JP2003317951A - Vapor deposition device and method of organic thin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition device and a method of an organic thin film sufficiently capable of observing the surface of a vapor deposition material in a simple structure and reducing malfunction of a vapor deposition film by suppressing the occurrence of a peeled film and dust in a vacuum tank. <P>SOLUTION: This vapor deposition device of the organic thin film is provided with a load lock chamber stocking substrates for forming the organic thin film, the vacuum tank 11 introducing the substrate carried from the load lock chamber via a carrier means and performing vapor deposition of the organic thin film, a substrate holder 12 provided in the vacuum tank, an evaporation source 15 for the vapor deposition material provided opposed to the thin film formation surface of the substrate 18, an inspection hole for observing the vapor deposition material provided in a wall part of the vacuum tank, and the organic film having a sticking prevention plate preventing the sticking of the vapor deposition material to the inspection hole. The inspection hole 17 is provided in the wall part of the vacuum tank opposed to the rear side face of the thin film formation surface and the sticking prevention plate 19 composed of a transparent material is provided between the inspection hole 17 and the substrate 18. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor deposition apparatus for forming an organic thin film on the surface of a substrate as a film forming object and a vapor deposition method using the apparatus.

[0002]

2. Description of the Related Art In recent years, the speed of information communication and the range of applications have been rapidly increasing. Among these, the display device is
2. Description of the Related Art Inventions and devices of high-definition display devices having low power consumption and high-speed response that can meet the requirements of portability and moving image display have been widely made.

Organic electroluminescence (organic EL)
The device is 1000 cd / m ² at an applied voltage of 10 V according to Tang et al.
A report on the above-mentioned stacked EL device that emits light with high brightness (Appl.P
hys.Lett., 51, 913 (1987), high contrast,
It is expected to be applied to the above-mentioned display devices, especially flat panel displays, because it has advantages over liquid crystal display devices in terms of low voltage drive, high viewing angle, and high-speed response. Active research is underway. Green and monochrome organic EL displays have already been commercialized, and the completion of high-definition full-color displays is awaited.

Despite this situation, the conventional vacuum evaporation apparatus for forming metal and inorganic thin films and its mechanism are diverted to the conventional organic thin film formation. A practical vapor deposition apparatus and vapor deposition method suitable for a film have not been developed so much.

FIG. 3 is a conceptual schematic diagram of a conventional organic thin film deposition apparatus. In FIG. 3, 11 is a vacuum chamber configured to be evacuated, 18 is a substrate for forming an organic thin film, 12 is a substrate holder, 15 is an evaporation source of an organic material, 16
Is the surface of the evaporation material, 17 is a peep window for observing the inside of the vacuum chamber, 19 is an attachment plate for preventing deposition of vapor deposition substances on the peep window, 23 is an evaporation shutter, and 22 is an organic thin film formation rate. It is a film thickness monitor for doing. Although not shown in FIG. 3, a load lock chamber for stocking a substrate for forming an organic thin film is usually provided, and the substrate is evacuated from the load lock chamber via a transfer means such as a transfer rod or a vacuum robot. It is configured to be loaded into. An open / close valve is provided between the load lock chamber and the vacuum chamber.

With the apparatus shown in FIG. 3, a thin film is formed by vapor deposition in the following procedure. After the substrate is introduced into the load lock chamber, the vacuum chamber is evacuated, the vapor deposition material is initialized (the vapor deposition material is melted and degassed), and the vapor deposition source is heated. To the substrate holder 12 in the vacuum chamber, vapor deposition is started, an organic thin film having a predetermined thickness is formed on the substrate, and after the vapor deposition is completed, the thin film-formed substrate is taken out from the vacuum chamber.

In the above vapor deposition thin film forming procedure, even if the vapor deposition source is heated, if the vaporization shutter 23 is closed, vapor of the organic material does not reach the substrate, and when vapor deposition on the substrate is started. , The evaporation shutter 23 is driven to the open state. At the start of vapor deposition, the deposition preventive plate 19 is driven to a closed state to prevent the deposition substance from adhering to the viewing window. After the start of vapor deposition, the vapor of the organic material adheres to the film thickness monitor 22 together with the substrate 18. Thereby, the organic thin film formation rate and the film thickness can be indirectly measured.

[0008]

By the way, in the conventional apparatus and method for depositing an organic thin film shown in FIG.
There were the following problems.

