JP2014109050A - Evaporation source for vapor deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporation source for vapor deposition apparatuses which enables preventing deficiencies due to adhesion of an evaporated vapor deposition material to a heat reflection plate.SOLUTION: An evaporation source 1 for vapor deposition apparatuses comprises a cylindrical crucible 4 containing a vapor deposition material 2, heaters 5a and 5b heating the vapor deposition material 2 to a temperature evaporating the vapor deposition material 2 and a body part 6 housing the crucible 4 and the heaters 5a and 5b. The crucible 4 includes a bottom part 4a in which the vapor deposition material 2 is arranged, an opening part 4b formed so as to be face the bottom part 4a, a side wall 4c connecting the bottom part 4a to the opening part 4b and a constricted part 4d formed in the side wall 4c in the vicinity of the opening part 4b. There is also provided with a heat reflection plate 7a arranged in the side surface of the constricted part 4d in such a way as to be separated from the opening part 4b and having a hole part 7b of an aperture smaller than the largest diameter Lof the constricted part 4d. The configuration prevents deficiencies due to adhesion of the evaporated vapor deposition material 2 to the heat reflection plate 7a in the evaporation source 1 for vapor deposition apparatuses.

Description

  The present invention relates to an evaporation source for an evaporation apparatus for forming a metal film for an organic EL (Electro Luminescence) light emitting element by evaporation.

  In recent years, an organic EL panel using an organic EL light-emitting element that is thin and has a good luminance and viewing angle as a light source has attracted attention. This organic EL panel generates excitons of organic compounds contained in the light emitting layer by applying a DC voltage from a constant current power source between the anode and the cathode, and is emitted when the excitons return to the ground state. Light to be extracted outside.

  One of the methods for forming a thin film such as a metal electrode layer of an organic EL element on a substrate is a vacuum vapor deposition apparatus using a resistance heating method. An example of the configuration of this type of vapor deposition apparatus will be described with reference to FIG.

  The vapor deposition apparatus includes an evaporation source 101 as shown in FIG. The evaporation source 101 includes a main body 104 that houses the vapor deposition material 102 and the crucible 103 therein, and a heat reflecting plate 105a. A heater 106 that heats the vapor deposition material 102 to evaporate is provided on the outer periphery of the crucible 103. The heat reflecting plate 105a and the main body 104 have a function of improving the heat retaining property of the crucible when the heater 106 is heated and a function of suppressing diffusion of radiant heat from the heater 106 to the substrate 107 side.

  When the evaporation source 101 is in operation, the vacuum chamber is depressurized to form a vacuum atmosphere, the vapor deposition material 102 is heated and vaporized by the heater 106, travels in the direction of the substrate 108, and is deposited on one surface side of the substrate 107. Form.

  For example, when evaporating an Al electrode material, which is one of the electrode materials, in a crucible as shown above, use a ceramic such as C or SiC as the crucible material instead of a metallic material in order to prevent reaction with Al. There is a case. However, the ceramic crucible has high wettability with respect to Al, and when heated at the evaporation temperature, there are many troubles that the dissolved Al scoops up the crucible and spills from the crucible (for example, see Patent Document 1). .

JP 2007-327125 A

  In the conventional evaporation source 101, while the thin film formation on the substrate 107 is repeated, for example, the edge 104a is deformed by heating, and the heat reflecting plate 105a is deformed along with this deformation, and the opening of the crucible 103 is formed. And the heat reflecting plate 105a are narrowed.

  In this case, as shown in FIG. 7B, vaporized vapor deposition material 102 (for example, Al material) is fixed between the opening of the crucible 103 and the heat reflecting plate 105a, and the vaporized vapor deposition material 102 is It goes around and adheres to the back surface of the heat reflecting plate 105a. Further, the vapor deposition material 102 deposited on another member such as a shutter may fall on the heat reflection plate 105a, and the vapor deposition material 102 may wrap around to the back side of the heat reflection plate 105a.

