KR20020089288A - source for vapor deposition of organic layers - Google Patents

Abstract

PURPOSE: A source for depositing organic matter is provided which improves yield and productivity of a device by improving temperature equilibrium of a heating element so that the organic matter is constantly deposited on a substrate to a certain thickness regardless of position of the substrate. CONSTITUTION: The source for depositing organic matter comprises a crucible an upper part of which is opened, and in which a sample is rested; a heating element(110) which is formed at an upper opening part of the crucible and formed of a conductive material, at the central part of which a crosswise extended vapor entrance and exit hole(111) is formed, and which is formed in such a manner that width is gradually getting widened as it goes from the edge part to the central side, wherein width of the edge is h, and width of the central part is m so that a ratio of h:m is 1.5-10, and the heating element(110) is connected to an external power source to be heated; a thermal insulating body that is formed in a shape that the thermal insulating body envelops the lower outer surface of the crucible and prevents heat of the crucible from being emitted to the outside; and a connection body formed at a power source connection part of the heating element(110).

Description

Source for vapor deposition of organic layers}

The present invention relates to a source for organic material deposition, and more particularly, to improve the temperature balance of the heating element, and to uniformly deposit the thickness of the organic material deposited on the substrate regardless of the position of the substrate to improve the yield and productivity of the device. It relates to a source for organic material deposition.

In general, the EL (Electro Luminescence) display device is one of the semiconductor flat display devices, and unlike the other flat surface devices, the EL (Electro Luminescence) display device is composed of a completely solid film and has an ideal structure with limited heat generation. Due to the advantages of its own cold light emitting device, the demand is increasing in the industry.

Currently, among the fields of R & D not only in academia but also in the general industry, the development competition is accelerating. Organic materials have many advantages, such as small driving voltage and high luminance, as display devices compared to inorganic materials. The possibility and applicability of next-generation display devices have been recognized worldwide.

However, it is difficult to deposit organic materials using existing inorganic deposition methods. Especially, in the development of full color display devices, development of organic deposition technologies is currently in progress worldwide.

Until now, some problems have been reported for full-color display devices using organic materials. The most well known difficulty is that organic materials, unlike inorganic materials, are molecules that are a group of atoms connected to each other. Therefore, organic molecules are much heavier than single or monomolecule inorganic materials. The bonds are easily broken, losing the properties of the original organic matter. Due to such characteristics, there are many difficulties in using the existing well-established deposition techniques on organic materials as they are for deposition of organic materials.

Currently, a representative technique used for depositing organic materials is a thermal evaporation method of depositing organic materials using relatively small thermal energy than a method using electron beams or plasma by heating organic materials to sublimation or evaporation. In addition, various methods such as using other ink-jet printing method are used, but thermal evaporation method is the most widely used so far in general mass production line.

This thermal evaporation method can be applied to the deposition of relatively light organic materials among organic materials, and cannot be used for the deposition of polymers including complex polymers containing polymers and containing many molecules. The coating (spin coating) or ink-jet printing (ink-jet printing) method is introduced and deposited, and the situation is not yet industrialized. In addition, the thermal conductivity of organic materials is about 1/1000 times less than that of other inorganic materials. Due to these characteristics, the shape of the crucible and the heater during the actual deposition causes a lot of difference due to the temperature distribution of the organic material, which plays a very important role in the uniform deposition of the organic material.

Sources for depositing organic EL films according to the prior art are shown in US Patent Registration No. 6237529 B1.

The prior art is to form a rectangular plate having a vapor diverging hole formed in the upper portion of the housing containing a solid organic EL material that can be vaporized, to form a baffle at the bottom spaced apart from the plate, heat the plate or the housing, etc. When evaporation is performed, the evaporated organic material is protected from passing directly through the vapor divergence hole and at the same time, the agglomerated organic material and water droplets are caught in the baffle, so that a stable deposition is achieved.

However, in the prior art, in the process of generating heat by applying external power to the plate, heat is not generated evenly in the plate and in the entire portion of the housing, and the amount of heat generated at the center portion is greater than the edge portion, so that The organic EL deposited on the substrate due to evaporation is smooth, and the center is thick and the edge is thin.

