KR101313706B1 - Apparatus and method of depositing aluminum electrode of organic light emitting diode device - Google Patents

Abstract

The present invention, the chamber is installed in the chamber, the substrate support for placing the substrate on the upper surface; A mask placed on the substrate and having a through portion of an electrode pattern; Gas injection means for injecting gas into the upper portion of the substrate stabilizer; An Al source supply part connected to the gas injection means and supplying an Al precursor Al precursor material; An Al electrode deposition apparatus of an organic light emitting diode device including a TiCl ₄ supply unit connected to the gas injection means and a deposition method using the same are provided.

According to the present invention, when forming an aluminum electrode of an organic light emitting diode (OLED), compared to the case of installing an evaporator inside the chamber, since the Al source material can be introduced into the chamber uniformly sprayed into the chamber, even thin film uniformity Can improve. In addition, since the process proceeds while maintaining the substrate temperature at 100 ° C. or lower, it is possible to prevent damage to the organic thin film vulnerable to high temperature.

Organic light emitting diode device, OLED, Al electrode

Description

Apparatus and method of depositing aluminum electrode of organic light emitting diode device

1 is a schematic cross-sectional view of an organic light emitting diode device

2 is a block diagram of a conventional bottom-up aluminum electrode deposition apparatus

3 is an aluminum electrode deposition apparatus of an organic light emitting diode device according to an embodiment of the present invention

4 is an aluminum electrode deposition apparatus of an organic light emitting diode device using an injector

5 is a flowchart illustrating a process of forming an aluminum electrode of an organic light emitting diode device according to an embodiment of the present invention.

Description of the Related Art [0002]

100: aluminum electrode deposition apparatus 110: chamber

120: substrate support 130: mask

140 gas distribution plate 150 plasma electrode

160: gas supply pipe 170: RF power

180: matching circuit 190: Al source supply unit

200: TiCl ₄ supply unit 210: purge gas supply unit

220,230: 1st, 2nd injector

The present invention relates to an Al electrode deposition apparatus and method of an organic light emitting diode device (OLED), and more particularly, to an apparatus and method for depositing an Al electrode thin film by chemical vapor deposition on an organic thin film at low temperature. will be.

Liquid crystal display (LCD), which is widely used among flat panel displays, has the advantages of light weight and low power consumption, but because it is not a light emitting device but a light receiving device, it has a constant technology such as brightness, contrast, viewing angle, and large area. There is a limit.

As an alternative to overcome these disadvantages, a flat panel display using an organic light emitting diode device has been actively researched and developed.

Since the organic light emitting diode device is a self-luminous type, it has better viewing angle, contrast, and the like than the liquid crystal display device, and it is possible to manufacture lighter and thinner since it does not require a backlight, and is advantageous in terms of power consumption.

In particular, unlike a liquid crystal display device or a plasma display panel (PDP), an organic light emitting diode device manufacturing apparatus has an advantage that the process is very simple because the deposition and encapsulation apparatuses are all.

FIG. 1 illustrates a simplified cross-sectional structure of an organic light emitting diode device 10, and includes a hole transport layer 12, an organic light emitting layer 13, and an electron transport layer made of an organic compound between an anode 11 and a cathode 15. 14 is formed sequentially, and typically, the anode 11 is coated with ITO (indiun-tin-oxide), and the cathode 15 is coated with Al.

When a voltage is applied between the anode 11 and the cathode 15 in the organic light emitting diode device 10, holes injected from the anode 11 are transferred to the organic light emitting layer 13 via the hole transport layer 12. As the electrons move and are injected into the organic light emitting layer 13 from the cathode 15 via the electron transport layer 14, electrons and holes are recombined in the organic light emitting layer 13 to form neutral excitons.

As the excitons change from the excited state to the ground state, molecules of the organic light emitting layer 13 emit light to form an image.

The organic light emitting layer is a region expressing the colors of red (R), green (G), and blue (B), and in general, a separate organic material emitting red, green, and blue is used for each pixel.

Currently, organic materials used in the manufacture of organic light emitting diode devices include Alq3, CuPc, TDP, NPB, and the like. In order to express color, DCJTB for red, coumarine derivative or quinacridone derivative for green, and DPA for blue Dopants are used.