  As a result, the opening of the crucible 103 and the heat reflecting plate 105 a are fixed by the vapor deposition material 102, and the heat reflecting plate 105 a cannot be removed from the crucible 103. Further, the vapor deposition material 102 adheres to the heat reflecting plate 105a and the edge 104a and flows out of the crucible 103, thereby causing a ground fault or failure of the evaporation source 101. Further, in the case where the edge 104a is formed of a metal member or the like, the deposited vapor deposition material 102 and the edge 104a chemically react with each other, and the metal piece of the edge 104a generated by corrosion is used during maintenance work. In some cases, it may enter the evaporation source 101 and cause a ground fault or failure of the evaporation source 101.

  The present invention has been made in view of the above problems, and provides an evaporation source for a vapor deposition apparatus capable of preventing the occurrence of problems caused by vaporized vapor deposition material adhering to a heat reflecting plate. With the goal.

  In order to solve the above-described problems, an evaporation source for a vapor deposition apparatus according to the present invention includes a cylindrical crucible for accommodating a vapor deposition material, a heater for heating the vapor deposition material to a temperature for vaporization, and the crucible and the heater inside. A vapor deposition apparatus evaporation source comprising: a crucible, wherein the crucible includes a bottom where the vapor deposition material is disposed, an opening formed opposite to the bottom, and the bottom and the opening. A side wall connected to each other and a constricted portion formed on the side wall in the vicinity of the opening, and arranged at a side surface of the constricted portion so as to be separated from the opening, and having a diameter smaller than a maximum diameter of the constricted portion. A heat reflecting plate having a hole is provided.

  Moreover, it is preferable that the said heat | fever reflecting plate of the evaporation source for vapor deposition apparatuses is supported so that it may touch the side surface of the said constriction part in the position of the said bottom part rather than the position used as the minimum diameter of the said constriction part.

  Moreover, it is preferable that the heat reflection plate of the evaporation source for the vapor deposition apparatus is formed integrally with the crucible.

  In addition, the evaporation source for the vapor deposition apparatus further includes an additional heat reflecting plate having a hole portion having a diameter smaller than the maximum diameter of the constricted portion, and the additional heat reflecting plate has an opening portion of the crucible than the heat reflecting plate. It is preferable to arrange | position so that it may space apart from the said heat | fever reflecting plate on the side.

  Moreover, it is preferable that the additional heat reflecting plate of the evaporation source for the vapor deposition apparatus is disposed so that the hole portion is separated from the side surface of the constricted portion of the crucible.

  Moreover, it is preferable that the diameter of the hole of the additional heat reflecting plate of the evaporation source for the vapor deposition apparatus is larger than the diameter of the hole of the heat reflecting plate.

  Moreover, it is preferable that the heat reflection plate of the evaporation source for the vapor deposition apparatus can be divided into two or more pieces.

  Moreover, it is preferable that the said heat | fever reflecting plate of this evaporation source for vapor deposition apparatuses has an inclination part which inclines below toward the outer periphery from the hole part.

  Moreover, the vapor deposition apparatus which concerns on this invention is provided with the evaporation source for vapor deposition apparatuses in any one of the above.

  According to the evaporation source for a vapor deposition apparatus according to the present invention, the heat reflecting plate having a hole portion having a diameter smaller than the maximum diameter of the constricted portion of the crucible is disposed on the side surface of the constricted portion of the crucible. Since the heat reflecting plate and the opening of the crucible are arranged so as to be separated from each other, the vaporized vapor deposition material can be appropriately prevented from adhering between the heat reflecting plate and the opening or flowing into the outside of the crucible. As a result, the occurrence of problems in the evaporation source for the vapor deposition apparatus can be prevented.

