JP2011162846A - Vacuum evaporation source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum evaporation source which allows a stable quality thin film to be deposited for a long period of time by reducing thermal deterioration in an organic material. <P>SOLUTION: The vacuum evaporation source 11 includes an evaporation chamber 14 storing the organic material 13 and evaporating the organic material 13 and jets the evaporated organic material 13. In the vacuum evaporation source 11, the heating region of the evaporation chamber 14 is partitioned into two or more ones in a depth direction, heaters 21 to 23 are respectively arranged for each partitioned heating region, the heating region with the surface of the organic material 13 is heated at the vaporization temperature of the organic material 13 by the heater in the heating region, the heating region higher than the heating region with the surface of the organic material 13 is heated at a temperature higher than the re-sticking temperature of the organic material 13 by the heater in the heating region, and the heating region lower than the heating region with the surface of the organic material 13 is heated at a temperature lower than the vaporization temperature by the heater in the heating region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vacuum evaporation source for evaporating a material for vacuum deposition.

  A vacuum evaporation source for a material for forming the thin film is indispensable for a thin film manufacturing apparatus by vacuum deposition. For example, an organic electroluminescent (hereinafter abbreviated as organic EL) panel manufacturing apparatus by vacuum deposition includes: A vacuum evaporation source for organic materials is essential. In the case of an organic EL panel manufacturing apparatus, there are several to a dozen film forming chambers, and each film forming chamber is equipped with a vacuum evaporation source, which is a process of laminating thin films formed in each film forming chamber. ing. In each vacuum vapor deposition source, a crucible is filled with a necessary amount of an organic material, and after continuous production for a certain time, the production is temporarily interrupted to supply the organic material.

  Examples of the structure of the nozzle portion of the vacuum evaporation source include a point evaporation source and a linear (linear) evaporation source. The structure of the heating part of the vacuum evaporation source is divided into an evaporation chamber and a vapor deposition chamber, but the whole vacuum evaporation source is heated (see Patent Document 1; FIG. 2 etc.), and the vacuum evaporation source evaporates. A chamber that heats the bottom of the chamber (see Patent Document 2; see FIG. 1B, etc.), a vacuum evaporation source is divided into an evaporation chamber and a pressure control chamber, and the evaporation chamber and the pressure control chamber have independent heaters. However, the organic material filled in the crucible portion has a structure in which the entire organic material is heated.

Japanese Patent Laid-Open No. 2005-213569 JP 2004-095275 A JP 2007-186787 A Japanese Patent No. 4001296

  Since many organic materials have a low melting point and a high vapor pressure, they evaporate at a low temperature. Therefore, when the organic material is used as the material for the vacuum evaporation source, the heating temperature is set low. For example, when forming an organic thin film for an organic EL element, the evaporation temperature is about 200 to 400 ° C. Therefore, when depositing an organic material, it is necessary to control the deposition amount in a low heating temperature range (see Patent Document 4; paragraph 0021).

  However, when an organic material used for manufacturing an organic EL element is maintained at a vaporization temperature at which a desired deposition amount is obtained or a temperature close thereto (for example, the evaporation temperature of 200 to 400 ° C. described above) for a long time, In some cases, the material itself deteriorates and the original performance cannot be obtained in the formed organic thin film. This is because organic materials (especially temperature-sensitive organic materials) change their molecular structure when exposed to high temperatures (e.g., vaporization temperature) for long periods of time. This is because the properties of the material change. Therefore, the degree of deterioration of the organic material differs depending on the temperature and the exposure time, and therefore, the original performance may not be obtained in the formed organic thin film.

  In the future, it is considered that phosphorescent organic materials with excellent luminous efficiency will become the mainstream of organic EL device production. However, in the above-described reservoir-type vacuum evaporation source, there is a concern about thermal deterioration of organic materials for the reasons described above. In the phosphorescent organic material, the problem is expected to become more prominent.

  The present invention has been made in view of the above problems, and an object thereof is to provide a vacuum evaporation source capable of reducing the thermal deterioration of an organic material and forming a thin film having a stable quality over a long period of time.