In addition, there is a problem that large diameter device production is impossible due to the nonuniformity of the deposited thickness.

Accordingly, the present invention has been made to solve the above problems, and uniformly distributes the temperature of the heater, which is a heating element, and at the same time uniformizes evaporation of the organic material, thereby uniformly depositing the thickness of the organic material deposited on the substrate. It is an object to provide a source for organic material deposition.

It is also an object of the present invention to provide a source for organic material deposition by forming a connector on the heating element connecting portion, reducing the temperature variation between the center and the edge of the heater and at the same time depositing organic materials evenly on a large area substrate.

1-Schematic illustration of a deposition source containing organic material according to the present invention.

2 is a schematic diagram of a deposition apparatus provided with a heating element.

3 is a schematic view of a heating element with a wide central portion;

4-Schematic diagram of a heating element fabricated using two or more heating elements in the longitudinal direction.

5-Schematic diagram of a heating element in which two or more heating elements are wired in a vertical direction.

6-Schematic diagram of the lower heating element.

7-Schematic diagram using two or more lower heating elements in the longitudinal direction.

8-Schematic diagram of the lower heating element formed in a band shape.

9 is a schematic diagram of a method of fastening an electrode and a heating element.

10 shows the result of measuring the uniformity of the deposited organic matter by ellipsometery according to the present invention.

<Description of Symbols for Major Parts of Drawings>

100: crucible 110: heating element

111: steam entry hole 112: unit heating element

113: bolt coupling hole 120: insulation

130: connector 140: lower heating element

141: lower unit heating element 150: thermocouple

160: auxiliary connector

In order to achieve the above object, the present invention provides an organic vacuum deposition apparatus comprising: a crucible having an upper portion opened and a sample placed therein; It is formed in the upper opening of the crucible, formed of a conductive material, and formed in the center of the vapor exit hole extending in the horizontal direction, is formed so as to gradually widen the width from the edge to the center, the width of the edge is h A width of the center portion is formed to be m, and a numerical ratio of h: m is 1.5 to 10, and is connected to an external power source and generates heat; A thermostat formed in a shape surrounding the lower outer surface of the crucible and preventing heat of the crucible from being released to the outside; A source for organic material deposition comprising a; a connecting body formed on the power connection portion of the heating element is a technical gist.

And the present invention, in the organic vapor deposition apparatus, the crucible having an upper portion is opened and the sample is placed therein; The unit heating elements are formed in the opening of the upper opening, and each unit heating element is formed of a conductive material, and each of the unit heating elements is formed with a vapor access hole extending in the horizontal direction, and the number of the unit heating elements is 2 to 10, respectively. A heating element connected to a power supply in series or in parallel to generate heat; A thermostat formed in a shape surrounding the lower outer surface of the crucible and preventing heat of the crucible from being released to the outside; A source for organic material deposition, including; a connection body formed at a power connection portion of the heating element is also a technical subject matter.

Here, the outer surface of the insulating body is wrapped, and further comprises a lower heating element which is connected to an external power source and an auxiliary connector to generate heat, wherein the lower heating element is formed in series or parallel in the box-shaped 2 to 10 unit lower heating elements. Regardless of the width of the upper heating element is formed to be spaced apart up and down in the shape of a band having a width, 2 to 10 is formed, it is preferable that the heating value of the upper heating element is configured to be relatively larger than the heating value of the lower heating element.

In addition, the connector and the auxiliary connector is preferably composed of a heating element containing a thin copper plate.