The cross-sectional block diagram of the evaporation source for vapor deposition apparatuses which concerns on the 1st Embodiment of this invention. The cross-sectional block diagram of the evaporation source for vapor deposition apparatuses which concerns on the 2nd Embodiment of this invention. Sectional block diagram of the evaporation source for vapor deposition apparatuses which concerns on the 3rd Embodiment of this invention. The cross-sectional block diagram of the evaporation source for vapor deposition apparatuses which concerns on the 1st modification of embodiment same as the above. Sectional block diagram of the evaporation source for vapor deposition apparatuses which concerns on the 2nd modification of embodiment same as the above. (A) The top view of the heat | fever reflecting plate with which the evaporation source for vapor deposition apparatuses which concerns on the 3rd modification of embodiment same as the above, (b) The heat with which the evaporation source for vapor deposition apparatuses which concerns on the 4th modification of embodiment same as the above is provided. The perspective view of a reflecting plate. (A) The cross-sectional block diagram of the conventional evaporation source for vapor deposition apparatuses, (b) The cross-sectional block diagram after the operation | movement stop of the evaporation source for vapor deposition apparatuses same as the above.

  An evaporation source for a vapor deposition apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
An evaporation source for a vapor deposition apparatus according to a first embodiment of the present invention (hereinafter referred to as an evaporation source) will be described with reference to FIG. The evaporation source 1 of the present embodiment is disposed in a vacuum chamber that maintains a high vacuum, and includes a heat protection plate 3, a crucible 4 for introducing the vapor deposition material 2, heaters 5a and 5b, a main body 6, and heat. And a reflecting plate 7a. A vacuum pump (not shown) is connected to the vacuum chamber, and a predetermined loading / unloading mechanism (not shown) is provided so that the substrate 8 can be easily replaced.

  The vapor deposition material 2 is a metal electrode material that is vapor-deposited on the substrate 8. For example, in an organic EL element, Al, Ag, or an alloy thereof having a high reflectance is used.

  The crucible 4 has a cross section formed in a cylindrical shape such as a cylinder or a rectangular tube, and serves as a flow path for introducing the vapor deposition material 2 vaporized by the heating of the heaters 5a and 5b to the substrate 8 side. The crucible 4 includes a bottom 4a on which the vapor deposition material 2 is disposed, an opening 4b formed on the substrate 8 side, a side wall 4c connecting the bottom 4a and the opening 4b, and a side wall 4c in the vicinity of the opening 4b. An internal space 4e is formed with the constricted portion 4d formed. In addition, the crucible 4 is comprised by the structure which consists of an aluminum nitride sintered compact, for example. Further, for example, the heat protection plate 3 has a function of moving the crucible 4 in the vertical direction in the drawing, and has a function of freely setting the height difference H from the horizontal surface of the opening 4b to the heat reflection plate 7a. Also good.

  The heaters 5a and 5b are provided outside the side wall 4c of the crucible 4, the heater 5a is above the crucible center and the entire lower part, and the heater 5b is above the crucible center and the entire upper part at a temperature above the temperature at which the vapor deposition material 2 is vaporized. Heating to a temperature at which the film formation temperature can be secured (for example, about 1100 to 1400 ° C.). At this time, the heaters 5a and 5b may be formed at different temperatures in order to ensure a predetermined film formation rate. The vaporized vapor deposition material 2 is discharged from the opening 4b through the internal space 4e of the crucible 4, and is deposited on one surface side of the substrate 8 to form a thin film. The heaters 5a and 5b heat the vapor deposition material 2 by causing a current to flow through a resistor made of a refractory metal such as tungsten or molybdenum to generate heat.

  The main body 6 houses the crucible 4 and the heaters 5a and 5b, and is mounted with thermocouples and current introduction terminals used for the heaters 5a and 5b. Moreover, the main-body part 6 also has a function which improves the crucible heat retention property at the time of heating heater 5a, 5b, and a function which suppresses that the radiant heat from heater 5a, 5b diffuses outside. The edge 6a is disposed on the upper surface of the main body 6, supports the heat reflecting plate 7a, and prevents the radiant heat from the heaters 5a and 5b from diffusing to the substrate 8 side.

