JP2009108375A - Vapor deposition apparatus and vapor deposition source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition source having excellent film thickness controllability in large-area vapor deposition when manufacturing an organic electroluminescence element. <P>SOLUTION: The vapor deposition source 10 equipped with a plurality of injection openings 11 within a vacuum chamber 1 is provided with branch points 14c between a crucible 14 for housing a deposition material and the plurality of the injection openings 11, and a supply flow passage 14a nearer the crucible 14 side than the branch points 14c is provided with a valve 12. The lengths of the flow passages from the branch points 14c through the branch flow passages 14a up to the respective injection openings 11 are made equal to each other so as to equal the conductances from the valve 12 up to the respective injection openings 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vapor deposition apparatus and a vapor deposition source for forming an organic material layer or the like of an organic electroluminescence element.

  In recent years, demand for thin displays such as liquid crystal displays and plasma displays is increasing. In particular, liquid crystal displays are mainstream as displays for mobile terminals (for example, mobile phones, digital cameras, etc.), and high definition is also progressing. However, the liquid crystal display has a structure in which white light emitted from a light source called a backlight is transmitted through a color filter to extract light. Most of the power consumption is consumed by the backlight, and the light extraction efficiency is drastically reduced by the color filter. In addition, the liquid crystal display has a problem that the color changes depending on the viewing angle. Mobile terminals will continue to be required to achieve low power consumption and wide viewing angles.

  An organic EL display using an organic electroluminescence element is expected as a next-generation display that solves power consumption and viewing angle dependency, which are problems of liquid crystal displays. Since the organic EL display is self-luminous, the backlight used in the liquid crystal display is not necessary, so that power consumption can be suppressed. In addition, there are advantages in that the response speed is faster than the liquid crystal display and the viewing angle is excellent. A display using a white organic EL as a backlight has been developed. In that case, a color filter is required, and the light extraction efficiency is significantly deteriorated.

  In contrast, the organic EL display of the full-color coating method has the advantage that the color filter is unnecessary and the light extraction efficiency is very excellent. Specifically, in order to coat the light emitting layer separately, generally, film deposition is performed by mask vapor deposition in the case of a dry process and ink jet method in the case of a wet process. An organic electroluminescence element is considered to be weak against moisture, and it is said that an organic electroluminescence element with higher luminous efficiency can be formed by a dry process at present.

  In recent years, the substrate has been increased in size, and the demand for large-area film formation has increased. Furthermore, since tact-up is also required, a vapor deposition source capable of forming a film with high speed and good film thickness control is required. Since the organic electroluminescence element has a very thin device structure, it is necessary to control the subtle film thickness, and a configuration in which a plurality of discharge ports are arranged in the film formation chamber to form a uniform film thickness. Is known (see Patent Document 1).

  As shown in FIG. 5, the configuration is such that the film forming material in the crucible 114 is heated and evaporated by the heater 113 of the vapor deposition source 110, and a plurality of discharge ports branch from the supply flow path 114 a connected to the opening of the crucible 114. Vapor of film forming material is released from 111 into the film forming chamber. Using two sets of the vapor deposition sources 110, the film forming materials are uniformly mixed to form a film. A valve 112 is provided in each branch flow path 114b connected to each discharge port 111, and the amount of vapor discharged from each discharge port 111 is individually adjusted.

JP 2006-57173 A

  However, the configuration disclosed in Patent Document 1 emphasizes easy adjustment of the component ratio in mixed film formation, and individually adjusts film forming materials supplied to a plurality of discharge ports for each discharge port. . However, since a minute amount of film-forming material is deposited per unit time, with a structure that is controlled individually for each discharge port, adjusting one location will affect other locations and control while maintaining the distribution. Becomes very complex. In particular, in a light emitting method that is self-luminous, it is necessary to manage the film forming rate and the film thickness distribution more easily and accurately in consideration of the color tone given by the film thickness distribution.

  The present invention improves the controllability of the film formation rate by equalizing the conductance from the flow rate adjusting means for adjusting the flow rate of the vapor to each discharge port, and maintains stable film thickness accuracy even when the substrate is enlarged. An object of the present invention is to provide a vapor deposition apparatus and a vapor deposition source that can be used.

  A vapor deposition apparatus according to the present invention includes a film formation chamber for forming an evaporated film formation material on a substrate, a plurality of discharge ports for ejecting a vapor flow of the film formation material into the film formation chamber, and a film formation material And a flow rate adjusting means for adjusting the flow rate of the vapor flow of the film forming material supplied from the material storage unit, connected to the opening of the material storage unit. And a plurality of branch channels that branch from the supply channel to the plurality of discharge ports, respectively, so that conductance from the flow rate adjusting means to each discharge port is equalized. The length and the pipe diameter of the pipe from the flow rate adjusting means to the plurality of discharge ports through the branch flow path are set.

