CN113699487A

CN113699487A - Evaporation source device, evaporation device, and control method for evaporation source device

Info

Publication number: CN113699487A
Application number: CN202110549052.4A
Authority: CN
Inventors: 竹见崇; 市原正浩; 山田尚人
Original assignee: Canon Tokki Corp
Current assignee: Canon Tokki Corp
Priority date: 2020-05-20
Filing date: 2021-05-20
Publication date: 2021-11-26
Anticipated expiration: 2041-05-20
Also published as: CN113699487B; JP7162639B2; KR20210143659A; JP2021181606A; KR102549982B1

Abstract

The invention relates to an evaporation source device, an evaporation device and a control method of the evaporation source device, and provides a technology capable of stabilizing the evaporation rate for a long time during evaporation. An evaporation source device is provided with: a container that accommodates a vapor deposition material; a heating member having a first heating unit that heats an upper region of the container including an outlet for the evaporation material, and a second heating unit that heats a lower region of the container including a bottom; and a control means that controls a heating output of the heating means, wherein the control means increases a heating output of the first heating section at a second time point after the first time point in the vapor deposition period, with respect to a heating output of the first heating section at the first time point in the vapor deposition period.

Description

Evaporation source device, evaporation device, and control method for evaporation source device

Technical Field

The invention relates to an evaporation source device, a vapor deposition device, and a control method for the evaporation source device.

Background

As a structure of an evaporation source apparatus used for vacuum deposition, a structure is known in which a deposition material accommodated in a crucible is heated by a heating member such as a heater disposed around the crucible. The material evaporated or sublimated from the vapor deposition material in the crucible by heating is ejected to the outside of the crucible through an opening in the upper part of the crucible, and adheres to the vapor deposition surface of the substrate disposed above the crucible, thereby forming a thin film on the substrate. Heating of the crucible is required to be controlled so as to achieve a stable deposition rate (film formation rate) in order to avoid a film formation failure due to bumping or the like and to achieve a uniform film thickness.

Patent document 1 discloses a technique for suppressing the occurrence of bumping in the initial stage of heating, that is, during the period from the start of heating until the vapor deposition material is melted from a solid state to a liquid state. In the technique of patent document 1, the heating member is divided into a bottom heater for heating the lower side from the middle section of the crucible including the bottom and a top heater for heating the upper side from the middle section of the crucible including the opening, and the bottom heater and the top heater are arranged and controlled individually, thereby suppressing the bumping at the initial stage. In addition, the following are described: in the case of vapor deposition after the evaporation of the vapor deposition material is stabilized, the temperature of each heater is controlled so that the upper portion of the vapor deposition material in the crucible is higher than the lower portion thereof in order to suppress condensation and deposition of the material, which makes the vapor deposition rate unstable, on the opening of the crucible.

However, since the height of the upper surface of the vapor deposition material in the crucible gradually decreases due to the consumption of the material as the vapor deposition time elapses, the radiant heat from the upper surface of the material gradually becomes weak, and as a result, the temperature in the vicinity of the opening of the crucible gradually decreases. As in the technique described in patent document 1, in the control of maintaining the heater output (power supplied to the heater) at a constant level during vapor deposition, condensation and deposition of the vapor deposition material on the openings are advanced with the lapse of the vapor deposition time, and the vapor deposition rate may become unstable in the latter half of the vapor deposition time. In particular, in a structure in which the nozzle member is mounted on the opening of the crucible, the condensation and deposition of the vapor deposition material on the discharge port of the nozzle member greatly affect the vapor deposition rate, and the instability of the vapor deposition rate tends to be conspicuously manifested.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2019-031705

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a technique capable of stabilizing the evaporation rate over a long period of time during evaporation.

Means for solving the problems

In order to achieve the above object, an evaporation source device according to the present invention includes:

a container that accommodates a vapor deposition material;

a heating member having a first heating unit that heats an upper region of the container including an outlet for the evaporation material, and a second heating unit that heats a lower region of the container including a bottom; and

a control part that controls a heating output of the heating part,

it is characterized in that the preparation method is characterized in that,

the control means increases the heating output of the first heating section at a second time point after a first time point in a vapor deposition period, with respect to the heating output of the first heating section at the first time point in the vapor deposition period.

Effects of the invention

According to the invention, the evaporation rate can be stabilized for a long time in evaporation.

