JP2023084558A - Crucible for vapor deposition, vapor deposition source and vapor deposition apparatus - Google Patents

Abstract

To provide a crucible for vapor deposition that is capable of diffusing vapor deposition material stably by suppressing deposition of vapor deposition material to an opening and its periphery, and a vapor deposition source and a vapor deposition apparatus including such a crucible for vapor deposition.SOLUTION: A crucible for vapor deposition has an opening and is heated by induction heating. An opening-side portion of the crucible is formed of a material that undergoes higher temperature rise associated with induction heating than other parts.SELECTED DRAWING: Figure 1

Description

The present invention relates to a crucible for vapor deposition, a vapor deposition source and a vapor deposition apparatus.

Display panels, metal electrode wiring of solar cells, etc., organic electroluminescence (EL) layers, semiconductor layers, other organic material thin films and inorganic material thin films, etc. are sometimes formed by vapor deposition such as vacuum vapor deposition. A vapor deposition apparatus that performs such vapor deposition usually includes a vapor deposition source (also called an evaporation source or the like) that heats a solid vapor deposition material at room temperature and injects the vaporized vapor deposition material toward the surface of a substrate, and a substrate. It is composed of a substrate holding portion and the like for holding. The vapor deposition source includes a crucible containing a vapor deposition material, and heating means for directly or indirectly heating the vapor deposition material to vaporize it. A method using induction heating as a means for heating a vapor deposition source is known (see Patent Documents 1 and 2). The induction heating method is said to have advantages over the resistance heating method, such as high heating efficiency and excellent thermal responsiveness.

Japanese Unexamined Patent Application Publication No. 2011-52301 Japanese Patent Application Laid-Open No. 2020-176298

However, in the induction heating method using a coil, the magnetic field is strongest at the central portion of the coil, and this central portion is most likely to be heated. When a coil is arranged so as to cover the periphery of the crucible and the crucible is heated by induction heating, the opening of the crucible and its surroundings have a relatively weak magnetic field. lower temperature compared to For this reason, when the vapor deposition material contained in the crucible is vaporized by heating and diffused out of the crucible, part of the vapor deposition material tends to precipitate in and around the opening of the crucible. The vapor deposition material deposited in and around the opening of the crucible hinders the diffusion of the vapor deposition material and may cause clogging.

The present invention has been made based on the above circumstances, and an object of the present invention is to suppress the deposition of the vapor deposition material on the opening and its surroundings, and to stably diffuse the vapor deposition material. An object of the present invention is to provide a crucible, and a vapor deposition source and a vapor deposition apparatus equipped with such a crucible for vapor deposition.

The present invention, which has been made to solve the above problems, is a crucible for vapor deposition that has an opening and is heated by induction heating, wherein the opening side portion is made of a material whose temperature rise due to induction heating is greater than that of other portions. A crucible for vapor deposition (A) formed from

Another aspect of the present invention, which has been made to solve the above problems, is a crucible for vapor deposition that is heated by induction heating, wherein the opening side portion is made of a ferromagnetic metal, and the other portion is made of a non-magnetic material. A vapor deposition crucible (B) made of metal.

In the vapor deposition crucible (A) and the vapor deposition crucible (B), it is preferable that both the material forming the opening side portion and the material forming the other portion are stainless steel.

In the vapor deposition crucible (A) and the vapor deposition crucible (B), the opening side portion preferably has a constriction.

Another present invention, which has been made to solve the above problems, is a vapor deposition crucible (A) or a vapor deposition device (B), and a vapor deposition crucible (A) or a vapor deposition device (B) that covers the periphery of the vapor deposition crucible (A) or the vapor deposition device (B). A vapor deposition source comprising a coil arranged in such a manner as to

Another present invention made to solve the above problems is a vapor deposition apparatus provided with the vapor deposition source.

ADVANTAGE OF THE INVENTION According to the present invention, a vapor deposition crucible in which deposition of a vapor deposition material on and around an opening of a vapor deposition material is suppressed and the vapor deposition material can be stably diffused, and a vapor deposition source and a vapor deposition apparatus provided with such a vapor deposition crucible. can be provided.