A vacuum evaporation source according to the first invention for solving the above-mentioned problems is as follows.
In a vacuum evaporation source containing an organic material and having an evaporation chamber for evaporating the organic material, and ejecting the evaporated organic material,
Dividing the heating area of the evaporation chamber into a plurality in the depth direction, each heater is arranged for each divided heating area,
A heating region having a surface of the organic material is heated at a vaporization temperature of the organic material by the heater in the heating region;
The heating area above the heating area where the surface of the organic material is present is heated at a temperature higher than the reattachment temperature of the organic material by the heater in the heating area,
The heating region below the heating region where the surface of the organic material is present is heated at a temperature lower than the vaporization temperature by the heater in the heating region, or the heating region is not heated.

A vacuum evaporation source according to the second invention for solving the above-mentioned problems is as follows.
There is an evaporation chamber for containing the organic material and evaporating the organic material, and a pressure adjusting chamber provided above the evaporation chamber for adjusting the pressure of the evaporated organic material. In a vacuum evaporation source for ejecting the organic material formed,
Dividing the heating area of the evaporation chamber into a plurality in the depth direction, each heater is arranged for each divided heating area,
A heating region having a surface of the organic material is heated at a vaporization temperature of the organic material by the heater in the heating region;
The heating region above the heating region where the surface of the organic material is present is heated by the heater in the heating region at a temperature higher than the reattachment temperature of the organic material or the temperature of the pressure adjustment chamber,
The heating region below the heating region where the surface of the organic material is present is heated at a temperature lower than the vaporization temperature by the heater in the heating region, or the heating region is not heated.

A vacuum evaporation source according to a third invention for solving the above-mentioned problem is
In a vacuum evaporation source containing an organic material and having an evaporation chamber for evaporating the organic material, and ejecting the evaporated organic material,
Dividing the heating region of the evaporation chamber into a plurality of depth directions, heaters arranged for each of the divided heating regions,
A detector for measuring a deposition amount of the organic material ejected from the vacuum deposition source;
A control device for controlling the heater based on the measurement of the detector;
The controller is
A first step of comparing a measured value of the deposition amount measured by the detector with a preset target value of the deposition amount, and calculating a target temperature for the target value;
When the difference obtained by subtracting the vaporization temperature of the organic material from the target temperature is equal to or less than a predetermined limit value, the control temperature is changed to the target temperature, and the heater in the heating region to be controlled is controlled. Process,
If the difference exceeds the limit value, the third step of fixing the control temperature to the currently controlled temperature and controlling the heater in the heating area to be controlled;
In the heating region to be controlled, the first step and the second step are repeated until the difference exceeds the limit value. When the difference exceeds the limit value, the third step is performed, and then the control target Having a procedure for changing to a heating area below the heating area,
The procedure is sequentially performed from the uppermost heating region to the lowermost heating region, and the heating region below the heating region to be controlled is controlled at a temperature lower than the vaporization temperature until the procedure is performed. Or not heated.

A vacuum evaporation source according to a fourth invention for solving the above-described problem is as follows.
There is an evaporation chamber for containing the organic material and evaporating the organic material, and a pressure adjusting chamber provided above the evaporation chamber for adjusting the pressure of the evaporated organic material. In a vacuum evaporation source for ejecting the organic material formed,
Dividing the heating region of the evaporation chamber into a plurality of depth directions, heaters arranged for each of the divided heating regions,
A detector for measuring a deposition amount of the organic material ejected from the vacuum deposition source;
A control device for controlling the heater based on the measurement of the detector;
The controller is
A first step of comparing a measured value of the deposition amount measured by the detector with a preset target value of the deposition amount, and calculating a target temperature for the target value;
When the difference obtained by subtracting the vaporization temperature of the organic material from the target temperature is equal to or less than a predetermined limit value, the control temperature is changed to the target temperature, and the heater in the heating region to be controlled is controlled. Process,
If the difference exceeds the limit value, a third step of controlling the heater in the heating area to be controlled by fixing the control temperature to the temperature currently controlled or the temperature of the pressure adjustment chamber;
In the heating region to be controlled, the first step and the second step are repeated until the difference exceeds the limit value. When the difference exceeds the limit value, the third step is performed, and then the control target Having a procedure for changing to a heating area below the heating area,
The procedure is sequentially performed from the uppermost heating region to the lowermost heating region, and the heating region below the heating region to be controlled is controlled at a temperature lower than the vaporization temperature until the procedure is performed. Or not heated.

  According to the present invention, the heating region where the surface of the organic material is present has a vaporization temperature, and the heating region below the surface has a temperature lower than the vaporization temperature or is not heated. Degradation is reduced, and a stable quality thin film can be formed over a long period of time. As a result, a highly reliable vacuum evaporation source can be realized at low cost, and it is possible to improve productivity and reduce product prices by preventing troubles.