Drawings

FIG. 1 is a schematic configuration diagram of a vapor deposition device according to an embodiment of the present invention

FIG. 2 is a schematic configuration diagram of an evaporation source according to an embodiment of the present invention

FIG. 3 is a diagram illustrating heating control in a comparative example

FIG. 4 is an explanatory view of heating control of the embodiment of the invention

FIG. 5 is a view showing the configuration of an organic EL display device

Description of the reference numerals

3 … evaporation source device, 6 … vapor deposition material, 31 … crucible, 32A, 32B … heater, 5 … control part

Detailed Description

Preferred embodiments and examples of the present invention will be described below with reference to the accompanying drawings. However, the following embodiments and examples merely illustrate preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. Note that the hardware configuration and software configuration, the process flow, the manufacturing conditions, the dimensions, the materials, the shapes, and the like of the devices in the following description are not intended to limit the scope of the present invention to these embodiments unless otherwise specified.

The present invention relates to an evaporation source apparatus and a control method thereof, and is particularly suitable for an evaporation source apparatus for forming a thin film on an object to be evaporated by evaporation and a control method thereof. The present invention can also be understood as a program for causing a computer to execute the control method and a storage medium storing the program. The storage medium may also be a non-transitory storage medium that can be read by a computer. The present invention can be preferably applied to, for example, an apparatus for forming a thin film (material layer) having a desired pattern on the surface of a substrate as a deposition target by vacuum deposition. As a material of the substrate, any material such as glass, resin, metal, or the like can be selected. The evaporation target of the evaporation source device is not limited to a flat plate-like substrate. For example, a mechanical member having irregularities or openings may be used as the vapor deposition object. As the vapor deposition material, any material such as an organic material or an inorganic material (metal, metal oxide, or the like) can be selected. The present invention can be particularly preferably applied to an evaporation source device for forming a metal film using a metal material as a vapor deposition material. Specifically, the technique of the present invention can be applied to manufacturing apparatuses for organic electronic devices (e.g., organic EL display devices, thin-film solar cells), optical members, and the like.

(examples)

< vapor deposition apparatus >

Fig. 1 is a sectional view schematically showing the structure of a vapor deposition device (film formation device) 1. The vapor deposition device 1 includes a chamber 2 and an evaporation source device 3. The chamber 2 is configured to have a vacuum atmosphere or an atmosphere filled with an inert gas such as nitrogen gas by using a vacuum pump or the like, not shown. The vacuum as used herein refers to a state filled with a gas having a pressure lower than the normal atmospheric pressure (typically 1023 hPa). A substrate 10 as a deposition target held by a substrate holding unit, not shown, a mask 22 and an evaporation source device 3 are provided inside the chamber 2. The substrate holding unit holds the substrate 10 by a support member such as a receiving claw for placing the substrate 10 thereon, and a pressing member such as a clamp for pressing and holding the substrate. The evaporation source device 3 heats a material (evaporation material) of a substance deposited on the substrate 10, thereby evaporating or sublimating the material. The evaporated or sublimated substance is attached to a deposition surface (surface on the evaporation source device 3 side) of the substrate 10 provided in the chamber 2, thereby forming a thin film on the substrate 10.

The substrate 10 is conveyed into the chamber 2 by a conveyance robot (not shown), and then held by a substrate holding unit, and is fixed so as to be parallel to a horizontal plane (XY plane) at the time of vapor deposition (at the time of film formation). The mask 22 is a mask having an opening corresponding to a predetermined thin film pattern formed on the substrate 10, and is, for example, a metal mask. At the time of vapor deposition, the substrate 10 is placed on the mask 22.

In addition, a cooling plate (not shown) for suppressing the temperature rise of the substrate 10 may be provided in the chamber 2. Further, a mechanism for aligning the substrate 10, for example, a driving member such as an actuator in the X direction or the Y direction, an actuator for a chucking mechanism for holding the substrate, or a camera (not shown) for imaging the substrate 10 may be provided above the chamber 2.

< evaporation source device >

The evaporation source apparatus 3 is composed of an evaporation source 30, a rate monitor 4, and a control unit 5. The evaporation source 30 includes a crucible (container) 31 capable of containing the vapor deposition material 6 therein, and

heaters

32A and 32B for heating. The evaporation source 30 may be provided with a reflector (not shown) as a heat insulator for improving the heating efficiency of the

heaters

32A and 32B. In addition, a frame, a shutter, or the like (none of which is shown) capable of accommodating the entire components of the evaporation source device 30 may be provided. Further, an evaporation source driving mechanism (not shown) may be provided for moving the evaporation source 30 to uniformly form a film. The shapes, positional relationships, and size ratios of the respective constituent elements of the evaporation source 30 in fig. 1 are merely examples. The control unit 5 is understood as a part of the evaporation source apparatus in the present specification, but may be understood as an apparatus different from the evaporation source apparatus.

