JP6918233B2 - Thin-film deposition source for vacuum-film deposition equipment - Google Patents

Description

The present invention relates to a vapor deposition source for a vacuum vapor deposition apparatus that is placed in a vacuum chamber to sublimate a sublimable material and deposit it on an object to be deposited.

For example, in the manufacturing process of an organic EL element, there is a step of depositing a sublimable material (organic material) _{such as an aluminum quinolinol complex (Alq 3} ) or an aromatic diamine on an object to be deposited such as a substrate in a vacuum atmosphere. Vacuum vapor deposition equipment is widely used in the vapor deposition process. A vapor deposition source used in such a vacuum vapor deposition apparatus is known, for example, in Patent Document 1. This includes a crucible with an open upper surface in the vertical direction and a heating means such as an induction coil for heating the crucible (see the column of prior art).

Here, the above-mentioned materials generally have poor thermal conductivity, and unlike materials that vaporize through the liquid phase, convection of the materials does not occur in the crucible during heating. Therefore, when, for example, a powdery material is filled in the crucible with the evaporation source of the above-mentioned conventional example and the crucible is heated by a heating means in a vacuum atmosphere, the material that comes into contact with the wall surface of the crucible that directly transfers heat is sublimated. To go. At this time, the sublimated material is scattered from the upper layer portion of the filled material facing the upper surface opening of the crucible toward the vapor-deposited material through the upper surface opening of the crucible, but is sublimated in the lower layer portion located below it. The resulting material collides with the relatively cold (in other words, not yet heated to the sublimation temperature) material around it and returns to a solid. As a result, the sublimated material scatters only from a limited range, so that the amount of sublimation per unit time under the same pressure is small and the deposition rate for the material to be deposited is low (that is, the productivity is low). There's a problem. In such a case, it is conceivable to raise the heating temperature of the pit, but in the case of (organic) materials such as aluminum quinolinol complex and aromatic diamine, if the heating temperature is raised, the material will be decomposed by the vapor deposition source. It is not possible to deposit a thin film with the desired film quality that determines the performance of the device. For this reason, in recent years, there has been a demand for the development of a vapor deposition source of a vacuum vapor deposition apparatus for vapor deposition of the above-mentioned sublimable materials, which can obtain a high vapor deposition rate at a relatively low temperature.

Japanese Unexamined Patent Publication No. 2010-1529

In view of the above points, the present invention provides a vapor deposition source for a vacuum vapor deposition apparatus, which can increase the amount of sublimation per unit time when vapor deposition a sublimable material and has a high vapor deposition rate on the material to be deposited. This is the subject.

In order to solve the above problems, the vapor deposition source for the vacuum vapor deposition apparatus of the present invention, which is arranged in a vacuum chamber and for sublimating a sublimable organic material and vapor-depositing it on the vapor-deposited material, is a thin-film deposition material. an outer container having a spout for jetting the organic materials sublimated toward and inner container for housing the interpolated by sublimable organic material at a distance from the wall surface to the outer container, the organic material in the inner container The inner container is composed of a tubular body formed by forming a metal mesh having a mesh size in the range of # 10 to # 50 into a bottomed tubular contour, and is provided with a heating means capable of heating the outer container. The outer container has a plurality of through holes that allow the sublimated organic material to communicate with each other in the portion facing the inner side wall of the container, and the outer container has an upper surface opened in the vertical direction so as to form the spout. A plurality of spacer members are provided on at least one of the outer wall of the vessel and the inner side wall of the outer container, and when the inner container is inserted into the outer container from the bottom wall side thereof, the inner container is positioned with respect to the outer container by the spacer members. Therefore, a gap in the range of 1 mm to 30 mm is formed between the outer wall of the inner container and the inner side wall of the outer container .

According to the present invention, when a sublimable material, for example, powdered, is filled in the inner container of the vapor deposition source and the outer container is heated by a heating means in a vacuum atmosphere, for example, when the outer container is heated by a heating means, radiant heat from the outer container passes through the through hole. It sublimates from a material that is directly heated or a material that transfers heat directly from an inner container that is heated by radiant heat. The sublimated material is guided from each through hole to the spout of the outer container through the space by the conductance of the space between the inner wall surface of the outer container and the outer wall surface of the inner container, and is vapor-deposited from this spout. It is scattered toward things. Thus, in the present invention, most of this sublimated material is taken out into each through hole, and it is suppressed as much as possible that it collides with a relatively low temperature material (that is, an unheated material) and returns to a solid. Therefore (in other words, the area where the sublimated material scatters increases), the amount of sublimation increases dramatically compared to the above-mentioned conventional example in which the sublimated material scatters only from a limited range. , The vapor deposition rate for the material to be deposited can be increased. 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 is therefore most suitable for vapor deposition of organic materials such as aluminum quinolinol complexes and aromatic diamines. The gap between the inner container and the outer container can be efficiently heated by radiation from the outer container, while the sublimated material is efficiently taken out from each through hole to the spout of the outer container through the above space. It is set in the range of 1 mm to 30 mm so that