However, these organic materials are mainly low molecular weight, and thus have disadvantages of being vulnerable to moisture or high energy particles.

The main method used to deposit these organic materials on a substrate is to vaporize (evaporate) the source organic material in the solid state so that the vaporized organic materials are deposited on the substrate through diffusion.

FIG. 2 illustrates a conventional deposition apparatus 20 for an organic light emitting diode device, and includes a chamber 21 and an evaporator 24 which vaporizes raw materials and is located inside the chamber 21. It is located on the top and includes a substrate support 22 for supporting the surface of the substrate (s) facing the lower evaporator 24.

A mask 23 having a penetrating portion of a predetermined pattern is provided directly below the substrate s. Thus, the raw material vaporized in the evaporator 24 is deposited on the surface of the substrate exposed through the pattern of the mask 23 through diffusion.

The evaporator 24 uses a ceramic crucible heated by a hot wire.

This deposition method is also used when forming Al cathodes.

However, the bottom-up deposition method in which the evaporator 24 is installed in the chamber 21 has some problems as follows.

First, the larger the substrate (s), the greater the degree of sagging of the substrate.

Second, in order to secure the uniformity of the thin film formed on the substrate s, the evaporator 24 and the substrate s should be installed as far as possible in order to diffuse the vaporized material sufficiently. Therefore, the efficiency of the raw material is greatly lowered, and the larger the substrate, the more difficult it is to secure thin film uniformity.

In order to solve this problem, a top-down deposition method and apparatus for supplying a raw material from an upper portion of the substrate stabilizer has been developed.

However, this top-down deposition method is limited to depositing organic materials that can be deposited in a relatively low temperature environment, and does not reach the top-down deposition of an aluminum cathode having a very high vaporization temperature.

Although aluminum cathodes may be deposited using a sputter, sputtering may be difficult to apply because the high energy of aluminum ions is highly likely to damage the organic thin film.

In addition, the method of vaporizing Al from the outside of the chamber and supplying it into the chamber not only hassle to maintain the internal temperature of the supply pipe and the chamber at a very high temperature so that the vaporized Al does not condense during the supply process, and the organic material due to the high temperature. There is a problem that it is difficult to prevent damage to the thin film.

Depending on the structure of the OLED, an Al thin film may be used instead of ITO for the anode, so this problem associated with Al deposition in the OLED is not necessarily limited to Al cathode. Therefore, hereinafter, the present invention will be described in terms of forming an Al electrode (cathode or anode) on a substrate for manufacturing an OLED.

An object of the present invention is to provide an apparatus and method for solving a problem of substrate deflection caused by a large area of a substrate by depositing an Al electrode of an organic light emitting diode device downward by using a chemical vapor deposition method. There is this.

In particular, an object of the present invention is to provide a deposition apparatus and a deposition method capable of preventing damage to an organic thin film by maintaining a temperature of a substrate at a low temperature of 100 ° C. or lower when forming an Al electrode.

The present invention to solve the above problems, the chamber; A substrate support stand installed inside the chamber and configured to place a substrate on an upper surface thereof; A mask placed on the substrate and having a through portion of an electrode pattern; Gas injection means for injecting gas into the upper portion of the substrate stabilizer; An Al source supply unit connected to the gas injection means and supplying an Al-based Al precursor material; Provided is an Al electrode deposition apparatus for an organic light emitting diode device including a TiCl ₄ supply part connected to the gas injection means.

At this time, the allene-based Al precursor material is H ₃ Al: MP. H ₂ Al (BH ₄ ): N (Me) ₃ , H ₂ Al (BH ₄ ): N (Et) ₃ , H ₂ Al (BH ₄ ): MP, H ₂ Al (BH ₄ ): MeN (Et) ₂ , H ₂ Al (BH ₄ ) :( Me) ₂ NEt may be any one material selected from.

The gas injection means may include a gas distribution plate having a plurality of injection holes.

The gas injection means may include an injector symmetrically installed along the inner wall of the chamber.

