JP2002241925A - Organic vapor deposition system, and organic thin film manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for cleaning masks. SOLUTION: A reflecting means 21 is disposed in a vacuum chamber 3 to make it reflect the laser beam emitted from a laser beam generator 27 and irradiate a mask 10 with the reflected laser beam. An organic thin film adhering to the surface of the mask 10 is evaporated and removed. The resultant vapor is exhausted out of the vacuum chamber 3 by a vacuum pumping system 52. In this way, cleaning can be carried out without removing the mask 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of an organic vapor deposition apparatus, and more particularly, to a technique for cleaning a mask.

[0002]

2. Description of the Related Art In recent years, an organic EL display device using an organic thin film has attracted attention. Reference numeral 201 in FIG.
This is an example of an L display device. On a transparent glass substrate 211, a transparent electrode film 212, a buffer layer 213, an organic thin film 214, a cathode electrode film 215, and a protective film 216
Are stacked in this order.

A transparent electrode film 212 and a cathode electrode film 215
When a voltage is applied during this time, electrons and holes are combined in the organic thin film and emit light. The light transmits through the glass substrate 211 and is radiated to the outside to display characters, figures, and the like.

In order to manufacture an organic EL display device capable of color display using the organic thin film 214 as described above, it is necessary to form three types of organic thin films for generating light of three primary colors on a transparent electrode film. There is.

[0007] Reference numeral 102 in FIG. 6 is a conventional organic vapor deposition apparatus, which is used for manufacturing an organic EL display apparatus capable of color display.

The organic vapor deposition apparatus 102 has a vacuum chamber 103, in which an organic vapor deposition source 155 is arranged on the bottom wall side, and a substrate holder 112 is arranged on the ceiling side.

The inside of the vacuum chamber 103 is evacuated, and the substrate holder 130 holds the glass substrate. Reference numeral 108 indicates the glass substrate in that state. On the surface of the glass substrate 108, a transparent electrode film 109 is formed in advance, and the transparent electrode film 109 is held on the substrate holder 130 so as to face the organic evaporation source 155.

The organic vapor deposition source 155 has a container 121 and a heater 122 wound around the container 121. In the container 121, an organic material 122 is previously disposed.

When the heater 123 of the organic vapor deposition source 155 is energized to raise the temperature of the organic material 122, vapor of the organic material 122 is generated.
Released into

In the organic vapor deposition apparatus 102, a mask 110 is provided between the glass substrate 109 and the organic vapor deposition source 155.
Is arranged. The mask 110 includes a plate-shaped shielding member 113 made of a nickel alloy, and a plurality of holes 111 formed in the shielding member 113.

From the organic vapor deposition source 155, a vapor of an organic material serving as a base material and a vapor of an organic material (dopant) added in a small amount to the base material are released. The thin film emits one of the three primary colors by an organic material serving as a dopant.

The organic material 12 released into the vacuum chamber 103
When the vapor of No. 2 passes through the holes 111 and reaches the surface of the transparent electrode film 109 on the glass substrate 108, an organic thin film is formed on the transparent electrode film 109 with a field turn corresponding to the pattern of the holes 111.

When the organic thin film is formed to a predetermined thickness in the vacuum chamber 103, the glass substrate 108 is transferred to another organic vapor deposition device.

FIG. 7 shows the arrangement of the holes 111 on the mask 110. The holes 111 are regularly arranged at predetermined intervals, and an organic thin film corresponding to another color is placed at a position on the transparent electrode film 109 adjacent to the organic thin film formed in the organic vapor deposition apparatus 102. Form.

As described above, in order to perform a color display, it is necessary to form a patterned organic thin film on the surface of the transparent electrode film 109. Therefore, a mask 110 having holes 111 is arranged on a glass substrate 108. When the organic thin film is grown, the organic thin film is also formed on the shielding member 113 of the mask 110.

When the organic thin film on the shielding member 113 grows toward the inside of the hole 111, the size of the hole 111 gradually decreases, and the organic thin film cannot be formed to a desired width or length. Therefore, the mask 110 had to be replaced frequently.