In the present invention, when the outer container is composed of a crucible having an open upper surface in the vertical direction, the inner container is composed of a bottomed tubular body having an open upper surface, and the outer bottom wall of the tubular body. A configuration in which a leg piece is provided may be adopted. According to this, the inner container can be easily set in the crucible simply by inserting the inner container into the crucible with one leg side down and bringing the leg piece into contact with the inner bottom wall of the crucible. In addition to the space between the inner wall of the crucible and the outer measuring wall of the inner container (first space), the sublimated material also passes between the inner bottom wall of the crucible and the outer bottom wall of the inner container. By forming a certain gap that defines the space (second space), the amount of sublimation can be further increased, which is advantageous. In this case, if a plurality of spacer members are provided on at least one of the inner wall surface of the crucible and the outer wall of the inner container, a certain gap defining the first space is formed only by installing the inner container. It is advantageous because the inner containers can be positioned concentrically in the crucible.

In the present invention, the tubular body is formed by assembling metal wire rods having a predetermined diameter in a grid pattern such as a metal mesh, or a circular or slit shape through which steam passes through a metal plate material such as punching metal. It is possible to use an expanded metal having an opening (through hole) or an expanded metal formed into a tubular shape, and on the other hand, a large number of pores through which steam passes through the tubular body like porous ceramics. It can also be composed of a porous body having. Further, if it has a through hole through which steam passes, the tubular body is formed by stacking a plurality of metal meshes to increase the thickness or entwining metal wire rods to form a non-woven fabric. You can also do it. For example, when the tubular body is made of a metal mesh, the wire diameter is in the range of Φ0.2 to 1.0 mm, and the size of the mesh that is a through hole that allows the sublimated material to communicate is # 10. The range is preferably in the range of ~ # 50. With such a metal mesh, even if a powdery material is filled, the sublimable material (organic material) such as an aluminum quinolinol complex or an aromatic diamine is generally cohesive, so that most of the material leaks from each mesh. It is piled up without any problem, and if a part of it leaks out, it is simply piled up on the inner bottom wall of the outer container and sublimated when the outer container is heated thereafter, so that no particular problem occurs.

(A) is a cross-sectional view schematically showing a vacuum vapor deposition apparatus including the vapor deposition source according to the embodiment of the present invention. (B) is a cross-sectional view for explaining the vapor deposition source by disassembling it. (A) is a partially enlarged cross-sectional view showing a state of scattering of the sublimated material from the vapor deposition source of the present invention. (B) is a partially enlarged cross-sectional view showing a state of scattering of the sublimated material from the vapor deposition source of the conventional example. The graph explaining the change of the vapor deposition rate with respect to a heating temperature.

Hereinafter, referring to the drawings, a glass substrate having a predetermined thickness having a rectangular outline (hereinafter referred to as “sublimation Sw”) and a vapor-deposited substance as a sublimable organic material are used as the vapor-deposited material on one surface of the substrate Sw. An embodiment of a vapor deposition source for a vacuum vapor deposition apparatus of the present invention will be described by taking the case of vapor deposition of a predetermined thin film as an example. In the following, the terms indicating the directions such as "up" and "down" are based on FIG. 1, which indicates the installation posture of the vacuum vapor deposition apparatus.

With reference to FIG. 1, Dm is a vacuum vapor deposition apparatus including the vapor deposition source DS of the present embodiment. The vacuum vapor deposition apparatus Dm includes a vacuum chamber 1, and although not particularly illustrated, a vacuum pump is connected to the vacuum chamber 1 and a vacuum is drawn to a predetermined pressure (vacuum degree) to create a vacuum atmosphere. Can be formed. Further, a substrate transfer device 2 is provided above the vacuum chamber 1. The substrate transfer device 2 has a carrier 21 that holds the substrate Sw in a state where the lower surface as a film forming surface is open, and the carrier 21 and thus the substrate Sw are predetermined in one direction in the vacuum chamber 1 by a drive device (not shown). It is designed to move at speed. Since a known substrate transfer device 2 can be used, further description thereof will be omitted.

