TW202000955A - Vapor deposition source for vacuum vapor deposition apparatus - Google Patents

Abstract

Provided is a vapor deposition source for a vacuum vapor deposition apparatus with which it is possible to increase the amount of sublimation per unit time when vapor-depositing a sublimatable material and the rate of vapor deposition on the vapor deposition-receiving object is high. This vapor deposition source DS for a vacuum vapor deposition apparatus Dm is disposed in a vacuum chamber 1 and is for sublimating a sublimatable organic material 7 and vapor-depositing the same on a vapor deposition-receiving object Sw. The vapor deposition source is provided with: an upper side opening 4 with a crucible 41 for jetting sublimated material toward the vapor deposition-receiving object Sw; a cylinder 5, which is inserted through said upper side opening 4, leaving a gap from the wall surface thereof, and is for holding the sublimatable material; and a heating means Ht, which enables heating of the material inside the cylinder 5. Multiple mesh openings 52 are provided in the cylinder 5 for allowing passage of sublimated material.

Description

Vapor deposition source for vacuum evaporation equipment

The present invention relates to a vapor deposition source for a vacuum vapor deposition apparatus which is arranged in a vacuum chamber to sublimate a sublimable material to vapor deposit a vapor-deposited object.

For example, in the manufacturing process of organic EL devices, it is possible to vapor-deposit tris(8-hydroxyquinoline) aluminum complex (Alq ₃ ) or aromatic diamine, etc. in a vacuum atmosphere on the substrate to be vaporized. In the sublimation material (organic material) project, vacuum evaporation equipment is widely used in this evaporation process. A vapor deposition source used in such a vacuum vapor deposition device is disclosed in Patent Document 1, for example. It is equipped with a heating means such as a crucible that opens in the vertical direction, and an induction coil that heats the crucible (refer to the prior art).

Here, the above-mentioned materials generally have poor thermal conductivity and are different from materials vaporized through the liquid phase. When heated, the materials in the crucible do not cause convection. Therefore, if the crucible is filled with a material such as powder in the evaporation source of the above-mentioned conventional example, and the crucible is heated by a heating means in a vacuum atmosphere, it will start from the material that comes into contact with the wall surface of the directly-conducting crucible. sublimation. At this time, starting from the upper part of the filled material facing the upper opening of the crucible, the sublimated material will be scattered toward the vapor-deposited object through the upper opening of the crucible, but in the lower part below it, it has been sublimated The material will collide with the material that has a lower temperature around it (in other words, it has not been heated to the sublimation temperature) and return to a solid. As a result, since the sublimated material can only be scattered from a limited range, there is little sublimation per unit time under the same pressure and the evaporation rate for the vapor-deposited object is low (that is, Low productivity). In this case, although it may be considered to increase the heating temperature of the crucible, in the case of tris(8-hydroxyquinoline) aluminum complex or aromatic diamine (organic) material, if the heating temperature is increased, the material will be It is decomposed at the vapor deposition source, and a thin film having a desired film quality that determines the performance of the device cannot be vapor deposited. Therefore, as a vapor deposition source of a vacuum vapor deposition apparatus that vapor-deposits the above-mentioned kinds of sublimable materials, development of those who obtain a high vapor deposition rate at a relatively low temperature has been required in recent years. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2010-1529

[Problems to be solved by the invention]

In view of the above viewpoints, the present invention is intended to provide a vacuum vapor deposition apparatus which can increase the amount of sublimation per unit time when vapor-depositing materials are vapor-deposited and has a high vapor deposition rate for the vapor-deposited material The deposition source is the subject. [Means to solve the problem]

In order to solve the above-mentioned problems, the vapor deposition source for the vacuum vapor deposition apparatus of the present invention, which is arranged in a vacuum chamber and sublimates a sublimation material to vapor-deposit a vapor-deposited object, is characterized by comprising: The container has an ejection port for ejecting the sublimated material toward the object to be vapor-deposited, and the inner container. For the container, the container is inserted at intervals from the wall surface and contains the sublimable material, and the heating means is The material in the inner container can be heated, and the inner container is provided with a plurality of through holes allowing the sublimated material to communicate.

