JP2014047382A - Evaporation source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporation source capable of heating easily and uniformly a crucible and a vapor deposition material filled in the crucible.SOLUTION: An evaporation source comprises a crucible 1 to be charged with a vapor deposition material, and a heating part 2 arranged around the crucible 1 for heating the crucible. A thermal shield 3 for shielding a radiant heat from the heating part 2 to adjust the heat transfer to the crucible 1 is interposed between the crucible 1 and the heating part 2 so as to homogenize the heating temperature distribution by the heating part 2 of the crucible 1.

Description

  The present invention relates to an evaporation source.

  As an evaporation apparatus used for manufacturing an organic EL element, there is an apparatus using an evaporation source having a rectangular shape in plan view. This evaporation source is provided with a plurality of openings in the longitudinal direction, and vapor of the vapor deposition material is ejected from these openings.

  In such a vapor deposition apparatus, the organic layer is formed on the substrate by transporting the substrate in a direction perpendicular to the longitudinal direction of the evaporation source.

  By the way, in an evaporation source, vapor deposition is performed by heating a crucible filled with a vapor deposition material by radiant heat from a heater provided around the crucible. Here, a heater is arrange | positioned so that it may wrap around the whole outer surface of a crucible for the purpose of heating a crucible uniformly (refer FIG. 1). In FIG. 1, symbol A is a crucible and symbol B is a heater.

  However, in the case of a rectangular crucible, the short side portion is heated from a heater in three directions, whereas the long side portion is mainly heated from one direction mainly in the vicinity of the center. This causes temperature irregularities such as high temperatures.

  Furthermore, the vapor deposition material filled in the crucible has poor thermal conductivity, particularly in the case of a sublimable powder material, since the packing density is low, the thermal conductivity is still poor, and the temperature unevenness becomes even larger. .

  As a result, the amount of material consumed in the crucible is uneven, the amount of material ejected from the opening of the evaporation source is changed, and the film thickness formed on the substrate becomes non-uniform.

  In order to solve the above problems, Patent Document 1 proposes a technique for uniformly heating a material by dividing and controlling a heater. However, in such a method, it is necessary to control each heater, but fine control is required to control the change in the amount of deposition material due to temperature unevenness, and it is not suitable for a production machine that performs deposition for a long time. . Further, since the number of members such as a power source increases, the manufacturing cost increases.

  Moreover, in patent document 2, although the technique which arrange | positions a shield in order to interrupt | block that the heat of a heater reaches | attains a crucible opening part is proposed, the heat | fever of a heater will be interrupted | blocked in the perimeter of the opening part of a crucible. On the other hand, the crucible temperature cannot be raised, so the above problem cannot be solved.

Japanese Patent No. 4436920 Japanese Patent Publication No. 3-37296

  The present invention has been made in view of the above-described situation, and a heat shield that regulates heat transfer to the crucible by blocking radiant heat from the heating unit, and uniformizing the heating temperature distribution by the heating unit of the crucible. Thus, it aims at providing the evaporation source which can heat the vapor deposition material with which the crucible and the crucible were filled uniformly evenly by providing between a crucible and a heating part.

  The gist of the present invention will be described with reference to the accompanying drawings.

  An evaporation source including a crucible 1 filled with a vapor deposition material and a heating unit 2 provided so as to surround the crucible 1 and heating the crucible 1, which cuts off radiant heat from the heating unit 2 and The heat shield 3 for adjusting the heat transfer to the crucible 1 is provided between the crucible 1 and the heating unit 2 so that the heating temperature distribution by the heating unit 2 of the crucible 1 is made uniform. It relates to a characteristic evaporation source.

  Further, in consideration of the heating temperature distribution of the crucible 1 due to the shape of the crucible 1 and the arrangement of the heating unit 2, a portion to be a high temperature region in the heating temperature distribution of the crucible 1 and the surroundings The evaporation source according to claim 1, wherein the heat shield (3) is provided between the heating unit (2) and the heating temperature distribution by the heating unit (2) of the crucible (1). is there.

  The crucible 1 has a rectangular shape in plan view, and the heat shield 3 is provided between the short side portions 4 at both ends of the crucible 1 and the heating unit 2 positioned around the crucible 1. It concerns on the evaporation source of Claim 2.

  Moreover, the said heat shield 3 was comprised by the 1 or several heat shield board 8, It concerns on the evaporation source of any one of Claims 1-3 characterized by the above-mentioned.

  5. The evaporation source according to claim 4, wherein the heat shield plate has an opening.

  6. The evaporation source according to claim 4, further comprising a movable mechanism 9 that moves the heat shield plate 8 with respect to the crucible 1.

  The evaporation source according to any one of claims 4 to 6, further comprising a cooling mechanism for cooling the heat shield plate (8).

  Since this invention was comprised as mentioned above, it becomes an evaporation source which can heat the vapor deposition material with which the crucible and the crucible were filled uniformly, easily.