The injector may include a first injector connected to the Al source supply unit; It may include a second injector connected to the TiCl ₄ supply and not in communication with the first injector.

A purge gas supply unit for purging the inside of the chamber may be further connected to the gas injection means.

A plasma electrode to which RF power is selectively applied may be installed on an upper portion of the substrate stabilizer, and an H ₂ supply part may be further connected to the gas injection means.

The present invention also provides a method for depositing a substrate on the substrate support inside the chamber, the organic thin film is formed, the aluminum deposition on top of the substrate, spraying TiCl ₄ to the upper portion of the substrate; Spraying an Al precursor material onto the substrate to generate an Al nucleus on the surface of the substrate; Stopping the injection of the Al precursor material; Removing Cl contained in the thin film of the substrate; The present invention provides a method for depositing Al electrodes of an organic light emitting diode device, the method comprising: spraying an Al precursor material back into the chamber to form an Al thin film using the Al nucleus as a seed.

Here, the step of spraying TiCl ₄ to the top of the substrate. The method may further include stopping the injection of TiCl ₄ and purging the inside of the chamber.

The removing of Cl may include generating Cl in a thin film of the substrate by generating an H ₂ plasma.

The allenic Al precursor material is H ₃ Al: MP. H ₂ Al (BH ₄ ): N (Me) ₃ , H ₂ Al (BH ₄ ): N (Et) ₃ , H ₂ Al (BH ₄ ): MP, H ₂ Al (BH ₄ ): MeN (Et) ₂ , H ₂ Al (BH ₄ ) :( Me) ₂ NEt may be any one material selected from.

In another aspect, the present invention, the chamber is provided with a substrate stabilizer to form a constant reaction space; Gas injection means formed on an upper portion of the substrate stabilizer to inject gas; A source material supply unit connected to the gas injection means and supplying an Al-containing source material; In the Al electrode deposition method of the organic light emitting diode device using a deposition apparatus connected to the gas injection means, comprising a catalyst material supply unit for supplying a Cl-containing catalyst material,

Placing the substrate on which the organic thin film is formed on the substrate support in the chamber; Spraying a Cl-containing catalyst material onto the substrate; Spraying an Al-containing source material onto the substrate to generate Al nuclei on the surface of the substrate; Stopping the injection of the Al-containing source material; Removing Cl contained in the thin film of the substrate; And spraying the Al-containing source material back into the chamber to form an Al thin film using the Al nucleus as a seed.

The Al-containing source material is H ₃ Al: MP. H ₂ Al (BH ₄ ): N (Me) ₃ , H ₂ Al (BH ₄ ): N (Et) ₃ , H ₂ Al (BH ₄ ): MP, H ₂ Al (BH ₄ ): MeN (Et) ₂ , H ₂ Al (BH ₄ ) :( Me) ₂ NEt may be any one material selected from.

TiCl ₄ may be used as the Cl-containing catalyst material.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

Generally, the Al-based aluminum precursor is not only difficult to produce Al nuclei on the dielectric or the organic material but also takes a very long time even if the nucleus is generated. It could not be used as a source material for electrodes.

However, after the resin substrate or the organic substrate is exposed to TiCl ₄ for a predetermined time, when spraying an allene aluminum precursor, decomposition of the allene aluminum precursor is activated due to the catalytic action of TiCl ₄ , thereby lowering the temperature below 100 ° C. Al nucleation was also found possible.

Accordingly, embodiments of the present invention propose an apparatus and method for depositing an Al electrode of an OLED in a low temperature environment.

3 illustrates a schematic configuration of an OLED aluminum electrode deposition apparatus 100 according to an embodiment of the present invention.

Looking at this, the substrate stabilizer 120 for placing the substrate (s) is installed in the chamber 110, the gas distribution plate 140 having a plurality of injection holes is installed on the upper portion of the substrate stabilizer (120). do.

Therefore, unlike the conventional method of installing a high temperature Al evaporator inside the chamber 110, an Al electrode is formed using an Al source material sprayed from the upper portion of the substrate stabilizer 130, similar to a general chemical vapor deposition (CVD) apparatus. Done.

