KR102453030B1 - Evaporation source for vacuum deposition equipment - Google Patents

Abstract

Provided is a deposition source for a vacuum deposition apparatus having a high deposition rate for a vapor-deposited object by increasing the amount of sublimation per unit time when depositing a sublimable material.
The vapor deposition source DS for the vacuum vapor deposition apparatus (Dm) in the present invention for sublimating the sublimable organic material 7 and depositing it on the vapor-deposited object Sw disposed in the vacuum chamber 1 is the vapor-deposited object Sw ) a top opening 4 having a crucible 41 for ejecting the sublimated material toward the tubular body 5 which is interpolated to the top opening 4 at a distance from its wall surface and accommodates the sublimable material; A plurality of meshes 52 are provided which are provided with heating means Ht that enable heating of the material in the cylindrical body 5 and which allow the communication of the sublimated material to the cylindrical body 5 .

Description

Evaporation source for vacuum deposition equipment

The present invention relates to a deposition source for a vacuum deposition apparatus disposed in a vacuum chamber to sublimate a sublimable material to deposit on an object to be deposited.

For example, in the manufacturing process of an organic EL device, there is a step of depositing a sublimable material (organic material) such as an aluminum quinolinol complex (Alq ₃ ) or an aromatic diamine on a vapor-deposited object such as a substrate in a vacuum atmosphere. A vacuum deposition apparatus is widely used in the process. The vapor deposition source used for such a vacuum vapor deposition apparatus is known in patent document 1, for example. It is provided with heating means, such as a crucible which opened the upper surface in the vertical direction, and an induction coil which heats the crucible (refer to the prior art column).

Here, this kind of material generally has poor thermal conductivity, and furthermore, it is different from a material that vaporizes through a liquid phase, and convection of the material does not occur in the crucible during heating. Therefore, when, for example, a powdery material is filled in a crucible at the evaporation source of the above-mentioned conventional example and the crucible is heated by a heating means in a vacuum atmosphere, the material in contact with the wall surface of the crucible directly transferred to heat is sublimated. At this time, the material sublimed from the upper layer portion of the material charged toward the upper surface opening of the crucible scatters toward the vapor-deposited material through the upper surface opening of the crucible, but the material sublimed in the lower portion located below it is at a relatively low temperature that exists around it. It collides with the material (that is, not yet heated to the sublimation temperature) and returns to a solid. As a result, there is a problem that the material sublimed only in a limited range does not scatter, and the amount of sublimation per unit time under the same pressure is small, so that the deposition rate on the vapor-deposited object is low (that is, the productivity is low). In this case, it is considered to increase the heating temperature of the crucible, but in the case of (organic) materials such as aluminum quinolinol complexes or aromatic diamines, if the heating temperature is increased, the material is decomposed at the evaporation source, and the desired film quality that determines the performance of the device It is not possible to deposit a thin film with In this regard, development of a product capable of obtaining a high deposition rate at a relatively low temperature as a deposition source for a vacuum deposition apparatus for depositing the above-mentioned sublimable material has been recently demanded.

Patent Document 1: Japanese Patent Laid-Open No. 2010-1529

In view of the above points, an object of the present invention is to provide a vapor deposition source for a vacuum vapor deposition apparatus having a high deposition rate for a vapor-deposited object by increasing the amount of sublimation per unit time when vapor-depositing a sublimable material.

In order to solve the above problems, an evaporation source for a vacuum deposition apparatus of the present invention for sublimating a sublimable material and depositing on an object to be deposited is disposed in a vacuum chamber. Outer) A container, an inner container for accommodating a sublimable material by being interpolated at a distance from the wall surface of the container, and a heating means that enables heating of the material in the inner container, It is characterized in that a plurality of perforations allowing communication of the material are opened.

According to the present invention, when a sublimable material is filled in, for example, a powder form in the inner container of the evaporation source, and the outer container is heated by a heating means in a vacuum atmosphere, for example, through a through hole by radiant heat from the outer container It sublimates from materials that are directly heated or materials that are heated directly from the inner container heated by radiant heat. This sublimated material is guided to the outlet 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 in each perforation, and from this outlet, it scatters toward the object to be deposited. As described above, in the present invention, since most of the sublimated material is taken out through each hole and collides with a relatively low-temperature material (that is, non-heating material) and returns to a solid state are suppressed as much as possible (in other words, the area where the sublimated material scatters) increase), the amount of sublimation is drastically increased compared to the above-mentioned example in which the material sublimed only in a limited range does not scatter, and the deposition rate on the vapor-deposited object can be increased. As a result, since the vapor deposition source for vacuum vapor deposition apparatuses in the present invention can obtain a high vapor deposition rate even at a low heating temperature, it is optimal for vapor deposition of organic materials such as aluminum quinolinol complexes and aromatic diamines. In addition, the gap between the inner container and the outer container can be heated efficiently by radiation of the outer container, while the sublimated material can be efficiently taken out from each through hole through the space to the outlet of the outer container 1mm ~ 30mm set in the range.

