Method for controlling indirect heating vapor deposition apparatus, and indirect heating vapor deposition apparatus

Abstract

To provide a method for controlling an indirect heating vapor deposition apparatus, capable of removing impurities included in a vessel to prevent bumping due to the impurities from occurring during vapor deposition operation, and an indirect heating vapor deposition apparatus.SOLUTION: A method for controlling an indirect heating vapor deposition apparatus, performed before vapor-depositing a vapor deposition material comprises the steps shown in the following (1)-(3): (1) a step of charging an impurity deposition material in a vessel charged with the vapor deposition material; (2) irradiating the vessel charged with the impurity deposition material with an electron beam from an electron beam source to melt and evaporate the impurity deposition material charged in the vessel; and (3) evaporating all the impurity deposition material charged in the vessel and irradiating the vessel with the electron beam from the electron beam source to evaporate the impurities remaining in the vessel.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an indirect heating evaporation device and a control method thereof, which heats a container filled with an evaporation material by electron beam bombardment to heat and evaporate the evaporation material. [Background technology]

[0002] Conventionally, deposition devices have been known in which a substrate is placed in a vacuum chamber and a deposition source is provided facing the substrate. Examples of indirect heating deposition devices include electron beam bombardment deposition sources that emit an electron beam (thermal electrons) into a container filled with deposition material (see, for example, Patent Document 1).

[0003] The indirect heating evaporation device described in Patent Document 1 describes a technology including a container (liner) filled with an evaporation material, an evaporation electron beam source, a preheating electron beam source, and an evaporation material supply mechanism. The evaporation electron beam source irradiates the container with thermoelectrons in an evaporation heating region. The preheating electron beam source irradiates the container with thermoelectrons in a preheating region. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-68958 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional indirect heating deposition apparatus, the container filled with the deposition material contains impurities. The impurities are precipitated during the deposition operation. Furthermore, there is a risk of bumping occurring in the container due to the precipitated impurities during the deposition operation. The occurrence of bumping causes the deposition material and impurities to scatter in the vacuum, and the scattered deposition material and impurities adhere to the substrate surface.

[0006] In consideration of the above problems, the object of the present invention is to provide a control method for an indirect heating evaporation apparatus and an indirect heating evaporation apparatus that can remove impurities contained in a container and suppress the occurrence of bumping caused by impurities during evaporation operation. [Means for solving the problem]

[0007] The method for controlling an indirectly heated evaporation apparatus of the present invention is a method for controlling an indirectly heated evaporation apparatus that is carried out before an evaporation operation using an evaporation material is performed, and includes the following steps (1) to (3). (1) A step of filling a vessel filled with a deposition material with an impurity deposition material. (2) A process of irradiating the container filled with the impurity-precipitating material with an electron beam from an electron beam generating source to melt and evaporate the impurity-precipitating material filled in the container. (3) After all of the impurity precipitation material filled in the container has evaporated, the container is irradiated with an electron beam from an electron beam generating source to evaporate impurities remaining in the container.

[0008] The indirect heating deposition apparatus of the present invention includes a container filled with deposition material, an electron beam generating source that irradiates the container filled with the deposition material with an electron beam that evaporates the deposition material, and a control unit that controls the electron beam generating source. The container is filled with an impurity deposition material before performing a deposition operation using the deposition material. The control unit controls the electron beam generating source to irradiate the container filled with the impurity deposition material with an electron beam, thereby melting and evaporating the impurity deposition material filled in the container. After all of the impurity deposition material filled in the container has evaporated, the control unit controls the electron beam generating source to irradiate the container with an electron beam from the electron beam generating source, thereby evaporating impurities remaining in the container. Effect of the Invention

[0009] As described above, according to one aspect of the present invention, impurities contained in a container can be removed, and bumping caused by the impurities during a vapor deposition operation can be suppressed. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an indirect heating evaporation apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 4 is a diagram showing a method for controlling an indirect heating evaporation apparatus according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a diagram showing a method for controlling an indirect heating evaporation apparatus according to an embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing a method for controlling an indirect heating evaporation apparatus according to an embodiment of the present invention. [Diagram 5] FIG. 4 is a diagram showing a method for controlling an indirect heating evaporation apparatus according to an embodiment of the present invention. [Figure 6] FIG. 4 is a diagram showing a time chart of a control method for an indirect heating evaporation apparatus according to an embodiment of the present invention. [Figure 7] FIG. 4 is a diagram showing a method for controlling an indirect heating evaporation apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, examples of embodiments of the present invention will be described with reference to the accompanying drawings. In addition, components having substantially the same functions or configurations in each figure are given the same reference numerals and duplicated explanations are omitted.