  The vapor deposition source of the present invention is a vapor deposition source of a vapor deposition apparatus having a plurality of discharge ports for ejecting a vapor flow of a film forming material into a film forming chamber for forming a film on a substrate, and contains the film forming material. A supply flow provided with a flow rate adjusting means for adjusting the flow rate of the vapor flow of the film forming material supplied from the material storage unit, which is connected to the material storage unit to be heated and evaporated, and is supplied from the material storage unit A flow path and a plurality of branch flow paths each branching from the supply flow path to the plurality of discharge ports, and the flow rate adjusting means so that conductance from the flow rate adjusting means to each discharge port is equalized The length and the pipe diameter of the pipe from the first through the branch flow path to the plurality of discharge ports are set.

  By configuring so that the conductance of the flow path including the branch flow paths from the flow rate adjusting means to the plurality of discharge ports is equal for each discharge port, the film thickness can be controlled uniformly.

  In addition, since the flow rate control by the flow rate adjusting means has almost no influence on the film thickness distribution, it is easy to control the film formation rate with high accuracy, and the production efficiency of the organic electroluminescence element can be greatly improved. it can.

  The best mode for carrying out the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a substrate W is held by a substrate holder 2 in a vacuum chamber 1 which is a film forming chamber of a vapor deposition apparatus, and vapor of a film forming material generated from a vapor deposition source 10 is attached to the substrate W to form an organic material. An organic material layer of the electroluminescence element is formed. The vapor deposition source 10 is a material container provided with a plurality of discharge ports 11 for discharging (ejecting) a vapor flow of the film forming material into the vacuum chamber 1, a valve 12 as a flow rate adjusting means, and a heater 13. And a crucible 14. Between the crucible 14 and the plurality of discharge ports 11, a supply channel 14a connected to the opening of the crucible 14 and a plurality of branch channels 14b branched from the supply channel 14a and connected to the discharge ports 11 are provided. .

  Then, a valve 12 is provided on the crucible side from the branch point 14c of the branch flow path 14b, and a flow path (pipe) from each discharge port 11 to the valve 12 so that conductance from the valve 12 to each discharge port 11 becomes equal. ) And the pipe diameter are set evenly. That is, as shown in FIG. 1 and FIG. 2, the length and the pipe diameter of the pipe bifurcated at all branch points are the same. Since the conductance to each discharge port 11 is constant, even when the substrate size is increased, film formation with good film thickness distribution and film thickness accuracy is possible without impairing film thickness controllability.

  As a result, it is possible to efficiently manufacture a high-quality organic electroluminescence element.

  Instead of equalizing the length of the pipe from each outlet 11 to the valve 12 and the pipe diameter, as shown in FIG. 3A, according to the difference in the length of the pipe in the path of the steam flow for each outlet. The conductance may be equalized by changing the pipe diameter of each branch flow path 24b. Further, as shown in FIG. 3B, the pipe diameter may be set to change along the length of the pipe of the branch flow path 34b and the steam flow path to the branch flow path 34b.

  The vapor deposition source 10 configured so that the conductances from the discharge port 11 to the valve 12 are equal to each other may be disposed in the vacuum chamber 1 as shown in FIG. Only the discharge port 11 may be arranged in the vacuum chamber.

An organic material is housed in the crucible 14 of the vapor deposition source 10 as a film forming material, and the crucible 14 is heated in a vacuum by a heater 13. The pressure in the vacuum chamber during film formation is 1.0 × 10 ⁻³ Pa or less. The crucible 14 heated by the heater 13 is heated by a desired temperature gradient. Preferably, the degassing process should be performed at a desired temperature for a certain period of time.

  The evaporation temperature of the film-forming material varies depending on the material. However, if the material is sublimable, the material may suddenly evaporate, so special care must be taken. If the material is a meltable material, gradually raise the temperature from the molten state. This makes it possible to deposit the material stably. In order to prevent clogging of the film forming material, a heater (not shown) is arranged so that the section from the discharge port to the crucible is heated substantially uniformly.

  As shown in FIGS. 1 and 2, the vapor deposition source 10 is disposed in the vacuum chamber 1 and is evacuated by a vacuum evacuation mechanism (not shown) in a state where a film forming material (organic material) is filled in a crucible 14 that is a material container. Is done. In this vapor deposition source 10, as shown in FIG. 1, a branched flow having a constant pipe diameter in the vapor flow path to the discharge port 11 so that the conductance from the valve 12 to each discharge port 11 is uniform. The lengths of the pipes including the path 14a are aligned.