FIG. 1 is a side view showing a vapor deposition crucible according to one embodiment of the present invention. FIG. 2 is a schematic side view showing a vapor deposition source according to one embodiment of the invention. FIG. 3 is a schematic diagram showing a vapor deposition apparatus according to one embodiment of the present invention.

Hereinafter, a vapor deposition crucible, a vapor deposition source, and a vapor deposition apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

<Cruscible for vapor deposition>
A vapor deposition crucible 10 of FIG. 1 is used as a vapor deposition source of a vapor deposition apparatus. The vapor deposition crucible 10 is a container that accommodates a vapor deposition material to be vaporized. The vapor deposition crucible 10 is heated by induction heating. The vapor deposition crucible 10 has a substantially cylindrical shape with a bottom. In the vapor deposition crucible 10 of FIG. 1, the lower side is the bottom and the upper side is open. That is, the vapor deposition crucible 10 has an opening 11 at its upper tip.

The vapor deposition crucible 10 is divided into an opening side portion 12 (upper portion in FIG. 1) and another portion 13 ( 1) are formed from different materials. The opening side portion 12 is a portion including the opening 11, and can be, for example, 10 to 50% of the height of the vapor deposition crucible 10 from the opening 11 (upper end in FIG. 1). . An opening side portion 12 of the crucible 10 for vapor deposition has a constricted portion 14 . The other portion 13 is a portion other than the opening side portion 12 and is a portion on the bottom side. The other portion 13 may be a portion that mainly accommodates the vapor deposition material. However, the vapor deposition material may be accommodated up to the opening side portion 12 .

In one embodiment of the present invention, the opening side portion 12 is made of a material that has a higher temperature rise due to induction heating than the other portion 13 . The opening-side portion 12 may be made of a material having a larger temperature rise than the other portions 13 when subjected to high-frequency induction heating at a frequency of 300 kHz, for example. According to the vapor deposition crucible 10 having such a configuration, the temperature of the opening side portion 12 tends to be higher than that of the other portion 13 when induction heating is performed using a coil. 11 and its surroundings are suppressed, and the vapor deposition material can be stably diffused. Note that the opening 11 and its periphery may be part or all of the opening-side portion 12 .

Materials for forming the opening side portion 12 and the other portion 13 are selected from conventionally known vapor deposition crucible forming materials, etc., in consideration of the type of vapor deposition material, vaporization temperature, etc., and materials satisfying the above conditions. can be selected and used. Materials forming the opening side portion 12 and the other portion 13 may be metals or non-metals (ceramics, oxides, carbon, etc.). If both the opening side portion 12 and the other portion 13 are made of metal, there is an advantage that these can be easily joined. In addition, when the other portion 13 is made of metal, even if the other portion 13 is not sufficiently heated by induction heating, the heat transfer from the opening-side portion 12 efficiently raises the temperature of the vapor deposition material contained therein. can be vaporized.

The easiness of temperature rise due to induction heating is affected by the electrical resistivity, magnetic permeability, etc. of the material. For example, the opening side portion 12 may be made of a material with higher electrical resistivity than the other portion 13 . Also, the opening side portion 12 may be made of a material having a higher magnetic permeability than the other portion 13 . As a form in which the opening side portion 12 is made of a material having a higher electrical resistivity than the other portion 13, for example, the opening side portion 12 is made of carbon and the other portion 13 is made of copper. I can give you an example. Further, in an example in which the opening side portion 12 is made of iron and the other portion 13 is made of copper, the opening side portion 12 is made of a material having a higher electrical resistivity than the other portion 13. It is also a mode in which the opening-side portion 12 is made of a material having a higher magnetic permeability than the other portion 13 . As a typical form in which the opening side portion 12 is made of a material having a higher magnetic permeability than the other portion 13, the opening side portion 12 is made of a ferromagnetic material, and the other portion 13 is made of A form formed from a non-magnetic material is mentioned. Among these forms, it is preferable that the opening side portion 12 is made of a ferromagnetic metal and the other portion 13 is made of a non-magnetic metal.