[0012] 1. Example of embodiment First, the configuration of an indirect heating evaporation apparatus according to an embodiment (hereinafter referred to as "this example") will be described with reference to FIG. FIG. 1 is a schematic diagram of the indirect heating evaporation apparatus of this embodiment.

[0013] The indirect heating deposition apparatus 1 shown in FIG. 1 is installed in a vacuum chamber, and heats and evaporates a deposition material filled in a container, thereby depositing the material on an object to be deposited. 1, the indirect heating evaporation apparatus 1 includes a plurality of liners 2 which are a specific example of containers, a holder 3 which is a specific example of a container holding part, a support 11 which supports the holder 3, an electron beam generating source 8 which is a specific example of an electron source, an electron gun power supply 22 and a rate control part 31 which are examples of a control part, and a film thickness meter 32. The indirect heating evaporation apparatus 1 also includes a substrate holding part which holds a substrate which is an object to be film-formed (not shown).

[0014] The liner 2 is formed in a cylindrical shape with a bottom, and has a circular bottom and a peripheral wall portion continuous with the periphery of the bottom. The liner 2 is formed of a high melting point material such as molybdenum or tungsten. The liner 2 is filled with a deposition material N1 and an impurity deposition material M1. Gold (Au), copper (Cu), or the like is used as the deposition material N1. In addition, the impurity deposition material M1 is preferably a metal that does not react with the liner 2 and that easily extracts and deposits the impurities P1 in the liner 2. As the impurity deposition material M1, a metal with a high vapor pressure, for example, silver (Ag), is used.

[0015] Although the example in which the liner 2 is formed into a cylindrical shape has been described, the present invention is not limited to this. For example, the liner 2 may be formed into a square tube shape, a ring shape, or any other shape.

[0016] The holder 3 is formed in a circular plate shape. The holder 3 has holding holes through which the liners 2 pass. The holding holes are formed in a circular shape. The material of the holder 3 may be any material that has a high thermal resistance. Therefore, the heat of the liners 2 is not easily transferred to the holder 3. The holder 3 is supported by a support 11.

[0017] Moreover, the number of holding holes provided in holder 3 is multiple, corresponding to the number of liners 2. However, the holder (container holding portion) according to the present invention may have one holding hole and hold one liner (container).

[0018] The holder 3 is supported by a support 11. A rotary drive shaft (not shown) may be connected to the center of the holder 3, and the holder 3 may be rotated by the rotary drive shaft to move the multiple liners 2 held by the holder 3 in the horizontal direction.

[0019] Furthermore, a deposition prevention cover (not shown) may be provided to cover the holder 3 and the liner 2. An evaporation opening through which evaporated particles generated when the deposition material N1 is heated pass may be formed on the upper surface of the deposition prevention cover.

[0020] A substrate holder for holding a substrate, which is an object to be film-formed, is disposed above the adhesion-preventing cover. The substrate holder is supported by a rotary drive unit so as to be rotatable in the horizontal direction.

[0021] A film thickness meter 32 for measuring the film thickness formed by the evaporated particles is disposed above the holder 3. The film thickness meter 32 outputs the measured film thickness information to a rate control unit 31 described later. The rate control unit 31 measures the deposition rate and the accumulated film thickness (accumulated film thickness) based on the film thickness information obtained from the film thickness meter 32. Then, the rate control unit 31 outputs a signal to the electron gun power supply 22 so that the measured deposition rate becomes a preset deposition rate.

[0022] Next, the electron beam generating source 8 will be described. The electron beam source 8 is disposed below the holder 3 at an arbitrary position on the rotation orbit of the liner 2. Thus, when the liner 2 held by the holder 3 is disposed at the deposition position, the liner 2 is positioned above the electron beam source 8. The electron beam source 8 has a filament and a Wehnelt that forms an electric field distribution. An opening that exposes the filament is formed in the Wehnelt. The filament is formed of a wire made of tungsten material. A cathode power supply 10 and an acceleration power supply 9 that constitute an electron gun power supply 22 are connected to this filament. A detailed configuration of the electron gun power supply 22 will be described later.