The control unit 5 performs control of the evaporation source device 3, for example, timing control of start and end of heating, temperature control, control of opening and closing timing of the shutter when the shutter is provided, and movement control of the evaporation source driving mechanism when the evaporation source driving mechanism is provided. Further, the control unit 5 may be configured by combining a plurality of control components. The plurality of control members are, for example, a heating control member, a shutter control member, an evaporation source drive control member, and the like. In the case where the

heaters

32A and 32B can be controlled for each portion, a heating control member may be provided for each portion. The heating control will be described in detail later. The control unit 5 may also serve as a control member for a mechanism other than the evaporation source device 3, such as a conveyance and alignment control member for the substrate 10.

The control unit 5 may be constituted by a computer having a processor, a memory, a storage device, I/O, UI, and the like, for example. In this case, the function of the control unit 5 is realized by causing a processor to execute a program stored in a memory or a storage device. As the computer, a general-purpose computer may be used, or an embedded computer or a PLC (programmable logic controller) may be used. Alternatively, a part or all of the functions of the control unit 5 may be configured by a circuit such as an ASIC or FPGA. Note that the control section 5 may be provided for each vapor deposition device, or a plurality of vapor deposition devices may be controlled by one control section 5.

The vapor deposition material 6 is accommodated in the crucible 31, and when preparation for placing, aligning, or the like of the substrate 10 on the mask 22 is completed, the

heaters

32A and 32B are started to operate under the control of the control section 5, and the vapor deposition material 6 is heated. When the temperature is sufficiently increased, the vapor deposition material 6 evaporates and adheres to the surface of the substrate 10, thereby forming a thin film. Co-evaporation can also be performed by accommodating other types of evaporation materials in advance in a plurality of crucibles. By controlling the vapor deposition rate (film formation rate) while measuring it by the rate monitor 4 or the like, a film having a desired thickness can be formed on the substrate 10. As the film thickness monitor 4, a quartz monitor that obtains a deposition rate based on a change amount of a natural frequency of the quartz resonator due to adhesion of a deposition material can be used. In order to form a film with a uniform thickness, for example, vapor deposition may be performed while rotating the substrate 10 or moving the evaporation source 30 by an evaporation source driving mechanism. Further, it is also preferable to heat a plurality of evaporation sources in parallel depending on the size of the substrate. The shape of the crucible 31 is arbitrary. The evaporation source 30 may be any of a point-like evaporation source, a linear evaporation source, and a planar evaporation source.

As described later, a multilayer structure can be formed by forming a film of another type of vapor deposition material on a substrate on which a film of a certain vapor deposition material has been formed. In this case, the vapor deposition material in the crucible may be replaced, or the crucible itself may be replaced with a crucible storing another type of vapor deposition material. Further, a plurality of evaporation sources may be provided in the chamber and used while being replaced, or the substrate 10 may be carried out from the current deposition apparatus and carried into another deposition apparatus having an evaporation source that stores another type of deposition material.

Fig. 2 is a schematic configuration diagram of an evaporation source 30 according to an embodiment of the present invention, and shows a schematic configuration of the evaporation source 30 in a sectional view. The evaporation source 30 includes: a crucible 31, the crucible 31 containing a material of a substance to be vapor-deposited on the substrate 10; and

heaters

32A and 32B as heating bodies, the

heaters

32A and 32B being provided so as to surround the crucible 31 and heating the crucible 31. Further, a heat insulating structure (reflector) may be provided so as to surround the

heaters

32A and 32B and block heat. The manner of heating the crucible 31 may take various configurations. For example, when the electric heating method is adopted, the

heaters

32A and 32B include cables to which electricity is supplied. In the case of the high-frequency induction heating method, the

heaters

32A and 32B are provided with heating coils.

The crucible 31 includes a container body 310, a nozzle member 330 attached to an opening of the container body 310, and an exterior plate 34. The container body 310 includes a bottomed cylindrical portion 311 that accommodates the vapor deposition material 6, and a flange portion 312 provided at an upper end of the bottomed cylindrical portion 311. The container body 310 is made of a material such as boron nitride (PBN). The nozzle member 330 is made of a high melting point metal material such as Mo, Ta, W, or the like.

The nozzle member 330 includes: a cylindrical portion 331; a nozzle part 333, the nozzle part 333 extending from the lower end of the cylindrical part 331 upward and having a diameter decreasing; and a flange portion 332, the flange portion 332 being provided at an upper end of the cylindrical portion 331. The cylindrical portion 331 serves as a heat receiving cylindrical portion for sufficiently receiving heat from the bottomed cylindrical portion 311 side of the container main body 310. The cylindrical portion 331 is provided along the inner circumferential surface of the container main body 310 (the inner circumferential surface of the bottomed cylindrical portion 311). The outer diameter of the cylindrical portion 331 is preferably smaller than the inner diameter of the bottomed cylindrical portion 311 by several%. For example, when the outer diameter of the cylindrical portion 331 is 60mm, the inner diameter of the bottomed cylindrical portion 311 may be set to 61mm or more and 62mm or less. This can suppress friction between the cylindrical portion 331 and the bottomed cylindrical portion 311 while maintaining the heat receiving function. Further, it is possible to suppress the occurrence of a large stress due to the close contact between the two caused by thermal expansion.