In the conventional vapor deposition apparatus, the surface of the vapor deposition material cannot be seen when the initialization (melting of the vapor deposition material and the degassing step) before the start of vapor deposition is carried out, resulting in insufficient melting of the material in the initialization step. was there. In addition, in order to solve this problem, there is also a method of completely melting and degassing the material and performing initialization over a longer period than necessary, but in this case, the material consumption is significantly increased, There was a cost problem.

A peep window for observing the inside of the vacuum chamber is provided at a position facing the surface of the vapor deposition material, and a rotary shutter is provided in front of the peep window to prevent the deposition substance from adhering to the peep window. An apparatus for trapping the light with this rotary shutter is disclosed in Japanese Patent Laid-Open No. 8-3742. However, in the case of this device, although the viewing window is provided at a position facing the surface of the vapor deposition material, many members intervening between the viewing window and the surface of the vapor deposition material interfere with observation of the surface of the vapor deposition material. However, the surface of the vapor deposition material is not sufficiently visible, and the rotary shutter and the drive unit are extremely complicated in structure, so that a simpler structure of the apparatus is desired.

Further, in the conventional apparatus shown in FIG. 3, the evaporation film and the like attached to the inside of the vacuum chamber during the initialization and film forming processes are driven by the evaporation shutter 23 and the deposition preventive plate 19 which are driven at the start and end of the evaporation. Peeling by the operation of, the dust generated from the peeling film and the drive shaft, etc. is mixed in the evaporation source,
Alternatively, the adhesion to the film-forming surface has been a cause of deterioration of film quality or generation of defects.

In particular, in the case of an organic thin film element such as an organic EL display, the organic film thickness thereof is as thin as about 100 nm, so that there is a problem that the deterioration or the defect of the film quality is likely to occur. The organic thin film element is required to have lower voltage and lower power consumption than before, and in this case it is necessary to further reduce the film thickness. Therefore, in order to reduce defects in the film forming process, dust in the vacuum chamber is reduced. It is necessary to suppress the occurrence of such problems and improve the cleanliness.

The present invention has been made in view of the above points, and an object of the present invention is to enable sufficient observation of the surface of a vapor deposition material with a simple structure, and to enable a peeling film or dust in a vacuum chamber to be observed. An object of the present invention is to provide a vapor deposition apparatus and a vapor deposition method for an organic thin film in which defects of the vapor deposition film are reduced by suppressing the occurrence of

[0014]

In order to solve the above-mentioned problems, the present invention provides a load lock chamber for stocking substrates for forming an organic thin film, and a substrate transferred from the load lock chamber via a transfer means. A vacuum chamber for introducing an organic thin film vapor deposition process, a substrate holder provided in the vacuum chamber, an evaporation source for the vapor deposition material provided facing the thin film formation surface of the substrate, and a wall part of the vacuum chamber. In a vapor deposition apparatus for organic thin films, comprising: a peep window for observing a vapor deposition material, and an adhesion preventive plate for preventing adhesion of a vapor deposition substance to the peek window, the peek window is a back side of a thin film formation surface of the substrate. It is provided on the wall of the vacuum chamber so as to face the surface, and the deposition preventive plate made of a transparent material is provided between the viewing window and the substrate (claim 1).
Invention).

According to the structure of the first aspect of the invention, the surface of the vapor deposition material can be sufficiently observed with a simple structure. Further, since there is no driving mechanism for the evaporation shutter 23 and the deposition preventive plate 19 shown in FIG. 3, it is possible to suppress the generation of a peeling film or dust in the vacuum chamber.

As an embodiment of the invention, the inventions of claims 2 to 5 below are preferable. That is, in the vapor deposition apparatus according to claim 1, the vacuum chamber is provided with a means for introducing an inert gas (the invention of claim 2). As a result, the vapor deposition method of the invention of claim 6 described later can be carried out, and the film quality can be improved.

Further, in the vapor deposition apparatus according to claim 1 or 2, the substrate holder has a deposition preventing function for preventing deposition material from adhering to the inner wall of the vacuum chamber (claim 3). invention). As a result, the substrate holder can also serve as an adhesion plate for the inner wall of the vacuum chamber, and by cleaning the substrate holder as necessary, the film quality can be improved with a simple structure.

Further, in the vapor deposition apparatus according to any one of claims 1 to 3, the deposition preventive plate for preventing deposition of a vapor deposition substance onto the viewing window is detachably attached to the substrate holder. (Invention of Claim 4). This makes it possible to improve the film quality and maintainability with a simple structure by performing cleaning of the deposition-prevention plate as needed, and sufficient observation of the surface of the vapor deposition material can be continued for a long period of time. Become.