1 shows an example of an embodiment of a vacuum evaporation source according to the present invention, and is a cross-sectional view of a film forming chamber provided with the vacuum evaporation source. (A) is the temperature graph in the conventional vacuum evaporation source, (b) is the temperature graph in the vacuum evaporation source shown in FIG. (A)-(c) is a figure explaining transition and temperature control of the organic material in the vacuum evaporation source shown in FIG. It is a block diagram which shows another example of embodiment of the vacuum evaporation source which concerns on this invention. It is a flowchart explaining the temperature control in the vacuum evaporation source shown in FIG.

  An embodiment of a vacuum evaporation source according to the present invention will be described with reference to FIGS.

Example 1
FIG. 1 shows an example of an embodiment of a vacuum evaporation source according to the present invention, and is a cross-sectional view of a film forming chamber provided with the vacuum evaporation source. FIG. 2A is a temperature graph in the conventional vacuum evaporation source, and FIG. 2B is a temperature graph in the vacuum evaporation source shown in FIG. 3 is a diagram for explaining the transition of the organic material and the temperature control in the vacuum evaporation source shown in FIG. 1. FIG. 3 (a) shows the initial operation time, FIG. 3 (b) shows the middle operation time, c) shows the latter half of the operation time.

  In the present embodiment, the film forming chamber 10 includes a vacuum deposition source 11 and a vacuum chamber 12 that is decompressed to a desired degree of vacuum by a vacuum pump (not shown). The vacuum evaporation source 11 is provided inside the vacuum chamber 12. In the case of an organic EL panel manufacturing apparatus, it has several to a dozen film forming chambers, in which a plurality of film forming chambers having the same structure as the film forming chamber 10 are provided, and organic thin films having different characteristics are provided. They are stacked.

  The vacuum evaporation source 11 has an evaporation chamber 14 under which the organic material 13 is accommodated and the organic material 13 is evaporated. Further, a pressure adjusting intermediate plate 15 for adjusting the pressure of the evaporated organic material 13 and a vapor nozzle 16 for ejecting the evaporated and adjusted organic material 13 are provided above the evaporation chamber 14. The pressure adjusting chamber 17 is provided.

  The pressure adjusting intermediate plate 15 is provided so as to divide the inside of the pressure adjusting chamber 17 into two vertically, and the pressure adjusting intermediate plate 15 is provided with a plurality of holes 15a having a small diameter. . The pressure of the evaporated organic material 13 is adjusted by controlling the temperature of the pressure adjusting chamber 17 with a heater 24 described later and passing the evaporated organic material 13 through a large number of holes 15a. Then, the organic material 13 which is evaporated and the pressure is adjusted is ejected from the steam nozzle 16.

  In FIG. 1, a point vapor deposition source is illustrated as an example of the simplest configuration, but a linear vapor deposition source capable of obtaining a uniform vapor deposition amount distribution in the substrate width direction may be used. The linear vapor deposition source is a long one in which one pressure adjustment chamber is provided long in the substrate width direction and a plurality of vapor nozzles are linearly arranged on the upper surface of the pressure adjustment chamber. The vapor flow velocity distribution in the longitudinal direction of the linear vapor deposition source can be optimized by the conductance of the hole in the pressure adjusting intermediate plate of the pressure adjusting chamber, the diameter of the vapor nozzle, and the installation interval in the longitudinal direction. When such a linear vapor deposition source is used, a configuration may be adopted in which evaporation chambers are provided at regular intervals at several locations below the pressure adjustment chamber. With such a configuration, when it is desired to temporarily stop the operation, only the temperature of the evaporation chamber is lowered, so that the evaporation amount can be reduced and the decrease in material can be suppressed. By reheating only the small evaporation chamber, the evaporation source can be restored to an operable state in a short time.

  A transport device (not shown) that transports the substrate 18 in the transport direction T is provided above the vapor nozzle 16. When the vapor of the organic material 13 ejected from the vapor nozzle 16 is deposited on the substrate 18, the vapor of the organic material 13 is vapor-deposited while continuously transporting the substrate 18. A thin film of the organic material 13 is formed on the entire surface. The deposition amount of the organic material 13 ejected from the steam nozzle 16 and deposited on the substrate 18 is monitored by a rate sensor 19 (detector) installed near the exit of the steam nozzle 16 or around the substrate 18. The organic material 13 ejected from the vapor nozzle 16 is controlled to a desired vapor deposition amount by feeding back the vapor deposition amount detected in step 1 and controlling heaters 21 to 24 described later.