The nozzle 333 plays a role of discharging the evaporated or sublimated vapor deposition material toward the substrate 10. A discharge port 333a for discharging the vapor deposition material is provided at the tip of the nozzle 333. As described above, the nozzle section 333 is formed of a tapered portion extending upward from the lower end of the cylindrical section 331 so as to have a smaller diameter, and functions as a guide wall for guiding the vapor deposition material toward the discharge port 333 a. As described above, the cylindrical portion 331, which is a heat receiving cylindrical portion provided along the inner circumferential surface of the container main body 310, is provided on the outer circumferential surface side of the nozzle portion 333. In the illustrated example, the nozzle 333 is formed only by a tapered portion, but the present invention is not limited to this shape, and for example, a cylindrical portion may be further provided at the tip of the tapered portion.

The exterior plate 34 is a disk-shaped member having a through hole in the center through which the nozzle portion 333 passes, is placed on the upper surface of the flange portion 332 of the nozzle member 330 so as to surround the nozzle portion 333, and functions as a heat retaining member for suppressing heat emitted from the nozzle member 330.

The flange portion 332 of the nozzle member 333 configured as described above is placed on the flange portion 312 of the container main body 310, whereby the nozzle member 330 is attached to the opening portion of the container main body 310. Further, the exterior plate 34 is mounted on the nozzle member 330.

The evaporation source apparatus 3 of the present embodiment includes, as heating means for heating the crucible 31, an upper heater 32A disposed at a position facing an upper region of the crucible 31, and a lower heater 32B disposed at a position facing a lower region of the crucible 31. The term "opposed position" does not need to be strictly understood, and may be any position that is slightly displaced in the height direction as long as it can affect the temperature of the heating target position. The upper heater 32A and the lower heater 32B each have a power supply controlled by the control unit 5 (the control unit 5 controls the power supply to adjust the heater output).

The upper region of the crucible 31, which is a heating target region (heatable region) of the upper heater 32A, includes at least the following regions. That is, this region is a region on the upper end side of the bottomed cylindrical portion 311 of the container main body 310, and is a region where at least the cylindrical portion 331 of the nozzle member 330 overlaps with the entire nozzle portion 333 of the nozzle member 330 including at least the cylindrical portion 331 and the discharge port 333 a.

The lower region of the crucible 31, which is a heating target region (heatable region) of the lower heater 32B, includes at least the following regions. That is, this region is a region of the container main body 310 located below the region facing the upper heater 32A and includes the bottom of the bottom cylindrical portion 311.

The ratio of the upper region to the lower region in the height of the crucible is not necessarily limited to a specific range, and may be different for each evaporation source. As described above, the upper region may be said to include the vapor deposition material emission port 333 a. The upper heater may be a heater provided at a position corresponding to the upper region and capable of heating the upper region. The lower region can be said to be included as long as the bottom of the container is included. The heater may be a lower heater as long as it is provided at a position corresponding to the lower region and can heat the lower region. Further, the height direction of the crucible 31 does not necessarily have to be classified into either the upper region or the lower region, and one or more middle regions may be set therebetween.

The control section 5 can independently control the upper heater 32A and the lower heater 32B, respectively. The control contents include start/end of heating, temperature change, and the like. The

heaters

32A and 32B and the external plate 34 used for heating the vapor deposition material 6 and/or the crucible 31 are also referred to as "heating means". The heater in the heating part is a heating source, and the exterior plate 34 is called a heat retaining member. The control unit 5 used for timing and temperature of heating is also referred to as "control means" related to heating of the evaporation source device 3. However, a temperature control means functioning as a control member related to heating may be provided separately from the control unit 5. The upper heater 32A and the lower heater 32B correspond to the first heating unit and the second heating unit of the present invention, respectively.

The control section 5 controls the upper heater 32A and the lower heater 32B by a method corresponding to the type of the heating member. For example, when a resistance heating type heater is used, the energization of the heat generating line is controlled. More specifically, the temperature is increased or decreased by increasing or decreasing the current density of the resistance heating type heater. The control section 5 determines control conditions based on input values input by a user via a UI of a computer or the like, conditions relating to the apparatus configuration and the vapor deposition material (for example, the performance of the heater, the shape and material of the container, the arrangement and characteristics of the reflector, the characteristics of other film forming apparatuses, the type of the vapor deposition material, and the amount of the vapor deposition material contained in the container). It is also preferable to provide a temperature sensor (not shown) in advance and use the detected value for control. It is also preferable that the control section 5 stores in advance in a memory the control conditions appropriate for the vapor deposition material and the device configuration in the form of a table or a mathematical expression and refers to the control conditions.