[0017]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages of the prior art, and an object of the present invention is to provide a technique capable of forming an organic thin film having an accurate pattern. Another object of the present invention is to provide a technique for easily reproducing a mask.

[0018]

Means for Solving the Problems In order to solve the above problems, the invention according to claim 1 comprises a vacuum chamber, a substrate holder arranged on the ceiling side of the vacuum chamber, and a bottom wall side of the vacuum chamber. An organic vapor deposition source disposed, a mask disposed at a position between the substrate disposed on the substrate holder and the organic vapor deposition source, and a laser light generator, which was emitted from the laser light generator. An organic vapor deposition apparatus configured to be able to irradiate the mask with the laser light. The invention according to claim 2 is the organic vapor deposition apparatus according to claim 1, further comprising a reflection unit disposed in the vacuum chamber, wherein the laser beam is reflected by the reflection unit and irradiates the mask. The organic vapor deposition apparatus configured as described above. The invention according to a third aspect is the organic vapor deposition apparatus according to the second aspect, wherein the organic vapor deposition apparatus includes a reflection unit moving device that moves the reflection unit in the vacuum chamber. The invention described in claim 4 is the organic vapor deposition apparatus according to any one of claims 1 to 3, wherein the organic vapor deposition apparatus includes a mask moving device that moves the mask in the vacuum chamber. is there. The invention according to claim 5 includes disposing a substrate in a vacuum chamber and discharging a vapor of an organic material from an organic vapor deposition source disposed in the vacuum chamber. A method for manufacturing an organic thin film, wherein an organic thin film is formed on the substrate by vapor passing through a hole of a mask disposed at a position between the masks, wherein the vacuum chamber is evacuated to a vacuum atmosphere, and a laser is applied to the organic thin film attached to the mask surface. An organic thin film manufacturing method comprising a mask cleaning step of irradiating light to evaporate the organic thin film on the mask surface. The invention according to claim 6 is the method for manufacturing an organic thin film according to claim 5, wherein the mask cleaning step includes irradiating the laser beam to the mask while evacuating the vacuum chamber. is there.

Generally, in order to constitute an organic EL display device capable of multicolor display, a mask having a large number of holes is used, and this mask is located at a position between an organic evaporation source and a substrate. , Is brought into contact with the substrate surface or is arranged in close proximity to the substrate surface.

When the vapor of the organic material is released from the organic evaporation source, the vapor of the organic material passes through the holes of the mask,
An organic thin film having a pattern according to the hole arrangement pattern is formed on the substrate.

However, since the vapor of the organic material adheres to the mask surface, an organic thin film is also formed on the mask.

According to the present invention, the mask is cleaned by irradiating the mask with a laser beam to evaporate the organic thin film formed on the mask surface. Therefore, the diameter of the hole is not reduced due to the organic thin film attached to the mask surface, and the organic thin film does not peel off from the mask surface and become dust.

In this case, by irradiating the laser beam while moving the mask by the mask moving device, the laser beam can be radiated to a desired position of the mask. Therefore, the laser beam having a small diameter is uniformly applied to the surface of the effective area of the mask. Can be irradiated.

Further, since the organic material forming the organic thin film is a powder or a liquid, the organic evaporation source containing the organic material therein must be disposed below the vacuum chamber, and the opening must be directed upward. Therefore, the substrate holder needs to be located at the ceiling side in the vacuum chamber and above the organic evaporation source.

As described above, in the organic vapor deposition apparatus, since the positions of the organic vapor deposition source and the substrate holder are determined, the organic vapor deposition source and the substrate holder cannot be arranged in accordance with the position of the laser beam generator.

Therefore, in the present invention, the reflecting means is disposed in the vacuum chamber, the laser light is reflected by the reflecting means, and the laser light is irradiated on the mask. Even if there is, the laser light generator can be arranged at a desired position.