Accordingly, it is possible to improve the temperature equilibrium of the heater and to uniformly deposit the thickness of the organic material deposited on the substrate regardless of the position of the substrate, thereby improving the yield and productivity of the device and producing a large diameter substrate. .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view of a deposition source containing an organic material according to the present invention, FIG. 2 is a schematic view of a deposition apparatus in which a heating element is installed, FIG. 3 is a schematic view of a heating element having a wide central portion, and FIG. 5 is a schematic diagram of a heating element manufactured using the above heating element, FIG. 5 is a schematic diagram of a heating element in which two or more heating elements are wired in a vertical direction, FIG. 6 is a schematic diagram of a lower heating element, and FIG. Figure 8 is a schematic diagram using a heating element, Figure 8 is a schematic diagram of a lower heating element formed in a band shape, Figure 9 is a schematic diagram of a method of coupling the electrode and the heating element, Figure 10 is the uniformity of the deposited organic matter according to the present invention measured by ellipsometery The results are shown.

As shown, the organic material deposition source according to the present invention is used in the organic material vacuum deposition apparatus, the crucible 100, the heating element 110, the thermal insulation member 120, the connector 130, The lower heating element 140 is configured.

First, the crucible 100 will be described.

The crucible 100 is formed in a cylindrical shape with an upper opening, and is mainly made of quartz, metal, ceramic, semiconductor, etc., and should not be reactive with other materials near the deposition temperature of the organic material to be deposited. Is selected in consideration of. The size is determined by the size of the substrate used and the time of use. In addition, the inside of the crucible 100 is an organic vapor evaporated to receive the heat is received, the inner wall of the crucible 100 may be embedded with an insulator or reflector for the conservation and insulation of radiant energy.

The heating element 110 is formed in the upper opening of the crucible 100 to seal the upper opening of the crucible 100, and the heating element 110 is formed in a plate shape.

The heating element 110 is connected to an external power source to generate heat to heat the organic material charged inside the crucible 100 by a heat transfer method such as radiation to the crucible 100 to immediately sublimate the organic material or phase change into a liquid. It is a heat source that will later evaporate.

In other words, the heat generated by the heating element 110 has an even distribution in the entire heating element 110 to evenly heat transfer to the organic material to uniform evaporation of the organic material is formed on the substrate 110 formed above the heating element 110 Even deposition of organic material is achieved.

According to the experiment, in the case of the linear heating element 110, the temperature is high in the middle portion of the heating element 110 in the longitudinal direction and the temperature is lower at both edges, and this tendency becomes larger as the temperature increases. This is the main reason that the amount of heat escapes to the electrode portion connected to both edge portions of the heater that is the heating element (110).

As a result of several experiments, the temperature decreases linearly from the center to the edge, and the difference in temperature between them increases as the temperature increases, making it difficult to ensure deposition uniformity.

In order to solve this problem, it is necessary to secure the overall temperature uniformity by making the heat generating element 110 generate more heat at both edge portions than the center portion, rather than using a simple linear model. In this way, the temperature of both edges is increased to obtain a uniform uniformity.

Therefore, as shown in FIG. 3, the heating element 110, which is the core of the present invention, is formed in a plate shape and gradually increases in width from the edge to the center portion.

If the width of the edge is h, and the width of the center is m, the numerical ratio of h: m should be 1.5 to 10, and it is linear depending on the material and properties of the metal used. This test can be used to determine the temperature difference in the actual linear and then proportionally determine the ratio of h and m to the resistance in the cross-sectional area.

And the edge portion of the heating element 110 is formed with a bolt coupling hole 113 is coupled to the connector 130 to be described later by a bolt or the like is coupled to the connector 130 stably.

In addition, a vapor access hole 111 is formed in a central portion of the heating element 110 in a horizontal direction along the central portion, and the organic material evaporated by the heat of the heating element 110 is upwardly formed through the steam access hole 111. Flows into the substrate to be deposited on the substrate.

On the other hand, the heating element 110 is connected to an external control unit is formed with a plurality of thermocouples 150 for sensing the temperature of the heating element 110 to properly control the amount of heat generated by the heating element (110).

In the above description, the heating element 110 having one heating element 110 is described. However, as shown in FIG. 4, each of the unit heating elements 112 formed at each unit heating element 112 is connected in series with each other. By using it, the amount of heat generated by the heat generating element 110 itself can be configured almost the same regardless of the position.

