KR20060080481A - Effusion cell for depositing material and deposition system having it - Google Patents

Abstract

The present invention relates to a deposition source for vapor deposition and a deposition system having the same, comprising: a vacuum chamber; A stage having a chuck supporting the substrate and the mask installed in one side of the vacuum chamber in an aligned state; A drive shaft installed at the other side of the vacuum chamber; And a deposition source installed to be movable along the drive shaft, wherein the deposition source is a crucible in which organic materials are stored, a first heating body for heating the crucible, and a heating operation of the first heating body. The nozzle clogging phenomenon is characterized in that it comprises a spray nozzle unit for spraying the organic gaseous material formed by evaporation of the organic material, and a second heating body that is heated and maintained at a higher temperature than the first heating body It is possible to efficiently perform large area display by uniformly depositing organic materials on the substrate by preventing the splash phenomenon.

Heating element, thermal efficiency, organic gaseous substance

Description

Evaporation source for material deposition and deposition system having same {EFFUSION CELL FOR DEPOSITING MATERIAL AND DEPOSITION SYSTEM HAVING IT}             

1 is a schematic view showing a vacuum deposition system in which a deposition source incorporating a heating apparatus according to the present invention is located in a buffer region;

2 is a schematic view showing a vacuum deposition system in which a deposition source incorporating a heating apparatus according to the present invention is located in a film formation region;

3 is a cross-sectional view showing a state in which a heating apparatus according to the present invention is installed in a deposition source.

<Description of Symbols for Major Parts of Drawings>

10: vacuum chamber

20: evaporation source

22: crucible

24: injection nozzle unit

30: substrate

40: mask

50: Chuck

100: vacuum deposition system

The present invention relates to a deposition source for injecting an organic vapor material formed by evaporating the stored organic material and a deposition system having the same, and more particularly, in the injection nozzle unit by the condensation phenomenon of the organic vapor material to be injected Heating element that heats the injection nozzle unit in which organic gas is injected, as compared with heating action of a crucible in which organic material is stored so as to prevent nozzle clogging and splash phenomenon and to uniformly deposit organic gas on the substrate. It relates to a deposition source and a deposition system having the same that can increase the heating action of.

In general, an electroluminescent display device, which is one of flat panel displays, is classified into an inorganic electroluminescent display device and an organic electroluminescent display device according to a material used as a light emitting layer, and the organic electroluminescent display device can be driven at low voltage and is light in weight. It is attracting attention because of its thinness and wide viewing angle as well as fast response speed.

The organic light emitting device of the organic light emitting display device includes an anode, an organic material layer, and a cathode that are stacked on a substrate. The organic material layer includes an organic material layer of an organic light emitting layer that recombines holes and electrons to form excitons and emits light, and also between the cathode and the organic light emitting layer to smoothly transport holes and electrons to the organic light emitting layer to improve luminous efficiency. The organic material layer of the hole injection layer and the electron transport layer is interposed between the anode and the organic light emitting layer while interposing the organic material layer of the electron injection layer and the electron transport layer.

The organic light emitting device having the above-described structure is generally manufactured by a physical vapor deposition method such as a vacuum deposition method, an ion plating method and a sputtering method or a chemical vapor deposition method by a gas reaction. In particular, in order to form an organic material layer of an organic light emitting device, a vacuum deposition method for depositing an organic material evaporated in a vacuum on a substrate is widely used. effusion cells) are used.

The evaporation source includes a crucible in which organic material is accommodated, heating means for heating the crucible, an injection nozzle unit for injecting organic vapor material evaporated by the heating means, and an organic vapor material from the crucible to the injection nozzle. It includes a taxiway to guide.

Therefore, in the state where the substrate is mounted in the vacuum chamber, the organic material heated and evaporated by the heating means is sprayed onto the substrate through the injection nozzle via the induction furnace and deposited. At this time, the vacuum vapor deposition worker is making efforts to improve the step coverage and uniformity of the organic material layer formed on the substrate.

In particular, under the trend of larger substrates, organic materials are formed by evaporating organic materials to a substrate in which a deposition source is moved while moving vertically in a vacuum chamber in a vertical direction to form an organic material layer having good step coverage and uniformity. A vertically movable organic material deposition apparatus for spraying gaseous substances has been developed.

However, in the vertically moving organic vapor deposition apparatus, the opening of the injection nozzle of the evaporation source was enlarged in order to increase the film formation area of the organic layer. Entailed. As a result, the non-uniform spraying of the organic gaseous substance through the spray nozzle acted as a cause of decreasing the uniformity of the organic material layer formed on the substrate.

In addition, it was not possible to reduce the size of the deposition source by an induction furnace for guiding the organic vapor material from the crucible to the injection nozzle unit.

Accordingly, in the vertically movable organic material deposition apparatus, a method for forming an organic material layer having a relatively good uniformity on the substrate while miniaturizing the size of the deposition source is required. In addition, a method for preventing clogging and splashing of the injection nozzle part due to the condensation of organic gaseous substances in the injection nozzle part has been required.