According to the present invention, if the inner container of the evaporation source is filled with a sublimable material such as powder, and the outer container is heated by heating means in a vacuum atmosphere, for example, the radiant heat from the outer container Sublimation begins with materials that are directly heated through the through-holes or materials that directly conduct heat through the inner vessel that is heated by radiant heat. This sublimated material is guided from each through hole through the space between the inner wall surface of the outer container and the outer wall surface of the inner container to the discharge port of the outer container through the space, and from this discharge port Flying toward the vapor-deposited object. In this way, in the present invention, almost all the sublimated material is taken out to each through hole, and it is suppressed as much as possible to collide with a lower temperature material (that is, a non-heated material) and return to a solid ( In other words, since the sublimated material is scattered and the area is increased), compared with the sublimated material, which only scatters from a limited range, the above-mentioned conventional example can dramatically increase the amount of sublimation and improve the The evaporation rate of the material to be evaporated. As a result, the vapor deposition source for the vacuum vapor deposition apparatus of the present invention can obtain a high vapor deposition rate even at a low heating temperature, and therefore, it is most suitable for vapor deposition of tris(8-hydroxyquinoline) aluminum oxide Organic materials such as compounds or aromatic diamines. In addition, the gap between the inner container and the outer container is to be efficiently heated by the radiation from the outer container, and to allow the sublimated material to be efficiently taken out to the outer container from each through-hole through the above space The discharge port is set in the range of 1mm to 30mm.

In the present invention, in the case where the outer container is constituted by a crucible having an opening in the vertical direction as described above, the inner container may also be constituted by a bottomed cylindrical body having an opening above, A leg piece structure is provided on the outer bottom wall of the cylindrical body. According to this, it is only necessary to insert the inner container into the crucible with the leg piece side down, and make the leg piece abut against the inner bottom wall of the crucible, the inner container can be simply set in the crucible, in this state, except In addition to the space between the inner side wall of the crucible and the outer side wall of the inner container (the first space), a space is formed between the inner bottom wall of the crucible and the outer bottom wall of the inner container to allow the sublimated material to pass through (Second space) A certain gap can be used to further increase the amount of sublimation, which is advantageous. In this case, as long as a plurality of spacers are provided on at least one of the inner side wall of the crucible or the outer side wall of the inner container, only by providing the inner container, it is possible to form a certain gap that defines the above-mentioned first space It is advantageous to locate the inner container concentrically in the crucible.

In addition, in the present invention, as the cylindrical body, it is possible to use a metal wire rod of a specific diameter assembled into a grid like a metal grid, and a metal plate is provided on the metal plate like a punching metal to allow steam Round or slit-shaped openings (through holes), or a porous metal mesh formed into a cylindrical shape, other, the cylindrical body can also be used to allow steam to pass through like a porous ceramic It consists of a porous body with many pores. In addition, as long as it has a through-hole for allowing steam to pass through, a plurality of metal meshes may be stacked to have a thickness, or a metal wire may be wound to form a non-woven fabric to form the cylindrical body . For example, when the above cylindrical body is constituted by a metal mesh, it is desirable that the wire diameter is in the range of Φ0.2 to 1.0 mm, and the mesh size of the through-hole that allows the sublimated material to communicate It is set to the range of #10～#50. As long as it is such a metal grid, even if it is filled with powdery materials, generally speaking, due to sublimation materials (organic materials) such as tris(8-hydroxyquinoline) aluminum complex or aromatic diamine, etc. Because it is cohesive, it hardly leaks from each mesh and will accumulate. Even if a part of it leaks, it will only accumulate on the inner bottom wall of the outer container. Subsequent sublimation occurs when the outer container is heated, so it does not occur. Special problem.

Hereinafter, referring to the drawings, the vapor-deposited object is a glass substrate having a rectangular outline and a specific thickness (hereinafter, referred to as "substrate Sw"), and the vapor-deposited substance is an organic material that is sublimable, and the substrate Sw A case where a specific thin film is vapor-deposited on one side is taken as an example to describe an embodiment of a vapor deposition source for the vacuum vapor deposition apparatus of the present invention. In the following, the terms representing the directions of "up" and "down" are based on the first figure showing the installation posture of the vacuum evaporation apparatus.