And, as shown in Figure 5, by forming the steam entry hole 111 in each unit heating element 112, by connecting each unit heating element 112 in parallel to use the temperature uniformity according to the position of the heating element 110 I can keep it.

In addition, each of the unit heating elements 112 described above is installed to check the temperature by installing a thermocouple 150 and is configured to be connected to a temperature controller to control the temperature.

In particular, when the unit heating elements 112 are connected in parallel, the temperature control of each unit heating element 112 may be separately, so that the calorific value of each of the unit heating elements 112 is individually deposited during the deposition. It is possible to partially control the deposition rate while monitoring the thickness of the deposited substrate by controlling it.

Here, the heating elements 110 may be used alone, or may be used in close contact with other ceramics in some cases.

Next, the thermostat 120 will be described.

The insulation body 120 is formed of a heat-resistant insulating material and is formed in a cylindrical shape with an upper opening to form a shape surrounding the lower surface and the side of the crucible 100 so that the heat of the crucible 100 is a crucible 100 It is prevented from leaking out through the side and bottom surface of the).

The connector 130 is used to process the heating element containing the material of the heating element 110 or copper foil in a thin plate shape, and by pressing at the end of the heating element 110 by a torque wrench or the like by a screw Combination is configured.

That is, the power connection portion of the heating element 110 serves as a passage through which the heat of the heating element 110 escapes, and thus plays a decisive role of lowering the temperature of the edge of the heating element 110. By installing the 130, it is possible to prevent the loss of heat to both edges by heating the temperature of the connection portion similar to the temperature of the heating element 110 as long as it does not interfere with the power supply can ensure the uniformity of the desired temperature. .

In general, the resistance of the connector 130 is preferably used in the range of 1% to 500% of the resistance of the heating element 110, but it is preferable to determine experimentally according to the size of the heating element 110 or the characteristics of the material.

Next, the lower heating element 140 will be described.

The lower heating element 140 is installed on the insulating body 120 to surround the outer surface of the insulating body 120.

The reason for installing the insulating body 120 is that when the organic material is less thermally conductive than the inorganic material, the heat generated from the heating element 110 is difficult to distribute evenly throughout the source, and the local heat is concentrated to increase the deposition rate. An abnormal increase causes a fatal effect on the homogeneity of the film thickness.

Therefore, the lower heating element 140 is used to increase the temperature homogeneity inside the crucible 100 by using the lower heating element 140. The deposited organic material has different characteristics for each organic material such as direct sublimation from a solid or evaporation after phase transition to a liquid phase. Accordingly, the lower heating element 140 also has longitudinal uniformity as well as longitudinal uniformity. Done.

That is, sublimation or evaporation occurs on the surface of the solid or liquid, but is also affected by the temperature distribution of the layer immediately below it.

In addition, when the lower heating element 140 is used, the amount of organic matter decreases as the deposition proceeds, and thus, the deposition conditions that change are changed, and as a result, the change in deposition rate occurs over time, and the lower heating element 140 is used. Can be controlled.

Here, the lower heating element 140 is connected by an external power source and the auxiliary connector 160, and the auxiliary connector 160 processes the heating element containing the material or copper foil of the lower heating element 140 into a thin plate shape. It is used to, by pressing at the end of the lower heating element 140, such as by a torque wrench and at the same time configured by a screw.

As shown in FIG. 6, the lower heating element 140 is formed in a cylindrical shape with an upper portion opened to surround the insulating body 120.

Although the lower heating element 140 is not shown in the drawing, the connection part is prevented from being lowered by connecting the connection part to the connection part.

Here, the lower heating element 140 is formed using materials such as carbon, metal, and ceramics, and if necessary, the crucible 100 itself may be used as the lower heating element 140.

In the above description, one lower heating element 140 has been described. However, as shown in FIG. 7, each lower unit heating element 141 is formed separately to connect each lower unit heating element 141 to each other in series or in parallel. Thus, the amount of heat generated by the heat generating element itself can be configured almost the same regardless of the position.

Each of the lower unit heating elements 141 described above is configured to check the temperature by installing a thermocouple and to be connected to a temperature controller to control the temperature.