Heat reflector 7a, the heater 5a, radiant heat from 5b is a member for preventing the diffusion of the 8-side substrate is disposed on the side surface of the constricted portion 4d, smaller than the maximum diameter L _max constricted portion 4d It has a substantially donut shape having a hole 7b having a diameter. The heat reflecting plate 7a is disposed on the side surface of the constricted portion 4d so as to be separated from the horizontal surface of the opening 4b of the crucible 4 with a height difference H of, for example, about 2 to 3 mm. With this arrangement relationship, it is ensured that the vaporized vapor deposition material 2 adheres between the heat reflecting plate 7a and the opening 4b, and that the vapor deposition material 2 adhering to the heat reflective plate 7a flows out of the crucible 4. Can be prevented.

  The substrate 8 is disposed in the vacuum chamber so as to face the bottom 4a of the crucible 4 when performing a vapor deposition operation, and is, for example, a glass substrate on which an ITO (transparent electrode) film is formed. Evaporate. The substrate 8 is transported at a predetermined transport speed in the vacuum chamber so as to pass above the plurality of evaporation sources 1 in the order of film formation. In the vacuum chamber, a transport roller for transporting the substrate 8 is provided. When the substrate 8 passes above the evaporation source 1, the organic material evaporated from the vapor deposition material 2 is deposited on one surface side of the substrate 8. As a result, a multilayer film is formed.

  Although not shown, the vapor deposition apparatus also includes a film thickness measurement unit that measures the vapor deposition film thickness per hour. The film thickness measurement unit is connected to a controller including a CPU and a memory. The controller controls the heating temperature of the heaters 5a and 5b in accordance with a control signal received from the film thickness measurement unit, and the vapor deposition rate of the vapor deposition material 2 Adjust.

  Next, the operation of the evaporation source 1 according to this embodiment will be described. First, when the evaporation source 1 is operated to deposit the deposition material 2 on the substrate 8, first, the inside of the vacuum chamber is decompressed to a vacuum state using a vacuum pump. Next, the crucible 4 is heated by operating the heaters 5a and 5b. The heating temperature at this time is set to a temperature at which the vapor deposition material 2 is vaporized (for example, 1100 to 1400 ° C.).

  The vaporized vapor deposition material 2 is discharged into the internal space 4e of the crucible 4, and then the vaporized vapor deposition material 2 is discharged from the opening 4b of the crucible 4 and is transported at a predetermined transport speed. Is deposited on one surface side to form a thin film.

  Next, when the vapor deposition operation of the substrate 8 is completed and the operation of the evaporation source 1 is stopped, the power sources of the heaters 5a and 5b are stopped. At this time, the heat reflecting plate 7a is disposed on the side surface of the constricted portion 4d so as to be separated from the opening 4b of the crucible 4 with a height difference H of a predetermined value or more. When the power sources of the heaters 5a and 5b are stopped, the heaters 5a and 5b and the crucible 4 adjacent thereto are in a high temperature state. On the other hand, the opening 4b of the crucible 4 is farthest from the heaters 5a and 5b, and heat from the heaters 5a and 5b is hardly transmitted by the heat reflecting plate 7a, so that it is cooled at a relatively early stage. . Therefore, the vaporized vapor deposition material 2 adheres preferentially in the vicinity of the opening 4b of the crucible 4 and hardly adheres to the heat reflecting plate 7a. Therefore, according to the arrangement relationship of the heat reflection plate 7 described above, the vaporized vapor deposition material 2 can be prevented from re-adhering between the heat reflection plate 7a and the opening 4b. It is possible to appropriately prevent the heat reflecting plate 7a and the edge 6a from going back to the back surface of the heat reflecting plate 7a and the vapor deposition material 2 attached to the heat reflecting plate 7a from flowing out of the crucible 4. As a result, it is possible to appropriately prevent the occurrence of defects such as a ground fault or failure of the evaporation source 1 due to the vaporized vapor deposition material 2 adhering to the heat reflecting plate 7a or the edge 6a.

(Second Embodiment)
Hereinafter, an evaporation source for a vapor deposition apparatus according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure similar to the evaporation source 1 which concerns on the said 1st Embodiment, and the detailed description is abbreviate | omitted (hereinafter the same).

