KR100656847B1 - Source for depositing electroluminescent layer - Google Patents

Abstract

The present invention discloses a deposition source having a structure capable of effectively securing heat transferred to an upper member having an opening to maintain a suitable temperature for relieving the blockage of an opening for vapor discharge formed on the upper member, and according to the present invention The evaporation source includes a sidewall member having heating means mounted thereon to supply heat to the evaporation material; Floor members; An upper member having an opening for discharging material vapor; And a metal layer formed on a bottom surface of the upper member and having a thermal conductivity higher than that of the upper member.

Evaporation source for organic electroluminescent layer deposition

Description

Source for depositing electroluminescent layer

1 is a cross-sectional view showing an internal configuration of a deposition apparatus equipped with a deposition source.

2 is a cross-sectional view of a general point deposition source.

3 is a partially enlarged cross-sectional view of an upper member of the point deposition source.

4 is a partially enlarged cross-sectional view of an upper member of a point deposition source according to the present invention;

The present invention relates to a deposition source for the deposition of the organic electroluminescent layer, in particular, the deposition source capable of effectively securing the heat transferred to the upper member having an opening to prevent clogging of the opening through which material vapor formed in the upper member is discharged. It is about.

Thermal physical vapor deposition is a technique of forming a light emitting layer on the surface of a substrate with vapor of a deposition material (organic), in which the deposition material contained in the vessel is heated to the vaporization temperature, and the vapor of the deposition material is moved out of the containing vessel and coated. It is condensed on the substrate to be. This deposition process is carried out in a chamber under pressure ranging from 10 ⁻⁷ to 10 ⁻² Torr with a container containing the deposition material and a substrate to be coated.

Generally, a deposition source, which is a container containing a deposition material, is made of an electrically resistive material that increases in temperature as current passes through walls (members). When a current is applied to the deposition source, the deposition material therein is heated by radiant heat from the walls of the deposition source and conduction heat from contact with the walls. A vapor efflux aperture through which the vaporized material vapor is discharged to the outside is formed in the upper member of the evaporation source.

1 is a cross-sectional view showing the internal configuration of a deposition apparatus equipped with a deposition source, the deposition source 1 mounted inside the chamber 3 of the deposition apparatus and the substrate 2 mounted on the deposition source 1. It is shown.

Although the substrate 2 on which the light emitting layer is deposited is mounted on the upper plate 3-1 of the chamber, the substrate 2 may be mounted in a fixed state, but as described above, the substrate 2 may be mounted to be movable in the width direction. Can be. The structure which mounts the board | substrate 2 so that horizontal movement (linear motion) is possible with respect to the upper plate 3-1 is common, Therefore the description is abbreviate | omitted.

The vapor deposition source 1 is mounted on the insulating structure 4 fixed to the bottom surface 3-2 of the chamber 3, and a cable for supplying power is connected. Meanwhile, the deposition source 1 may be mounted on the insulating structure 4 in a fixed state, but as described above, the deposition source 1 may be mounted in a horizontal direction (linear motion) in the width direction of the substrate 2. . The configuration in which the evaporation source 1 is mounted to allow the horizontal movement with respect to the insulation structure 4 is common, and thus description thereof is omitted.

In FIG. 1, the upper member has a vapor discharge opening 1A-1 through which vaporized material vapor is discharged outward toward the substrate in the internal space of the deposition source 1. As shown in FIG. 1, a vapor discharge control plate may be formed at the bottom of the vapor discharge opening of the upper member for effective deposition of material vapor. Generally, the deposition source 1 which performs the above structure and function has a point deposition source and a linear deposition source according to the overall shape and the shape of the vapor discharge opening 1A (hereinafter referred to as “opening” for convenience). (linear deposition source).

The point deposition source is cylindrical in overall shape, and the opening formed in the upper member is circular. In addition, the linear vapor deposition source has a hexahedral shape, and the upper member is formed with an opening having a predetermined width in the longitudinal direction of the member.

The point evaporation source and the linear evaporation source are used depending on the deposition process conditions, the substrate conditions, or the shape of the deposition film to be formed. For convenience, the point deposition source will be described as an example.