In particular, when the lower unit heating elements 141 are connected in parallel, the temperature control of each lower unit heating element 141 may be separated separately, and the deposition of each lower unit heating element 141 is performed. It is possible to partially control the deposition rate by monitoring the thickness of the deposited substrate by individually controlling the amount of heat generated.

And another form of the lower heating element 140 is shown in Figure 8, each of the strip-shaped lower heating element 140 is installed in a shape surrounding the outer surface of the heat insulating body 120 of the crucible 100 of the upper and lower temperatures To ensure homogeneity. The strip-shaped lower heating element 140 is preferably lowered from the top to the bottom to prevent a sudden evaporation at the bottom and is effective in ensuring temperature uniformity and thickness homogeneity.

In the case of using the heating element 110 and the lower heating element 140 installed on the upper side of the crucible 100 at the same time, the temperature distribution of the organic material contained in the crucible 100 as the lower heating element 140 to be uniform, By controlling the temperature of the heating element 110 installed in the can be formed a uniform film quality on the substrate.

Therefore, in the present invention, the connecting body 130 is connected to the heating element 110 installed above the crucible 100, and at the same time, the width of the central portion of the heating element 110 is larger than the edge, or several heating elements 110 are serially connected. Alternatively, the amount of heat transferred to the crucible 100 by connecting in parallel is made constant regardless of the position.

The lower heating element 140 is formed to maintain a uniform temperature distribution of the organic material contained in the crucible 100 using the lower heating element 140.

Therefore, the organic material deposited on the crucible 100 is evaporated by receiving a uniform amount of heat, and thus the thickness of the organic material deposited on the substrate becomes constant.

The present invention has the effect of uniformly distributing the temperature of the heater, which is the heating element, and uniform evaporation of the organic material to uniformly deposit the thickness of the organic material deposited on the substrate.

In addition, by forming a connector on the heating element connecting portion, the temperature difference between the center and the edge of the heater is reduced, and at the same time, the organic material is deposited evenly on the large-area substrate.

Claims (8)

In organic matter vacuum deposition apparatus, A crucible in which an upper portion is opened and a sample is placed therein; It is formed in the upper opening of the crucible, formed of a conductive material, and formed in the center of the vapor exit hole extending in the horizontal direction, is formed so as to gradually widen the width from the edge to the center, the width of the edge is h A width of the center portion is formed to be m, and a numerical ratio of h: m is 1.5 to 10, and is connected to an external power source and generates heat; A thermostat formed in a shape surrounding the lower outer surface of the crucible and preventing heat of the crucible from being released to the outside; And a connection member formed at a power connection portion of the heating element. In organic matter vacuum deposition apparatus, A crucible in which an upper portion is opened and a sample is placed therein; The unit heating elements are formed in the opening of the upper opening, and each unit heating element is formed of a conductive material, and each of the unit heating elements is formed with a vapor access hole extending in the horizontal direction, and the number of the unit heating elements is 2 to 10, respectively. A heating element connected to a power supply in series or in parallel to generate heat; A thermostat formed in a shape surrounding the lower outer surface of the crucible and preventing heat of the crucible from being released to the outside; And a connection member formed at a power connection portion of the heating element. The organic material deposition source of claim 1 or 2, further comprising a lower heating element surrounding the outer surface of the insulating body and connected to an external power source and an auxiliary connector to generate heat. According to claim 3, wherein the lower heating element is a source for deposition of organic material, characterized in that the box-shaped 2 to 10 unit lower heating elements are formed in series or in parallel. The source of claim 3, wherein the lower heating elements are formed in a band shape having a width and are spaced apart from each other vertically, and 2 to 10 are formed. The method of claim 5, wherein the lower heating element is a source for deposition of organic material, characterized in that the calorific value of the upper heating element is relatively larger than the calorific value of the lower heating element. The source for organic material deposition according to claim 1 or 2, wherein the connector is a heating element including a thin copper plate. The source for organic material deposition according to claim 3, wherein the auxiliary connector is a heating element including a thin copper plate.