The plasma electrode 150 is installed on the upper portion of the gas distribution plate 140, and the edge of the gas distribution plate 140 is fixed to the lower edge of the plasma electrode 150. The gas supply pipe 160 is coupled to the center portion of the plasma electrode 150, and the raw material supplied through the gas supply pipe 160 is diffused in the space between the plasma electrode 150 and the gas distribution plate 140. After the injection is to the top of the substrate support 120.

A mask 130 having a penetrating portion of the aluminum electrode pattern is provided on the substrate s.

In addition, an Al source supply unit 190 and a TiCl ₄ supply unit 200 are connected to the gas supply pipe 160, respectively.

The Al source supply unit 190 is an apparatus for storing and supplying an Allen-based aluminum precursor. Allen-based aluminum precursors that can be used in the embodiment of the present invention are H ₃ Al: MP. H ₂ Al (BH ₄ ): N (Me) ₃ , H ₂ Al (BH ₄ ): N (Et) ₃ , H ₂ Al (BH ₄ ): MP, H ₂ Al (BH ₄ ): MeN (Et) ₂ , H ₂ Al (BH ₄ ) :( Me) ₂ NEt.

Where Me is CH ₃ , Et is C ₂ H ₅ , MP is methylpyrrolidine, N (Me) ₃ is Tri-Methylamine, and N (Et) ₃ is triethylamine ( Tri-Ethylamine) and N (Et) ₂ represent Diethylamine (Di-Ethylamine), respectively.

The Al source supply unit 190 stores and supplies one of these materials.

TiCl ₄ serves to catalyze the decomposition of allene-based aluminum precursor (precursor) to form Al nuclei on the surface of the substrate (s) in a low temperature environment.

The gas supply pipe 160 may further be connected to a purge gas supply unit 210 for supplying a purge gas such as N ₂ or Ar.

On the other hand, the material is introduced from the Al source supply unit 190, TiCl ₄ supply unit 200, purge gas supply unit 210, the upper portion of the gas distribution plate 140 through one gas supply pipe 160, specifically The inflow into the buffer space between the plasma electrode 150 and the gas distribution plate 140 is shown.

However, in order to minimize the Al source is influenced by TiCl ₄ , at least two gas supply pipes 160 are connected to the plasma electrode 150, and at least the Al source and TiCl ₄ may be formed through gas distribution plates through different gas supply pipes. More preferably, it is to be introduced into the upper space of 140).

On the other hand, the Al thin film formed on the substrate s may contain Cl due to TiCl ₄ serving as a catalyst, and Cl is likely to deteriorate the durability and electrical properties by corroding the Al thin film.

Therefore, an embodiment of the present invention proposes a method of removing Cl contained in an Al thin film by generating an H ₂ plasma. The plasma electrode 150 is a device necessary for generating H ₂ plasma, and when the plasma electrode 150 is installed, an H ₂ supply unit (not shown) for supplying H ₂ must be further connected to the gas supply pipe 160.

An RF power supply 170 for supplying RF power is connected to the plasma electrode 150, and a matching circuit 180 for impedance matching is installed between the RF power supply 170 and the plasma electrode 150.

When the Cl content is negligibly small in the actual process, since the H ₂ plasma treatment is unnecessary, the plasma electrode 150, the RF power source 170, the matching circuit 180, and the H ₂ supply unit (not shown) are omitted. It is okay.

4 illustrates an Al electrode deposition apparatus using the injectors 220 and 230 instead of the gas distribution plate 140. The same parts as in FIG. 3 are denoted by the same reference numerals, and description thereof will not be repeated.

A plurality of injectors may be symmetrically installed along the inner wall of the vacuum chamber 110, or may have a ring shape in which a plurality of injection holes are symmetrically formed.

Although the Al source supply unit 190, the TiCl ₄ supply unit 200, and the purge gas supply unit 210 may be connected to the same injector, as shown, at least the Al source supply unit 190 and the TiCl ₄ supply unit 200 may each be formed of a first source. It is preferable to connect the injector 220 and the second injector 230 so as not to influence each other in the injector before being injected into the chamber.

The purge gas supply unit 210 may be connected to any one of the first injector 220 or the second injector 230, and may further include a separate third injector (not shown) for purge gas.

