KR100518147B1 - Evaporation apparatus, organic material evaporation source, and method of manufacturing thin organic film - Google Patents

Abstract

In the organic thin film production method using the vapor deposition apparatus of the present invention or the organic thin film imaginary method of the present invention, an inert gas is introduced into an organic evaporation source, and the organic thin film material in the organic evaporation source is placed in a relatively high pressure atmosphere. The temperature is raised to a predetermined temperature, followed by vacuum evacuation to a state where the pressure is low to generate steam of the organic thin film material. Since the useless vapor is not released, the organic thin film material can be effectively utilized. In addition, since the inert gas becomes a heat medium, the temperature increase rate is high and the cracking property is good. Even when the temperature is lowered, the cooling rate is increased by performing in an inert gas atmosphere.

In the organic evaporation source of the present invention, since the inert gas can be introduced directly into the organic evaporation source by the on-off valve, the time required for the vacuum exhaust can be shortened.

In the organic evaporation source of the present invention, since the liquid organic thin film material is heated by the heat medium, the organic thin film material is not heated above the temperature of the heat medium. none.

Description

Evaporation apparatus, organic evaporation source and organic thin film manufacturing method {EVAPORATION APPARATUS, ORGANIC MATERIAL EVAPORATION SOURCE, AND METHOD OF MANUFACTURING THIN ORGANIC FILM}

The present invention provides an organic vapor deposition apparatus for forming an organic thin film on the surface of a film forming object, an organic evaporation source that can be used for the organic vapor deposition apparatus, and an organic thin film production method suitable for forming an organic thin film.

Conventional electronics technology has been targeting inorganic materials mainly on semiconductors. Recently, functional organic thin films using organic compounds have attracted attention.

As a reason for using an organic compound,

① Various reaction systems and characteristics can be used than inorganic materials.

② It has the advantage that surface treatment is possible with lower energy than inorganic material.

The use of a functional organic thin film includes an organic EL element, a piezoelectric sensor, a pyroelectric sensor, an electric insulating film, and the like, and among these, the organic EL element is attracting attention because it can be used as a display panel. There is a need for a technology capable of forming an organic thin film uniformly on a large area substrate.

However, in the conventional organic thin film production process, a vacuum deposition apparatus for forming a metal thin film or an inorganic thin film such as an Al thin film or an SiO ₂ thin film is dedicated, and a vapor deposition apparatus suitable for forming an organic thin film has not been developed yet.

Here, when the organic thin film material and the inorganic thin film material are compared, the following characteristics can be seen in the organic thin film material.

(1) The organic thin film material has a high vapor pressure, and its evaporation source temperature is in the range of 0 ° C (in some cases below zero) to 400 ° C while the metal evaporation source is at a high temperature of 600 ° C to 2000 ° C, and a temperature range of 20 ° C to 400 ° C. Many cause decomposition. Therefore, it is desirable to perform precise temperature control at the time of evaporation.

When forming a metal thin film, generally, the E / B vapor deposition apparatus which irradiates an electron beam to a metal evaporation source is used, but energy is too high depending on an organic thin film material, and when an electron beam is irradiated, it will decompose.

(2) Some organic thin film materials have powders. However, generally, powder-like materials have poor thermal conductivity, and especially when they are heated in a vacuum, it is difficult to increase the temperature or cool down due to the thermal insulation effect of the vacuum. There may be a delay between the actual temperature.

On the other hand, once the temperature of the evaporation source rises, such a powder-like material is hard to cool only by radiative cooling, and the evaporation may not be immediately terminated even when the heating is stopped. The so-called "finishing" of evaporation is bad.

(3) Since organic thin film material has high vapor pressure, what is adsorbed on the wall of vacuum chamber at low temperature may be separated (re-evaporated) due to the rise of temperature of vacuum chamber, and the characteristics of organic thin film may be caused when leaving particles are mixed in organic thin film. May deteriorate.

④ There are many substances that are easy to adsorb moisture in organic thin film material, but the property is changed when the moisture is adsorbed. Moreover, when moisture enters an organic thin film at the time of forming a multilayer organic thin film, the characteristic of an interface may change. In particular, when producing functional elements, such as an organic EL element and a piezoelectric element, final performance may be impaired.

(5) The metal evaporation source has directionality when evaporated, and its direction is almost straight from the evaporation source according to COS LAW, but depending on the organic thin film material, it may cause a bypass by entering the diffusion.

(6) In the case of forming a deposition polymer film, it is necessary that the composition ratio of two organic thin film materials to be deposited simultaneously conforms to the stoichiometric ratio. When the composition ratio deviates from the stoichiometric ratio, the function is lost or degraded in the piezoelectric element. In order to make the composition ratio a stoichiometric ratio, precise control of the film formation rate is necessary.

As described above, many organic thin film materials are difficult to handle. There are the following types of evaporation sources of vacuum deposition apparatuses conventionally used (FIGS. 8A to 8E), but they are not suitable for use due to the properties of the aforementioned organic thin film materials and the required characteristics of the organic thin films.