  A plurality of heaters 21 to 23 are provided around the evaporation chamber 14, and the evaporation chamber 14 functions as a crucible. The heaters 21 to 23 are independent of each other and are controlled independently by the temperature controllers 31 to 33, respectively. More specifically, the heating region of the evaporation chamber 14 is divided into a plurality of portions in the depth direction, and the heaters 21 to 23 are arranged corresponding to the divided heating regions (depth positions), respectively. In the present embodiment, as an example, the heating region of the evaporation chamber 14 is divided into three in the depth direction, the heater 21 is located in the upper heating region of the evaporation chamber 14, the heater 22 is located in the middle heating region below it, A heater 23 is arranged in the lower heating region, which is below.

  A heater 24 is also provided around the pressure adjustment chamber 17. The heater 24 is independent of the heaters 21 to 23, and the entire heater 24 is collectively controlled by the temperature controller 34. The A shielding plate 25 that shields radiant heat from the heaters 21 to 24 is provided around the heaters 21 to 24.

  In such a configuration of the heaters 21 to 24, the temperature control of the evaporation chamber 14 and the pressure control chamber 17 is made independent from each other, and the evaporation chamber 14 is also divided into a plurality of heating regions divided in the depth direction. The temperature control of each heating area is made independent of each other.

  Although not shown in FIG. 1, as shown in FIG. 4 described later, temperature sensors 41 to 44 are provided in each heating region including the pressure adjustment chamber 17. Each heater 21-24 is controlled by each temperature controller 31-34 (control apparatus) so that it may become desired target temperature based on the temperature detected by each temperature sensor 41-44.

  In this embodiment, in order to simplify the description, the heating region of the evaporation chamber 14 is divided into three in the depth direction, and three heaters 21 to 23 are arranged corresponding to the divided heating regions. However, the heating region of the evaporation chamber 14 may be further divided in the depth direction, and more heaters may be arranged corresponding to the divided heating regions.

  Here, temperature control in the vacuum deposition source will be described with reference to FIGS. 2 (a) and 2 (b), the initial period of operation time is the period immediately after the organic material is filled in the evaporation chamber (crucible) (see FIG. 3 (a)), and the intermediate period is organic The period when the remaining amount of the material becomes about half (see FIG. 3B), and the latter period is the period when the remaining amount of the organic material becomes small (see FIG. 3C).

  First, temperature control in a conventional vacuum evaporation source will be described with reference to FIG. In a conventional vacuum evaporation source, the temperature of the vapor nozzle and the pressure adjustment chamber is controlled at a temperature sufficiently higher than the re-adhesion temperature at which the vapor of the organic material re-adheres to the vapor nozzle and the pressure adjustment chamber, and the passage of time (initial to intermediate period) -> Regardless of late) The temperature of the evaporation chamber varies somewhat to obtain a desired deposition amount, but is controlled by the vaporization temperature of the organic material and is substantially constant regardless of the passage of time, that is, the decrease of the organic material. Further, all the locations (upper, middle, and lower) of the evaporation chamber are controlled at the same temperature, that is, the vaporization temperature of the organic material. This is because the organic material filled in the evaporation chamber has a structure in which the entire organic material is similarly heated. Therefore, the organic material remaining in the evaporation chamber is exposed to the vaporization temperature for a long time at the later stage of the operation time. As a result, the molecular structure changes and the properties of the organic material change.

  Next, temperature control in the vacuum evaporation source of the present embodiment will be described with reference to FIGS. In the vacuum evaporation source 11 of the present embodiment, as shown in FIG. 2B, the temperature control of the vapor nozzle 16 and the pressure adjusting chamber 17 is equivalent to the conventional vacuum evaporation source, and the organic material 13 is reattached. It is controlled at a temperature sufficiently higher than the temperature, for example, optimally at a temperature 20 ° C. or more higher than the vaporization temperature. However, the temperature control of the evaporation chamber 14 is different from the conventional vacuum vapor deposition source, and as the time elapses, that is, the organic material 13 decreases, the heating region where the surface of the organic material 13 is located is vaporized temperature (however, In order to obtain a desired deposition amount, there is some variation.)