Hereinafter, a method of depositing an aluminum electrode of an OLED according to an exemplary embodiment of the present invention will be described with reference to the flowchart of FIG. 5 and FIG. 3. When the injector is installed instead of the gas distribution plate, the deposition apparatus of FIG. 4 is used.

First, the substrate s is introduced into the chamber 110 and placed on the substrate support 120, and the substrate s is covered by using a mask 130 having a penetrating portion of the electrode pattern. Subsequently, the substrate entrance (not shown) is closed and the chamber is vacuum pumped to 10 ⁻⁵ Torr or less.

The substrate s is deposited with an organic material forming an organic light emitting layer, and so the temperature of the substrate s is maintained at 100 ° C. or lower, preferably 80 ° C. or lower, in order to prevent damage to the organic thin film. (ST 11)

Subsequently, when TiCl ₄ is injected through the gas distribution plate 140 for about 1 minute, the injected TiCl ₄ is adsorbed onto the substrate s through the penetrating portion of the mask 130.

The injection of TiCl ₄ is stopped and purge gas such as N ₂ or Ar of the purge gas supply unit 210 is injected to purge the inside of the chamber 110. (ST12, ST13)

Subsequently, an allene-based Al source material, for example, H ₂ Al (BH ₄ ): N (CH ₃ ) ₃ is injected into the chamber 110 through the gas distribution plate 140.

H ₂ Al (BH ₄ ): N (CH ₃ ) ₃ forms Al nuclei on the surface of the substrate s while being decomposed by the catalytic action of TiCl ₄ adsorbed on the surface of the substrate s.

The decomposition mechanism of H ₂ Al (BH ₄ ): N (CH ₃ ) ₃ is as follows.

(1) H ₂ Al (BH ₄ ): N (CH ₃ ) ₃ (g) → AlH ₃ (g) + (BH ₃ ): N (CH ₃ ) ₃ (g)

(2) AlH ₃ (g) + 2Al (s) → 3AlH (s)

(3) H ₂ Al (BH ₄ ): N (CH ₃ ) ₃ (g) → AlH (s) + (BH ₃ ): N (CH ₃ ) ₃ (g) + H ₂

(4) 3AlH (s) → 3 / 2H ₂ + 3Al (s)

Once the Al nucleus is generated through this process, the Al thin film continues to grow even if only the Al-based Al precursor is supplied without supplying TiCl ₄ . (ST14)

Therefore, once the Al nucleus is generated, the allene-based Al precursor may be continuously supplied until an Al thin film having a desired thickness is formed.

However, in the exemplary embodiment of the present invention, since TiCl ₄ is used as the decomposition catalyst, Cl component is contained in the Al thin film as described above, and thus, the Al thin film is corroded to deteriorate the durability and electrical properties of the thin film.

To prevent this, the supply of Al source material is temporarily suspended at the initial stage of Al nucleation, and H ₂ is applied to Al thin film. Preference is given to performing a plasma treatment. (ST15)

For the H ₂ plasma treatment, after Al nucleation is made, the supply of Al source material is temporarily suspended, and the plasma electrode 150 is injected through the RF power supply 170 while injecting H ₂ gas into the chamber 110. Supply RF power to

Since the substrate stabilizer 120 is grounded, it is formed between the plasma electrode 150 and the substrate stabilizer 120, specifically, the gas distribution plate 140 having the equipotential with the plasma electrode 150 and the substrate stabilizer 120. As the electrons accelerated by the RF electric field collide with the H ₂ neutral gas, plasma, which is a mixture of active species and ions, is generated.

Subsequently, active species or ions having high reactivity enter the substrate s and react with Cl contained in the Al thin film to remove Cl from the Al thin film. (ST16)

H ₂ plasma processing, for example, is conducted for about 10 seconds to 10 minutes, H ₂ after completion of the plasma treatment is discontinued the H ₂ supply, to interrupt the connection of the RF power source 170 is destroyed with H ₂ plasma Let's do it. (ST 17)

After the H ₂ plasma treatment is completed, when the allene-based Al precursor is injected into the chamber 110 again, the Al thin film is continuously deposited using the Al nucleus already formed on the substrate s as a seed, and desired aluminum An electrode is formed. (ST 18)

According to the present invention, in forming an aluminum electrode of an organic light emitting diode (OLED), since the Al source material can be introduced from the outside and uniformly sprayed into the chamber, compared to the conventional method of installing an Al evaporator inside the chamber. Thin film uniformity can be greatly improved.