Referring to FIG. 1, Dm is a vacuum deposition apparatus provided with a deposition source DS of this embodiment. The vacuum vapor deposition apparatus Dm is provided with a vacuum chamber 1. The vacuum chamber 1 is not illustrated, but is connected to a vacuum pump through an exhaust pipe and can be vacuum-sucked to a certain pressure (vacuum degree) to form a vacuum atmosphere. In addition, a substrate transfer device 2 is provided above the vacuum chamber 1. The substrate conveying device 2 has a carrier 21 that holds the substrate Sw in a state where the lower surface as the film-forming surface is opened, and the carrier 21 and the substrate Sw are directed toward the inside of the vacuum chamber 1 by a driving device outside the figure The direction moves at a specific speed. As the substrate transfer device 2 is well known, other explanations are omitted.

Between the substrate Sw transferred by the substrate transfer device 2 and the vapor deposition source DS, a plate-shaped mask plate 3 is provided. In this embodiment, the mask plate 3 is configured to be mounted integrally with the substrate Sw and to be transported by the substrate transport device 2 together with the substrate Sw. In addition, the mask plate 3 may be fixedly arranged in the vacuum chamber 1 in advance. In the mask plate 3, a plurality of openings 31 penetrating the thickness direction of the plate are formed, which can be used to vaporize the substrate Sw by the sublimated material at a position where the openings 31 do not exist. As a limitation, a film is formed (deposited) on the substrate Sw in a specific pattern. As the shielding plate 3, in addition to metal made of invar (INVAR), aluminum, alumina, stainless steel, etc., resin made of polyimide or the like can also be used. Further, on the bottom surface of the vacuum chamber 1, the vapor deposition source DS of this embodiment is provided opposite to the substrate Sw.

The vapor deposition source DS has a crucible 4 that constitutes a container other than this embodiment. The crucible 4 has a bottomed cylindrical profile with an opening in the vertical direction, and is formed of a material with good thermal conductivity and high melting point, such as molybdenum, titanium, stainless steel, or carbon. In this case, the upper opening 41 of the crucible 4 constitutes the discharge port of the sublimated material of this embodiment. Around the crucible 4, a heating means Ht constituted by a well-known person such as a sheath heater or a lamp heater is provided. In addition, the crucible 4 is inserted with a cylindrical body 5 constituting the inner container of the present embodiment. Like the crucible 4, the cylindrical body 5 is composed of a material with good thermal conductivity and high melting point, such as molybdenum, titanium, or stainless steel. In this embodiment, the wire grid 51 is assembled into a grid-like metal grid Formed so as to have a bottomed cylindrical contour, the portions of each mesh 52 of the metal mesh constitute the through hole of this embodiment. In this case, the wire diameter of the wire 51 is preferably set to the range of Φ0.2 to 1.0 mm, and the size of the mesh 52 is preferably set to the range of #10 to #50. If the mesh (opening) 52 is too large, it will cause a problem that the material cannot be held. On the other hand, if the mesh 52 is too small, there will be a problem that the passage of the sublimated material will be hindered.

A plurality of rod-shaped leg pieces 54 are erected on the outer bottom wall 53 of the cylindrical body 5 at intervals. In addition, the outer peripheral wall 55 of the cylindrical body 5 constituting the outer sidewall of the present embodiment is provided with a plurality of rods standing at intervals in the circumferential direction at the same height position from the inner bottom wall 42 of the crucible 4状的 Apart Member 56. When the cylindrical body 5 is installed in the crucible 4 in the vacuum chamber 1 at atmospheric pressure, an opening 41 on the upper surface of the crucible 4 is inserted into the cylindrical body 5 from the leg 54 side, and each spacer member 56 is moved along The inner peripheral surface 43 of the crucible 4 constituting the inner side wall of the present embodiment moves the cylindrical body 5 downward while sliding. Next, if each leg piece 54 abuts on the inner bottom surface 42 of the crucible 4, it is positioned concentrically on the cylindrical body 5 of the crucible 4. In this state, between the inner peripheral surface 43 of the crucible 4 and the outer peripheral wall 55 of the cylindrical body 5, a first space 6a constituted by a gap W1 corresponding to the length of the spacer member 56 is defined. Between the inner bottom surface 42 of the crucible 4 and the outer bottom wall 53 of the cylindrical body 5, a second space 6b constituted by a gap W2 corresponding to the length of the partition member 56 is defined.