FIG. 2 is a cross-sectional view of a general point deposition source and shows the internal configuration of the point deposition source 1 composed of a cylindrical side wall member 1B, a disc shaped bottom member 1C, and an upper member 1A. In the internal space formed by the upper member 1A, the side wall member 1B, and the bottom member 1D, an organic substance as the vapor deposition material M is accommodated.

Inside the side wall member 1B, means 1B-1 (for example, a heating coil connected to a power source) for heating the deposition material M accommodated in the internal space is located. This heating means 1B-1 is mounted over the entire height of the side wall member 1B, and therefore can supply heat to all the vapor deposition materials M. FIG.

The opening 1A-1 is formed in the center of the upper member 1A, and the vapor of the vapor deposition material M heated and vaporized by the heat generated by the heating means 1B-1 attached to the side wall member 1B. Is discharged toward the outside through the opening 1A-1, that is, the substrate (2 in FIG. 1). Since the diameter of this opening 1A-1 is extremely small compared with the diameter of the vapor deposition source 1, it performs the function of the nozzle which distributes a fluid at high speed. In other words, the vapor of the vapor deposition material M generated in the internal space having a large cross-sectional area has a high flow rate and a low pressure in the course of passing through the opening 1A-1 having a small area, and thus efficient material vapor distribution is achieved. Can be. The opening 1A-1 may have some protrusions formed in the opening inclined in a V shape as shown in FIG. 3, or may have only a V shape without protrusions. For convenience, the following will be described using the shape of the opening in which some projections are formed.

In this way, the temperature at the opening 1A-1 through which the material vapor is discharged becomes significantly lower than the temperature of the internal space where the material vapor is generated. That is, since no heating means is provided in the upper member 1A and the state is exposed to the outside, the heat transferred from the inner space to the upper member 1A must be dissipated to the outside. Inevitably, the temperature is lower than the temperature.

Due to the low temperature around the opening 1A-1, a part of the material vapor discharged through the opening 1A-1 solidifies around the opening 1A-1. As the deposition process proceeds, solidification of the material vapor around the opening 1A-1 accumulates and thus the material vapor is not smoothly discharged, which greatly affects the formation of the deposited film on the substrate 2 surface. In particular, in some cases, the opening 1A-1 may be clogged by the solidified material vapor.

In order to prevent the material vapor solidification around the opening 1A-1, the temperature around the opening, that is, the upper member 1A should be maintained at a certain level or higher. For this purpose, as shown in FIG. (1B) The structure which provided the disc shaped cover 11 of the metallic material in the upper end is used.

The cover 11 fixed to the top of the side wall member 1B is located on the upper member 1A, but maintains a constant distance from the upper member 1A. The cover 11 is formed with a material vapor discharge opening 11-1 at a position corresponding to the opening 1A-1 formed in the upper member 1A. Accordingly, it has been considered that the heat transferred from the inner space to the upper member 1A is prevented from dissipating outwardly by this cover 11 so that the upper member 1A can maintain a certain temperature.

However, since the cover 11 is made of a metallic material, the heat transmitted from the upper member 1A must be dissipated to the outside, so that heat transfer is continuously performed from the upper member 1A. Eventually, despite the installation of the cover 11 for preventing heat dissipation, the upper member 1A cannot maintain an appropriate temperature and completely prevents the material vapor from solidifying around the opening 1A of the upper member 1A. There is a problem that cannot be done.

Therefore, the present invention is to prevent the phenomenon of the material vapor is solidified around the opening, it is possible to effectively secure the heat transferred to the upper member having the opening to maintain a suitable temperature for relieving the clogging of the steam discharge opening of the upper member The purpose is to provide a source of deposition.

The deposition source according to the present invention for achieving the above object is a side wall member is mounted to the heating means for supplying heat to the deposition material; Floor members; An upper member having an opening for discharging material vapor; And a metal layer formed on a bottom surface of the upper member and having a thermal conductivity higher than that of the upper member.

Preferably, the metal layer having high thermal conductivity formed on the bottom of the upper member effectively conducts heat supplied from the sidewall member to the opening using Au (gold), Ag (silver) or Al (aluminum). The upper member of preferably uses titanium with low thermal conductivity to prevent heat dissipation to the outside.