The present invention has been proposed in order to solve the conventional problems as described above, in an organic vapor deposition apparatus for evaporating organic materials in a crucible while miniaturizing the size of a deposition source in a vertically movable organic material deposition apparatus to cope with the enlargement of a substrate. It is an object of the present invention to provide a deposition source and a deposition system having the same that can improve the uniformity of the organic material layer formed on the substrate by preventing the nozzle clogging phenomenon or splash of the injection nozzle by the material.

In order to achieve the above object, according to an embodiment of the present invention, the deposition source for vapor deposition material and the crucible in which the organic material is stored; A first heating body for heating the crucible; An injection nozzle unit for spraying an organic vapor material formed by evaporating the organic material by a heating action of the first heating body; It is made of a second heating body for heating the injection nozzle, characterized in that the second heating body is maintained at a higher temperature than the first heating body.

According to another embodiment of the invention, the deposition system comprises a vacuum chamber; A stage having a chuck supporting the substrate and the mask installed in one side of the vacuum chamber in an aligned state; A drive shaft installed at the other side of the vacuum chamber; And a deposition source installed to be movable along the drive shaft, wherein the deposition source is a crucible in which organic materials are stored, a first heating body for heating the crucible, and a heating operation of the first heating body. And an injection nozzle unit for spraying the organic gaseous substance formed by evaporation of the organic material, and a second heating unit which heats the injection nozzle unit and is maintained at a higher temperature than the first heating unit.

Preferably, the number of winding of the heating wire of the second heating body is higher than the number of winding of the first heating body so that more heat is generated in the injection nozzle part.

More preferably, further comprising a control unit for individually performing the heating control for the first heating body and the second heating body.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention. The term 'organic material' refers to a material stored in a crucible in a liquid state or a solid state to form an organic material layer on a substrate, and the term 'organic material' is formed by evaporation of an organic material when heating the crucible. Means a gaseous substance. As such, the specific terminology used in the description of the present invention is defined for convenience of description, and may vary according to the intention or custom of a person skilled in the art, and also to limit the technical components of the present invention. It should not be understood.

First, a vacuum deposition method for forming an organic material layer of an organic light emitting device is performed in a vacuum deposition system including a vacuum chamber.

Referring to FIG. 1, the vacuum chamber 10 of the vacuum deposition system 100 includes a substrate 30 on which an organic layer is to be formed, a mask 40 provided on the entire surface of the substrate 30, and a mask 40. Deposition sources 20 spaced at predetermined intervals are provided. The mask 40 and the substrate 30 are fixed in close contact with the chuck 50 in an aligned state by an alignment system (not shown). The mask 40 includes a pattern forming part (indicated by a virtual line) in which a pattern corresponding to an organic layer to be formed on the substrate 30 is formed, and a fixing part fixed by welding to a mask frame (not shown). . At this time, the vacuum chamber 10 is divided into a film forming area B corresponding to the installation position of the mask 40 and the substrate 30 and a buffer area A corresponding to a position other than the film forming area B.

The deposition source 20 moves vertically in the vacuum chamber 10 by the operation of a moving means (not shown).

Referring to FIG. 3, the deposition source 20 is a crucible 22 in which organic materials are stored, a first heating body 20a for heating the crucible, and a heating operation of the first heating body 20a. An injection nozzle unit 24 into which the evaporated organic vapor substance is injected, and a second heating body 20b for heating the injection nozzle unit 24.

The crucible 22 is heated by the heating action of the first heating body 20a so that the organic material stored in the crucible 22 is evaporated. The organic gaseous substance evaporated from the crucible 22 is heated by the heating action of the second heating body 20b so that the organic gaseous substance evaporated from the crucible 22 passes through the injection nozzle part 24 in a gas state without condensation. Condensation at

In this case, the first heating body 20a and the second heating body 20b mean a member that dissipates heat by energization, such as a heating wire, but is not limited thereto.

According to the present invention, the thermal efficiency of the second heating body 20b is largely maintained as compared with the thermal efficiency of the first heating body 20a. This is to prevent the organic gaseous substance formed by evaporating the organic substance by the heating action of the first heating body 20a as it will be described later, when it passes through the injection nozzle unit 24.

In addition, the above-described heating action is proportional to the number of windings of the heat dissipating member provided in the crucible 22 and the injection nozzle unit 24, for example, the number of windings of the hot wire. In other words, as the number of turns of the heating wire increases, the heating action increases. Therefore, by increasing the number of windings of the heating wire installed around the injection nozzle unit 24 compared to the number of windings of the heating wire installed around the crucible 22, when the same power is applied to the heating wire without a separate control variable, the injection nozzle The portion 24 is heated faster than the crucible 22.

In particular, the heating control for the first heating body 20a and the second heating body 20b is preferably performed separately. This individual control is performed by a controller (not shown) so that the spray nozzle portion 24 can be heated relatively quickly compared to the crucible 22.

On the other hand, since the heat retention increases as the number of windings of the hot wire increases, when there is a need to stop the organic material layer forming operation, for example, when all the organic materials stored in the crucible 22 are exhausted, the heating body 20a , 20b) even if the power applied to the injection nozzle unit 24 retains heat for a longer time than the crucible 22.