In one embodiment of the invention, the opening side portion 12 is made of a ferromagnetic metal and the other portion 13 is made of a non-magnetic metal. Even with the vapor deposition crucible 10 having such a configuration, the temperature of the opening side portion 12 tends to be higher than that of the other portion 13 when induction heating is performed using a coil. and its surroundings are suppressed, and the vapor deposition material can be stably diffused.

Ferromagnetic metals include iron, nickel, ferritic stainless steel (JIS SUS430, etc.), martensitic stainless steel (JIS SUS410, etc.), austenitic/ferritic stainless steel (JIS SUS329J1, etc.), precipitation hardened stainless steel (JIS SUS630, etc.). ) and the like.

Examples of non-magnetic metals include titanium, copper, aluminum, austenitic stainless steel (JIS SUS304, SUS316, SUS201, etc.), and titanium and austenitic stainless steel are preferable from the viewpoint of being able to be heated appropriately. .

In one embodiment of the present invention, both the material forming the opening side portion 12 and the material forming the other portion 13 are preferably stainless steel. Specifically, the opening side portion 12 is made of ferritic stainless steel (JIS SUS430, etc.), martensitic stainless steel (JIS SUS410, etc.), austenitic/ferritic stainless steel (JIS SUS329J1, etc.), precipitation hardening stainless steel (JIS SUS630, etc.). ), etc., and the other portion 13 is preferably formed of austenitic stainless steel (JIS SUS304, SUS201, etc.) or the like. Thus, when both the material forming the opening side portion 12 and the material forming the other portion 13 are stainless steel, the opening portion side portion 12 and the other portion 13 can be relatively easily and strongly welded together by welding or the like. can be joined to Further, stainless steel is suitable as a material for forming the crucible 10 for vapor deposition, because stainless steel includes both ferromagnetic and non-magnetic materials.

As described above, the constricted portion 14 is formed in the opening side portion 12 of the vapor deposition crucible 10 . That is, the opening side portion 12 has a portion with a small diameter. According to the findings of the present inventors, by providing the constricted portion 14 in the opening side portion 12 of the crucible 10 for vapor deposition, the diffusion of the vapor deposition material occurs uniformly regardless of the amount of the vapor deposition material, the degree of heating, etc. benefits are obtained. On the other hand, in a conventional vapor deposition crucible having such a constricted portion on the side of the opening, the vapor deposition material is particularly likely to precipitate in this constricted portion, resulting in clogging. Therefore, when the present invention is applied to a crucible for vapor deposition having a constricted portion, it is possible to significantly obtain the advantage that deposition of the vapor deposition material on the opening and its surroundings (constricted portion, etc.) can be suppressed.

The height of the vapor deposition crucible 10 may be, for example, within the range of 36 mm or more and 190 mm or less. The diameter (inner diameter) of the vapor deposition crucible 10 may be, for example, within the range of 9 mm or more and 45 mm or less. The diameter (inner diameter) of this vapor deposition crucible 10 may be the diameter (inner diameter) at the other portion 13 or at the bottom. The ratio of the diameter (inner diameter) of the constricted portion 14 to the diameter (inner diameter) of the vapor deposition crucible 10 may be, for example, in the range of 0.1 or more and 0.9 or less, or 0.2 or more and 0.7 or less. may be within the range of The average thickness of the side wall of the crucible 10 for vapor deposition may be, for example, within the range of 0.3 mm or more and 1 mm or less.

When vapor deposition is performed using the crucible 10 for vapor deposition, a vapor deposition material is accommodated in the crucible 10 for vapor deposition. The vapor deposition material is not particularly limited, and examples thereof include organic materials for forming organic EL layers and the like, inorganic materials for forming semiconductor layers, metal wiring and the like. Thus, the vapor deposition crucible 10 can be suitably used for both organic vapor deposition and inorganic vapor deposition.