< control of heating >

Referring to fig. 3 and 4, characteristic heating control of the evaporation source device 3 of the present embodiment will be described. The evaporation source apparatus 3 of the present embodiment is characterized in that in a dual-heater type evaporation source apparatus in which a heating block for heating the crucible 31 is divided vertically into an upper heater 32A and a lower heater 32B, the heating control of the upper heater 32A is different from the control performed in the related art. Hereinafter, in order to explain the difference from the conventional control content, the control content of the present embodiment is compared with a comparative example in which the conventional control is performed, and the description is given.

Fig. 3 is a graph illustrating heating control of the comparative example. The graph shows (1) the output current value of the upper heater, (2) the output current value of the lower heater, (3) the temperature of the upper region of the crucible, (4) the temperature of the lower region of the crucible, and (5) the time passage during vapor deposition control of the evaporation rate of the vapor deposition material. (1) And (2) show temporal changes in the current value (a) detected by a detection means such as a current detection circuit in accordance with the power supplied to each heater. (3) Showing a temporal change in temperature (deg.c) detected by the temperature detection element Ta shown in fig. 2, and (4) showing a temporal change in temperature (deg.c) detected by the temperature detection element Tb shown in fig. 2. (5) The time change of the vapor deposition amount (□/s) per unit time obtained from the detection result of the rate monitor 4 is shown.

In the evaporation source apparatus of the comparative example, the apparatus structure itself was the same as that of the example, but the heating control was performed in the same manner as in the conventional example. That is, the rate control is performed on the lower heater 32B, and the control is performed on the upper heater 32A so as to be fixed at a constant output. In the rate control, the control target temperature is changed in such a manner that the monitored value (actual measurement value) of the deposition rate obtained by the rate monitor 4 matches a desired target rate (theoretical value), and the amount of power supplied to the

heaters

32A and 32B is controlled by controlling the power supply based on the set control target temperature.

As shown in fig. 3, the period of the heating control includes a preparation period in which heating of the crucible and the vapor deposition material is started and heating is performed until the temperatures of the crucible and the vapor deposition material become predetermined temperatures at which the vapor deposition process can be started, and a vapor deposition period in which the melted state (sublimation state) of the vapor deposition material in the crucible is stable and vapor deposition onto the substrate is actually performed. Here, in the control for maintaining the output (power supply) of the conventional upper heater 32A constant, the vapor deposition rate may become unstable in the latter stage of the vapor deposition period.

In the example shown in fig. 3, the following situation is shown: since the evaporation material is depleted in the latter stage of the evaporation period, the variation in the evaporation rate gradually increases from a time point about 10 hours before the end of the evaporation period, and the evaporation rate becomes unstable. This is caused by the deposition of the vapor deposition material in the vicinity of the discharge port of the nozzle, and according to the findings of the present inventors, the following factors are considered as the cause of the progress of the condensation and deposition of the vapor deposition material. That is, as the evaporation time elapses, the height of the upper surface (interface) of the evaporation material in the crucible gradually decreases due to the consumption of the material, and therefore, the radiant heat from the upper surface of the evaporation material gradually weakens, and as a result, the temperature near the discharge opening of the crucible gradually decreases. Therefore, it is considered that the deposition material is likely to adhere to the vicinity of the nozzle outlet of the evaporation source, and the condensation and deposition of the deposition material on the opening portion are advanced with the passage of the deposition time.

As described above, since the vapor deposition material condensed and deposited at the discharge port of the nozzle affects the discharge amount of the vapor deposition material from the discharge port, the vapor deposition rate fluctuates at a later stage of the vapor deposition period as shown in fig. 3. As a result, the output current value of the lower heater for rate control greatly fluctuates according to the fluctuation of the deposition rate, which is also shown in fig. 3. In the control shown in fig. 3, since the variation in the deposition rate becomes excessively large, the following control is performed: the power input to the upper heater controlled at the fixed output is increased so that the vapor deposition material condensed and deposited at the nozzle discharge opening is evaporated (this control is an experimental control different from the conventional control). As a result, as shown in fig. 3, the output current value of the upper heater temporarily increases at the end of the deposition period.