  Specifically, at the beginning of the operation time, as shown in FIG. 3A, the organic material 13 is filled up to the upper part of the evaporation chamber 14, and therefore the first heater 21 arranged in the upper heating region. The temperature of the upper heating region where the surface of the organic material 13 is present is controlled by the vaporization temperature of the organic material 13. And in the heating area | region (middle part and lower part) below the heating area | region with the surface of the organic material 13, it does not heat or it is set as temperature sufficiently lower than vaporization temperature. For example, in FIG. 2B, there is a temperature gradient in which the temperature decreases from the upper part toward the lower part.

  Next, in the middle of the operation time, as shown in FIG. 3B, the surface position of the organic material 13 is lowered to a half depth position of the evaporation chamber 14 due to the decrease of the organic material 13 in the evaporation chamber 14. Therefore, the second heater 22 disposed in the middle heating region is controlled to control the temperature of the middle heating region where the surface of the organic material 13 is present by the vaporization temperature of the organic material 13. And in the heating area | region (upper part) above the heating area | region with the surface of the organic material 13, it is set as the temperature higher than the reattachment temperature or the temperature of the pressure regulation chamber 17, and the surface with the surface of the organic material 13 exists. In the heating region (lower part) below the region, heating is not performed or the temperature is sufficiently lower than the vaporization temperature. For example, in FIG. 2B, the upper and middle heating regions are set to the same temperature (vaporization temperature), and only the lower heating region is set to a temperature lower than the vaporization temperature.

  Finally, in the later stage of the operation time, as shown in FIG. 3C, the surface position of the organic material 13 is lowered to a position near the bottom of the evaporation chamber 14 due to the decrease in the organic material 13 in the evaporation chamber 14. Therefore, the temperature of the lower heating region where the surface of the organic material 13 is located is controlled by the vaporization temperature of the organic material 13 by controlling the third heater 23 disposed in the lower heating region. And in the heating area | region (upper part and center part) of the position away from the surface position of the organic material 13, it is set as the temperature higher than the reattachment temperature, or the temperature of the pressure regulation chamber 17. FIG. For example, in FIG. 2B, the upper, middle and lower heating regions are all set to the same temperature (vaporization temperature).

  When the above is arranged, in this embodiment, the heating region having the surface of the organic material 13 is heated at the vaporization temperature by the heater of the heating region, and the heating region above the heating region having the surface of the organic material 13 is Heating is performed at a temperature higher than the reattachment temperature by the heater in the heating region or the temperature of the pressure adjustment chamber 17, and the heating region below the heating region where the surface of the organic material 13 is located is lower than the vaporization temperature by the heater in the heating region Heating is performed or heating of the heating region is not performed.

  As described above, in this embodiment, the heating region (heater) controlled by the vaporization temperature is moved downward with the passage of time, whereby the heater corresponding to the surface position of the organic material 13 is moved at the vaporization temperature. I try to control it.

  By performing such temperature control, the temperature of the organic material 13 at a position away from the evaporation surface (the surface of the organic material 13) in the evaporation chamber 14 is lowered, and the deterioration rate can be slowed down for a long time. Can be operated continuously. Therefore, thermal deterioration of the organic material 13 can be reduced, and a thin film having a stable quality can be formed over a long period of time. Further, in the heating region below the heating region where the surface of the organic material 13 is present, heating is not performed or the temperature is sufficiently lower than the vaporization temperature, so that it is possible to achieve lower power than in the past.

  The vaporization temperature and re-deposition temperature will be described by taking Alq3 (Tris (8-hydroxyquinolinato) aluminum (III)), which is a typical organic material, as an example. In the case of Alq3, the vaporization temperature is 270 ° C. or higher. The reattachment temperature increases or decreases depending on the conductance (hole diameter, number of holes) of the pressure adjusting intermediate plate 15 and the conductance (length, diameter) of the steam nozzle 16, that is, depending on the pressure in the pressure adjusting chamber 17. In general, the temperature is 250 ° C. or lower, which is 20 ° C. or more lower than the vaporization temperature. Therefore, in the present embodiment, when Alq3 is used, the temperature of the pressure adjusting chamber 17 is 290 ° C., the temperature of the heating region where the surface of the organic material 13 is located is 270 ° C. which is the vaporization temperature, and the above temperature depends on the operation time. Control is performed.

(Example 2)
FIG. 4 is another example of the embodiment of the vacuum vapor deposition source according to the present invention, and is a block diagram for explaining the temperature control. FIG. 5 is a flowchart for explaining the temperature control.