In the present invention, when the outer container is composed of a crucible with an open upper surface in the vertical direction, the inner container is composed of a bottomed cylindrical body with an open upper surface, and each piece ( A configuration in which a leg piece) is installed may be employed. According to this, the inner container can be easily installed in the crucible simply by inserting the inner container into the crucible with each piece facing down and making the each piece abut against the inner bottom wall of the crucible. In this state, the space between the inner wall of the crucible and the outer wall of the inner container ( In addition to the first space), a certain gap is formed between the inner bottom wall of the crucible and the outer bottom wall of the inner container to partition the space (second space) through which the sublimated material passes, which is advantageous because it is possible to further increase the amount of sublimation. . In this case, if a plurality of spacer members are provided on at least one of the inner wall of the crucible or the outer wall of the inner container, the inner container is positioned concentrically within the crucible so that a certain gap dividing the first space can be formed even if only the inner container is installed. It is advantageous to be able

In addition, in the present invention, the cylindrical body is formed by assembling a metal wire of a predetermined diameter, such as a metal mesh, in a grid shape, and a circular or slit-shaped opening (perforation) through which steam passes through a metal plate such as punched metal. An open or expanded metal formed in a cylindrical shape may be used. On the other hand, the cylindrical body may be configured as a porous body having a plurality of pores through which steam passes, such as a porous ceramic. In addition, as long as it has a hole through which steam passes, the said cylindrical body can also be comprised by what was made to have a thickness by overlapping a plurality of metal meshes, or by entangled metal wires to form a nonwoven fabric. For example, when the cylindrical body is made of a metal mesh, the wire diameter is in the range of Φ0.2 to 1.0mm, and the mesh size to be a through hole that allows communication of the sublimated material is #10 to # It is preferable to set it as the range of 50. If it is such a metal mesh, even if it is filled with a powdery material, generally sublimable materials (organic materials) such as aluminum quinolinol complex and aromatic diamine have cohesive properties, so each accumulates almost without leaking from the mesh, and a part of it leaks. Even if it does, it only accumulates on the inner bottom wall of the outer container and then sublimes when the outer container is heated, so there is no special problem.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 (a) is sectional drawing which shows typically the vacuum vapor deposition apparatus provided with the vapor deposition source of embodiment of this invention. (b) is a cross-sectional view explaining the evaporation source by disassembling it.
Fig. 2 (a) is a partially enlarged cross-sectional view showing the scattering of a material sublimated from an evaporation source in the present invention; (b) is a partially enlarged cross-sectional view showing the scattering of the sublimated material from the evaporation source of the prior art.
3 is a graph illustrating a change in deposition rate with respect to heating temperature.

Hereinafter, with reference to the drawings, the vapor-deposited object is a glass substrate of a predetermined thickness having a rectangular outline (hereinafter referred to as 'substrate Sw'), the deposition material is a sublimable organic material, and the substrate Sw is applied to one side of the An embodiment of the vapor deposition source for a vacuum vapor deposition apparatus of the present invention will be described by taking the case of depositing a predetermined thin film as an example. In the following, terms indicating directions such as 'up' and 'down' are based on FIG. 1 showing the installation posture of the vacuum deposition apparatus.

With reference to FIG. 1, (Dm) is a vacuum vapor deposition apparatus provided with the vapor deposition source DS of this embodiment. The vacuum vapor deposition apparatus Dm includes a vacuum chamber 1, and although the vacuum chamber 1 is not specifically illustrated and described, a vacuum pump is connected through an exhaust pipe and evacuated to a predetermined pressure (vacuum degree) to form a vacuum atmosphere it is possible to do Further, a substrate transfer device 2 is provided above the vacuum chamber 1 . The substrate transfer apparatus 2 has a carrier 21 that holds the substrate Sw in a state in which the lower surface as a film forming surface is opened, and the carrier 21 and further the substrate Sw are moved into a vacuum chamber ( 1) It is designed to move at a predetermined speed in one direction in the interior. Since a well-known thing can be used as the board|substrate transfer apparatus 2, further description is abbreviate|omitted.