A plate-shaped mask plate 3 is provided between the substrate Sw transported by the substrate transport device 2 and the vapor deposition source DS. In the present embodiment, the mask plate 3 is integrally attached to the substrate Sw and is conveyed together with the substrate Sw by the substrate transfer device 2. The mask plate 3 may be fixedly arranged in the vacuum chamber 1 in advance. The mask plate 3 is formed with a plurality of openings 31 penetrating in the plate thickness direction, and the vapor deposition range of the sublimated material on the substrate Sw is limited at a position where these openings 31 are absent, so that the substrate Sw has a predetermined pattern. It is designed to be filmed (deposited). As the mask plate 3, a metal such as Invar, aluminum, alumina or stainless steel, or a resin such as polyimide is used. The vapor deposition source DS of the present embodiment is provided on the bottom surface of the vacuum chamber 1 so as to face the substrate Sw.

The vapor deposition source DS has a crucible 4 that constitutes the outer container of the present embodiment. The crucible 4 has a bottomed tubular contour with an open upper surface in the vertical direction, and is formed of a material having good heat conduction such as molybdenum, titanium, stainless steel, and carbon, and having a high melting point. In this case, the upper surface opening 41 of the crucible 4 constitutes the spout of the sublimated material in the present embodiment. Around the crucible 4, a heating means Ht made of a known material such as a sheath heater or a lamp heater is provided. Then, the tubular body 5 constituting the inner container of the present embodiment is inserted into the crucible 4. Like the crucible 4, the tubular body 5 is made of a material having good thermal conductivity, such as molybdenum, titanium, and stainless steel, and has a high melting point. It is formed so as to have a tubular contour, and each mesh 52 portion of the metal mesh constitutes the through hole of the present embodiment. In this case, the wire diameter of the wire rod 51 is preferably in the range of Φ0.2 to 1.0 mm, and the size of the mesh 52 is preferably in the range of # 10 to # 50. If the mesh (opening) 52 is too large, there will be a problem that the material cannot be held, while 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 tubular body 5 at intervals. Further, on the outer peripheral wall 55 of the tubular body 5 constituting the outer wall of the present embodiment, rod-shaped spacer members 56 are provided at the same height position from the inner bottom wall 42 of the crucible 4 and at intervals in the circumferential direction. There are multiple erections. When the tubular body 5 is installed in the crucible 4 in the vacuum chamber 1 under atmospheric pressure, the tubular body 5 is inserted into the upper surface opening 41 of the crucible 4 from the leg piece 54 side, and each spacer member 56 is inserted into the crucible 4. The tubular body 5 is moved downward while sliding along the inner peripheral surface 43 of the crucible 4 constituting the inner side wall of the embodiment. Then, when each leg piece 54 comes into contact with the inner bottom surface 42 of the crucible 4, the tubular body 5 is concentrically positioned and installed in the crucible 4. In this state, a first space 6a composed of a gap W1 corresponding to the length of the spacer member 56 is defined between the inner peripheral surface 43 of the crucible 4 and the outer peripheral wall 55 of the tubular body 5, and in addition to this. A second space 6b composed of a gap W2 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 tubular body 5.

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

Examples of the organic material 7 used for vapor deposition at the vapor deposition source of the present embodiment include aluminum quinolinol complex (Alq ₃ ), aromatic diamine, and the like, and powdered ones are filled from the upper surface opening of the tubular body 5. It has become so. Even if the tubular body 5 is filled with the powdered organic material 7 in this way, since these organic materials 7 are cohesive, they are stacked with almost no leakage from each mesh 52 of the metal mesh. Assuming that a part of the leak leaks, it is only accumulated on the inner bottom surface 42 of the crucible 4, and then sublimates when the crucible 4 is heated, and the crucible 4 passes through the first space 6a and the second space 6b. Since it is guided to the upper surface opening 41, no particular problem occurs.

Here, the organic material 7 as described above generally has a poor thermal conductivity, and unlike a material that vaporizes through a liquid phase, convection of the material does not occur in the crucible during heating. Therefore, when the organic material 7 is directly filled in the pit Pc and vaporized as in the conventional example, as shown in FIG. 2A, when the pit Pc is heated by a heating means (not shown), heat is directly transferred. Sublimation starts from the organic material 7 in contact with the wall surface of the 坩 堝 Pc, but the sublimated organic material 7a faces the upper surface opening Po of the 坩 堝 Pc from the upper layer portion Pu of the filled organic material 7 facing the upper surface opening Po of the 坩 堝 Pc. The organic material 7b, which is scattered through and toward the substrate (not shown) but sublimated in the lower layer portion Pd located below it, is heated to a relatively low temperature (in other words, still sublimation temperature) existing around it. It collides with the organic material 7 (which has not been) and returns to a solid state. As a result, the sublimated organic material 7 scatters only from a limited range, so that the amount of sublimation per unit time under the same pressure is small and the vapor deposition rate for the object to be deposited is low.