If a reflecting means moving device is provided so that the reflecting means can be moved, the reflecting means does not hinder the formation of the organic thin film. In addition, the reflecting means can be moved during the irradiation of the laser light.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 2 indicates an organic vapor deposition apparatus according to an embodiment of the present invention.

The organic vapor deposition apparatus 2 has a vacuum chamber 3, and a plurality of organic vapor deposition sources are arranged on a bottom wall in the vacuum chamber 3. Here, the first to third organic evaporation sources 55 are used.
And _to 554 ₃ are placed with organic vapor deposition source (not shown). The first to third organic deposition source 551 _to 554 _3, 3 kinds of organic materials 56 _{1-56 3} corresponding to each of the three primary colors are arranged, also, to the organic vapor deposition Gennai not shown , An organic vapor deposition material serving as a base material of an organic thin film is disposed.

A substrate holder 30 is provided on the ceiling side in the vacuum chamber 3.
Is arranged. The substrate holder 30 is positioned to the first to third organic deposition source 551 _to 554 ₃ and the organic vapor deposition source (not shown).

The substrate holder 30 includes a mask moving device 31
, A mask suspension plate 32, and a substrate suspension plate 33.

The mask moving device 31 has one end attached to the ceiling of the vacuum chamber 3 and the other end attached to a mask suspending plate 32 and a substrate suspending plate 33 in a horizontal state. ing.

The mask moving device 31 is connected to a motor arranged outside the vacuum chamber 3, and moves the mask suspension plate 32 and the substrate suspension plate 33 in the horizontal direction by the driving force of the motor. Further, it is configured to rotate in a horizontal plane.

At the four corners of the mask suspension plate 32 and the substrate suspension plate 33, hooks 35 and 36 are attached vertically downward. The lower ends of the hooks 35 and 36 are bent in the horizontal direction along the sides of the mask suspension plate 32 and the substrate suspension plate 33, and a plate-like shape is placed on the bent portion. It is configured so that the member can be placed.

Reference numeral 10 in FIG. 1 indicates a mask placed in the substrate holder 30 by the hook 35 of the mask suspension plate 32. Further, the reference numeral 8 in FIG.
2 shows a glass substrate placed in the substrate holder 30 by the hook 36 of FIG.

The lower end of the hook 35 attached to the mask suspension plate 32 is located lower than the lower end of the hook 36 attached to the substrate suspension plate 33, and the substrate 8 is located directly above the mask 10. It is located at.

The substrate 8 and the mask 10 are connected to the hook 3
The substrate 8 is leveled by 5 and 36, and the substrate 8 is arranged at a position close to the mask 10.

When an organic thin film is laminated by using the organic vapor deposition apparatus 2 as described above, each organic vapor
_{1 to} 55 ₃ , organic vapor deposition materials 56 ₁ to 56 corresponding to the _three primary colors
56 ₃ arranged without placing a substrate 8 on the substrate holder 30,
The vacuum evacuation device 52 connected to the vacuum chamber 3 is operated with the mask 10 attached, and the inside of the vacuum chamber 3 is evacuated.

While maintaining the vacuum atmosphere in the vacuum chamber 3,
The substrate 8 is carried into the vacuum chamber 3 by the substrate transfer robot. The substrate 8 is made of glass, and a transparent conductive film that has been patterned in advance is formed on the surface thereof. Substrate 8
Is the substrate holder 3 with the surface on which the transparent conductive film is formed facing down.
0 and rests on the lower end of the hook 36 as described above.

Reference numeral 34 denotes a pressing plate, which is lowered from above the substrate 8 and is brought into close contact with the surface of the substrate 8 so that the substrate 8 does not move on the hook 36.

A CCD camera 38 is arranged on the ceiling of the vacuum chamber 3, and the CCD camera 38 observes the alignment mark formed on the mask 10 and the alignment mark formed on the substrate 8 while moving the mask moving device. By using 31, the mask 10 and the substrate 8 are relatively moved to perform alignment.