The plate-shaped mask plate 3 is provided between the board|substrate Sw conveyed by the board|substrate conveyance apparatus 2, and the evaporation source DS. In this embodiment, the mask plate 3 is mounted integrally with the board|substrate Sw, and it is made to be conveyed by the board|substrate conveying apparatus 2 together with the board|substrate Sw. Also, the mask plate 3 may be fixedly arranged in the vacuum chamber 1 in advance. A plurality of openings 31 penetrating in the plate thickness direction are formed in the mask plate 3, and the deposition range of the material sublimated at the positions where these openings 31 are not present on the substrate Sw is limited, thereby forming a predetermined pattern. A film is formed (deposited) on the substrate Sw. As the mask plate 3, a resin material such as polyimide is used in addition to a metal material such as invar, aluminum, alumina or stainless steel. And the vapor deposition source DS of this embodiment is provided in the bottom surface of the vacuum chamber 1 facing the board|substrate Sw.

The vapor deposition source DS has the crucible 4 which comprises the outer container of this embodiment. The crucible 4 has a bottomed tubular outline with an open upper surface in the vertical direction, and is formed of a high-melting-point material such as molybdenum, titanium, stainless steel or carbon with good thermal conductivity. In this case, the upper surface opening 41 of the crucible 4 constitutes the ejection port of the material sublimated in this embodiment. Around the crucible 4, heating means Ht made of known materials such as a sheath heater and a lamp heater is provided. And the cylindrical body 5 which comprises the inner container of this embodiment is interpolated in the crucible 4 . Like the crucible 4, the cylindrical body 5 has good thermal conductivity such as molybdenum, titanium and stainless steel, and is made of a high-melting-point material. It is molded so as to have a tubular outline with teeth, 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 1.0mm, and the size of the mesh 52 is preferably in the range of #10 to #50. If the mesh (opening) 52 is too large, a defect in which the material cannot be held occurs, while if the mesh 52 is too small, a defect in which the passage of the sublimated material is inhibited occurs.

On the outer bottom wall 53 of the tubular body 5, a plurality of rod-shaped square pieces 54 were installed at intervals. In addition, on the outer peripheral wall 55 of the cylindrical body 5 constituting the outer wall of the present embodiment, a rod-shaped spacer member 56 is provided at the same height from the inner bottom wall 42 of the crucible 4 and the circumference It was installed multiple times with a gap in the direction. When the tubular body 5 is installed in the crucible 4 in the vacuum chamber 1 under atmospheric pressure, the tubular body 5 is placed in the upper surface opening 41 of the crucible 4 from the side of the respective piece 54. It is inserted, and the cylindrical body 5 is moved downward, sliding each spacer member 56 along the inner peripheral surface 43 of the crucible 4 which comprises the inner wall of this embodiment. Then, when each piece 54 abuts against the inner bottom surface 42 of the crucible 4 , the cylindrical body 5 is concentrically positioned and installed in 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 formed from a gap W1 corresponding to the length of the spacer member 56 is formed. A second space (W2) that is partitioned, and is formed of a gap W2 corresponding to the length of the spacer member 56 between the inner bottom surface 42 of the crucible 4 and the outer bottom wall 53 of the tubular body 5 6b) is compartmentalized.

When the crucible 4 is heated by the heating means Ht in a state in which the vacuum chamber 1 is in a vacuum atmosphere, the length of each piece 54 and the spacer member 56 depends on radiation from the crucible 4 . While the organic material sublimated by the conductance of the first space 6a and the second space 6b can be heated efficiently by the It is set in the range of 1mm to 30mm so that it can be efficiently guided to the upper surface opening 41 of the crucible 4 via (6b). After the tubular body 5 is interpolated into the crucible 4 , the sublimable organic material 7 is filled in the tubular body 5 .

An aluminum quinolinol complex (Alq ₃ ), an aromatic diamine, etc. are mentioned as the organic material 7 used for vapor deposition in the vapor deposition source of this embodiment, What was made into powder form from the upper surface opening of the cylindrical body 5 is intended to be charged. Even if the cylindrical body 5 is filled with the powdery organic material 7 in this way, since these organic materials 7 have cohesive properties, they can be piled up with little leakage from each mesh 52 of the metal mesh. In addition, even if a part of it leaks, it sublimes when the crucible 4 is heated after that only by accumulating on the inner bottom surface 42 of the crucible 4, thereby forming the first space 6a and the second space 6b. Since it is guided through the upper surface opening 41 of the crucible 4, there is no particular problem.