  In this embodiment, the hardware configuration is the same as that of the vacuum evaporation source 11 shown in Embodiment 1 (FIG. 1), but there is a difference in temperature control. Therefore, temperature control in the present embodiment will be described on the premise of the configuration of the vacuum evaporation source 11 described above.

  In the first embodiment, the heating region (heater) corresponding to the surface position of the organic material 13 is simply controlled with the vaporization temperature as time elapses. On the other hand, in this embodiment, the deposition amount is measured by the rate sensor 19, and a heating region (heater) corresponding to the surface position of the organic material 13 is measured by the temperature controller (control device) based on the measured vapor amount. ) Is controlled at the vaporization temperature, and in the heating region below the surface position of the organic material 13, the temperature is controlled at a temperature lower than the vaporization temperature or not heated until the following procedure is performed. I have to.

  Specific temperature control will be described with reference to FIGS. 4 and 5. In the following description, T0 is the vaporization temperature of the organic material 13, and ΔT is a limit value of the temperature rise in the evaporation chamber 14. Since the limit value ΔT differs depending on the material, an appropriate value is set according to the characteristics of the material. For example, in the above-described Alq3, ΔT = + 5 to + 10 ° C.

[First Procedure F1]
(1) Step S11: Using the rate sensor 19, an actual measured value of the vapor deposition amount with respect to a predetermined target value of the vapor deposition amount is determined. Specifically, the actual value is measured by the rate sensor 19 and compared with the target value (first half of the first step).
(2) Step S12: Based on the target value and the actual measurement value, the target temperature Tb1 of the first heater 21 for calculating a preset target value is calculated (the second half of the first step).
(3) Step S13: It is determined whether or not [Tb1−T0 ≦ ΔT] is satisfied. If satisfied, the process proceeds to Step S14. Otherwise, the process proceeds to Step S15.
(4) Step S14: When the difference obtained by subtracting the vaporization temperature T0 from the target temperature Tb1 is equal to or less than a predetermined limit value ΔT, the control temperature is changed to the target temperature Tb1, and the temperature detected by the temperature sensor 41 is the target. The first temperature controller 31 is used to control the output Mb1 to the first heater 21 in the heating region to be controlled so that the temperature Tb1 is reached (second step). Then, the process returns to step S11.
(5) Step S15: If the difference obtained by subtracting the vaporization temperature T0 from the target temperature Tb1 exceeds a predetermined limit value ΔT, the control temperature is the temperature currently controlled (the target temperature Tb1 obtained last time), Alternatively, the first temperature controller 31 is used to fix the temperature Ta of the pressure adjustment chamber 17 and the temperature detected by the temperature sensor 41 to the first heater 21 in the heating region to be controlled. Output Mb1 is controlled (third step). Then, the process proceeds to step S21, that is, the second procedure F2.

[Second procedure F2]
(1) Step S21: Using the rate sensor 19, an actual measured value of the vapor deposition amount with respect to a predetermined target value of the vapor deposition amount is determined. Specifically, the actual value is measured by the rate sensor 19 and compared with the target value (first half of the first step).
(2) Step S22: A target temperature Tb2 of the second heater 22 for calculating a preset target value is calculated based on the target value and the actually measured value (the second half of the first step).
(3) Step S23: It is determined whether or not [Tb2−T0 ≦ ΔT] is satisfied. If satisfied, the process proceeds to Step S24, and if not, the process proceeds to Step S25.
(4) Step S24: When the difference obtained by subtracting the vaporization temperature T0 from the target temperature Tb2 is equal to or less than a predetermined limit value ΔT, the control temperature is changed to the target temperature Tb2, and the temperature detected by the temperature sensor 42 is the target. The output Mb2 to the second heater 22 in the heating region to be controlled is controlled using the second temperature controller 32 so that the temperature becomes Tb2 (second step). Then, the process returns to step S21.
(5) Step S25: When the difference obtained by subtracting the vaporization temperature T0 from the target temperature Tb2 exceeds a predetermined limit value ΔT, the control temperature is the temperature currently controlled (the target temperature Tb2 obtained last time), Alternatively, the second temperature controller 32 is used to fix the temperature Ta of the pressure adjustment chamber 17 and the temperature detected by the temperature sensor 42 to the second heater 22 in the heating region to be controlled. Output Mb2 is controlled (third step). Then, the process proceeds to step S31, that is, the third procedure F3.