It is a schematic explanatory perspective view of the conventional evaporation source. It is a schematic explanatory perspective view of a present Example. It is a schematic explanatory side view of the principal part of a present Example. It is a schematic explanatory drawing which shows the heating temperature distribution of a rectangular crucible. It is an expansion outline explanatory side view of the principal part of a present Example. It is an expansion schematic explanatory plan view of the principal part of another example of a present Example. It is an expansion outline explanatory side view of the principal part of a present Example. It is a schematic explanatory front view of the heat shield of a present Example. It is a schematic explanatory front view of a heat shield. It is an expansion outline explanatory side view of the principal part of a present Example.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  The crucible 1 is heated by the heating unit 2 to evaporate the vapor deposition material, and vapor deposition is performed on a deposition target such as a substrate.

  At this time, the heat shield 3 is provided between the crucible 1 and the heating unit 2 so that the heating temperature distribution by the heating unit 2 of the crucible 1 is made uniform, and the radiant heat to the crucible 1 is adjusted, whereby the crucible 1 In addition, the vapor deposition material filled in the crucible 1 can be heated uniformly, the vapor deposition material temperature becomes uniform, the material consumption is not biased, and a stable film thickness distribution can be obtained.

  Specifically, for example, in consideration of the heating temperature distribution of the crucible 1 due to the shape of the crucible 1 and the arrangement of the heating unit 2, the crucible 1 is located in a portion that becomes a high-temperature region in the heating temperature distribution and its surroundings. In the case of the crucible 1 having a rectangular shape in plan view, for example, between the heating unit 2 and the short side portion 4 at both ends thereof, and the heating unit 2 positioned around the crucible 1, the crucible 1 is provided. Therefore, it is possible to prevent the crucible 1 from being heated uniformly by preventing the short side portion 4 of 1 (the portion that becomes the high temperature region) from being excessively heated.

  Further, for example, the heat shield 3 is composed of one or a plurality of heat shield plates 8 having the openings 6, and the number of openings, the shape of the openings, the number of heat shield plates 8 to be used, and the heat shield. By appropriately setting the position of the plate 8, the crucible and the vapor deposition material filled in the crucible can be easily and uniformly heated with a simple configuration.

  Specific embodiments of the present invention will be described with reference to the drawings.

  The present embodiment is an evaporation source including a crucible 1 filled with a vapor deposition material and a heating unit 2 provided so as to surround the crucible 1 and heating the crucible 1, and radiant heat from the heating unit 2 Between the crucible 1 and the heating unit 2 so as to make the heating temperature distribution by the heating unit 2 of the crucible 1 uniform. Is provided.

  Specifically, as shown in FIG. 2, the present embodiment is a so-called linear evaporation source having a crucible 1 having a rectangular shape in plan view, and a deposition object such as a substrate is provided in a vacuum chamber provided with an exhaust mechanism. And are provided in an opposing state.

  Each part will be specifically described.

  The crucible 1 is made of titanium, and a plurality of nozzles 7 for injecting a vapor deposition material heated and evaporated inside the crucible 1 are arranged in parallel in the longitudinal direction of the crucible 1. Not only titanium but also other materials such as tantalum, molybdenum or tungsten may be used.

  As the heating unit 2, a general sheath heater is adopted. The heating unit 2 is disposed in a coiled state so as to surround the outer surface of the crucible 1. Moreover, the space | interval of the heating part 2 and the outer surface of the crucible 1 is set to about several cm.

  A heat shield 3 is provided between the short sides 4 at both ends of the crucible 1 and the heating unit 2 positioned around the crucible 1 as shown in FIGS.

  That is, in consideration of the heating temperature distribution of the crucible 1 due to the shape of the crucible 1 and the arrangement of the heating unit 2, a portion that becomes a high-temperature region in the heating temperature distribution of the crucible 1, and the heating unit 2 that is positioned around it In between, the heat shield 3 is provided.

  Heating temperature distribution by a crucible 1 having a rectangular shape in plan view and a heating unit 2 disposed in a wound state so as to surround the outer surface of the crucible 1 (the crucible of a crucible when heated for a certain time without providing the heat shield 3) In the temperature distribution, as shown by broken lines in FIG.

  Therefore, as in the present embodiment, the temperature of the short side portion 4 and the heating portion 2 positioned around the short side portion 4 are set so that the temperature of the short side portion 4 is approximately the same as the temperature in the vicinity of the center of the long side portion 5. A heat shield 3 is provided between them.

  The heat shield 3 is composed of one or a plurality of plate-shaped heat shields 8. The heat shield plate 8 has a rectangular shape that can substantially cover the outer surface of the short side portion 4 of the crucible 1. In this embodiment, as shown in FIG. 5, the heat shield plate 8 is formed of three identical shapes. The heat shield plate 8 is made of a thin metal plate having high heat reflectivity that can withstand high temperatures such as stainless steel, titanium, or tantalum.