The length of the leg piece 54 or the spacer member 56 is to enable the crucible 4 to be efficiently heated by the heating means Ht when the vacuum chamber 1 is in a vacuum atmosphere, by radiation from the crucible 4 Heating, and by conducting the first space 6a and the second space 6b, the sublimated organic material can be efficiently guided from each mesh 52 of the metal grid through the first space 6a and the second space 6b to The upper surface 41 of the crucible 4 is set to a range of 1 mm to 30 mm. After inserting the cylindrical body 5 into the crucible 4, the cylindrical body 5 is filled with a sublimable organic material 7.

Examples of the vapor-deposited organic material 7 used in the vapor deposition source of the present embodiment include tris(8-hydroxyquinoline) aluminum complex (Alq ₃ ) and aromatic diamine, etc., which are in powder form. It can be filled from the upper opening of the cylindrical body 5. Even if the cylindrical body 5 is filled with the powdered organic material 7 in this way, the organic material 7 has cohesiveness, so it hardly leaks from each mesh 52 of the metal mesh and is accumulated. In addition, even if a part of it leaks, it will only accumulate on the inner bottom surface 42 of the crucible 4, and then sublimate when the crucible 4 is heated, and then be guided to the crucible through the first space 6a and the second space 6b 4 has an upper opening 41, so there is no particular problem.

Here, the organic material 7 as described above generally has a poor thermal conductivity, and unlike the material vaporized through the liquid phase, the material in the crucible does not cause convection when heated. Therefore, when the organic material 7 is directly filled in the crucible Pc and vapor-deposited as in the conventional example, as shown in FIG. 2(a), if the crucible Pc is replaced by a heating means outside the figure Heating will start sublimation from the organic material 7 that contacts the wall surface of the directly conductive crucible Pc, however, from the upper part Pu of the filled organic material 7 facing the upper opening Po of the crucible Pc, although it has been sublimated The organic material 7a will be scattered toward the substrate (not shown) through the upper opening Po of the crucible Pc. However, in the lower part Pd located below it, the sublimated organic material 7b will have a lower temperature than the surrounding ( In other words, the organic material 7 that has not been heated to the sublimation temperature collides and returns to a solid. As a result, since the sublimated organic material 7 can only be scattered from a limited range, the amount of sublimation per unit time under the same pressure is small, and the vapor deposition rate for the vapor-deposited object is low.

On the other hand, in the evaporation source DS of this embodiment, when the organic material 7 is vapor-deposited on the substrate Sw in a vacuum atmosphere, if the crucible 4 is heated by the heating means Ht, the crucible 4 4. The organic material 7 directly heated by the radiant heat through each mesh 52 or the organic material 7 directly heat-conducted by the wire 51 of the metal mesh heated by the radiant heat is sublimated. Among the sublimated organic materials 71, from the upper portion of the filled organic material 7 directly through the upper opening 41 of the crucible 4, and from the lower portion of the filled organic material 7 through the first space 6a and Conduction of the second space 6b passes through the first space 6a and the second space 6b, passes through the first space 6a, is guided to the upper opening 41 of the crucible 4, and is scattered from the ejection port toward the substrate Sw.

