KR100761112B1 - Method of Manufacturing Light Emitting Diode Device - Google Patents

Abstract

The present invention is the formation of the metal layer on a substrate and forming a conductive layer on the metal layer and the first electrode forming step of forming a first electrode, a conductive layer in the process on the first electrode by an oxidation reaction occurs oxide H ₂ An electrode post-treatment step of removing the plasma process, a light-emitting part forming step of forming a light emitting part on the first electrode which has been subjected to the electrode post-processing step, and a second electrode forming step of forming a second electrode on the light emitting part. Provided is a method of manufacturing an electroluminescent device.

EL, Plasma

Description

Method of Manufacturing Light Emitting Diode Device

1 is a cross-sectional view of an electroluminescent device according to the prior art.

FIG. 2 is a partially enlarged view of region A on FIG. 1.

3 and 4 are H ₂ plasma treatment process diagram of the electroluminescent device according to an embodiment of the present invention.

5 is a cross-sectional view of an electroluminescent device formed after the H ₂ plasma treatment of FIGS. 3 and 4.

Explanation of the main symbols in the drawings

10 electroluminescent element 12 substrate

14: first electrode 16: hole injection / transport layer

18: light emitting layer 20: electron injection / transport layer

22: second electrode 24: protective part

24a: protective substrate 24b: getter

52 substrate 54 metal layer

56 conductive layer 58 first charge injection / transport layer

60 emitting layer 62 second charge injection / transport layer

D: oxide layer E1: first electrode

E2: second electrode F1: first light emission

F2: second light emitting L: light emitting

S: Sealant

The present invention relates to a method of manufacturing an electroluminescent device.

The electroluminescent device injects electrons and holes into the light emitting layer from an electron injection electrode and a hole injection electrode, respectively, and excitons of the injected electrons and holes combine from the excited state. It is a self-luminous device that emits light when it falls to the ground state.

In addition, the electroluminescent device can be driven at a low voltage and has advantages such as thinness. The electroluminescent device is attracting attention as a next-generation display that can solve the disadvantages pointed out as a problem in the conventional liquid crystal display, such as wide viewing angle and fast response speed.

The electroluminescent device is classified into a top-emitting LED emitting light in a direction opposite to the substrate and a bottom emitting LED emitting in the direction of the substrate according to the light emitting method.

1 is a cross-sectional view of an electroluminescent device according to the prior art.

Referring to FIG. 1, the electroluminescent device 10 according to the related art has a light emitting part L formed on a substrate 12 on which a first electrode and a driving part are patterned as a top emission type, and a light emitting part L. The second electrode 24 was formed on the top. In addition, in order to prevent oxidation and deterioration due to moisture, air, and the like of the light emitting part L and the second electrode 24, the protecting part 24 including the protective substrate 24a and the getters 24b and getters is sealed. It sealed on the board | substrate 12 by (S).

FIG. 2 is a partially enlarged view of region A on FIG. 1.

Referring to FIG. 2, the first electrode 14 is formed on the substrate 12, and the first charge injection / transport layer 16, the light emitting layer 18, and the second charge injection / transport layer 20 are disposed thereon. The light emitting portion L was formed by stacking sequentially. On the above-mentioned light emitting portion L, the second electrode 22 was formed.

In this case, the aforementioned first electrode 14 serves as a reflecting film that reflects the light emitted from the above-described light emitting part L in the opposite direction of the substrate 12, so that light emission of the device is directly external from the light emitting part L. The first light emission F1 is emitted by the light emitting unit L, and the second light emission F2 is emitted from the light emitting unit L to the substrate 12 and reflected by the first electrode 14 described above.

In fabricating the conventional electroluminescent device 10 having the above structure, since the first electrode 14 formed relatively close to the substrate side has to serve as a reflecting film, high reflectance was a very important characteristic and a low surface Properties such as roughness, excellent bonding with the substrate, easy etching, and environmental resistance were further required.

For example, Ag alloy or Al alloy is suitable as a material that satisfies these characteristics. However, Al alloy has been mainly used since Ag alloy has poor environmental resistance. However, in the case of Al alloys, high reactivity with oxygen, moisture, and the like has become a problem. In particular, when an alloy electrode containing Al of 50% or more is used, an oxide layer is formed on the surface of the electrode, and it is not easy to inject holes or electrons into the light emitting part.

Accordingly, the leakage current (leakage current) increases the driving voltage increases a serious problem that greatly reduces the stability of the device.

In addition, since the increased driving voltage increases the driving heat and deteriorates the organic material in the device, dark spots occur on the display, thereby degrading lifetime and reliability.