In consideration of vaporization efficiency, the vapor deposition crucible 10 may contain a granular heat transfer medium that is thermally and chemically stable and has a higher thermal conductivity than the vapor deposition material together with the vapor deposition material. . Alternatively, a composite material composed of a granular heat transfer medium and a vapor deposition material covering the heat transfer medium may be accommodated in the vapor deposition crucible 10 . Further, the vapor deposition crucible 10 may contain a heating medium to be heated by induction heating together with the vapor deposition material.

<Vapor deposition source>
A vapor deposition source 20 in FIG. 2 includes a vapor deposition crucible 10 , a coil 21 arranged to cover the vapor deposition crucible 10 , and a power supply device 22 connected to the coil 21 . The coil 21 is arranged so that the central axis A of the vapor deposition crucible 10 and the central axis A of the coil 21 are aligned. The specific form of the vapor deposition crucible 10 provided in the vapor deposition source 20 is as described above.

The coil 21 is for heating the vapor deposition crucible 10 by induction. As the coil 21, a known cylindrical coil formed by spirally winding an electric wire can be used.

A power supply 22 is connected to the coil 21 and normally supplies the coil 21 with alternating current. The power supply device 22 is connected to a commercial power supply or the like, and normally generates alternating current of a predetermined frequency. The frequency of the current supplied from the power supply device 22 to the coil 21 is not particularly limited, and can be set according to the material forming the vapor deposition crucible 10. For example, it can be in the range of several tens to several hundred kHz. It can be in the range of 100-600 kHz, it can be in the range of 300-500 kHz.

According to the vapor deposition source 20, the temperature of the opening side portion 12 of the vapor deposition crucible 10 tends to be higher than that of the other portion 13 in the induction heating caused by the current flowing through the coil 21, so that the vaporized vapor deposition material is heated. Deposition on the opening 11 and its periphery is suppressed, and the vapor deposition material can be stably diffused.

The vapor deposition source may be configured to have, for example, a vapor deposition material storage chamber and a diffusion chamber. In this case, the vapor deposition crucible containing the vapor deposition material is placed in the vapor deposition material storage chamber with its periphery covered with a coil. An injection nozzle for injecting the vapor deposition material may be connected to the diffusion chamber. In such a vapor deposition source, the vapor deposition material in the vapor deposition crucible that has been vaporized by heating moves from the vapor deposition material storage chamber to the diffusion chamber. The gaseous vapor deposition material moved to the diffusion chamber is injected from the injection nozzle. The injection nozzles can be arranged, for example, on the upper side of the diffusion chamber. The vapor deposition material storage chamber and the diffusion chamber may be integrated or separated. The vapor deposition source may be configured to be able to control the discharge amount of the vapor deposition material by means of a power supply device, a valve provided in the flow path of the vapor deposition material, or the like.

<Evaporation equipment>
A vapor deposition apparatus 30 in FIG. 3 includes a vapor deposition source 20 , a substrate holder 31 and a vacuum chamber 32 . At least the vapor deposition crucible 10 and the coil 21 of the vapor deposition source 20 and the substrate holder 31 are arranged in the vacuum chamber 32 . The power supply 22 may be located outside the vacuum chamber 32 .

An evaporation source 20 (evaporation crucible 10 with a coil 21 surrounding it) is arranged below in a vacuum chamber 32 . A solid vapor deposition material X is accommodated in the vapor deposition crucible 10 .

The substrate holder 31 is arranged above in the vacuum chamber 32 . A substrate Y on which vapor deposition is to be performed is arranged downward on the substrate holding unit 31 . The material forming the substrate Y is not particularly limited and may be resin, metal, oxide, or the like.

The vacuum chamber 32 allows the space for vapor deposition to be maintained at an appropriate degree of vacuum. That is, the vapor deposition device 30 may be a vacuum vapor deposition device. The vacuum chamber 32 has a vacuum pump that discharges the gas in the vacuum chamber 32 to reduce the pressure in the vacuum chamber 32, and injects a certain amount of gas into the vacuum chamber 32 to increase the pressure in the vacuum chamber 32. Venting means or the like may be provided.