Furthermore, in the vapor deposition apparatus according to any one of claims 1 to 4, a plurality of vacuum chambers for vapor-depositing an organic thin film are connected to the load lock chamber ( The invention of claim 5). This makes it possible to form a plurality of thin films and provide an apparatus suitable for mass production.

Next, as the invention of the vapor deposition method, the inventions of the following claims 6 to 8 are preferable. That is, in the method for depositing an organic thin film on a substrate by the vapor deposition apparatus according to claim 2, after introducing the substrate into the load lock chamber, evacuation in a vacuum chamber, initialization of a vapor deposition material, After heating the evaporation source and confirming that the evaporation source has reached the specified temperature or the evaporation material has reached the specified melting state, an inert gas is introduced into the vacuum chamber, and then the substrate is vacuumed from the load lock chamber. After transporting to a predetermined position in the tank and performing vacuum evacuation, vapor deposition is started, an organic thin film having a predetermined film thickness is formed on the substrate, and after the vapor deposition is completed, an inert gas is introduced again to remove the thin film formed substrate. It is led out from a vacuum chamber (the invention of claim 6).

According to the invention of claim 6, it is possible to sufficiently observe the surface of the vapor deposition material, and it is possible to suppress the generation of a peeling film or dust in the vacuum chamber. By introducing the inert gas before vapor deposition, it is possible to prevent the vaporized substance from reaching the substrate standing by in the load lock chamber. As described above, it is possible to provide a method for depositing an organic thin film, which aims to reduce defects in the deposited film as a whole.

As the pressure of the inert gas, the invention of claim 7 is preferable. That is, in the vapor deposition method according to claim 6, the pressure of the inert gas atmosphere in the vacuum chamber before starting the vapor deposition is 0.5 Pa to 10 Pa. Details will be described later.

Further, in the vapor deposition method according to claim 6 or 7, the film thickness of the organic thin film is controlled by the temperature of the vapor deposition source and the vapor deposition time (the invention of claim 8). Although the film thickness monitor 22 shown in FIG. 3 may be used as in the prior art, application of the invention of claim 8 simplifies the apparatus configuration.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram of an organic thin film deposition apparatus according to the present invention. In FIG. 1, members having the same functions as those of the device shown in FIG.
The same numbers are assigned and detailed description is omitted.

The difference between the apparatus of FIG. 1 and the apparatus of FIG. 3 is that, in FIG. 1, first, in FIG. 1, the observation window 17 is located at the wall portion of the vacuum chamber 11 facing the back side of the thin film forming surface of the substrate 18. In addition, a deposition preventing plate 19 made of a transparent material is provided between the viewing window 17 and the substrate 18. Furthermore, vacuum chamber 1
Reference numeral 1 includes an inert gas introducing unit including an inert gas cylinder 14, a mass flow controller 21, a valve 20, and the like.

The substrate holder 12 shown in FIG. 1 has a skirt portion along the side wall of the vacuum chamber and a ceiling plate portion parallel to the ceiling wall of the vacuum chamber in order to prevent the deposition material from adhering to the inner wall of the vacuum chamber 11. Is equipped with. Furthermore, as mentioned above, FIG.
In the apparatus shown in FIG. 3, the evaporation shutter 2 in FIG.
3 and its driving mechanism, the driving mechanism for the deposition preventive plate 19, the film thickness monitor 22 and the like are not present, which is also a difference from FIG. As the deposition preventive plate 19 made of the transparent material in FIG. 1, for example, a soda lime glass plate can be used, and the deposition preventive plate 19 can be attached to and detached from the substrate holder 12 via the deposition preventive plate holding member 13. Mounted as possible.

A procedure for forming a vapor deposition film using the apparatus shown in FIG. 1 will be described below. FIG. 2 is a flowchart showing a procedure for forming a vapor deposition film. The substrate is introduced into a load lock chamber (not shown), the organic material is stored in the evaporation source 15 attached to the bottom plate of the vacuum chamber 11, and vacuum exhaust (S _{1 in} FIG. 2) is performed. After reducing the internal pressure of the vacuum chamber to 1 × 10 ⁻⁴ Pa, the vapor deposition source 15 is heated in a state where the substrate 18 is not present in the vacuum chamber 11 to initialize the vapor deposition material (S _{2 in} FIG. ₂ ).