  Although the heat shield plate 8 has a flat plate shape in the present embodiment, it may have a U shape in a plan view as in another example shown in FIG. That is, not only between the short side part 4 of the crucible 1 and the heating part 2 facing this, but also between the end part of the long side part 5 of the crucible 1 and the heating part 2 facing it. 8 may be used.

  Further, the heat shield plate 8 is provided with a movable mechanism 9 composed of a cylinder mechanism, a ball screw mechanism, or the like that moves the heat shield plate 8 in the up / down / front / back / left / right directions (see FIG. 7).

  Accordingly, the position of the plurality of heat shield plates 8 with respect to the crucible 1, that is, the degree of overlap of the heat shield plates 8 can be adjusted as appropriate even in a vacuum atmosphere, and the heat transfer to the crucible 1 by the heat shield plates 8 is further adjusted. Easy to do.

  The heat shield plate 8 is provided with an opening 6 for adjusting radiation to the crucible 1. Therefore, the heat shield effect of the heat shield plate 8 can be adjusted by adjusting the degree of opening.

  In the present embodiment, the front and rear heat shield plates 8 have a configuration in which a plurality of rectangular openings 6 that are long in the left-right direction are arranged in parallel in each heat shield plate 8 as shown in FIG. By adjusting the upper and lower positions of the two by the movable mechanism 9 and adjusting the degree of opening, the heat transfer to the crucible 1 can be adjusted more finely.

  For example, when the heat shield 3 is composed of two heat shield plates 8 with an aperture ratio of 50%, the aperture ratio changes between 0 and 50% by moving the heat shield plates 8 relative to each other up and down. (See FIG. 8B).

  In addition, the opening 6 of the heat shield 8 is not limited to the above-described configuration. For example, as illustrated in FIG. 9, the circular opening 6 may be arranged in a lattice shape.

  In the present embodiment, each heat shield plate 8 is provided with a water cooling type or electronic cooling mechanism for cooling the heat shield plate 8. Accordingly, as shown in FIG. 10A, the heat shield plate 8 can be cooled during vapor deposition to enhance the heat shield effect, and of course, as shown in FIG. The crucible 1 can be forcibly cooled by bringing it into contact with the crucible 1 and the crucible can be efficiently cooled down when the apparatus is turned off.

  Therefore, according to the present embodiment, the heat shield 3 is provided between the crucible 1 and the heating unit 2 so as to make the heating temperature distribution by the heating unit 2 of the crucible 1 uniform, and the radiant heat to the crucible 1 is adjusted. By doing so, the crucible 1 and the vapor deposition material filled in the crucible 1 can be heated uniformly, the vapor deposition material temperature becomes uniform, the material consumption is not biased, and a stable film thickness distribution is obtained. Is possible.

  That is, for example, in consideration of the heating temperature distribution of the crucible 1 due to the shape of the crucible 1 and the arrangement of the heating unit 2, a portion that becomes a high-temperature region in the heating temperature distribution of the crucible 1 and the heating unit 2 positioned around it. By providing the heat shield 3 between the two, it is possible to prevent the crucible 1 from being excessively heated and to heat the crucible 1 uniformly.

  Further, the heat shield 3 is composed of one or a plurality of heat shield plates 8 having openings 6, and the number of openings, the shape of the openings, the number of heat shield plates 8 to be used, and the heat shield plate 8. By appropriately setting the positions, it is possible to easily uniformly heat the crucible and the vapor deposition material filled in the crucible with a simple configuration.

  Note that the present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate.

DESCRIPTION OF SYMBOLS 1 Crucible 2 Heating part 3 Heat shield 4 Short side part 6 Opening part 8 Heat shield board 9 Movable mechanism

Claims (7)

  An evaporation source including a crucible filled with a vapor deposition material and a heating unit provided so as to surround the crucible and heating the crucible, blocking radiation heat from the heating unit and transferring heat to the crucible An evaporation source, characterized in that a heat shield for adjusting the temperature is provided between the crucible and the heating unit so as to uniformize a heating temperature distribution by the heating unit of the crucible.   Considering the heating temperature distribution of the crucible due to the shape of the crucible and the arrangement of the heating part, between the part that becomes a high temperature region in the heating temperature distribution of the crucible and the heating part located around the part. The evaporation source according to claim 1, wherein the heat shield is provided so as to uniformize a heating temperature distribution by the heating unit of the crucible.   The crucible has a rectangular shape in a plan view, and the heat shield is provided between a short side portion at both ends of the crucible and the heating portion positioned around the crucible. Evaporation source.   The evaporation source according to any one of claims 1 to 3, wherein the heat shield is composed of one or a plurality of heat shield plates.   The evaporation source according to claim 4, wherein the heat shield plate has an opening.   The evaporation source according to claim 4, further comprising a movable mechanism that moves the heat shield plate relative to the crucible.   The evaporation source according to claim 4, further comprising a cooling mechanism that cools the heat shield plate.

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