(A) A method of forming the evaporation source container 101 from metal, directly conducting heating and evaporating the thin film material (FIG. 8A: direct resistance heating type)

This method has excellent temperature stability in the temperature range in which the metal melts, but poor stability and controllability in the temperature range in which the organic thin film material evaporates. Therefore, the generation rate of organic compound vapor (vapor of organic thin film material) becomes unstable.

Moreover, although some organic thin film material corrodes a metal and reacts with a metal, the organic thin film material which is corrosive and reactive with the metal which comprises a container cannot be used.

(B) Resistive heating elements (112, 122) are placed around the evaporation source containers (111, 121) and indirectly heated by energizing heating to evaporate the thin film material (Fig. 8B: unique basket type, Fig. 8C: K). Cell type).

This method has excellent temperature stability in the temperature range in which the metal melts, but poor stability and controllability in the temperature range in which the organic thin film material evaporates. Therefore, the rate of generation of organic compound vapor becomes unstable.

In addition, the resistive heating body 112 of this system generally uses an uncoated metal material. However, the organic thin film material is more likely to circumvent the organic thin film material than the inorganic thin film material. When metal chelate etc. are contained in an organic thin film material, the resistance heating body 112 may be short-circuited.

In addition, since the K cell type evaporation source has a complicated structure, it is difficult to clean internally and the thin film material cannot be completely removed. Therefore, when the thin film materials in the evaporation source containers 111 and 121 are replaced with other types, contamination of the previous thin film material may occur.

(C) A method of radiantly heating and evaporating a thin film material by an infrared lamp 133 using an evaporation source container 131 made of a light transmissive material such as quartz (Fig. 8D: Lamp heater type evaporation source).

Although this method is excellent in temperature controllability at low temperature, since the specific heat capacity of the evaporation source container 131 is large, a temperature difference occurs between the control temperature and the actual thin film material temperature. On the other hand, when control is performed by measuring the temperature of the thin film material itself, it is easy to cause a temperature overshoot, and the organic thin film material may be decomposed.

In addition, in order to transmit the heat rays emitted from the infrared lamp 133, the evaporation source container 131 needs to be made of a transparent material such as quartz, but the transparent material tends to be damaged during cleaning or replacement.

In addition, when the evaporation source container 131 is clouded with long-term use and the infrared ray transmission intensity varies depending on the position, there is a fear that local overheating occurs in the organic thin film material having poor thermal conductivity.

In addition, some organic thin film materials are deteriorated by light of a specific wavelength, and such organic thin film materials cannot generate steam in this manner.

(D) The electron beam 145 is irradiated to a thin film material and evaporated (FIG. 8E: E / B electron gun).

When the electron beam 145 is irradiated, the organic thin film material is decomposed and cannot be used.

As described above, the methods (A) to (D) of the prior art for evaporating the inorganic thin film material are incomplete for application to the organic thin film material. In particular, the problem of decomposition due to the temperature overshoot of the organic thin film material and the difficulty of heating the organic thin film material have not been seen in the inorganic thin film material.

The present invention has been made to solve the problems of the prior art, the object of which is that the temperature can not be changed over temperature at the time of temperature increase, it is possible to change the temperature to the desired temperature in a short time without thermal decomposition of the main component of the organic thin film material To provide the technology.

Moreover, it is providing the technique which can suppress generation | occurrence | production of the vapor | steam from the organic thin film material other than at the time of vapor deposition, and can utilize an organic thin film material effectively.

Moreover, although there exist a liquid form in organic thin film material, it aims at providing the evaporation source for organic materials which can be heated uniformly at a constant temperature, and is easy to handle.

The present invention has a vacuum exhaust machine, a vacuum chamber and an organic evaporation source, by evacuating the inside of the vacuum chamber by the vacuum exhaust machine, by controlling the temperature of the organic thin film material entered into the organic evaporation source to generate the vapor, An evaporation apparatus configured to form an organic thin film on the surface of a film formation object disposed therein, wherein a gas introduction system is connected to the vacuum chamber so as to introduce an inert gas into the vacuum chamber.

In this case, after evacuating the inside of the vacuum chamber, an inert gas may be introduced to place the organic thin film material in the organic evaporation source in an inert gas atmosphere. In the case of temperature control of the organic thin film material, convection of an inert gas occurs around the organic thin film material, and as a result, the temperature rising rate and the temperature lowering rate can be increased faster than in the case where the organic evaporating material is placed in a vacuum atmosphere. . In particular, in the case where the organic thin film material is powder, inert gas infiltrates between the molecules of the powder to act as a heat medium, and thus the heat transfer rate between the particles constituting the powder increases, so that the temperature controllability of the organic thin film material is improved. Local overheating and temperature overshoot of the thin film material do not occur, and decomposition of the organic thin film material can be prevented.

The organic evaporation source of the present invention has a container, a gas valve, and a discharge port. When the gas valve is opened, the internal atmosphere of the container is connected to the external atmosphere, and when the gas valve is closed, the internal atmosphere of the container is provided. Is configured to be blocked from the external atmosphere.

In the case of this organic evaporation source, after introducing an inert gas into a vacuum chamber, it becomes possible to close a gas valve and to put an organic thin film material in an inert gas atmosphere.