  The evaporation source 10 includes a heater 13 that can be heated at a desired temperature, and evaporates the film forming material. The film forming material may be meltable or sublimable. The substrate W is transported to the vacuum chamber 1 in a vacuum atmosphere by a transport mechanism (not shown). In this embodiment, as shown in FIG. 2, a film is formed while the substrate W is transported in the vacuum chamber 1 by the transport roller 3. In addition, an evaporation source shutter (not shown) is provided in the vacuum chamber 1 so as to prevent the deposition material from adhering to the inner wall of the vacuum chamber 1.

  The film forming material ejected from the vapor deposition source 10 is measured in real time by a film thickness monitor (not shown). In this embodiment, a film thickness monitor is disposed in the vicinity of each discharge port 11 and film formation is performed while monitoring the distribution of the deposition rate (film formation rate). The film thickness monitor needs to be arranged outside the film formation area on the substrate W.

When film formation was performed using an actual substrate, results of good film thickness distribution could be obtained.
Thus, by making the conductance from the valve to the discharge port equal, the film thickness distribution can be made uniform. Further, by providing a valve in the flow path before branching, the deposition rate can be easily controlled, and the productivity in manufacturing the organic electroluminescence element can be improved.

  In this embodiment, the vapor deposition source 20 having the configuration shown in FIG. The vapor deposition source 20 is disposed in a vacuum chamber, and is exhausted by a vacuum exhaust mechanism (not shown) in a state where the crucible 24 is filled with a film forming material. In the vapor deposition source 20, the diameter of the discharge port 21 and the branch channel 24b are set so that the conductance from the valve 22 arranged in the supply channel 24a to the discharge port 21 at the tip of the branch channel 24b is uniform. The pipe diameter is changed depending on the position of the discharge port 21.

  The vapor deposition source 20 includes a heater 23 that can be heated at a desired temperature, and can evaporate the film forming material. The film forming material may be meltable or sublimable. The substrate is transported in a vacuum atmosphere to a vacuum chamber by a transport mechanism (not shown). In this embodiment, the film is formed while the substrate is transported in the vacuum chamber by the transport roller. In addition, an evaporation source shutter (not shown) is provided in the vacuum chamber, and has a structure that prevents the deposition material from adhering to the vacuum chamber.

  The film forming material ejected from the vapor deposition source 20 is measured in real time by a film thickness monitor (not shown). In this example, a film thickness monitor was disposed in the vicinity of each discharge port 21, and film formation was performed while monitoring the distribution of the deposition rate. The film thickness monitor needs to be arranged outside the film formation area on the substrate.

When film formation was performed using an actual substrate, results of good film thickness distribution could be obtained.
Thus, by making the conductance from the valve to the discharge port equal, the film thickness distribution can be made uniform. Further, by providing a valve in the flow path before branching, the deposition rate can be easily controlled, and the productivity in manufacturing the organic electroluminescence element can be improved.

  In this embodiment, the vapor deposition source 30 having the configuration shown in FIG. The vapor deposition source 30 is disposed in a vacuum chamber, and is exhausted by a vacuum exhaust mechanism (not shown) in a state where the crucible 34 is filled with a film forming material. In the vapor deposition source 30, the length of the branch flow path 34b and a part of the piping reaching the branch flow path 34b are configured so that the conductance from the valve 32 disposed in the supply flow path 34a to the discharge port 31 is configured equally. The diameter is changed depending on the position of the discharge port 31.

  The vapor deposition source 30 includes a heater 33 that can be heated at a desired temperature, and can evaporate the film forming material. The film forming material may be meltable or sublimable. The substrate is transported in a vacuum atmosphere to a vacuum chamber by a transport mechanism (not shown). In this embodiment, the film is formed while the substrate is transported in the vacuum chamber by the transport roller. In addition, an evaporation source shutter (not shown) is provided in the vacuum chamber, and has a structure that prevents deposition of a film forming material on the vacuum chamber.

  The film forming material ejected from the vapor deposition source 30 is measured in real time by a film thickness monitor (not shown). In this example, a film thickness monitor was disposed in the vicinity of each discharge port 31, and film formation was performed while monitoring the distribution of the deposition rate. The film thickness monitor needs to be arranged outside the film formation area on the substrate.

When film formation was performed using an actual substrate, results of good film thickness distribution could be obtained.
Thus, by making the conductance from the valve to the discharge port equal, the film thickness distribution can be made uniform. Further, by providing a valve in the flow path before branching, the deposition rate can be easily controlled, and the productivity in manufacturing the organic electroluminescence element can be improved.