The vapor deposition device 30 can be used in the same manner as a conventional vapor deposition device (for example, a conventional vacuum vapor deposition device). According to the vapor deposition apparatus 30, deposition of the vapor deposition material X on the opening of the vapor deposition crucible 10 and its periphery can be suppressed during vapor deposition. Therefore, according to the vapor deposition apparatus 30, vapor deposition can be stably performed over a long period of time.

<Other embodiments>
The present invention is not limited to the above-described embodiments, and its configuration can be changed without changing the gist of the present invention. For example, the shape of the vapor deposition crucible is not particularly limited, and may be any shape other than cylindrical. Further, the vapor deposition crucible may have a shape in which there is no constriction on the side of the opening.

The vapor deposition crucible may be made of, for example, three or more materials. Even in such a case, the opening-side portion is made of a material that causes a larger temperature rise due to induction heating than any other portion, or the opening-side portion is made of a ferromagnetic metal, Any other portion may be made of a non-magnetic metal. However, if there is a material that connects each material (between each part), such as between the opening side part and other parts, this connecting material is not considered.

EXAMPLES Hereinafter, the content of the present invention will be described more specifically with reference to Examples. In addition, the present invention is not limited to the following examples.

<Example 1>
A substantially cylindrical crucible with a capacity of 2 cm ³ having a constricted portion on the opening side is made of SUS430, which is a ferromagnetic metal on the opening side, and SUS316, which is a non-magnetic metal on the other part. bottom. A vapor deposition source of Example 1 was assembled using this crucible and a coil formed by spirally winding an electric wire at equal intervals.

<Example 2>
A crucible similar to the crucible produced in Example 1 was produced, except that the volume was 5 cm ³ . A vapor deposition source of Example 2 was assembled in the same manner as in Example 1, except that this crucible was used.

<Comparative Example 1>
A vapor deposition source of Comparative Example 1 was assembled in the same manner as in Example 1, except that a crucible with a capacity of 2 cm ³ made of a uniform titanium material was used.

<Comparative Example 2>
A vapor deposition source of Comparative Example 2 was assembled in the same manner as in Example 2, except that a crucible made of a uniform material made of titanium and having a capacity of 5 cm ³ was used.

[evaluation]
For each of the vapor deposition sources of Examples 1 and 2 and Comparative Examples 1 and 2, the vapor deposition material was placed in a crucible and induction-heated to vaporize the vapor deposition material. Alq3 (tris(8-quinolinolato)aluminum) was used as the vapor deposition material, and induction heating was performed by passing an alternating current with a frequency of 350 kHz through the coil. In each of the vapor deposition sources of Comparative Examples 1 and 2, the vapor deposition material was gradually deposited around the opening and finally clogged. No deposition of the vapor deposition material occurred.

The crucible for vapor deposition, the vapor deposition source and the vapor deposition apparatus of the present invention can be suitably used for forming metal electrode wiring of display panels and solar cells, semiconductor layers, organic EL layers, other organic material thin films and inorganic material thin films. can be done.

REFERENCE SIGNS LIST 10 vapor deposition crucible 11 opening 12 opening side portion 13 other portion 14 constricted portion 20 vapor deposition source 21 coil 22 power supply device 30 vapor deposition device 31 substrate holding portion 32 vacuum chamber A central axis B imaginary plane perpendicular to central axis A X Vapor deposition material Y Substrate

Claims (6)

A vapor deposition crucible having an opening and heated by induction heating,
A vapor deposition crucible in which a portion on the side of an opening is made of a material having a larger temperature rise due to induction heating than other portions. A vapor deposition crucible heated by induction heating,
The opening side portion is made of ferromagnetic metal,
A crucible for vapor deposition in which other parts are made of non-magnetic metal. 3. The vapor deposition crucible according to claim 1, wherein the material forming the opening side portion and the material forming the other portion are both stainless steel. 4. The vapor deposition crucible according to claim 1, wherein the opening side portion has a constricted portion. a vapor deposition crucible according to any one of claims 1 to 4;
and a coil arranged to cover the crucible for vapor deposition. A vapor deposition apparatus comprising the vapor deposition source according to claim 5 .

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