In general, the amount of generated organic compound vapor is less in an inert gas atmosphere than in a vacuum atmosphere. Therefore, when heating and cooling of the organic thin film material are performed in an inert gas atmosphere, steam from the organic thin film material is generated during that time. This suppresses the useless vapor which is not used for thin film formation, thereby increasing the use efficiency of the organic thin film material and lowering the manufacturing cost.

In the vacuum atmosphere, even when the organic thin film material is heated to a temperature at which steam is generated, steam may not be generated in an inert gas atmosphere depending on the pressure of the inert gas. Therefore, if the organic thin film material is heated in an inert gas atmosphere and then evacuated, it becomes possible to form the organic thin film without releasing useless vapor.

In this case, the organic evaporation source is configured to be connected to the gas introduction system, and when the inert gas is introduced into the vessel while the gas valve is closed, the organic thin film material is placed in an inert gas atmosphere in a vacuum atmosphere. It becomes possible to set.

Therefore, it is not necessary to introduce an inert gas into a large vacuum chamber in order to suppress the discharge of steam.

In this case, if the vacuum exhaust machine can be connected to the organic evaporation source, and the gas valve is closed, and the inside of the container can be evacuated, the inert gas introduced is evacuated, and then the gas valve is opened. It becomes possible.

Therefore, in the case of an organic evaporation source to which a vacuum exhaust machine is connectable, it is preferable to be configured so that a gas introduction system can be connected and gas can be introduced into the container while the gas valve is closed.

In addition, since the vapor of the organic thin film material is precipitated when it cools, in the case of the organic evaporation source of the present invention, at least the heating means is provided between the container and the discharge port so that the vapor is not cooled until the vapor is released into the vacuum chamber. You can do that.

On the other hand, when steam is generated from the liquid organic thin film material, a container in which the liquid organic thin film material is disposed therein and a heat medium pure path, which is a heat medium flow path therein, are provided in the organic evaporation source, and the heat medium circulation path is formed around the container. In this case, since the whole container can be heated or cooled uniformly with the heat medium, the cracking property of the organic thin film material is improved.

In this case, when a heat medium source for controlling the heat medium to a predetermined temperature is provided so as to heat or cool the organic thin film material in the container, heat exchange between the liquid organic thin film material and the temperature controlled heat medium is achieved. As a result, the temperature rise or cooling of the organic evaporation material can be performed accurately. In particular, at the time of temperature increase, the organic thin film material does not become higher than the temperature of the heat medium, so that the organic thin film material does not become a local overheating state.

In addition, since no heating is performed by radiation of the hot wire, the organic evaporation material is not unevenly heated by the clouding of the container. In addition, since transparency is not required for the material of the container, it is possible to make a ceramic material having high thermal conductivity. Therefore, handling becomes easy.

The organic evaporation source is configured such that the container has a double structure of an inner container and an outer container, and the heat medium circulation path is formed between the inner container and the outer container.

In this case, since the heat exchange is performed between the organic thin film material and the heat medium through the wall surface of the inner container, the heat exchange efficiency is high, and as a result, the temperature controllability is improved.

Moreover, when a heat insulating material is arrange | positioned around the said outer container, thermal efficiency and temperature controllability will be improved further.

When the said container of the organic evaporation source of this invention is comprised by the dual structure of an inner container and an outer container, and the said heat container and the said outer container are the said heat medium circulation path, a heat medium source is connected and the said heat medium source The heat medium circulating in the heat medium circulation path can be controlled to a predetermined temperature so that the organic thin film material in the container can be heated or cooled.

As described above, the organic thin film material changes the discharge rate of steam at the pressure of the ambient atmosphere, and according to the organic thin film manufacturing method of the present invention, the organic thin film material is disposed in an organic evaporation source to release steam, thereby forming the surface of the film forming object. In the case of forming the organic thin film on the substrate, the pressure of the atmosphere in which the organic thin film material is placed can be controlled, and the release rate of the vapor can be controlled. As a result, the growth rate of the organic thin film can be controlled.

Further, according to the organic thin film production method of the present invention, when the organic thin film material is disposed in an organic evaporation source to release steam, and the organic thin film is formed on the surface of the film forming object, the organic thin film material is heated when the organic thin film material is heated. The pressure of the atmosphere in which the thin film material is placed can be increased to suppress the release of the vapor, and then the pressure of the atmosphere in which the organic thin film material is placed can be lowered to initiate the release of the vapor.

In particular, if the pressure is increased when the organic thin film material is raised, the temperature uniformity is improved. Therefore, the heating time when the organic thin film material is raised to a predetermined temperature is shortened. Since the release is started, the time required for the start of the forming operation of the organic thin film is shortened.

As described above, according to the organic thin film production method of the present invention, after the temperature of the organic thin film material is raised, the vapor release can be started and terminated only by controlling the vacuum degree of the atmosphere in which the organic thin film material is placed. This eliminates the waste of expensive organic thin film materials.

Since the organic thin film material has high reactivity, the pressure increase may be performed by introducing an inert gas into the atmosphere in which the organic thin film material is placed. In addition, pressure reduction can be performed by evacuating the atmosphere.

