pixel area. The insulating film 49 is formed in the boundary region between them. In this case, the insulating layer 49 is formed on a portion of the pixel electrode 48 and the planarization insulating layer 46. In addition, an auxiliary electrode (not shown) that is electrically connected to the common electrode 51 may be further formed on the insulating layer 49.

Subsequently, as shown in FIG. 1E, an organic electroluminescent (EL) layer 50 is deposited on the pixel electrode 48 using the shadow mask 170. The organic electroluminescent layer 50 is divided into RED, GREEN, and BLUE organic electroluminescent layers according to the emission color, and these R, G, and B organic electroluminescent layers 50 are formed in each pixel region in turn. The organic electroluminescent layer 50 is deposited only in the pixel region. The organic electroluminescent layer 50 may include a hole injection layer (50a of FIG. 4), a hole transport layer (50b of FIG. 4), a light emitting layer (not shown), an electron injection layer (not shown), and an electron transport layer. It has a laminated structure (not shown). The hole injection layer 50a and the hole transport layer 50b inject and transfer holes supplied from the pixel electrode 48 to the light emitting layer, and the electron injection layer and the electron transport layer are supplied from the common electrode 51. Electrons are injected and transferred into the light emitting layer.

As shown in FIG. 1F, a common electrode 51 is formed on the organic electroluminescent layer 50 and the insulating layer 49. In the case of a bottom-emission EL device, the common electrode 51 is formed of a metal material having high reflectivity. In contrast, in the case of a top-emitting EL device, the common electrode 51 is formed of ITO. It is formed of a transparent material. In the case of the EL device of the top emission type, a method of depositing the common electrode 51 using ITO will be described in detail below.

Although not shown in the drawings, a protective film (not shown) is formed to protect the organic electroluminescent layer 50 from oxygen or moisture. Then, a protective cap is formed using a sealant and a transparent substrate.

As described above, the materials forming the pixel electrode 48 and the common electrode 51 vary according to the light emission method. In the case of the top emission method, since the common electrode 51 is a transparent electrode, the common electrode 51 is formed of ITO. In the case of the bottom emission method, the pixel electrode 48 should be a transparent electrode. 48) is formed of ITO.

Referring to FIGS. 2 and 3, a method of forming a transparent electrode using ITO is as follows.

The sputtering deposition method is mainly used for ITO deposition because of the advantages of easy deposition of the metal material and high adhesion of the deposition material. As shown in FIG. 2, in the vacuum chamber 100 for sputter deposition, the substrate 41 is seated at a position opposite to the target 300 on the plate 200, and the substrate 41 and the target 300 are disposed. The shadow mask 400 having the slots 410 or the holes of the minute size is disposed between the holes. In addition, a magnet 500 forming a magnetic force line in order to increase the sputtering efficiency is disposed on the rear surface of the target 300. In addition, a cooling water pipe 210 for cooling heat passes through the plate 200.

First, an inert gas such as argon (Ar +) or oxygen (O2) gas is filled in the vacuum chamber 100, and then a high-voltage DC or pulsed DC or radio frequency (RF) voltage is applied to the target 300. The inert gas is ionized. The ionized inert gas sputters particles of the target 300 by using ions emitted while colliding with the target 300.

When a DC voltage is applied to the target 300, the electrons in the vacuum chamber 100 are accelerated by the electric field to obtain sufficient energy to ionize the neutral argon gas, and then the neutral argon gas particles and Collisions produce pairs of electrons and cations. The generated cations are accelerated in the opposite direction to the electrons by the electric field and collide with the target 300. At this time, the target material is sputtered by the collision of cations.

When the RF voltage is applied to the target 300, the target 300 such that the net charge flowing toward the target 300 to which the RF power is applied during the period of the RF becomes zero due to the rapid movement of electrons relatively lighter than the positive ions. ), And a DC bias voltage is formed between the plasma and the DC bias voltage, which causes the positive ions to collide with the target 300 with great energy and erode. That is, the target material is sputtered into the plasma region by direct collision between incident ions and atoms on the surface of the target 300 or continuous collision between atoms on the surface of the target 300.