[Third procedure F3]
(1) Step S31: The rate sensor 19 is used to determine an actual measured value of the deposition amount with respect to a preset target value of the deposition amount. Specifically, the actual value is measured by the rate sensor 19 and compared with the target value (first half of the first step).
(2) Step S32: Based on the target value and the actual measurement value, a target temperature Tb3 of the third heater 23 for calculating a preset target value is calculated (the second half of the first step).
(3) Step S33: It is determined whether or not [Tb3-T0 ≦ ΔT] is satisfied. If satisfied, the process proceeds to Step S34, and if not, the process proceeds to Step S35.
(4) Step S34: When the difference obtained by subtracting the vaporization temperature T0 from the target temperature Tb3 is equal to or less than a predetermined limit value ΔT, the control temperature is changed to the target temperature Tb3, and the temperature detected by the temperature sensor 43 is the target. The output Mb3 to the third heater 23 in the heating area to be controlled is controlled using the third temperature controller 33 so that the temperature becomes Tb3 (second step). Then, the process returns to step S31.
(5) Step S35: When the difference obtained by subtracting the vaporization temperature T0 from the target temperature Tb3 exceeds a predetermined limit value ΔT, the control temperature is the temperature currently controlled (the target temperature Tb3 obtained last time), Alternatively, the third temperature controller 33 is used to fix the temperature Ta of the pressure adjustment chamber 17 and the temperature detected by the temperature sensor 43 to the third heater 23 in the heating region to be controlled. Output Mb3 is controlled (third step). And a series of control is complete | finished. At this time, it may be notified that the organic material 13 in the evaporation chamber 14 is empty, and the film forming process may be stopped.

  In the present embodiment, in order to simplify the explanation, the control for the three heaters 21 to 23 (first procedure F1 to third procedure F3) is described, but the heating region of the evaporation chamber 14 is set in the depth direction. When more heaters are divided and more heaters are arranged corresponding to the divided heating areas, the same control is sequentially performed from the uppermost heating area (heater) to the lowermost heating area (heater). Just do it.

  To summarize the above, in the present embodiment, the first procedure F1, the second procedure F2, and the third procedure F3 differ only in the heating area (heater, temperature controller, temperature sensor) to be controlled, and the control contents thereof. Are substantially the same. That is, in the heating region to be controlled, the first step and the second step are repeated until the difference obtained by subtracting the vaporization temperature from the calculated target temperature exceeds the limit value ΔT, and the difference obtained by subtracting the vaporization temperature from the calculated target temperature is When the limit value ΔT is exceeded, after the third step is performed, the control target is changed to a heating region below the current heating region. Then, the above procedure is sequentially performed from the uppermost heating area to the lowermost heating area. On the other hand, in the heating region below the heating region to be controlled, control is performed at a temperature lower than the vaporization temperature or heating is not performed until the above procedure is performed.

  The temperature of the pressure adjusting chamber 17 is set to a temperature sufficiently higher than the re-deposition temperature of the organic material 13 (optimally, a temperature 20 ° C. or more higher than the vaporization temperature of the organic material 13) as in the first embodiment. Then, the output to the heater 24 is controlled by using the temperature controller 34 so that the temperature detected by the temperature sensor 44 becomes the set temperature.

  Thus, in the present embodiment, the actual value of the vapor deposition amount by the rate sensor 19 is monitored, the target temperature at which the vapor deposition amount serving as the target value is obtained is calculated based on the actual value, and the vaporization temperature of the organic material 13 is determined. When the increase in the target temperature exceeds a predetermined limit value, the heating region (heater) controlled by the vaporization temperature is moved downward, and thereby the heater corresponding to the surface position of the organic material 13 is moved. Control is done at the vaporization temperature.

  By performing such temperature control, the temperature of the organic material 13 at a position away from the evaporation surface (the surface of the organic material 13) in the evaporation chamber 14 is lowered, and the deterioration rate can be slowed down for a long time. Can be operated continuously. Therefore, thermal deterioration of the organic material 13 can be reduced, a stable deposition amount can be achieved over a long period of time, and a stable quality thin film can be formed. Further, in the heating region below the heating region where the surface of the organic material 13 is present, heating is not performed or the temperature is sufficiently lower than the vaporization temperature, so that it is possible to achieve lower power than in the past.

  The present invention is suitable as a vacuum deposition source for organic materials.