With respect to the vapor of the organic thin film material once the release is started, the release of the atmosphere can be stopped by raising the pressure of the atmosphere in which the organic thin film material is placed.

In this case, since the vapor discharge is immediately stopped, so-called "finishing" can perform good control. In addition, waste of expensive organic thin film materials is eliminated. Even when the organic thin film forming operation is completed and the organic thin film material is cooled, the cooling rate is increased when the organic thin film material is placed in a high pressure atmosphere.

According to the experiment, even in the low pressure atmosphere, even if the organic thin film material is heated up to the temperature at which steam is released, depending on the type of organic thin film material, the ambient atmosphere is 13.3 Pa (0.1 Torr) to 2.0 × 10 ³ Pa (15 Torr). It has been confirmed that when the pressure rises to a degree, no steam is released.

However, if the pressure is set too high, the amount of inert gas used increases, and the time from evacuating to low pressure becomes long. Therefore, in the case of suppressing vapor release, the pressure of about 66.5 Pa (0.5 Torr) is recommended. desirable.

On the other hand, when the organic thin film material is heated in such a high pressure atmosphere and then evacuated to a low pressure atmosphere to release steam, in order to improve the quality of the organic thin film, 1.33 x 10 ^-4 Pa (1.0) It is preferable to lower the pressure up to a pressure of × 10 ⁻⁶ Torr) or less, preferably to 1.33 × 10 ⁻⁵ Pa (1.0 × 10 ⁻⁷ Torr) or less.

Since gas or water may be adsorbed to the organic thin film material, the organic thin film material may be degassed by placing the organic thin film material in a vacuum atmosphere before introducing the inert gas. In the case of degassing, it is preferable to heat the organic thin film material to a temperature lower than the evaporation temperature.

When raising the pressure of the atmosphere in which the organic thin film material is placed, an inert gas can be introduced.

In addition, it can carry out in the state which introduced an inert gas also when temperature-falling an organic thin film material.

Example

Reference numeral 10 in FIG. 1 denotes a vapor deposition apparatus of one example of the present invention, and has a vacuum chamber 11.

The vacuum chamber 11 is connected to the vacuum exhaust machine 19 and the gas introduction system 18. When the vacuum pump 21 installed in the vacuum exhaust system 19 is started, the inside of the vacuum chamber 11 is in a high vacuum state. It is configured to be able to evacuate until.

Plural organic evaporation sources are provided in the bottom wall of the vacuum chamber 11, and two organic evaporation sources 12 ₁ and 12 ₂ are shown here. The organic evaporation sources 12 ₁ and 12 ₂ have discharge openings 14 ₁ and 14 ₂ , respectively. When organic thin film materials are put into organic evaporation sources 12 ₁ and 12 ₂ and heated to a predetermined temperature, 14 ₁ and 14 ₂ , the vapor of the organic compound constituting the organic thin film material is released from the vacuum chamber 11.

The substrate holder 30 is provided above the organic evaporation sources 12 ₁ , 12 ₂ , and the film is formed on the surface of the organic evaporation source 12 ₁ , 12 _{2 with} the surface to which the organic thin film is to be directed toward the discharge ports 14 ₁ , 14 ₂ . The object to be formed 13 (here, a glass substrate) is supported.

The gas introduction system 18 includes a gas pipe 28, a mass flow controller 23, a gas container 22, and two valves 24 ₁ and 24 ₂ . 22 is connected to the internal atmosphere of the vacuum chamber 11 by the gas pipe 28 via the valve 24 ₁ , the mass flow controller 23, and the valve 24 ₂ .

The gas container 22 is filled with an inert gas such as vacuum gas or argon gas (herein, nitrogen gas), and when the two valves 24 ₁ and 24 ₂ are opened, the mass flow controller 23 The furnace is configured to introduce an inert gas into the vacuum chamber 11 in a flow rate controlled state.

In the vicinity of the surface of the film-forming object 13, a substrate shutter 35 freely open and close is provided, while an evaporation source freely open / close near the discharge openings 14 ₁ , 14 _{2 of the} organic evaporation sources 12 ₁ , 12 ₂ . Shutters 33 ₁ and 33 ₂ are provided. Therefore, even when vapor of organic thin film material is discharged from the discharge ports 14 ₁ and 14 ₂ , when the substrate shutter 35 and the evaporation source shutters 33 ₁ and 33 ₂ are closed, the surface of the film forming object 13 Since the vapor of the organic thin film material does not reach, the organic thin film does not grow.

In addition, at the upper positions of the evaporation source shutters 33 ₁ and 33 ₂ , the film thickness monitor (so as not to prevent the vaporization of the organic thin film material emitted from the discharge ports 14 ₁ and 14 ₂ to the film forming target 13) ( 36 ₁ and 36 ₂ are arranged, and when the evaporation source shutters 33 ₁ and 33 ₂ are opened, vapor of the organic thin film material adheres to the film thickness monitors 36 ₁ and 36 ₂ , respectively, and the film forming target 13 It is configured to measure the organic thin film formation rate of the phase.