In order to solve this problem, an object of the present invention is to provide a method of manufacturing an electroluminescent device capable of realizing an electroluminescent device having a low driving voltage and a driving heat, and having improved stability, lifespan, and reliability.

In order to achieve the above object, the present invention provides a first electrode forming step of forming a metal layer on a substrate, and forming a conductive layer on the metal layer, and forming a first electrode on the first electrode. An electrode post-treatment step of removing the oxide generated by the oxidation of the conductive layer by H ₂ plasma treatment, a light-emitting part forming step of forming a light-emitting part on the first electrode which has undergone the electrode post-treatment step, And forming a second electrode in the second electrode, wherein the oxide of the conductive layer is more reactive with H ₂ plasma than the oxide of the metal layer.

In the first electrode forming step, the above-described metal layer is formed of an opaque or translucent material so as to reflect light emitted from the light emitting part in a direction opposite to the substrate.

In the first electrode forming step, the metal layer is formed of Al or an Al alloy.

In the first electrode forming step, the conductive layer may be formed of any one or more of Ti, Cr, Ag, Mn, Fe, Nd, Mo, Nb, and Sn.

In the light emitting unit forming step, at least one charge injection / transport layer and the light emitting layer may be stacked to form a light emitting unit.

In the electrode post-processing step, any one of a capacitively coupled plasma (CCP), a transfer coupled plasma (TCP), an inductive coupled plasma (ICP), and an electron cyclotron resonance plasma (ECRP) may be used as a plasma power source. .

In the light emitting part forming step, the light emitting layer is formed of an organic material.
Hereinafter, a method of manufacturing an electroluminescent device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 and 4 illustrate an H ₂ plasma treatment process of an electroluminescent device according to the present invention, in which an oxide layer D formed on an electrode serving as a reflective film, which is a cause of the above-described problems in the prior art, can be seen.

In the exemplary embodiment of the present invention, the first electrode E1 is formed by stacking the metal layer 54 and the conductive layer 56 on the substrate 52, wherein the conductive layer 56 is the metal layer 54 during the oxidation reaction during the process. ) Is a thermodynamically less stable than the oxide produced by the oxidation reaction, so that a material that forms an oxide that is easy to H ₂ plasma treatment is adopted. In other words, the material is selected so that the oxide of the conductive layer 56 is less thermodynamically stable than the oxide of the metal layer 54 and is more reactive with the H ₂ plasma, thereby facilitating the H ₂ plasma treatment.
The conductive layer is a method of manufacturing an electroluminescent device, characterized in that the reduction power is less than the oxidation compared to the metal layer.

As such, the electroluminescent device of the present invention is subjected to an H ₂ plasma treatment step to remove the oxide layer (D) on the unwanted electrode generated in the process.

3 and 4 focus on the substrate and the reactant to be processed in the chamber according to each process step.

In detail, FIGS. 3 and 4 illustrate a process of removing the oxide layer D generated on the surface of the first electrode E1 formed on the substrate 52 according to the manufacturing process of the electroluminescent device. H ₂ plasma The state before and after the treatment process is shown.

The process and principle of the aforementioned H ₂ plasma treatment process are described in detail below.

For example, the metal layer on the substrate 52 may be formed by any one of thermal evaporation, E-beam evaporation, sputtering, and chemical vapor deposition (CVD). 54 and the conductive layer 56 are deposited to pattern the first electrode E1.

At this time, since the above-described metal layer 54 must have high conductivity and reflectance, for example, Al or Al alloy is formed.

However, since the Al alloy has good reactivity with moisture or oxygen as described above, the oxide layer is generated by the reaction between the moisture or oxygen generated in the process and the metal layer 54 of the first electrode E1.

At this time, since the oxide layer of Al is a very stable compound, H ₂ plasma treatment efficiency is lowered.
Therefore, on the metal layer 54, the reactivity with moisture or oxygen is less than the material of the metal layer 54 (small reduction force), so that oxidation is not good, and even after the reaction, the compound (oxide) is relatively unstable and H ₂ plasma The conductive layer 56 is formed of a material having high reactivity with and easily removable by the H ₂ plasma treatment. For example, when the metal layer 54 is made of Al, the conductive layer 56 is formed of any one or more of Ti, Cr, Ag, Mn, Fe, Nd, Mo, Nb, Sn.

Accordingly, as shown in FIG. 3, the oxide layer D is thermodynamically unstable than the oxide layer of Al and reacts better with the H ₂ plasma on the first electrode E1.

In order to remove this oxide layer (D), in the present invention is that the H ₂ plasma process At this time, inside the process chamber to the high efficiency of the H ₂ plasma process, for example, H _2, Ar, N _2, Ne, He , Kr, or Xe, or one or more gas atmospheres. In addition, the use of H ₂ gas atmosphere, the composition ratio of 10% or more of the above-described process.