In this embodiment, the heat reflecting plates 7a, in the position of the bottom portion 4a side of a position N which is a minimum diameter L _min constricted portion 4d, and is supported in contact with the side surfaces of the constricted portion 4d. According to this configuration, since the heat reflecting plate 7a is arranged at a position away from the opening 4b of the crucible 4, the deposition material 2 is less adhered to the heat reflecting plate 7a. Further, since the heat reflecting plate 7a is in contact with the side surface of the constricted portion 4d, it becomes difficult for the vapor deposition material 2 to enter between them. The deposited vapor deposition material 2 can be prevented from flowing out to the side surface of the crucible 4. Therefore, in this embodiment, generation | occurrence | production of malfunctions, such as a ground fault and a failure resulting from vaporized vapor deposition material 2 adhering to the heat | fever reflecting plate 7a, can be prevented appropriately.

(Third embodiment)
Hereinafter, an evaporation source for a vapor deposition apparatus according to a third embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, in this embodiment, the evaporation source 1 is supported so that the heat | fever reflecting plate 7a may contact the side surface of the constriction part 4d. In addition to the heat reflecting plate 7a, a heat reflecting plate 7c (additional heat reflecting plate) is further provided. The heat reflecting plate 7c is disposed closer to the opening 4b than the heat reflecting plate 7a so as to be separated from the heat reflecting plate 7a by a predetermined distance (for example, 1 mm) or more.

The heat reflecting plate 7c has a hole portion 7d having a diameter smaller than the maximum diameter L _max of the constricted portion 4d and is formed in a substantially donut shape. The diameter of the hole portion 7d is the hole portion 7b of the heat reflecting plate 7a. It is possible to appropriately prevent the vapor deposition material 2 from falling on the side surface of the crucible 4.

  As described above, in this embodiment, in addition to the effects of the first and second embodiments, the heat reflecting plate 7a reliably prevents the deposited vapor deposition material 2 from flowing out to the side of the crucible 4. To do. Moreover, it can also prevent that the vapor deposition material 2 and the edge 6a chemically react, and the metal piece of the edge 6a corroded mixes in the inside of the evaporation source 1 at the time of a maintenance operation. Furthermore, there is a gap through which the vapor deposition material 2 flows between the heat reflecting plate 7a and the heat reflecting plate 7c. For this reason, the vapor deposition material 2 is not blocked by the heat reflecting plate 7a, and the vapor deposition material 2 adheres to the heat reflecting plates 7a and 7c. The occurrence of defects can be prevented appropriately. Furthermore, since the heat reflecting plates 7a and 7c are doubled, the radiant heat to the substrate 8 can be further reduced. Further, since the vaporized vapor deposition material 2 is preferentially attached to the vicinity of the opening 4b of the crucible 4, adhesion to the heat reflecting plates 7a and 7c is further reduced.

  In addition, as shown in FIG. 3, the vapor deposition material 2 can be reliably placed on the back surface side of the edge 6a by making the diameter formed by the edge 6a smaller than the diameter formed by the edge 104a of the conventional evaporation source 101. You can prevent it from getting in.

(Modification 1)
A first modification of the present embodiment will be described with reference to FIG. In the first modification, the heat reflecting plate 7 a is formed integrally with the crucible 4. With this configuration, the same effects as those of the third embodiment can be obtained, and the process during maintenance of the evaporation source 1 can be simplified.

(Modification 2)
A second modification of the present embodiment will be described with reference to FIG. In the second modification, the heat reflecting plate 7a has an inclined portion 7e inclined downward from the hole portion 7b toward the outer periphery. With this configuration, the same effects as those of the second embodiment can be obtained, and the vapor deposition material 2 that has flowed into the gap between the heat reflecting plate 7a and the heat reflecting plate 7c can be efficiently absorbed by the inclination of the inclined portion 7e. It flows out to the outside. Therefore, it is possible to appropriately prevent the occurrence of problems such as a ground fault or failure of the evaporation source 1 due to the vaporized vapor deposition material 2 adhering to the heat reflecting plate 7a or the like.