DESCRIPTION OF SYMBOLS 10 Deposition chamber 11 Vacuum deposition source 12 Vacuum chamber 13 Organic material 14 Evaporation chamber 17 Pressure control chamber 18 Substrate 19 Rate sensor 21-24 Heater 31-34 Temperature controller

Claims (4)

In a vacuum evaporation source containing an organic material and having an evaporation chamber for evaporating the organic material, and ejecting the evaporated organic material,
Dividing the heating area of the evaporation chamber into a plurality in the depth direction, each heater is arranged for each divided heating area,
A heating region having a surface of the organic material is heated at a vaporization temperature of the organic material by the heater in the heating region;
The heating area above the heating area where the surface of the organic material is present is heated at a temperature higher than the reattachment temperature of the organic material by the heater in the heating area,
A vacuum characterized in that a heating region below a heating region where the surface of the organic material is present is heated at a temperature lower than the vaporization temperature by the heater in the heating region, or the heating region is not heated. Evaporation source. There is an evaporation chamber for containing the organic material and evaporating the organic material, and a pressure adjusting chamber provided above the evaporation chamber for adjusting the pressure of the evaporated organic material. In a vacuum evaporation source for ejecting the organic material formed,
Dividing the heating area of the evaporation chamber into a plurality in the depth direction, each heater is arranged for each divided heating area,
A heating region having a surface of the organic material is heated at a vaporization temperature of the organic material by the heater in the heating region;
The heating region above the heating region where the surface of the organic material is present is heated by the heater in the heating region at a temperature higher than the reattachment temperature of the organic material or the temperature of the pressure adjustment chamber,
A vacuum characterized in that a heating region below a heating region where the surface of the organic material is present is heated at a temperature lower than the vaporization temperature by the heater in the heating region, or the heating region is not heated. Evaporation source. In a vacuum evaporation source containing an organic material and having an evaporation chamber for evaporating the organic material, and ejecting the evaporated organic material,
Dividing the heating region of the evaporation chamber into a plurality of depth directions, heaters arranged for each of the divided heating regions,
A detector for measuring a deposition amount of the organic material ejected from the vacuum deposition source;
A control device for controlling the heater based on the measurement of the detector;
The controller is
A first step of comparing a measured value of the deposition amount measured by the detector with a preset target value of the deposition amount, and calculating a target temperature for the target value;
When the difference obtained by subtracting the vaporization temperature of the organic material from the target temperature is equal to or less than a predetermined limit value, the control temperature is changed to the target temperature, and the heater in the heating region to be controlled is controlled. Process,
If the difference exceeds the limit value, the third step of fixing the control temperature to the currently controlled temperature and controlling the heater in the heating area to be controlled;
In the heating region to be controlled, the first step and the second step are repeated until the difference exceeds the limit value. When the difference exceeds the limit value, the third step is performed, and then the control target Having a procedure for changing to a heating area below the heating area,
The procedure is sequentially performed from the uppermost heating region to the lowermost heating region, and the heating region below the heating region to be controlled is controlled at a temperature lower than the vaporization temperature until the procedure is performed. Or a vacuum evaporation source characterized by not being heated. There is an evaporation chamber for containing the organic material and evaporating the organic material, and a pressure adjusting chamber provided above the evaporation chamber for adjusting the pressure of the evaporated organic material. In a vacuum evaporation source for ejecting the organic material formed,
Dividing the heating region of the evaporation chamber into a plurality of depth directions, heaters arranged for each of the divided heating regions,
A detector for measuring a deposition amount of the organic material ejected from the vacuum deposition source;
A control device for controlling the heater based on the measurement of the detector;
The controller is
A first step of comparing a measured value of the deposition amount measured by the detector with a preset target value of the deposition amount, and calculating a target temperature for the target value;
When the difference obtained by subtracting the vaporization temperature of the organic material from the target temperature is equal to or less than a predetermined limit value, the control temperature is changed to the target temperature, and the heater in the heating region to be controlled is controlled. Process,
If the difference exceeds the limit value, a third step of controlling the heater in the heating area to be controlled by fixing the control temperature to the temperature currently controlled or the temperature of the pressure adjustment chamber;
In the heating region to be controlled, the first step and the second step are repeated until the difference exceeds the limit value. When the difference exceeds the limit value, the third step is performed, and then the control target Having a procedure for changing to a heating area below the heating area,
The procedure is sequentially performed from the uppermost heating region to the lowermost heating region, and the heating region below the heating region to be controlled is controlled at a temperature lower than the vaporization temperature until the procedure is performed. Or a vacuum evaporation source characterized by not being heated.

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