As described above, in the conventional control for maintaining the heater output at a constant level while fixing it, it is sometimes difficult to perform stable rate control for a long period of time during the vapor deposition period. In particular, in the structure in which the nozzle member is mounted on the opening of the crucible, the size of the discharge opening is smaller than the width of the vapor deposition material accommodating portion of the crucible when viewed in the height direction, so that the condensation and accumulation of the vapor deposition material in the discharge opening greatly affect the vapor deposition rate, and the instability of the vapor deposition rate tends to be conspicuously manifested.

In contrast, in the evaporation source device of the present embodiment, in order to suppress adhesion of the vapor deposition material in the vicinity of the nozzle discharge opening for a long period of time, control is performed to gradually increase the output of the upper heater 32A so as to compensate for a reduction in radiant heat due to a decrease in the interface caused by consumption of the vapor deposition material in the crucible. This suppresses a temperature decrease in the vicinity of the nozzle discharge opening, suppresses condensation and deposition of the vapor deposition material in the vicinity of the nozzle discharge opening, and enables stable rate control over a long period of time during vapor deposition.

Fig. 4 is a graph illustrating the heating control of the present embodiment. The reading of the graph is the same as the graph of fig. 3. As shown in fig. 4, in the present embodiment, the vapor deposition period is roughly divided into three periods, and individual heating control is performed for each period. The control is performed such that the output of the upper heater 32A gradually increases as the entire vapor deposition period.

Specifically, the control of the output current value (supply power) is set to be fixed control, small rising ratio control, and large rising ratio control for three periods divided by the elapsed time from the start of vapor deposition in the vapor deposition period. For example, the magnitude of the heating output of the upper heater 32A is larger at a certain time point (second time point) of a period C (second period) as a control period having a larger increase ratio later than the certain time point (first time point) than at the certain time point (first time point) of a period B (first period) as a control period having a smaller increase ratio. The amount of increase per unit time of the heating output of the upper heater 32A is also set at a predetermined timing and amount of increase, and the amount of increase in the period C (second amount of increase) is larger than the amount of increase in the period B (first amount of increase). On the other hand, the predetermined period (third period) from the start of vapor deposition, that is, the period a, is maintained at a predetermined level.

For example, when the output current value at the start of vapor deposition is 18.5A and the output current value at the end is 21A, the control is performed as follows.

"period a (0 to 5 hours)": maintain 18.5A.

"period B (5 to 20 hours)": increase by 0.1A (18.5A → 19A) every 3 hours.

"period C (20 to 40 hours)": a rise of 0.05A (19A → 21A) was made every 30 minutes.

The rising rate of the output current value, the final arrival temperature, and the like can be determined based on, for example, preliminary experiment results and simulation results, and the above control amount is merely an example. That is, the output current value is controlled at a timing and an increase rate set in advance in accordance with the specification of the device or the like. The output current value is increased in a stepwise manner in the example, but is not limited to a stepwise manner as long as it does not affect the deposition rate of the material, and can be arbitrarily controlled. Even if such control is performed so as to include a portion where the output temporarily drops, the control may be performed so as to increase the entire area so as to suppress the condensation and deposition of the vapor deposition material in the vicinity of the discharge port of the nozzle. The control of heating the nozzle discharge opening may be enhanced so as to compensate for a decrease in the action of radiant heat from the interface (surface) of the vapor deposition material in the crucible at the later stage of the vapor deposition period, and the content of the control is not limited to the one exemplified here.

As described above, the current value of the upper heater 32A is gradually increased in the form of an inclined shape (inclined shape), whereas the lower heater 32B is controlled at the same rate as in the conventional case. This can further stabilize the deposition rate. As shown in fig. 4, according to the heating control of the present embodiment, the vapor deposition rate can be stabilized for a long period of time during vapor deposition.

For example, control may be performed to detect a decrease in the deposition rate and increase the amount of increase in the output current value in response to the decrease, but product defects may occur at the time when a change in the deposition rate is detected. Therefore, it is necessary to control the output of the upper heater 32A so as not to decrease the evaporation rate. On the other hand, if the output of the upper heater 32A is excessively increased from the start of vapor deposition (in a state where the upper surface of the vapor deposition material is close to the upper heater 32A), the influence on the upper portion of the vapor deposition material becomes large, and the vapor deposition rate may abruptly change. Therefore, it is preferable to gradually increase the output of the upper heater 32A.

< Others >

In the present embodiment, the number of divisions of the vapor deposition period is three, but four or more finer divisions may be used. In the present embodiment, the heating member is divided into two systems, i.e., an upper system and a lower system, but other dividing methods may be used. The system may be increased so that the control can be more finely performed according to the size of the container and the assumed storage amount of the vapor deposition material. The structure of the crucible is not limited to the above structure of the present embodiment, and for example, a double structure of an inner crucible and an outer crucible may be employed. Instead of the nozzle, a structure including an intermediate plate may be employed. In the configuration having the intermediate plate having the plurality of through holes through which the evaporated vapor deposition material passes, there is a problem that the vapor deposition material is likely to adhere to the intermediate plate, as in the nozzle.