On the periphery of the film forming object 13 and the bottom wall of the vacuum chamber 11, cooling walls 31 and 32 are formed, respectively, capable of introducing liquid nitrogen in an airtight manner, and the vacuum chamber 11 is in a vacuum state. Thereafter, when liquid nitrogen is introduced into each of the cooling walls 31 and 32, moisture present in the vacuum chamber 11 is efficiently adsorbed to the cooling walls 31 and 32, and from the internal atmosphere of the vacuum chamber 11, It is configured to remove moisture.

If the cooling walls 31 and 32 do not exist, the organic thin film formed on the surface of the film-forming object 13 is resorbed during vapor deposition of the organic thin film material adsorbed on the wall of the vacuum chamber 11 during the formation of the organic thin film. Although mixed in the air, the cooling walls 31 and 32 do not trap the vapor of the organic thin film material in the wall direction of the vacuum chamber 11 during vapor deposition and do not discharge again, so that a high quality organic thin film can be obtained. .

On the other hand, the pipe 37 is wound in the board | substrate holder 30, and the pipe 37 is comprised so that a heat medium can be sent. Accordingly, by circulating the heat-controlled heat medium, the film forming target 13 in forming the organic thin film can be heated with good controllability in the temperature range of 50 ° C to 100 ° C. Thus, the film forming target 13 By controlling the temperature of the substrate), the organic thin film having good adhesion can be formed on the surface thereof.

The organic evaporation sources 12 ₁ and 12 ₂ are configured to be hermetically attached to the bottom wall of the vacuum chamber 11 by the flange 59 and the O-ring 58 as shown in FIG. 2, and the upper part of the casing 51. The discharge ports 14 ₁ and 14 _{2 of the} are configured to face the vacuum chamber 11.

In the casing 51, a container 50 is disposed, and a bottomed cylindrical crack plate 55 is disposed around the container 50. In addition, a micro heater 52 is wound around the crack plate 55. The micro heater 52 is formed by inserting a resistance heating element such as a nichrome wire into a thin stainless steel tube filled with an inorganic insulator.

The thermocouple 56 is provided in the bottom part of the crack board 55, and the thermocouple 56 is monitored from the power source arrange | positioned outside the vacuum chamber 11, monitoring so that the temperature of the crack board 55 may become predetermined temperature. When the microheater 52 is energized to generate heat, the organic thin film material 54 contained in the container 50 can be maintained at a desired temperature in a temperature range of 150 ° C to 400 ° C.

The reflector 53 is disposed around the micro heater 52, and reflects the heat radiation from the micro heater 52 toward the casing 51, thereby suppressing the temperature rise of the casing 51, and thus, the container 50. It is comprised so that it may heat efficiently.

In addition, the density of winding the microheater 52 is densely located at the discharge port 14 ₁ , 14 ₂ side, and rarely at the bottom surface side of the container 50, and the temperature of the discharge port 14 ₁ , 14 ₂ is increased. 50 and the temperature of the organic substance 54, and as a result, the vapor | steam of the organic thin film material which generate | occur | produced is prevented from adhering to the discharge port 14 ₁ and 14 ₂ vicinity.

In one organic evaporation source (12 ₁ ) of such an organic evaporation source (12 ₁ , 12 ₂ ),

Alq ₃ (tris (8-hydroxyquinoline) aluminum, sublimed), which is represented by, was disposed as the organic thin film material. Alq ₃ is a powdery sublimable organic thin film material.

First, the said vacuum pump 21 was started, the inside of the vacuum chamber 11 was made into the vacuum atmosphere, and the film formation object 13 was carried in in that state. The inside of the vacuum chamber 11 was evacuated again, and the film forming object 13 and Alq ₃ in the organic evaporation source 12 ₁ were placed in a vacuum atmosphere of 1.0 × 10 ⁻⁶ Torr (step S _{1 in} FIG. 4).

In that state, the micro heater 52 in the organic evaporation source 12 ₁ was energized, and Alq ₃ was heated to 100 ° C to 200 ° C. At this temperature, the amount of vapor generated from Alq ₃ is small and adsorbed gas is released.

Subjected to degasification for 20 minutes ~ 30 minutes and (S _2), and then, while vacuum exhaust the inside of the vacuum tank 11, gas was also introduced into the nitrogen gas from the inlet (29) with an inert gas (S _3).

In the state where the inside of the vacuum chamber 11 and the organic evaporation source 12 ₁ are stabilized under an inert gas atmosphere having a pressure of 13.3 Pa (0.1 Torr), the amount of current supplied to the micro heater 52 is increased, and Alq ₃ in the evaporation source 12 ₁ is increased. (the Alq ₃ is about 300 ℃) evaporating temperature was raised to (S _4). Since Alq ₃ is placed in an inert gas atmosphere at the time of the temperature increase, heat is efficiently transferred between Alq ₃ particles, no temperature overshoot occurs, and no generation of Alq ₃ vapor is observed.

When Alq ₃ was stabilized at the evaporation temperature, introduction of the inert gas was stopped, and the inside of the vacuum chamber 11 was brought into a vacuum state of 1.33 × 10 ⁻⁴ Pa (1.0 × 10 ⁻⁶ Torr) again (S ₅ ).