In this way, in the present embodiment, the sublimated organic material 71 is almost taken out from each mesh 52 of the metal grid, and it is suppressed as much as possible from the lower temperature material (that is, non-heated Materials) collide and return to a solid state (in other words, the sublimated material will scatter and increase the area). Therefore, compared with the sublimated material, it will only scatter from a limited range. The amount increases dramatically, and the evaporation rate for the object to be deposited can be increased. That is, as shown in FIG. 3, if the evaporation rate of the heating temperature of Pc for the crucible 4 is measured, compared to the conventional example shown by the -〇- line, the -●- line In the embodiment of the present invention shown, a vapor deposition rate of 1.1 to 2 times can be obtained.

Although the embodiments of the present invention have been described above, various modifications can be made without departing from the technical idea of the present invention. In the above-mentioned embodiment, the inner container is described by taking the metal mesh into a cylindrical shape as an example, but it is not limited to this, and it is possible to use a punching metal as a circle on a metal plate The shape or slit-shaped opening (through hole) is formed into a cylindrical shape, or the porous metal mesh is formed into a cylindrical shape, and the above cylindrical body can also be constituted by porous ceramics. The bottom wall of the inner container does not have to have through holes. In this case, the pore size of the through-hole is not particularly limited as long as it permits the passage of sublimated organic materials, and the ratio of the total area of the total through-holes to the surface area outside the cylindrical body is considered The evaporation rate is appropriately set.

In addition, in the above-mentioned embodiment, the outer container is described by taking the crucible 4 having an opening on the top as an example. However, in order to adjust the conductivity of the first space 6a and the second space 6b, it may be On the upper surface of the crucible 4, a cover body provided with at least one spray nozzle is installed. In this case, although there is no special illustration as the outer container, it is also possible to use one in which the spray nozzles are arranged on the top of the storage box (so-called linear source).

Dm‧‧‧vacuum evaporation device DS‧‧‧Vapor deposition source for vacuum evaporation equipment Ht‧‧‧Heating means Sw‧‧‧substrate (to be deposited) 1‧‧‧Vacuum chamber 4‧‧‧Crucible (outer container) 41‧‧‧ Upper opening (spray outlet) 5‧‧‧Cylinder (inner container) 52‧‧‧mesh (through hole)

[Figure 1] (a) is a cross-sectional view schematically showing a vacuum vapor deposition apparatus provided with a vapor deposition source according to an embodiment of the present invention. (b) is a cross-sectional view for explaining the decomposition of the vapor deposition source. [Figure 2] (a) is a partially enlarged cross-sectional view showing how the sublimated material from the vapor deposition source of the present invention is scattered. (b) is a partially enlarged cross-sectional view showing how the sublimated material from the conventional deposition source has scattered. [Figure 3] A graph illustrating the change in the vapor deposition rate with respect to the heating temperature.

Pc‧‧‧Crucible

Po‧‧‧Open above

Pu‧‧‧ Upper part

Pd‧‧‧Lower part

Ht‧‧‧Heating means

4‧‧‧Crucible (outer container)

5‧‧‧Cylinder (inner container)

6a‧‧‧First Space

6b‧‧‧ 2nd space

7, 7a, 7b, 7c ‧‧‧ organic materials

41‧‧‧Open above

43‧‧‧Inner peripheral surface

51‧‧‧Wire

52‧‧‧mesh (through hole)

53‧‧‧Outer bottom wall

54‧‧‧Foot

55‧‧‧Outer wall

56‧‧‧Spacer

71‧‧‧ organic materials

Claims (2)

A vapor deposition source for a vacuum vapor deposition device, which is arranged in a vacuum chamber, is used to sublimate sublimable materials to vapor-deposit the vapor-deposited object, and is characterized by: The outer container has an ejection port for ejecting the sublimated material toward the object to be vapor-deposited, and an inner container. The outer container is inserted into the outer container at intervals from the wall surface and contains the sublimable material, and heating means, It can heat the material in the inner container, The inner container is provided with a plurality of through holes that allow the communication of sublimated materials. The vapor deposition source for a vacuum vapor deposition device as described in item 1 of the scope of the patent application, wherein the outer container is constituted by a crucible having a vertical upper opening, The inner container is composed of a bottomed cylindrical body with an opening on the top, and a leg piece is provided on the outer bottom wall of the cylindrical body.

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