Specific example of method for manufacturing organic electronic device

An example of a method for manufacturing an organic electronic device using a vapor deposition apparatus (film forming apparatus) including the evaporation source apparatus of the present embodiment will be described. Hereinafter, the structure and the manufacturing method of the organic EL display device are exemplified as an example of the organic electronic device. First, an organic EL display device to be manufactured will be described. Fig. 5(a) is an overall view of the organic EL display device 60, and fig. 5(b) shows a cross-sectional structure of one pixel.

As shown in fig. 5(a), in a display region 61 of an organic EL display device 60, a plurality of pixels 62 each including a plurality of light-emitting elements are arranged in a matrix. The following description will explain details, but each of the light-emitting elements has a structure including an organic layer sandwiched between a pair of electrodes. Here, the pixel is a minimum unit that can display a desired color in the display region 61. In the case of a color organic EL display device, the pixel 62 is configured by a combination of a plurality of sub-pixels, i.e., a first light-emitting element 62R, a second light-emitting element 62G, and a third light-emitting element 62B, which emit light differently from each other. The pixel 62 is often configured by a combination of three kinds of sub-pixels, i.e., a red (R) light-emitting element, a green (G) light-emitting element, and a blue (B) light-emitting element, but is not limited thereto. The pixel 62 may include at least one sub-pixel, preferably two or more sub-pixels, and more preferably three or more sub-pixels. As the sub-pixel constituting the pixel 62, for example, a combination of four kinds of sub-pixels, i.e., a red (R) light emitting element, a green (G) light emitting element, a blue (B) light emitting element, and a yellow (Y) light emitting element, may be used.

Fig. 5(B) is a partial cross-sectional view at the line a-B of fig. 5 (a). The pixel 62 includes a plurality of sub-pixels each including an organic EL element including a first electrode (anode) 64, any one of a hole transport layer 65, a red layer 66R, a green layer 66G, and a blue layer 66B, an electron transport layer 67, and a second electrode (cathode) 68 on a substrate 63 as a deposition object. The hole transport layer 65, the red layer 66R, the green layer 66G, the blue layer 66B, and the electron transport layer 67 correspond to organic layers. The red, green, and blue color layers 66R, 66G, and 66B are formed in patterns corresponding to light emitting elements (also referred to as organic EL elements) that emit red, green, and blue light, respectively. The first electrode 64 is formed separately for each light emitting element. The hole transport layer 65, the electron transport layer 67, and the second electrode 68 may be formed in common to the plurality of

light emitting elements

62R, 62G, and 62B, or may be formed for each light emitting element. That is, as shown in fig. 5(B), the hole transport layer 65 may be formed as a common layer over a plurality of sub-pixel regions, and in addition, the red layer 66R, the green layer 66G, and the blue layer 66B may be formed separately for each sub-pixel region, and further, the electron transport layer 67 and the second electrode 68 may be formed as a common layer over a plurality of sub-pixel regions. In addition, in order to prevent short-circuiting between the first electrodes 64 which are close to each other, an insulating layer 69 is provided between the first electrodes 64. Since the organic EL layer is deteriorated by moisture and oxygen, a protective layer 70 for protecting the organic EL element from moisture and oxygen is provided.

Next, an example of a method for manufacturing the organic EL display device will be specifically described.

First, a substrate 63 on which a circuit (not shown) for driving the organic EL display device and the first electrode 64 are formed is prepared.

An acrylic resin (photoresist) is formed on the substrate 63 on which the first electrode 64 is formed by spin coating, and the acrylic resin is patterned by photolithography to form an opening at a portion where the first electrode 64 is formed, and an insulating layer 69 is formed. The opening corresponds to a light-emitting region where the light-emitting element actually emits light.

The substrate 63 on which the insulating layer 69 is patterned is carried into the first vapor deposition device, is held by the substrate holding means, and the hole transport layer 65 is formed as a common layer on the first electrode 64 in the display region. The hole transport layer 65 is formed by vacuum evaporation. Since the hole transport layer 65 is actually formed to have a size larger than the display region 61, a high-definition mask is not required. Here, the vapor deposition device used for film formation in this step and film formation of the following layers includes the evaporation source device of the above-described embodiment. The evaporation source apparatus has the configuration of the above-described embodiment, and by performing the heating control described in the above-described embodiment, it is possible to form a film at a stable deposition rate (film formation rate).