In the state where the vacuum chamber 11 was stable at the pressure, the substrate shutter 35 opened the evaporation source shutter 33 ₁ in a closed state, and released Alq ₃ vapor from the discharge port 14 ₁ .

Since the Alq ₃ vapor reaches the film thickness monitor 36 ₁ , and an organic thin film is formed on the surface thereof, the growth rate is measured, and the substrate shutter 35 is opened while the growth rate is stable, thereby forming the film forming target 13 ) Formation of organic thin film (Alq ₃ thin film) on the surface is started (S ₆ ).

And by performing the formation of an organic thin film for 5 minutes, close the substrate shutter 35 and the evaporation source shutter (33 ₁₎ in a predetermined film thickness condition, by stopping the power supply to the micro-heater (52) terminate deposition (S ₇ ).

Subsequently, an inert gas is introduced into the vacuum chamber 11 from the gas inlet 29, Alq ₃ in the organic evaporation source 12 ₁ is placed in an inert gas atmosphere at a pressure of 13.3 Pa (0.1 Torr) to generate Alq ₃ vapor. To stop. At this time, the inert gas becomes the heat medium and convection occurs, so that cooling of Alq ₃ is accelerated.

FIG. 5 shows a change in temperature and evaporation rate of Alq ₃ from the start of the temperature rise of Alq _{3 in} the inert gas atmosphere in the above-described organic thin film formation step until the deposition is completed and cooled. In addition, Alq _{3 in a} vacuum atmosphere, and the following chemical formula

The relationship between the temperature and evaporation rate of TPD shown by is shown in the graph of FIG.

From the graph of FIG. 6, it can be seen that in the vacuum atmosphere, vapor of the organic thin film material is generated at a temperature around 300 ° C. in Alq ₃ and at a temperature around 230 ° C. in TPD. On the other hand, in the graph of Figure 5, in a vacuum environment even if raising the temperature of the Alq ₃ to a temperature at which the vapor of the organic thin film material occurs, in an inert gas atmosphere, it can be seen that no Alq ₃ vapor is generated. Therefore, it can be seen that generation of steam of the organic thin film material can be suppressed by the pressure of the inert gas atmosphere.

As can be seen from the graph of Fig. 5, when the organic thin film material is heated in an inert gas atmosphere, no temperature overshoot is observed.

Compared with the organic thin film production method described above, the temperature change and the evaporation rate of Alq ₃ in the case of forming an organic thin film without using an inert gas as in the prior art are shown in the graph of FIG. 7. During the temperature increase, Alq ₃ is because the heat-insulating vacuum, the temperature overshoot is observed to be partially caused by overheating. In addition, it can be seen that Alq ₃ vapor is generated at the time of temperature increase and cooling, and a large amount of Alq ₃ vapor is generated which does not contribute to the formation of an organic thin film.

Next, an organic evaporation source suitable for heating and cooling the liquid organic thin film material will be described.

Referring to Fig. 3, reference numeral 42 is a system oil bath (oil bath) for performing a temperature control (heating and cooling) of the organic thin film material by a liquid phase heat medium to the organic evaporation source, even the organic evaporation source (12 ₁ of the first substrate, 12 ₂ ) can be replaced and installed in the vacuum chamber 11.

The organic evaporation source 42 is particularly suitable for the case where the temperature of the organic thin film material is kept constant in the temperature range of -20 ° C to 180 ° C to generate steam of the organic thin film material, and the casing 71 and It has the container 70 and the heat source 60.

The container 70 is fitted in the casing 71 so that the casing 71 is in the outer container, and the container 70 is a double structure in which the container 70 is the inner container, and between them is the circulation path 78 of the heat medium. The heat medium source 60 has an oil bath 63, a heater 65, and an input cooler 64, and heats or cools a heat medium 61 made of silicon oil stored in the oil bath 63. It is configured to be.

The tip of the supply pipe 66 ₁ is immersed in the heat medium 61, and when the circulation pump 62 provided in the middle of the supply pipe 66 ₁ is operated, the heat medium 61 in the oil bath 63 is sucked up. And supplied into the circulation path 78 through the supply pipe 66 ₁ to exchange heat with the organic thin film material 74 through the vessel 70, and then return to the oil bath 63 through the discharge pipe 66 ₂ . Consists of.

One end of the vapor discharge tube 75 is hermetically connected to the upper end of the container 70, and vapor of the organic thin film material generated in the container 70 from the discharge port 44 at the other end is not shown in FIG. 3. It is configured to be discharged into a vacuum chamber.

In the middle of the steam discharge pipe 75, an on-off valve 45 capable of controlling the passage of gas is provided, and the vapor discharge pipe 75 positioned between the open / close valve 45 and the container 70 is a gas. One end of the pipe 43 is connected. The other end of the gas pipe 43 is provided with a gas container 46 filled with an inert gas such as nitrogen gas or argon gas, and gas valves 48 ₁ and 48 ₂ are provided in the middle of the gas pipe 43. It is. Gas pipe 43, and is branched between the gas valves (48 _1, 48 _2), the middle of the branch part and the gas valve (48 ₃₎ installed, the front end is connected to a vacuum pump 47.