Referring back to FIG. 1, in the vacuum deposition system 100 having the above-described structure, one side of the vacuum chamber 10 includes a chuck 50 for supporting the substrate 30 and the mask 40 in an aligned state. Is provided. A driving shaft is provided on the other side of the vacuum chamber 10, and the deposition source 20 for spraying the organic gaseous material is installed on the driving shaft to be movable in the vertical vertical direction.

The deposition source 20 is located in the buffer region A in the vacuum chamber 10. The mask 40 and the substrate are positioned away from the deposition source 20, and they are in close contact with the chuck 50 of the alignment system (not shown) in alignment with each other.

Then, when power is applied to the heaters 20a and 20b (see FIG. 3) by a controller (not shown) to form an organic material layer on the substrate 30, the first heater 20a and the second heater ( The crucible 22 and the injection nozzle part 24 are heated by the heating action of 20b). In this case, the controller may separately perform heating control on the first heating body 20a and the second heating body 20b. As a result, the injection nozzle part 24 in which the heating wire is installed relatively is heated rapidly compared with the crucible 22. As shown in FIG.

Therefore, the organic gaseous substance formed by evaporation of the organic substance in the crucible 22 is injected through the injection nozzle unit 24 without condensation, thereby preventing nozzle clogging and splashing in the injection nozzle unit 24.

After that, as shown in FIG. 2, the first heating body 20a is heated while the deposition source 20 moves vertically along the driving axis in the deposition region B of the vacuum chamber 10. By action, the organic vapor substance generated by evaporation of the organic substance stored in the crucible 22 is injected through the injection nozzle part 24. In addition, a film forming process of forming an organic material layer on the substrate 30 is performed by spraying the organic vapor material on the substrate 30.

When there is a need to stop the above-described film forming process, for example, when all the organic materials stored in the crucible 22 are exhausted, the deposition source 20 is moved to the buffer region A of the vacuum chamber 10. Let's do it. Then, the power applied to the heaters 20a and 20b is cut off by the control operation of the controller.

As a result, the heating action of the first heating body 20a with respect to the crucible 22 and the heating action of the second heating body 20b with respect to the injection nozzle part 24 are stopped so that the organic gaseous substance is discharged to the injection nozzle part 24. Stop spraying through).

As described above, since the injection nozzle part 24 in which the heating wire is relatively installed has a relatively large amount of heat compared to the crucible 22, when the power applied to the heating elements 20a and 20b is cut off. The crucible 22 is cooled faster than the injection nozzle part 24. This prevents the presence of the organic vapor material in the deposition source 20, thereby preventing the nozzle clogging and the splash phenomenon caused by the condensation of the organic vapor material.

The foregoing is merely illustrative of the preferred embodiments of the present invention and those skilled in the art to which the present invention pertains recognize that modifications and variations can be made to the present invention without departing from the spirit and gist of the invention as set forth in the appended claims. shall.

According to the present invention, the heat capacity of the crucible in which the organic material is stored and the heating element for heating the injection nozzle part to which the organic vapor material is injected are set differently, and in particular, the heating element for heating the injection nozzle part is compared with the heating body for heating the crucible. By maintaining the high temperature to prevent the condensation of the organic vapor material in the injection nozzle unit to prevent nozzle clogging phenomenon and splash phenomenon, it is possible to efficiently produce a large-area display by uniformly depositing the organic material on the substrate.

Claims (8)

A crucible in which organic materials are stored; A first heating body for heating the crucible; An injection nozzle unit for spraying an organic vapor material formed by evaporating the organic material by a heating action of the first heating body; It consists of a second heating element for heating the injection nozzle, And the second heating body is maintained at a higher temperature than the first heating body. The method of claim 1, The first heating element and the second heating element deposition deposition source, characterized in that consisting of a heating wire. The method of claim 2, The number of winding of the heating wire of the second heating body is higher than the number of winding of the first heating body deposition source for the material deposition, characterized in that more heat is generated in the injection nozzle portion. Vacuum chamber; A stage having a chuck supporting the substrate and the mask installed in one side of the vacuum chamber in an aligned state; A drive shaft installed at the other side of the vacuum chamber; And It is composed of a deposition source which is installed to be movable along the drive shaft, The evaporation source may include a crucible in which an organic material is stored, a first heating body for heating the crucible, and an injection nozzle for spraying an organic vapor material formed by evaporation of the organic material by a heating action of the first heating body. And a second heating body which heats the injection nozzle unit and is maintained at a high temperature compared with the first heating body. The method of claim 4, wherein The first heating element and the second heating element is a deposition system, characterized in that composed of a hot wire. The method of claim 5, The number of windings of the heating wire of the second heating body is higher than the number of windings of the first heating body so that more heat is generated in the injection nozzle portion. The method of claim 4, wherein And a control unit which can individually perform heating control on the first heating body and the second heating body. The method of claim 7, wherein Deposition system, characterized in that the same power is applied to the first heating body and the second heating body.

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