[0023] A scanning coil (deflection coil) 17 is disposed near the electron beam generating source 8. This scanning coil 17 is housed in a cooled block 18. A scanning coil current driver 25 of an electron gun power supply 22, which will be described later, is connected to the scanning coil 17. The scanning coil current driver 25 controls the output of a current flowing through the scanning coil 17.

[0024] Moreover, an anode 16 having an opening is fixed to the upper surface of the block 18. The anode 16 is disposed between the bottom of the liner 2 and the electron beam generating source 8, and the opening of the anode 16 faces the electron beam generating source 8 at a predetermined distance. The anode 16 is made of a high melting point material since it is subject to a strong thermal load due to radiant heat and reflected electrons from the liner 2. The scanning coil 17 is disposed on the side of the anode 16 facing the liner 2. The scanning coil 17 generates an AC magnetic field when a current flows through it.

[0025] When a predetermined current is supplied to the filament, the filament is heated by Joule heating to a temperature at which thermoelectrons can be supplied, for example, around 2300° C. When a negative high voltage with respect to the earth potential is applied by the acceleration power supply 9, thermoelectrons emitted from the filament are accelerated by the electric field between the electron beam generating source 8 and the anode 16, generating an electron beam 19. This electron beam 19 is deflected by the AC magnetic field generated by the scanning coil 17, and is irradiated onto the liner 2 in a predetermined scanning pattern.

[0026] When the bottom of the liner 2 is electron impact heated by the electron beam 19, the temperature of the liner 2 rises. Then, the deposition material N1 and the impurity deposition material M1 are heated by conductive heat and radiation from the liner 2. When the electron impact heating of the bottom of the liner 2 is continued for a certain period of time, the deposition material N1 and the impurity deposition material M1 sublimate or evaporate. The evaporated particles of the deposition material N1 and the impurity deposition material M1 advance toward the upper part of the liner 2. During the deposition operation, the evaporated particles of the deposition material N1 are deposited on the substrate, and a deposition film of a desired thickness is attached to the object to be deposited.

[0027] Next, the configuration of the electron gun power supply 22 will be described. The electron gun power supply 22 has a cathode power supply 10 and an acceleration power supply 9 connected to the electron beam generation source 8, a scan coil current driver 25, a cathode current driver 26, an emission current control unit 24, and an electron gun control unit 23.

[0028] The cathode power supply 10 supplies a predetermined current to the cathode. Then, the cathode is heated by Joule heating to a temperature at which thermions can be emitted. The acceleration power supply 9 is grounded, and a negative high voltage with respect to the earth potential, for example, a voltage of 300V to 6kV, is applied. The holder 3 is at earth potential, and the liner 2 held by the holder 3 is at earth potential.

[0029] Furthermore, the cathode power supply 10 is connected to a cathode current drive unit 26. The cathode current drive unit 26 is connected to an emission current control unit 24 and controlled by this emission current control unit 24. The emission current control unit 24 is connected to an electron gun control unit 23 and controlled by the electron gun control unit 23. The acceleration power supply 9 is connected to the electron gun control unit 23 and controlled by this electron gun control unit 23.

[0030] The scanning coil current driver 25 is connected to the scanning coil 17. The electron gun control unit 23 is connected to the scanning coil current driver 25. The electron gun control unit 23 controls the waveform of the current supplied to the scanning coil 17 (hereinafter referred to as the "scanning coil current waveform"). The electron gun control unit 23 also outputs a signal received from the rate control unit 31 to the scanning coil current driver 25 according to the status of the deposition operation. That is, the electron gun control unit 23 controls the scanning coil current driver 25 to adjust the coil current waveform.

[0031] Next, the rate control unit 31 will be described. The rate control unit 31 is connected to the film thickness meter 32 and acquires film thickness information from the film thickness meter 32. Then, the rate control unit 31 measures the deposition rate and the accumulated film thickness based on the film thickness information acquired from the film thickness meter 32. The rate control unit 31 performs feedback control so that the deposition rate approaches a set value, and outputs a signal to the electron gun control unit 23. As a result, the emission current control unit 24 adjusts the electron current, thereby changing the deposition rate on the substrate.

[0032] 2. Example of operation of indirect heating evaporation equipment Next, an example of the operation of the indirect heating evaporation apparatus 1 having the above-mentioned configuration will be described with reference to FIGS. 1 to 5 are diagrams showing an example of the operation of the indirect heating evaporation apparatus 1. FIG. 6 is a time chart showing an example of the operation of the indirect heating evaporation apparatus 1. The horizontal axis in FIG. 6 indicates elapsed time, and the vertical axis (first axis) indicates the electron beam output of the electron beam generating source 8 and the bottom surface temperature of the liner 2. The solid line indicates the electron beam output of the electron beam generating source 8. And the dotted line indicates the bottom surface temperature of the liner 2.