In addition, since the process proceeds while maintaining the substrate temperature at 100 ° C. or lower, it is possible to prevent damage to the organic thin film vulnerable to high temperature.

In addition, since the deposition is performed in a top-down manner by using a chemical vapor deposition method, the substrate can be placed on the upper portion of the substrate stabilizer, thereby solving the problem of substrate deflection due to the large area.

Claims (15)

delete delete delete delete delete delete delete In the method of placing the substrate on which the organic thin film is formed on a substrate support inside the chamber, and depositing aluminum on the substrate, Spraying TiCl ₄ onto the substrate; After spraying the TiCl ₄ , spraying Al precursor material onto the substrate to generate Al nuclei on the surface of the substrate; Stopping the injection of the Al precursor material; Generating an H ₂ plasma to remove Cl contained in the thin film of the substrate; And Injecting an Al precursor material into the chamber to form an Al thin film using the Al nucleus as a seed, Generating the H ₂ plasma to remove Cl contained in the thin film of the substrate, after stopping the injection of the Al precursor material, the Al precursor material is injected into the chamber to seed the Al nucleus. The organic light emitting diode device manufacturing method, characterized in that proceeded before the step of forming an Al thin film (seed). 9. The method of claim 8, Injecting TiCl ₄ into the upper portion of the substrate, The method of manufacturing an organic light emitting diode device further comprising the step of stopping the injection of the TiCl ₄ , purging the interior of the chamber. delete 9. The method of claim 8, The Al precursor material is H ₃ Al: MP. H ₂ Al (BH ₄ ): N (Me) ₃ , H ₂ Al (BH ₄ ): N (Et) ₃ , H ₂ Al (BH ₄ ): MP, H ₂ Al (BH ₄ ): MeN (Et) ₂ , H ₂ Al (BH ₄ ): A method for manufacturing an organic light emitting diode device which is any one material selected from (Me) ₂ NEt. A chamber having a substrate stabilizer formed therein to form a constant reaction space; Gas injection means formed on an upper portion of the substrate stabilizer to inject gas; A source material supply unit connected to the gas injection means and supplying an Al-containing source material; A catalyst material supply unit connected to the gas injection means and supplying a Cl-containing catalyst material; In the organic light emitting diode device manufacturing method using a deposition apparatus comprising a, Placing the substrate on which the organic thin film is formed on the substrate support in the chamber; Spraying the Cl-containing catalyst material onto the substrate; After spraying the Cl-containing catalyst material, spraying the Al-containing source material onto the substrate to generate Al nuclei on the surface of the substrate; Stopping the injection of the Al-containing source material; Generating an H ₂ plasma to remove Cl contained in the thin film of the substrate; And Re-injecting the Al-containing source material into the chamber to form an Al thin film on the substrate using the Al nucleus as a seed; Generating the H ₂ plasma to remove the Cl contained in the thin film of the substrate, after stopping the injection of the Al-containing source material, by spraying the Al-containing source material back into the chamber to the An organic light emitting diode device manufacturing method comprising the step of forming an Al thin film on the substrate using an Al nucleus as a seed. 13. The method of claim 12, The Al-containing source material is H ₃ Al: MP. H ₂ Al (BH ₄ ): N (Me) ₃ , H ₂ Al (BH ₄ ): N (Et) ₃ , H ₂ Al (BH ₄ ): MP, H ₂ Al (BH ₄ ): MeN (Et) ₂ , H ₂ Al (BH ₄ ): (Me) A method for manufacturing an organic light emitting diode device which is any one material selected from ₂ NEt. 13. The method of claim 12, A method of manufacturing an organic light emitting diode device using TiCl ₄ as the Cl-containing catalyst material. delete

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