Here, the organic material 7 as described above generally has poor thermal conductivity and is different from a material that vaporizes through a liquid phase, and convection of the material does not occur in the crucible during heating. Therefore, as in the conventional example, when the organic material 7 is directly filled in the crucible Pc for vapor deposition, as shown in FIG. The organic material 7a sublimed from the organic material 7 in contact with the wall surface of (Pc), but sublimed from the upper layer portion Pu of the organic material 7 filled toward the upper surface opening Po of the crucible Pc. scatters toward the substrate (not shown) through the top opening Po of the crucible Pc; It collides with the organic material 7 (that is, not yet heated to the sublimation temperature) and returns to a solid. As a result, since the organic material 7 sublimed only in a limited range does not scatter, the amount of sublimation per unit time under the same pressure is small and the deposition rate on the vapor-deposited object is low.

In contrast, 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, the crucible 4 is heated by the heating means Ht. It sublimates in the organic material 7 which is directly heated through each mesh 52 by the radiant heat from the organic material 7, or the organic material 7 which is directly transferred from the wire material 51 of the metal mesh heated by the radiant heat. Among the sublimated organic materials 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 includes the first The conductance of the space 6a and the second space 6b leads from the first space 6a to the upper surface opening 41 of the crucible 4 through the first space 6a from the second space 6b. , is scattered toward the substrate Sw from this jet port.

As such, in this embodiment, since most of this sublimated organic material is taken out from each mesh 52 of the metal mesh and collides with a relatively low temperature material (that is, unheated material) and returns to a solid state as much as possible is suppressed (in other words, Since the area where the sublimated material scatters increases), the amount of sublimation increases dramatically compared to the conventional example in which the sublimated material does not scatter only in a limited range, thereby increasing the deposition rate on the vapor-deposited object. That is, when the deposition rate with respect to the heating temperature of the crucibles 4 and Pc is measured as shown in FIG. 3, compared with the conventional example shown by the -0-line, in the embodiment of the present invention indicated by the -●-line, A deposition rate of 1.1 to 2 times can be obtained.

As mentioned above, although embodiment of this invention was described, various deformation|transformation is possible as long as it does not deviate from the scope of the technical idea of this invention. In the above embodiment, an example was described in which a metal mesh was molded into a cylindrical shape as an inner container, but it is not limited thereto, and a circular or slit-shaped opening (perforation) in a metal plate such as punched metal is opened in a cylindrical shape. Molded or expanded metal molded into a tubular shape may be used. On the other hand, the tubular body may be made of porous ceramic, and a hole in the bottom wall of the inner container is not necessarily required. In this case, the diameter of the through holes is not particularly limited as long as it can allow the passage of the sublimated organic material, and the ratio of the total total area of the through holes to the outer surface area of the cylindrical body is appropriately set in consideration of the deposition rate.

In addition, in the above embodiment, as an outer container, the crucible 4 with the upper surface opened was described as an example, but in order to adjust the conductance of the first space 6a and the second space 6b, the crucible 4 You may make it attach the cover body which provided at least 1 spray nozzle on the upper surface. In this case, although it does not show and demonstrate in particular as an outer container, what provided the spray nozzle in line on the upper surface of the accommodation box (so-called line source) can also be used.

Dm… Vacuum vapor deposition apparatus, DS… Evaporation source for vacuum deposition apparatus, Ht... heating means, Sw... substrate (substrate), 1 . . . vacuum chamber, 4... Crucible (outer container), 41... upper surface opening (jet port), 5 . . . Cylindrical body (inner container), 52... mesh (網目).

Claims (2)

A vapor deposition source for a vacuum vapor deposition apparatus disposed in a vacuum chamber to sublimate a sublimable organic material to deposit on a vapor-deposited object, the vapor deposition source comprising:
an outer container having a jet port for ejecting the sublimable organic material toward the vapor-deposited object; heating means for enabling heating of the sublimable organic material in the inner container;
The inner container has a plurality of perforations allowing communication of the sublimable organic material in a portion opposite to the inner wall of the outer container, and the inner container has a mesh size of #10 to #50 Consists of a tubular body molded into a tubular contour with a bottom of a metal mesh that is
The outer container is to open the upper surface in the vertical direction to constitute the outlet,
A plurality of spacer members are provided on at least one of the outer wall of the inner container and the inner 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 moves the said outer container with respect to the outer container. An evaporation source for a vacuum deposition apparatus, characterized in that the inner container is positioned so 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 wall of the outer container.
The method according to claim 1,
The inner container is further installed with a leg piece on its outer bottom wall, characterized in that a gap in the range of 1 mm to 30 mm is formed between the outer bottom wall of the inner container and the inner bottom wall of the outer container, vacuum deposition Vapor source for the device.

Images