[0033] First, as shown in Fig. 1, the liner 2 is filled with an impurity precipitation material M1. Next, the electron gun control unit 23 increases the electron beam output of the electron beam generation source 8 according to a program preset in the rate control unit 31. That is, the electron gun control unit 23 applies a negative high voltage to the electron beam generation source 8 by the acceleration power supply 9. Then, the thermoelectrons emitted from the filament are accelerated by the electric field between the electron beam generation source 8 and the anode 16, and an electron beam 19 is generated. This electron beam 19 is deflected by an AC magnetic field generated by the scanning coil 17, and is irradiated onto the liner 2 in a predetermined scanning pattern.

[0034] When the bottom of the liner 2 is bombarded and heated by the electron beam 19, the temperature of the liner 2 increases. Then, as shown in FIG. 2, the impurity precipitation material M1 is heated by conductive heat and radiation from the liner 2 and melts.

[0035] At this time, the output of the electron beam 19 irradiated from the electron beam generating source 8 is controlled by the electron gun control unit 23 to a temperature below the melting point of the liner 2. As shown in Fig. 6, the output of the electron beam 19 is controlled by the electron gun control unit 23 to be below the boiling point of the impurity deposition material M1 and to be equal to or higher than the melting point and evaporation temperature of the impurity deposition material M1. At this time, the bottom surface temperature of the liner 2 is heated to, for example, about 1200°C. The temperature to which the liner 2 is heated at this time is set appropriately depending on the material of the impurity deposition material M1.

[0036] When the liner 2 is heated, impurities P1 contained in the liner 2 are extracted and precipitated in the molten impurity-precipitation material M1, as shown in Fig. 2. Then, when the heating of the liner 2 continues, the impurity-precipitation material M1 evaporates, as shown in Fig. 3. Furthermore, as the impurity-precipitation material M1 evaporates, the impurities P1 extracted and precipitated in the impurity-precipitation material M1 also evaporate.

[0037] In addition, by heating the liner 2 at a temperature lower than the boiling point of the impurity-precipitation material M1 to melt and evaporate the impurity-precipitation material M1, the impurity-precipitation material M1 can be prevented from boiling. This makes it possible to prevent the impurity-precipitation material M1 from boiling and overflowing from the liner 2.

[0038] 4, the impurity deposition material M1 filled in the liner 2 is completely evaporated. Whether the impurity deposition material M1 has evaporated or not can be determined based on the amount of evaporation rate detected by the film thickness meter 32 and the time. For example, when the evaporation rate detected by the film thickness meter 32 falls below 0.005 nm / s for 10 seconds, the rate control unit 31 determines that the impurity deposition material M1 has completely evaporated.

[0039] When the impurity precipitating material M1 is completely evaporated, impurities P1 having a low vapor pressure remain in the liner 2 as shown in FIG. 4. When the rate control unit 31 determines that the impurity precipitating material M1 is completely evaporated, it outputs a control command to the electron gun control unit 23. Then, as shown in FIG. 6, the electron gun control unit 23 controls the electron beam generating source 8 for a predetermined time (for example, 5 minutes) so that the liner 2 is heated as high as possible within a range in which the electron beam 19 irradiated from the electron beam generating source 8 does not melt the liner 2. That is, in this step, the liner 2 is heated to a temperature higher than that in the step of melting and evaporating the impurity precipitating material M1. The bottom surface temperature of the liner 2 at this time is heated to, for example, about 1800°C.

[0040] Here, the impurities P1 evaporate at a temperature lower than the temperature at which the liner 2 melts. Therefore, when the liner 2 is heated to a high temperature, the impurities P1 remaining in the liner 2 evaporate and are removed, as shown in Fig. 5. By carrying out such a process, the impurities P1 can be removed from the liner 2 before filling the liner 2 with the deposition material N1 and depositing the deposition material N1.

[0041] The heating time of the liner 2 in the process of evaporating and removing the impurities P1 remaining in the liner 2 may be determined, for example, based on information from the film thickness meter 32 or visual inspection by an operator.