In addition, as a power source for forming H ₂ plasma, for example, any one of Capacitively Coupled Plasma (CCP), Transfer coupled Plasma (TCP), Inductive coupled Plasma (ICP), and Electron Cyclotron Resonance Plasma (ECRP). One may be used, preferably using a high plasma density method.

At this time, the power source to be used should be selected differently according to the area of the electrode, it is preferable to select in the power range of 0.01W / cm ² to 100W / cm ² .

In addition, while biasing the substrate side for effective reactivity of the H ₂ plasma treatment, it is preferable to apply a bias within the range of -10 to -1000V by applying RF power (Radio Frequency Power).

In the reaction relationship between materials in the H ₂ plasma treatment process, H ₂ injected into the plasma is decomposed into H ⁺ ions and reacts with an oxide on the surface of the first electrode E1 to the outside in the form of H ₂ O or OH ⁻ ions. By emitting, the oxide layer on the surface of the first electrode E1 is removed.

Through the H ₂ plasma treatment of the oxide layer according to the structure of the first electrode E1 as described above, an embodiment of the present invention can achieve a desired object, and as a result of the process, FIG. 5 illustrates the electroluminescent device of the present invention. The structure is shown.

5 is a cross-sectional view of an electroluminescent device formed after the H ₂ plasma treatment of FIGS. 3 and 4.

Referring to FIG. 5, the first charge injection / transfer layer 58, the light emitting layer 60, and the second charge injection / transfer are formed on the substrates 52, 54, and 56 of FIG. 4 after the H ₂ plasma treatment shown in FIG. 3. The light emitting portion L composed of the layer 62 is laminated, and the second electrode 64 is formed thereon to complete the electroluminescent device of the present invention having improved light emission F1 and F2 efficiency.

The embodiments of the present invention are applicable not only to the active matrix type but also to the passive matrix type.

As described above, the embodiment of the present invention has been described with reference to, for example, a unidirectional light emitting type, but the present invention is not limited thereto and may be applied to a double sided light emitting type.

Embodiment of the present invention is to be understood as a category of electroluminescent display (LED) that is applicable to organic as well as inorganic material in the light emitting portion.

While the present invention has been described with reference to various embodiments, the scope of the present invention is indicated by the following claims rather than the foregoing description, and all changes derived from the meaning and scope of the claims and their equivalent concepts. Or variations should be construed as being included in the scope of the invention.

According to the present invention, it is possible to efficiently remove the oxide layer formed on the surface by improving the structure of the electrode acting as a reflective film in the electroluminescent device in the process. Accordingly, the drive voltage of the device can be lowered by facilitating the injection of charge from the electrode as described above in the light emitting portion.

In addition, according to the present invention, the driving heat can be lowered to suppress deterioration of organic matter in the device and generation of dark spots on the display.

In addition, according to the present invention, it is possible to provide an electroluminescent device having improved stability, lifetime and reliability.

Claims (7)

A first electrode forming step of forming a metal layer on the substrate and forming a first electrode by forming a conductive layer on the metal layer; An electrode post-treatment step of removing an oxide generated by oxidation of the conductive layer during the process on the first electrode by H ₂ plasma treatment; A light emitting part forming step of forming a light emitting part on the first electrode after the electrode post-processing step; And Forming a second electrode on the light emitting part; Including; The oxide of the conductive layer is a method of manufacturing an electroluminescent device, characterized in that it is more reactive with H ₂ plasma than the oxide of the metal layer. The method of claim 1, In the first electrode forming step, the metal layer is formed of an opaque or semi-transparent material to reflect the light emitted from the light emitting portion in a direction opposite to the substrate. The method of claim 1, In the first electrode forming step, the metal layer is formed of Al or Al alloy manufacturing method of the electroluminescent device. The method of claim 3, wherein In the first electrode forming step, the conductive layer is formed of any one or at least one of Ti, Cr, Ag, Mn, Fe, Nd, Mo, Nb, Sn. The method according to any one of claims 1 to 4, In the light emitting unit forming step, at least one charge injection / transport layer and the light emitting layer by laminating a method of manufacturing an electroluminescent device, characterized in that to form a light emitting unit. The method of claim 5, In the electrode post-treatment step, electroluminescence, characterized in that any one of capacitively coupled plasma (CCP), transfer coupled plasma (TCP), inductive coupled plasma (ICP), and electrophoretic cyclones (ECRP) is used as a plasma power source. Method of manufacturing the device. The method of claim 5, In the forming of the light emitting portion, the method of manufacturing an electroluminescent device, characterized in that the light emitting layer is formed of an organic material.

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