[0042] After the alignment, first, the vapor of the organic material serving as a base material, the release of the organic material ₆₁ of the first color, which is disposed on the first organic deposition source 55 _1.

[0043] Figure 3 is a mask 3, a substrate 8 is a diagram showing the relative positional relationship between the first organic deposition source 55 _1. Code 57 ₁ in the figure shows the steam and the first organic material 56 ₁ in the vapor of the organic compound serving as a base material.

The mask 10 has a shielding member 13 made of a plate-like nickel alloy and a plurality of holes 11 formed in the shielding member 13.

[0045] Steam 57 _1, passes through the hole 11 of the mask 10, and reaches the substrate 8, the transparent conductive film surface, the first organic thin film is formed in the same pattern as the arrangement pattern of holes 11.

It should be noted that the first organic thin film and a second
When forming the third organic thin film, the mask suspension plate 31 and the substrate suspension plate 21 were rotated together about the central axis 64 to keep the substrate 8 and the mask 10 relatively stationary. It is rotated together in this state so that the vapor of the organic material reaches the surface of the substrate 8 uniformly.

FIGS. 4 (a) and (b) to (e) show steps in the case of forming three types of organic thin films on the substrate 8, and as shown in FIG. When the organic thin film 41 is formed to a predetermined thickness, the vapor release is once stopped, and the mask moving device 31 relatively moves the mask 10 and the substrate 8 by a predetermined amount (FIG. 4B). and steam of the organic material serving as a base material, to release the second organic thin film material 56 ₂ of the steam disposed in the second deposition source 55 in the _2, first at a position adjacent to the first organic thin film 41 2 The organic thin film 42 of
(FIG. 4 (c)).

After the formation of the second organic thin film 42, the mask 10 and the substrate 8 are similarly moved relatively by a predetermined amount (FIG.
(d)), a third organic thin film 43 is formed at a position adjacent to the first and second organic thin films 41 and 42 (FIG. 4E).

The substrate 8 on which the first to third organic thin films 41 to 43 are formed is carried out of the organic vapor deposition apparatus 2 and transported to a film forming apparatus for forming a cathode electrode film and the like. On the other hand, an untreated substrate is carried into the organic vapor deposition apparatus 2, and the first to third organic thin films are formed in the same procedure as described above.

As described above, using the mask 10 and the substrate 8
When a patterned organic thin film is formed thereon, the mask 1
The organic thin film also grows on the surface of the 0 shielding member 13.
1 and 2 indicates an organic thin film on the shielding member 13.

The organic vapor deposition apparatus 2 according to the present invention comprises a shielding member 13
Laser light generator 2 for removing the upper organic thin film 14
7, a reflection unit 21, and a reflection unit moving device 24.

The laser light generator 27 is disposed outside the vacuum chamber 3, and the laser light emitted from the laser light generator 27 passes through a window 26 provided in the vacuum chamber 3 and enters the vacuum chamber 3. It is configured to be incident.

The reflecting means 21 is arranged in the vacuum chamber 3 and on the optical path of the laser beam incident on the vacuum chamber 3.

Therefore, the laser beam incident on the vacuum chamber 3 is irradiated on the reflecting means 21 and is reflected by the reflecting means 21. The reflection means 21 transmits the reflected laser beam to the vacuum chamber 3.
It is arranged so as to irradiate the ceiling side.

The reflecting means 21 is attached to the reflecting means moving device 24 via the supporting member 23, and operates the reflecting means moving apparatus 24 to expand and contract the supporting member 23 so that the reflecting means 21 moves on the optical path of the laser beam. It is configured to be mobile.

Therefore, when the reflecting means 21 is moved by the reflecting means moving device 24 and is positioned below the mask 10, the mask 10 is irradiated with the reflected laser light.

The reference numeral 28 in FIG.
And the laser beam emitted from the reflector 21 and reflected by the reflection means 21. The vacuum evacuation device 52 is operated, the inside of the vacuum chamber 3 is evacuated to a vacuum atmosphere, and the laser beam 29 is irradiated on the mask 10 to raise the temperature of the mask 10. Then, the organic thin film 14 formed on the surface of the mask 10 evaporates and is removed.