(Modification 3)
A third modification of the present embodiment will be described with reference to FIG. In the third modification, the heat reflecting plate 7a is divided into two small pieces. With this configuration, the same effect as that of the third embodiment can be obtained, and the heat reflecting plate 7a can be attached even if the diameter of the hole 7b of the heat reflecting plate 7a is smaller than the diameter of the opening 4b of the crucible 4. Therefore, it is possible to simplify the process at the time of maintenance of the evaporation source 1.

(Modification 4)
A fourth modification of the present embodiment will be described with reference to FIG. In the fourth modification, a plurality of groove portions 7f into which the vapor deposition material 2 flows are formed on the upper surface of the heat reflecting plate 7a divided into two small pieces. With this configuration, the same effects as those of the third embodiment can be obtained, and the vapor deposition material 2 flowing into the upper surface of the heat reflecting plate 7d can be more unlikely to flow out.

  The evaporation source 1 according to the present invention is suitably used for a vapor deposition apparatus for depositing a metal electrode film of an organic EL element by vapor deposition, but is also used appropriately for deposition of a vapor deposition film other than an organic film. Can be. Further, in each of the above embodiments, an example is shown in which the vaporized vapor deposition material 2 proceeds in the upward direction and is deposited on the substrate 8, but is not necessarily limited to this configuration. It is also conceivable to divide not only the heat reflecting plate 7a but also the heat reflecting plate 7c into small pieces.

DESCRIPTION OF SYMBOLS 1 Evaporation source for vapor deposition apparatus 2 Vapor deposition material 4 Crucible 4a Bottom part 4b Opening part 4c Side wall 4d Constriction part 4e Internal space 5a, 5b Heater 6 Main body part 6a Edge part 7a Heat reflecting plate 7c Heat reflecting plate (additional heat reflecting plate)
7b, 7d Hole 7e Inclined part 7f Groove part 8 Substrate

Claims (9)

In an evaporation source for a vapor deposition apparatus, comprising: a cylindrical crucible that contains a vapor deposition material; a heater that is heated to a temperature at which the vapor deposition material is vaporized; and a main body that contains the crucible and the heater inside.
The crucible is formed on a bottom portion on which the vapor deposition material is disposed, an opening formed to face the bottom portion, a side wall connecting the bottom and the opening, and a side wall in the vicinity of the opening. And
An evaporation source for a vapor deposition apparatus, comprising: a heat reflecting plate disposed on a side surface of the constricted portion so as to be separated from the opening, and having a hole having a smaller diameter than the maximum diameter of the constricted portion.   2. The vapor deposition according to claim 1, wherein the heat reflecting plate is supported so as to be in contact with a side surface of the constricted portion at a position closer to the bottom than a position where the constricted portion has a minimum diameter. Evaporation source for equipment.   The evaporation source for a vapor deposition apparatus according to claim 1, wherein the heat reflecting plate is formed integrally with the crucible. An additional heat reflection plate having a hole portion having a diameter smaller than the maximum diameter of the constricted portion;
The said additional heat reflection board is arrange | positioned so that it may space apart from the said heat reflection board in the opening part side of the said crucible from the said heat reflection board. Evaporation source for evaporation equipment.   The evaporation source for an evaporation apparatus according to claim 4, wherein the additional heat reflecting plate is disposed such that a hole portion thereof is separated from a side surface of the constricted portion of the crucible.   The evaporation source for a vapor deposition apparatus according to claim 4 or 5, wherein a diameter of the hole portion of the additional heat reflecting plate is larger than a diameter of the hole portion of the heat reflecting plate.   The evaporation source for a vapor deposition apparatus according to claim 1, wherein the heat reflecting plate can be divided into two or more pieces.   The evaporation source for a vapor deposition apparatus according to any one of claims 1 to 7, wherein the heat reflecting plate has an inclined portion inclined downward from the hole portion toward the outer periphery.   A vapor deposition apparatus comprising the evaporation source for a vapor deposition apparatus according to any one of claims 1 to 8.

Images