On the other hand, in the vapor deposition source DS of the present embodiment, when the organic material 7 is vapor-deposited on the substrate Sw in a vacuum atmosphere, when the 坩 堝 4 is heated by the heating means Ht, it is directly heated through each mesh 52 by the radiant heat from the 坩 堝 4. It is sublimated from the organic material 7 to be heat-transferred and the organic material 7 which directly transfers heat from the wire rod 51 of the metal mesh heated by radiant heat. Of the sublimated organic material 71, the upper layer portion of the filled organic material 7 directly passes through the upper surface opening 41 of the crucible 4, and the lower layer portion of the filled organic material 7 passes through the first space 6a and the second space 6a. The conductance of the space 6b guides the crucible 4 from the first space 6a and from the second space 6b through the first space 6a to the upper surface opening 41 of the crucible 4, and is scattered from this spout toward the substrate Sw.

Thus, in the present embodiment, most of the sublimated organic material 71 can be taken out from each mesh 52 of the metal mesh and collide with a relatively low temperature material (that is, unheated material) to return to a solid. Since it is suppressed (in other words, the area where the sublimated material scatters increases), the sublimated material scatters only from a limited range, which is dramatically compared with the above-mentioned conventional example. The amount of sublimation can be increased, and the vapor deposition rate for the material to be deposited can be increased. That is, as shown in FIG. 3, when the vapor deposition rate with respect to the heating temperature of the crucible 4 and Pc is measured, the embodiment of the present invention shown by the − ● − line is compared with that of the conventional example shown by the − ○ − line. With the crucible, 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 are possible as long as they do not deviate from the scope of the technical idea of the present invention. In the above embodiment, as the inner container, a metal mesh formed into a tubular shape has been described as an example, but the present invention is not limited to this, and a circular or slit-shaped opening (a circular or slit-shaped opening) is formed in a metal plate material such as punching metal. It is possible to use a tubular body having a through hole) or a tubular molded expanded metal, and on the other hand, the tubular body can be made of porous ceramics. Further, the bottom wall of the inner container does not necessarily require a through hole. In this case, the pore diameter of the through hole is not particularly limited as long as it allows the passage of the sublimated organic material, and the ratio of the total through hole to the outer surface area of the tubular body to the total total area is the vapor deposition rate. It is set appropriately in consideration.

Further, in the above embodiment, the outer container is described by using a crucible 4 having an open upper surface as an example, but in order to adjust the conductance of the first space 6a and the second space 6b, the upper surface of the crucible 4 is formed. , A lid provided with at least one injection nozzle may be attached. In this case, as the outer container, although not particularly illustrated and described, a container in which injection nozzles are arranged in a row on the upper surface of the storage box (so-called line source) can also be used.

Dm ... Vacuum deposition equipment, DS ... Deposition source for vacuum deposition equipment, Ht ... Heating means, Sw ... Substrate (material to be deposited), 1 ... Vacuum chamber, 4 ... Crucible (outer container), 41 ... Top opening (spout) ), 5 ... Cylindrical body (inner container), 52 ... Mesh (through hole).

Claims (2)

In a vapor deposition source for a vacuum vapor deposition apparatus, which is placed in a vacuum chamber to sublimate a sublimable organic material and deposit it on an object to be deposited.
An outer container having a spout that ejects the sublimated organic material toward the vapor-deposited material, an inner container that is interpolated into the outer container at intervals from the wall surface to contain the sublimable organic material, and an inner container. Equipped with a heating means that enables heating of the organic material inside,
The inner container is composed of a tubular body formed by forming a metal mesh having a mesh size in the range of # 10 to # 50 into a bottomed tubular contour, and is an organic sublimated portion facing the inner side wall of the outer container. Has multiple through-holes that allow material to communicate,
The outer container has an upper surface opened in the vertical direction so as to form the spout.
A plurality of spacer members are provided on at least one of the outer wall of the inner container and the inner side wall of the outer container, and when the inner container is inserted into the outer container from the bottom wall side thereof, the spacer member causes the inner container to be opposed to the outer container. A vapor deposition source for a vacuum deposition apparatus, characterized in that a gap in the range of 1 mm to 30 mm is formed between the outer wall of the inner container and the inner side wall of the outer container after being positioned. Before Symbol inner container has its legs in the outer bottom wall is provided, wherein the gap in the range of 1mm~30mm is formed between the outer bottom wall and the outer container inner bottom wall of the inner container The vapor deposition source for the vacuum deposition apparatus according to claim 1.

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