At this time, the vapor deposition material surface 1 is seen through the viewing window 17.
Since 6 is visible, the melting of the material can be visually observed. Therefore, the initialization process can be ended immediately after melting, and the amount of material consumption can be reduced. Further, since there is the deposition prevention plate 19 made of soda lime glass, it is possible to prevent the film from adhering to the viewing window 17. Further, since the deposition-prevention plate 19 is arranged on the deposition-prevention plate holding member 13, it can be easily attached and detached, and the cover plate (not shown) provided on the upper part of the vacuum chamber 11 is opened to remove the deposition-prevention plate 19. Maintenance that removes and removes the attached film can be easily performed.

Next, after the initialization (S _{2 in} FIG. ₂ ) is completed,
The evaporation source 15 is heated (S _{3 in} FIG. 2), and the evaporation source 15 is controlled so that the evaporation material is in a state where a predetermined temperature or a predetermined film forming rate is obtained. After confirming that the evaporation source 15 has reached a predetermined temperature or the vapor deposition material is in a predetermined molten state, an inert gas is introduced into the vacuum chamber (S _{4 in} FIG. 2).

By introducing an inert gas and raising the pressure in the vacuum chamber 11, it is possible to prevent the substance evaporated from the evaporation source 15 from reaching the surface of the substrate standing by in the load lock chamber. . The pressure of the inert gas atmosphere required for this is 0.5 Pa to 10 Pa, more preferably 1 Pa to 5 P.
Experiments have confirmed that the range of a is preferable. If the pressure is set too high, it takes time to evacuate, and the film quality at the initial stage of film formation deteriorates. If the pressure is too low, the evaporated material reaches the surface of the substrate from the evaporation source 15. Although 1 Pa of Ar gas was introduced in this example, the type of gas is not limited to this.
Nitrogen gas may be used.

In this state, the substrate 18 is introduced onto the substrate holder in the vacuum chamber 11 from the load lock chamber (S _{5 in} FIG. 2). The substrate is transported from the side wall of the vacuum chamber by, for example, a transfer rod. At that time, the inert gas is introduced into the load lock chamber in advance,
Prevents pressure fluctuation during valve opening and closing between the vacuum chamber and load lock chamber. This makes it possible to suppress dust generation due to the air flow.

After the substrate 18 is introduced into the position shown in FIG. 1 (S _{5 in} FIG. 2), the introduced inert gas is evacuated (in FIG. 2, this step is not shown) to start vapor deposition. (S _{6 in} FIG. 2) is performed to form a film on the substrate 18. Then, when the film thickness reaches a desired time or when the film thickness is reached, the inert gas is introduced again (the illustration of this step is also omitted in FIG. 2) to end the vapor deposition (S _{7 in} FIG. 2).

Then, the substrate 18 is taken out (S _{8 in} FIG. 2), the vacuum chamber 11 is evacuated (S _{9 in} FIG. 2), and the evaporation source 11 is discharged.
Is cooled (S _{10 in} FIG. 2), and the process is completed.

As described above, when the apparatus of the present invention is used, since there is no mechanically driven portion inside the vacuum chamber 11, peeling of the adhered film due to driving and dust from the driving shaft etc. There is no occurrence. Therefore, organic EL
Even an element using an extremely thin film such as a display can prevent the occurrence of defects. Further, since the vapor deposition material surface 16 can be visually observed during the initialization of the evaporation material, the state of the material can be confirmed quickly, the efficiency of the initialization process can be improved, and the material consumption amount can be reduced. Besides,
No film is attached to the viewing window 17, and only by cleaning or replacing the deposition-inhibiting plate 19, visual observation can be continued for a long time and maintainability can be improved.

In the above description, the case where only one thin film is formed using one vacuum chamber has been described.
The same configuration can be applied to a cluster type or in-line type device having a plurality of vacuum chambers.