As shown in FIG. 3, target particles emitted from the target 300 pass through minute slots 410 or holes of the shadow mask 400. In this case, a DC or AC voltage is applied to the shadow mask 400 from the power supply 600. As the target particles pass through the slot 410 to which a voltage is applied, their acceleration energy decreases, and at the same time, the target particles are diffracted / dispersed in various directions due to the influence of the fine slot 410 having a size of 10 Å-1 cm. The number will be reduced. Therefore, the target particles deposited on the substrate 41 do not damage the surface of the planarization insulating film 46 or the surfaces of the organic electroluminescent layer 50 and the insulating film 49. In addition, a transparent electrode having a good interface state can be formed.

As a result, as shown in FIG. 4, the transparent electrode having a good interface state reduces the potential barrier during hole injection into the organic electroluminescent layer 50, thereby enabling the movement of many holes.

When the transparent electrode is deposited in a vacuum chamber, the present invention applies a voltage to a mask having a plurality of slots and sputters target particles through the slots, thereby reducing the acceleration energy of the target particles and reducing the number of target particles. . Therefore, damage caused on the surface of the organic material layer or the insulating film due to the target particles can be reduced, and a transparent electrode having a good interface state can be formed.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

1A to 1F are plan views illustrating a method of manufacturing an organic electroluminescent device;

2 is a block diagram showing a transparent electrode manufacturing apparatus of an organic electroluminescent device according to the present invention;

3 is a view for explaining a method for manufacturing a transparent electrode of an organic electroluminescent device according to the present invention;

4 is a diagram illustrating movement of potential barriers and holes of a transparent electrode and an organic electroluminescent layer.

Explanation of symbols on main parts of drawing

41 substrate 42 thin film transistor

43: interlayer insulating film 44: electrode line

45, 49 insulating film 46 planarization insulating film

47: via hole 48: pixel electrode

50: organic electroluminescent layer 51 common electrode

100: vacuum chamber 200: plate

210: coolant pipe 300: target

400: shadow mask 410: slot

500: magnet 600: power supply

Claims (10)

Placing a substrate having a layer of organic material in the chamber and filling inert gas; Applying a voltage to a target for forming a transparent electrode; Method of manufacturing a transparent electrode of an organic electroluminescent device comprising the step of depositing target particles on the substrate using a mask having a plurality of slits or holes. The method of claim 1, In the step of applying a voltage to the target for forming a transparent electrode, Transparent electrode manufacturing method of an organic electroluminescent device, characterized in that applying a DC or RF voltage. The method of claim 1, In the step of depositing the target particles, Method of manufacturing a transparent electrode of the organic electroluminescent device, characterized in that the DC or AC voltage applied to the mask. The method of claim 1, The slit or hole is a transparent electrode manufacturing method of an organic electroluminescent device, characterized in that having a size of 10Å-1cm. The method of claim 1, The transparent electrode forming target is a transparent electrode manufacturing method of an organic electroluminescent device, characterized in that made of an ITO-based material. The method of claim 1, The inert gas is a transparent electrode manufacturing method of an organic electroluminescent device, characterized in that argon or oxygen. A plate disposed in a vacuum chamber at a position opposite the substrate; A target for forming a transparent electrode disposed on the plate; A mask disposed between the substrate and the target for forming a transparent electrode and having a plurality of slots or holes; Transparent electrode manufacturing apparatus of an organic electroluminescent device comprising a power supply for supplying a voltage to the mask. The method of claim 7, wherein The slit or hole is a transparent electrode manufacturing apparatus of an organic electroluminescent device, characterized in that having a size of 10Å-1cm. The method of claim 7, wherein The power supply unit is a transparent electrode manufacturing apparatus of an organic electroluminescent device, characterized in that for applying a DC or AC voltage to the mask. The method of claim 8, The transparent electrode forming target is a transparent electrode manufacturing apparatus of an organic electroluminescent device, characterized in that made of an ITO-based material.