Next, the substrate 63 formed on the hole transport layer 65 is carried into the second vapor deposition device and held by the substrate holding unit. Alignment between the substrate and the mask is performed, the substrate is placed on the mask, and the light-emitting layer 66R that emits red light is formed in a portion of the substrate 63 where the element that emits red light is disposed.

Similarly to the formation of the light-emitting layer 66R, the light-emitting layer 66G emitting green light is formed by the third vapor deposition device, and the light-emitting layer 66B emitting blue light is formed by the fourth vapor deposition device. After the completion of the formation of the light-emitting

layers

66R, 66G, and 66B, the electron transport layer 67 is formed in the entire display region 61 by the fifth vapor deposition device. The electron transport layer 65 is formed as a common layer in the light-emitting

layers

66R, 66G, and 66B of three colors.

The substrate on which the electron transport layer 65 was formed was moved to a vapor deposition device to form a second electrode 68, and then moved to a plasma CVD device to form a protective layer 70, thereby completing the organic EL display device 60.

Claims

1. An evaporation source device, comprising:

a container that accommodates a vapor deposition material;

a control part that controls a heating output of the heating part,

it is characterized in that the preparation method is characterized in that,

2. The evaporation source apparatus according to claim 1,

the outer diameter of the discharge port is smaller than the outer diameter of the vapor deposition material accommodating portion of the container when viewed in the height direction.

3. The evaporation source apparatus according to claim 2,

the container includes a container body and a nozzle member that is fitted to an opening portion of the container body and is provided with the discharge port.

4. The evaporation source apparatus according to claim 3,

the nozzle member has:

a nozzle portion having the discharge opening and a guide wall that guides the evaporation material toward the discharge opening; and

a cylindrical portion for heat reception provided along an inner peripheral surface of the container body on an outer periphery of the nozzle portion.

5. The evaporation source apparatus according to claim 1,

the control means gradually increases the heating output of the first heating section during the vapor deposition period.

6. The evaporation source apparatus according to claim 5,

the control means increases an amount of increase in the heating output per unit time when the heating output of the first heating unit is gradually increased by a first amount of increase in a first period of a vapor deposition period, and increases an amount of increase in the heating output per unit time when the heating output of the first heating unit is gradually increased by a second amount of increase larger than the first amount of increase in a second period after the first period.

7. The evaporation source apparatus according to claim 1,

the evaporation source device further comprises an acquisition means for acquiring a deposition rate of the deposition material on a deposition surface,

the control means controls the heating output of the second heating section so that the vapor deposition rate is maintained at a predetermined value.

8. The evaporation source apparatus according to claim 1,

the control means maintains the heating output of the first heating section at a predetermined level for a predetermined period of time from the start of vapor deposition.

9. The evaporation source apparatus according to claim 6,

the control means maintains the heating output of the first heating section at a predetermined level during a third period before the first period in the vapor deposition period.

10. A vapor deposition apparatus is characterized in that,

the vapor deposition device is provided with:

a chamber;

the evaporation source device according to claim 1, which is disposed in the chamber and performs evaporation on an evaporation surface of a substrate provided in the chamber; and

a rate monitor that monitors a rate of deposition of the deposition material onto the deposition surface.

11. A method for controlling an evaporation source device having a first heating unit that heats an upper region of a container containing a vapor deposition material, the upper region including a discharge port for the vapor deposition material, and a second heating unit that heats a lower region of the container, the lower region including a bottom portion,

controlling a heating output of the first heating section at a first time point in a vapor deposition period to a first output,

and a control unit configured to control a heating output of the first heating unit at a second time point after the first time point in a vapor deposition period to a second output larger than the first output.

12. The evaporation source apparatus control method according to claim 11,

the heating output of the first heating unit is gradually increased during the vapor deposition period.

13. The evaporation source apparatus control method according to claim 12,

in a first period of a vapor deposition period, an amount of increase in the heating output per unit time when the heating output of the first heating unit is gradually increased is increased by a first amount of increase, and in a second period after the first period, the amount of increase in the heating output per unit time when the heating output of the first heating unit is gradually increased is increased by a second amount of increase larger than the first amount of increase.

14. The evaporation source apparatus control method according to claim 11,

the heating output of the second heating unit is controlled so that the deposition rate of the deposition material on the deposition surface is maintained at a predetermined value.

15. The evaporation source apparatus control method according to claim 11,

the heating output of the first heating unit is maintained at a predetermined level for a predetermined period of time from the start of vapor deposition.

16. The evaporation source apparatus control method according to claim 13,

in a third period before the first period in the vapor deposition period, the heating output of the first heating unit is maintained at a predetermined level.