In the vessel 70 in the casing 71 for example

MDA (4,4'-diaminediphenylmethane) represented by

A liquid organic thin film material 74 such as MDI (4,4'-diphenylmethane diisocyanate), which is represented by the above, is placed in front of the gas valve 46 and the on-off valve 45 provided in the vapor discharge tube 75. When the gas valve 48 ₂ is closed and the vacuum pump 47 is operated to open the other gas valves 48 ₁ and 48 ₃ , the container 70 is evacuated and the organic thin film material 74 is placed in a vacuum atmosphere. Lose.

In this state, the circulation pump 62 is operated, the organic thin film material 74 is heated to a temperature at which no vapor of the organic thin film material is generated in a vacuum atmosphere, and degassing is performed.

Subsequently, when the gas valve 48 _{3 in} front of the vacuum pump 47 is closed and the gas valve 48 _{2 in} front of the gas container 46 is opened, the inert gas in the gas container 46 is discharged from the gas pipe 43. Flows into the container 70, and the organic thin film material 74 is placed in an inert gas atmosphere.

After the inside of the container 70 is set to an inert gas atmosphere at a pressure of about 1.33 Pa to 2.0 x 10 ³ Pa (0.1 to 15.0 Torr), the two gas valves 48 ₁ and 48 ₂ on the inert gas flow path are closed, Subsequently, when the heat medium 61 is raised in temperature and introduced into the circulation path 78, the heat medium 61 flows while in contact with the periphery and the bottom of the container 70, and the entire container 70 is heated uniformly. As a result, the organic thin film material 74 is uniformly heated.

In this state, when the temperature of the heat medium 61 is increased at a predetermined temperature increase rate, the organic thin film material 74 increases in temperature.

At this time, the organic thin film material 74 is placed in an atmosphere of an inert gas at a predetermined pressure, and even if the organic thin film material 74 rises to a temperature at which steam is generated under low pressure (vacuum atmosphere), the organic thin film material The steam at 74 is not generated.

In the state where the organic thin film material 74 is stable at its evaporation temperature, the gas valve 48 ₂ immediately in front of the gas container 46 is opened, and the gas valves 48 ₁ and 48 ₃ are opened to open the vacuum pump 47. Vacuum evacuation of the inside of the evaporation vessel 70 decreases the pressure of the atmosphere around the organic thin film material 74, and as a result, vapor of the organic thin film material 74 begins to be generated.

When the opening / closing valve 45 is opened in the state in which the container 70 was stabilized at the predetermined pressure, the vapor | steam of the organic thin film material 74 is discharged | emitted from the discharge port 44 into the vacuum chamber via the vapor discharge pipe 75. As shown in FIG.

A micro heater 72 is wound around the vapor discharge tube 75, and is configured to control temperature independently from the heat medium 61. When steam is discharged from the organic thin film material 74, the microheater 72 is energized beforehand and heated so that the temperature of the vapor discharge tube 75 becomes higher than the temperature of the organic thin film material 74.

In this way, when the vapor passage is heated, the vapor of the organic thin film material 74 is not cooled, and thus, the vapor of the organic thin film material 74 is opened and closed without depositing in the middle of the vapor discharge tube 75. The valve 45 is not blocked.

After the inside of the vacuum chamber was stabilized at a pressure of 1.33 × 10 ⁻⁴ Pa (1.0 × 10 ⁻⁶ Torr), the evaporation source shutter provided at the upper portion of the discharge port 44 was opened in the same manner as in the case of the deposition apparatus 10 of FIG. After confirming that the vapor of the organic thin film material 74 is stably released by the film thickness monitor disposed above the discharge port 44, the substrate shutter is opened to start the formation of the organic thin film on the surface of the film forming object.

After the organic thin film is formed to a predetermined film thickness, the opening / closing valve 45 is closed to terminate vapor discharge of the organic thin film material 74 into the vacuum chamber. Then, an inert gas is introduced into the container 70, and the cooler 64 is operated to lower the heat medium 63. At this time, since the inert gas is introduced into the container 70 and the pressure is increased, the generation of the vapor of the organic thin film material 74 is suppressed, and the organic thin film material 74 is cooled in a state in which useless vapor is not generated. This is carried out.

On the other hand, after the completion of vapor deposition, in the vacuum chamber, the film formation object in which the organic thin film is formed is exchanged with the untreated film formation object, and the next deposition operation is started.

In the above, the case where only one organic thin film is formed is described. In the case where a multilayer organic thin film is formed by using a plurality of organic evaporation sources, an inert gas is used during the temperature raising and cooling of the organic thin film material in each organic evaporation source. Put it in the mood.

The organic thin film material may be either a liquid or a solid. In particular, since the inert gas penetrates through the powder particles to form a heat medium, the temperature rise and cooling rate can be increased, and the crackability of the organic thin film material can be improved.

On the other hand, in the case of a liquid organic thin film material, since the temperature rises and cools with a heat medium, the efficiency of heat exchange is high. In particular, at the time of raising the temperature, the organic thin film material does not become higher than the temperature of the heat medium, so no dolby is generated. The heat medium may be a gas in addition to a liquid such as silicon oil.