  FIG. 4 shows a method for manufacturing an organic electroluminescent element according to Example 4. In the present embodiment, in order to confirm the effect of the present invention even in the static film formation, the arrangement of the discharge ports 41 by the bifurcated branch channel 44b corresponding to the entire surface of the substrate W corresponds to the same as in the first embodiment. It was changed.

  The vapor deposition source 40 is disposed in a vacuum chamber, and is exhausted by a vacuum exhaust mechanism (not shown) in a state where the crucible 44 is filled with a film forming material. In this vapor deposition source 40, the lengths of the pipes in the path of the vapor flow are aligned to the discharge port 41 so that the conductance from the valve 42 disposed in the supply flow path 44a to the discharge port 41 is uniform.

  The vapor deposition source 40 includes a heater 43 that can be heated at a desired temperature, and can evaporate the film forming material. The film forming material may be meltable or sublimable. The substrate W is transferred to a vacuum chamber in a vacuum atmosphere by a transfer mechanism (not shown). In this embodiment, the film is formed while the substrate W is stationary in a vacuum chamber. In addition, an evaporation source shutter (not shown) is provided in the vacuum chamber, and has a structure that prevents the deposition material from adhering to the vacuum chamber.

  The film forming material ejected from the vapor deposition source 40 is measured in real time by a film thickness monitor (not shown). In this example, a film thickness monitor was disposed in the vicinity of each discharge port 41, and film formation was performed while monitoring the deposition rate distribution. The film thickness monitor needs to be arranged outside the film formation area on the substrate W.

When film formation was performed using an actual substrate, results of good film thickness distribution could be obtained.
Thus, by making the conductance from the valve to the discharge port equal, the film thickness distribution can be made uniform. Further, by providing a valve in the flow path before branching, the deposition rate can be easily controlled, and the productivity in manufacturing the organic electroluminescence element can be improved.

  The present invention is not limited to the above embodiment. Transport film formation using the vapor deposition source of FIG. 4 may be performed, or static deposition may be performed by arranging a plurality of vapor deposition sources in the apparatus of FIG.

  The vapor deposition apparatus and vapor deposition source of this invention are applicable to the apparatus which forms various thin films besides manufacture of an organic electroluminescent element.

The vapor deposition apparatus by Example 1 is shown, (a) is a schematic diagram explaining a vapor deposition source, (b) is a schematic diagram which shows the whole vapor deposition apparatus. 1 is a perspective view showing a vapor deposition device of Example 1. FIG. FIG. 6 is a schematic diagram showing a configuration of a vapor deposition source according to Example 2 and Example 3. 10 is a perspective view showing a vapor deposition device according to Example 4. FIG. It is a schematic diagram which shows the structure of the vapor deposition source by one prior art example.

Explanation of symbols

11, 21, 31, 41 Release port 12, 22, 32, 42 Valve 13 Heater 14, 24, 34, 44 Crucible 14a, 24a, 34a, 44a Supply flow path 14b, 24b, 34b, 44b Branch flow path

Claims (3)

A deposition chamber for depositing the evaporated deposition material on the substrate;
A plurality of discharge ports for ejecting a vapor flow of the film forming material into the film forming chamber;
A material container for containing a film forming material and heating and evaporating;
A supply flow path provided with a flow rate adjusting means for adjusting the flow rate of the vapor flow of the film forming material supplied from the material storage unit, connected to the opening of the material storage unit;
A plurality of branch flow paths each branching from the supply flow path to the plurality of discharge ports,
A length and a pipe diameter of a pipe from the flow rate adjusting unit to the plurality of discharge ports are set so that conductance from the flow rate adjusting unit to each discharge port becomes equal. Vapor deposition equipment. A deposition source of a deposition apparatus having a plurality of discharge ports for ejecting a vapor flow of a film forming material into a film forming chamber for forming a film on a substrate,
A material container for containing a film forming material and heating and evaporating;
A supply flow path provided with a flow rate adjusting means for adjusting the flow rate of the vapor flow of the film forming material supplied from the material storage unit, connected to the opening of the material storage unit
A plurality of branch flow paths each branching from the supply flow path to the plurality of discharge ports,
The length of the pipe and the pipe diameter from the flow rate adjusting unit to the plurality of discharge ports through the branch flow paths are set so that conductance from the flow rate adjusting unit to each discharge port becomes equal. Vapor deposition source. Using the vapor deposition source according to claim 2 to form a film of an organic material layer of an organic electroluminescence element,
A method of manufacturing an organic electroluminescence element, wherein the film thickness distribution of the organic material layer is uniformly controlled by adjusting a flow rate of a vapor flow in a supply channel of the vapor deposition source by a flow rate adjusting unit.

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