In addition, it is preferable to further coat the metal layer using Ta (tantalum) or W (tungsten) on the bottom of the metal layer of Au, Ag or Al to prevent the adhesion of organic matter.

The invention will be more fully understood by the detailed description of the preferred embodiment with reference to the attached drawings.

4 is a partial cross-sectional view of the upper member of the point deposition source according to the present invention, wherein the point deposition source according to the present invention also has a cylindrical sidewall member (not shown) equipped with a heating means (heating coil), and a disk-shaped bottom member. (Not shown) and the upper member 100A formed with the material vapor discharge opening 100A-1.

In addition, a disc shaped cover (not shown), which can be fixed to the top of the side wall member, may be additionally located on the upper member 100A, and it is preferable to maintain a constant distance from the upper member 100A. The vapor discharge opening 100A-1 formed in the upper member 100A and the opening formed in the cover correspond to each other.

The biggest feature of the deposition source according to the present invention is to form a first metal layer having a high thermal conductivity on the bottom surface of the upper member 100A, preferably having a higher thermal conductivity than that of the upper member 100A. The first metal layer may be made of Au, Ag, or Al, which has high thermal conductivity, and in the case of Au, the thermal conductivity is about 317 W / mK (300 K, at 1 atmosphere), and the thermal conductivity is very high to transfer heat transferred from the sidewall member. By efficiently passing to the opening 100A-1, solidification of the material vapor can be prevented and the clogging phenomenon of the opening 100A-1 can be prevented.

Also, in the deposition source, the upper member 100A may be made of titanium. Titanium has a low thermal conductivity of 21.9 W / m-K (at 300 K at 1 atmosphere). Therefore, the upper member 100A made of titanium does not dissipate heat to the outside of the deposition source, and thus the upper member 100A can maintain an appropriate temperature, and the temperature around the opening 100A-1 also maintains a constant value. By doing so, it is possible to prevent the phenomenon of material vapor solidifying around the opening 100A-1.

As described above, the upper titanium layer preserves heat, and the lower Au, Ag, or Al layer can effectively block the blockage of the opening by the material vapor by increasing the conduction of heat to the opening 100A-1.

More preferably, a second metal layer made of Ta or W may be additionally formed on the bottom surface of the first metal layer (in the case of Ta, the thermal conductivity is 57.5 W / mK (300 K, 1 atm). )). This makes it possible to more effectively block the clogging of the opening due to the material vapor.

The first metal layer and the second metal layer may be formed of the material using, for example, a frame spray method, a plasma spray method or a thermal spray method such as high velocity oxygen-fuel (HVOF) or an electro chemical metalizing (ECM) or electroplating method. Can be coated on the cover surface.

On the other hand, in the present description, the point deposition source has been described as an example, but of course, the same can be applied to the linear deposition source in which the upper member does not act as a heater.

In the present invention as described above, by forming a metal layer having a high thermal conductivity on the bottom surface of the upper member of the deposition source, it is possible to effectively secure the heat transferred to the upper member to maintain the temperature around the opening at an appropriate value. Therefore, it is possible to effectively prevent the phenomenon of vapor discharged to the outside through the opening to solidify around the opening.

Claims (5)

In a deposition source that is heated by an applied power source and transfers heat to a deposition material contained therein, and heats it, and discharges the generated material vapor to the outside to form a deposition material layer on the substrate surface. A side wall member mounted with heating means to supply heat to the deposition material; Floor members; An upper member having an opening for discharging material vapor; And And a first metal layer formed on a bottom surface of the upper member and having a higher thermal conductivity than that of the upper member. The deposition source of claim 1, wherein the first metal layer is made of Au, Ag, or Al. The deposition source of claim 1, wherein the upper member is made of titanium. The deposition source according to claim 1 or 2, wherein a second metal layer made of Ta or W is further formed on the bottom of the first metal layer. 5. The method of claim 4, wherein at least one of the first metal layer and the second metal layer is a frame spray method, a plasma spray method or a thermal spray method such as high velocity oxygen-fuel (HVOF) or electro chemical metalizing (ECM) or electroplay. Evaporation source, characterized in that the coating on the bottom of the upper member using a coating method.

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