In addition, although nitrogen gas was used as said inert gas, other gas can be used as long as it does not react with organic thin film material.

As described above, according to the present invention, vapor of the organic thin film material which is useless at the time of temperature rising and cooling does not generate | occur | produce, and the temperature increase rate and cooling rate of an organic thin film material become high.

Moreover, since temperature controllability improves and temperature overshoot does not generate | occur | produce, the Dolby ratio of an organic thin film material does not generate | occur | produce.

In addition, since the cracking property of the organic thin film material is improved, the time until the generation rate of vapor of the organic thin film material is stabilized is shortened.

1 shows an example of the vapor deposition apparatus of the present invention;

2 shows an example of an organic evaporation source used in the vapor deposition apparatus;

3 shows an example of an organic evaporation source of the present invention;

4 is a flow chart for explaining the process of the method of the present invention;

5 is a graph for explaining the change in temperature and the evaporation rate of the organic thin film material when the organic thin film is formed by the method of the present invention;

6 is a graph for explaining the relationship between the temperature and the evaporation rate of Alq ₃ and TPD;

7 is a graph for explaining changes in temperature and evaporation rate of an organic thin film material in the case of forming an organic thin film according to the prior art; And

8a to 8e are views for explaining the evaporation source of the prior art.

* Description of the symbols for the main parts of the drawings *

10 deposition apparatus 11: vacuum chamber

12 ₁ , 12 ₂ , 42: organic evaporation source 13: film forming target

29: gas inlet 50, 70: evaporation source container

54, 74: organic thin film material

Claims (15)

Vacuum exhaust machine, vacuum chamber, organic evaporation source, Evacuating the inside of the vacuum chamber by the vacuum exhaust machine, A vapor deposition apparatus configured to control the temperature of an organic thin film material entered into the organic evaporation source to generate a vapor thereof to form an organic thin film on the surface of a film forming object disposed in the vacuum chamber. A gas introduction system is connected to the vacuum chamber, and configured to introduce an inert gas into the vacuum chamber. The organic evaporation source has a container, an opening / closing valve, a discharge port, When the on-off valve is opened, the internal atmosphere of the container is connected to the external atmosphere, and when the closing valve is closed, the internal atmosphere of the container is shut off from the external atmosphere. Gas introduction system and vacuum exhaust machine can be connected And the gas is introduced into the vessel and the vacuum exhaust in the vessel is enabled in the state where the on-off valve is closed. Has a container, an on-off valve, a discharge port, When the on-off valve is opened, the internal atmosphere of the container is connected to the external atmosphere, and when the closing valve is closed, the internal atmosphere of the container is shut off from the external atmosphere. Gas introduction system and vacuum exhaust machine can be connected The organic evaporation source, characterized in that configured to enable the introduction of gas into the vessel and the vacuum exhaust in the vessel in the closed state valve. The organic evaporation source according to claim 2, wherein a heating means is provided between at least the container and the discharge port. The organic evaporation source according to claim 2, wherein a heat medium circulation path, which is a flow path through which a heat medium flows, is disposed around the container. A container in which a liquid organic thin film material is disposed therein, The heat medium flows inside, and the heat medium circulation path arrange | positioned around the said container, It has a heat medium source for controlling the heat medium to a predetermined temperature, Organic evaporation source, characterized in that configured to heat or cool the organic thin film material in the container. The organic evaporation source according to claim 5, wherein the container has a double structure of an inner container and an outer container, and the heat medium circulation path is formed between the inner container and the outer container.  The organic evaporation source according to claim 5, wherein a heat insulating material is disposed around the outer container.  The organic evaporation source according to claim 6, wherein the heating medium circulates in the heating medium circulation path by the heating medium is controlled to a predetermined temperature to heat or cool the organic thin film material in the container. An organic thin film manufacturing method for forming an organic thin film on the surface of a film forming object by disposing an organic thin film material in an organic evaporation source to release steam. And controlling the discharge rate of the vapor by controlling the pressure of the atmosphere in which the organic thin film material is placed. An organic thin film manufacturing method for forming an organic thin film on the surface of a film forming object by disposing an organic thin film material in an organic evaporation source to release steam. When raising the organic thin film material, the pressure of the atmosphere in which the organic thin film material is placed is increased to suppress the release of the vapor, Subsequently, the pressure of the atmosphere in which the organic thin film material is placed is lowered to initiate the release of the vapor. The method of claim 10, wherein the pressure is increased by introducing a gas into the atmosphere in which the organic thin film material is placed. The organic thin film production method according to claim 10, wherein the pressure of the atmosphere in which the organic thin film material is placed is raised to stop the release of the vapor. The organic thin film production method according to claim 10, wherein the organic thin film material is degassed by raising the organic thin film material at a low pressure before heating the organic compound in a high pressure state. The method of claim 10, wherein an inert gas is introduced when the pressure of the atmosphere in which the organic thin film material is placed is increased. The method of claim 10, wherein an inert gas is introduced when the pressure of the atmosphere in which the organic thin film material is placed is increased, The temperature reduction of the organic thin film material is carried out in the state in which the inert gas is introduced.