[0042] When the impurities P1 are removed from the liner 2, the liner 2 is cooled. Next, as shown in FIG. 7, the liner 2 is filled with the desired deposition material N1, and deposition is performed. As described above, the impurities P1 are removed from the liner 2 by the preliminary operation before deposition, so that the occurrence of bumping caused by the impurities P1 in the liner 2 can be suppressed. As a result, it is possible to prevent droplets from scattering from the container during deposition due to bumping, and to suppress the droplets from scattering and adhering to the substrate.

[0043] 1 to 6 is performed before performing a first deposition operation using the indirect heating deposition apparatus 1. Alternatively, the operation of removing impurities P1 from the liner 2 shown in Fig. 1 to 6 may be performed after performing a predetermined number of deposition operations using the indirect heating deposition apparatus 1.

[0044] The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the spirit of the invention described in the claims.

[0045] In the above-mentioned embodiment, the judgment as to whether the impurity deposition material M1 has completely evaporated or not has been described based on the information from the film thickness meter, but the present invention is not limited to this. For example, the judgment as to whether the impurity deposition material M1 has completely evaporated or not may be performed by visual inspection by an operator. Alternatively, the amount of the impurity deposition material M1 filled, the heating temperature, and the heating time are measured during the first impurity P1 removal operation. Then, during the second or subsequent impurity P1 removal operation, the judgment as to whether the impurity deposition material M1 has completely evaporated or not may be performed based on the amount of the impurity deposition material M1 filled, the heating temperature, and the heating time.

[0046] In this specification, the words "parallel" and "orthogonal" are used, but these do not mean only "parallel" and "orthogonal" in the strict sense, but may also mean a "substantially parallel" or "substantially orthogonal" state that includes "parallel" and "orthogonal" and is within a range in which the respective functions can be exerted. [Explanation of symbols]

[0047] 1...indirect heating evaporation apparatus, 2...liner (container), 3...holder, 8...electron beam source, 9...acceleration power supply, 10...cathode power supply, 11...support, 16...anode, 17...scanning coil, 18...block, 19...electron beam, 22...electron gun power supply, 23...electron gun control section, 24...emission current control section, 25...scanning coil current drive section, 26...cathode current drive section, 31...rate control section, 32...film thickness gauge, M1...impurity deposition material, N1...evaporation material, P1...impurity

Claims

1. A method for controlling an indirect heating evaporation apparatus, which is carried out before an evaporation operation of an evaporation material is performed, filling a container filled with the deposition material with an impurity deposition material; irradiating the container filled with the impurity precipitating material with an electron beam from an electron beam generating source to melt and evaporate the impurity precipitating material filled in the container; After the impurity precipitation material filled in the container has been completely evaporated, the container is irradiated with the electron beam from the electron beam generating source to evaporate impurities remaining in the container; Includes A method for controlling an indirect heating evaporation apparatus.

2. In the step of melting and evaporating the impurity precipitation material filled in the container, the output of the electron beam is controlled to be lower than the boiling point of the impurity precipitation material and higher than the melting point and evaporation temperature of the impurity precipitation material. A method for controlling the indirect heating deposition apparatus according to claim 1.

3. In the step of melting and evaporating the impurity precipitation material filled in the container, the output of the electron beam is controlled to a temperature lower than the melting point of the container. A method for controlling an indirect heating deposition apparatus according to claim 2.

4. In the step of evaporating impurities remaining in the container, the container is heated at a temperature higher than that in the step of melting and evaporating the impurity deposition material filled in the container. A method for controlling an indirect heating deposition apparatus according to claim 3.

5. In the step of evaporating impurities remaining in the container, the container is heated at a temperature lower than the temperature at which the container is melted. A method for controlling an indirect heating deposition apparatus according to claim 4.

6. The determination as to whether the impurity deposition material filled in the container has completely evaporated is made based on information from a film thickness gauge disposed above the container. A method for controlling the indirect heating deposition apparatus according to claim 1.

7. A container filled with a deposition material; an electron beam generating source that irradiates a container filled with the deposition material with an electron beam that evaporates the deposition material; a control unit for controlling the electron beam generation source, Before performing a deposition operation using the deposition material, the container is filled with an impurity deposition material; The control unit is controlling the electron beam generating source to irradiate the container filled with the impurity precipitating material with the electron beam, thereby melting and evaporating the impurity precipitating material filled in the container; After the impurity precipitation material filled in the container is all evaporated, the electron beam generating source is controlled to irradiate the container with the electron beam from the electron beam generating source, thereby evaporating the impurities remaining in the container. Indirect heating vapor deposition equipment.

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