[0036]

As described above, according to the present invention, the load lock chamber for stocking the substrate for forming the organic thin film and the substrate transferred from the load lock chamber through the transfer means are introduced to remove the organic thin film. A vacuum tank for performing a vapor deposition process, a substrate holder provided in the vacuum tank, an evaporation source for the vapor deposition material provided facing the thin film formation surface of the substrate, and a vapor deposition material observation provided on the wall of the vacuum vessel. In the vapor deposition apparatus for an organic thin film, comprising: a peep window and an adhesion preventive plate for preventing deposition of a vapor deposition substance on the peek window, the peek window is opposed to a back surface of a thin film formation surface of the substrate in a vacuum chamber. And the protection plate made of a transparent material is provided between the viewing window and the substrate, and the vacuum chamber is provided with a means for introducing an inert gas. , Organic Thin Film Deposition Procedure to Form Organic Thin Film on Substrate , After introducing the substrate into the load lock chamber, evacuate the vacuum chamber, initialize the vapor deposition material, and heat the vapor deposition source to confirm that the vapor deposition source has reached the prescribed temperature or the vapor deposition material has reached the prescribed melting state. After that, an inert gas is introduced into the vacuum chamber, and then the substrate is transferred from the load-lock chamber to a predetermined position in the vacuum chamber, vacuum evacuation is performed, and then vapor deposition is started to a substrate having a predetermined film thickness. Forming an organic thin film,
After the vapor deposition was completed, the inert gas was introduced again, and the substrate on which the thin film was formed was taken out from the vacuum chamber, so that it is possible to observe the surface of the vapor deposition material with a simple structure, and By suppressing the generation of a peeling film or dust, it is possible to provide a vapor deposition apparatus and a vapor deposition method for an organic thin film that reduce defects in the vapor deposition film.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an organic thin film deposition apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure for depositing an organic thin film according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing an example of a conventional vapor deposition apparatus for organic thin films.

[Explanation of symbols]

11: Vacuum tank, 12: Substrate holder, 13: Deposition plate holding member, 14: Inert gas cylinder, 15: Evaporation source, 16: Surface of vapor deposition material, 17: Viewing window, 18: Substrate, 19: Deposition plate, 20: valve, 21: mass flow controller.

Claims (8)

[Claims] 1. A load lock chamber for stocking a substrate for forming an organic thin film, a vacuum tank for introducing a substrate transferred from the load lock chamber via a transfer means, and performing an evaporation process of an organic thin film, and this vacuum chamber. A substrate holder provided in the tank, and an evaporation source for the vapor deposition material provided facing the thin film formation surface of the substrate,
A viewing window for observing the vapor deposition material provided on the wall of the vacuum chamber,
In an organic thin film vapor deposition apparatus comprising a deposition preventive plate for preventing deposition of a vapor deposition material onto the viewing window, the viewing window is provided on a wall portion of a vacuum chamber facing a back surface of a thin film forming surface of the substrate. Further, the vapor deposition apparatus for an organic thin film, wherein the deposition preventive plate made of a transparent material is provided between the viewing window and the substrate. 2. The vapor deposition apparatus according to claim 1, wherein the vacuum chamber is provided with a means for introducing an inert gas. 3. The vapor deposition apparatus according to claim 1, wherein the substrate holder has a deposition preventing function for preventing deposition material from adhering to the inner wall of the vacuum chamber. apparatus. 4. The vapor deposition apparatus according to claim 1, wherein the deposition preventive plate for preventing the deposition substance from adhering to the viewing window is detachably attached to the substrate holder. Organic thin film vapor deposition device. 5. The vapor deposition apparatus according to any one of claims 1 to 4, wherein a plurality of vacuum chambers for performing vapor deposition processing of organic thin films are connected to the load lock chamber. Thin film deposition equipment. 6. The method of depositing an organic thin film on a substrate by the vapor deposition apparatus according to claim 2, wherein after the substrate is introduced into the load lock chamber, the chamber is evacuated and a vapor deposition material is removed. After initializing and heating the evaporation source and confirming that the evaporation source has reached the specified temperature or the evaporation material has reached the specified melting state, an inert gas is introduced into the vacuum chamber, and then the substrate is load-locked. The film is transferred from the chamber to a predetermined position in the vacuum chamber, vacuum evacuation is started, and then evaporation is started to form an organic thin film of a predetermined film thickness on the substrate. After the completion of evaporation, an inert gas is introduced again to form a thin film. A method of vapor-depositing an organic thin film, characterized in that the substrate is taken out from a vacuum chamber. 7. The vapor deposition method according to claim 6, wherein the pressure of the inert gas atmosphere in the vacuum chamber before starting the vapor deposition is 0.5 Pa to 10 Pa. 8. The vapor deposition method according to claim 6, wherein the film thickness of the organic thin film is controlled by the temperature of the vapor deposition source and the vapor deposition time.