When the vacuum pumping system 52 is operated while the laser beam 29 is being irradiated, the vapor of the organic thin film 14 generated from the mask 10 is exhausted by the vacuum pumping device 52.

During the irradiation with the laser beam 29, an organic vapor deposition source on which an organic material serving as a base material is disposed,
Kept closed to the disposed in an opening portion of the organic deposition source 551 _to 554 ₃ shutters, vapor of the organic thin film 14 that is released into the vacuum chamber 3 is kept to prevent the entrance.

The laser beam 29 is irradiated as described above.
Since the laser beam generated by the laser beam generator 27 has a width of about 5 mm, the mask 10 and the reflector 21 are irradiated with the laser beam to the reflector 21 using the mask moving device 31 and the reflector moving device 24. Is moved, the laser beam 29 is completely irradiated into the effective area on the surface of the mask 10 and cleaning is performed.

Reference numeral 22 in FIG. 2 denotes a housing member for housing the reflecting means 21. When an organic thin film is formed on the surface of the substrate 8, the reflecting means 21 is retracted from a position below the mask 10, and It is preferable that the reflection means 21 be accommodated in the vacuum chamber 22 so as not to hinder the diffusion when the vapor of the organic vapor deposition material is diffused in the vacuum chamber 3.

[0062]

Since the mask can be easily cleaned, the organic thin film can be formed in an accurate pattern. By cleaning the mask, the cost can be reduced because the mask can be reused. Since the cleaning can be performed while the mask is placed in the vacuum chamber, the working efficiency is improved.

[Brief description of the drawings]

FIG. 1 shows an example of an organic vapor deposition apparatus of the present invention.

FIG. 2 is a view for explaining mask cleaning according to the present invention.

FIG. 3 is a diagram for explaining a relative positional relationship between a mask, a substrate, and an organic deposition source.

FIGS. 4A to 4E are diagrams for explaining a step of forming an organic thin film.

FIG. 5 is a diagram illustrating a structure of an organic EL display device.

FIG. 6 shows a conventional organic vapor deposition apparatus.

FIG. 7 is a diagram for explaining an arrangement state of holes on a mask;

[Explanation of symbols]

 2 Organic vapor deposition apparatus 3 Vacuum chamber 8 Substrate 10 Mask 11 Hole 21 Reflecting means 24 Reflecting means moving device 29 Laser light 31 Mask moving device 41 to 43 … Organic thin film

Claims (6)

[Claims] A vacuum chamber; a substrate holder arranged in the vacuum chamber; an organic vapor deposition source arranged in the vacuum chamber at a position facing the substrate holder; and a substrate arranged in the substrate holder. And a mask disposed at a position between the organic vapor deposition source and a laser light generator. An organic vapor deposition apparatus configured to be able to irradiate the mask with laser light emitted from the laser light generator. . 2. The organic vapor deposition apparatus according to claim 1, further comprising a reflection unit disposed in the vacuum chamber, wherein the laser beam is reflected by the reflection unit and is irradiated on the mask. 3. An organic vapor deposition apparatus according to claim 2, further comprising a reflection means moving device for moving said reflection means in said vacuum chamber. 4. The organic vapor deposition apparatus according to claim 1, further comprising a mask moving device for moving the mask in the vacuum chamber. 5. A substrate is placed in a vacuum chamber, and a vapor of an organic material is discharged from an organic vapor deposition source disposed in the vacuum chamber.
A method for manufacturing an organic thin film, wherein an organic thin film is formed on the substrate by the steam that has passed through a hole of a mask disposed at a position between the substrate and the organic deposition source. A method for producing an organic thin film, comprising a mask cleaning step of irradiating a laser beam to an organic thin film attached to the surface of the mask, evaporating the organic thin film on the surface of the mask. 6. The method according to claim 5, wherein in the mask cleaning step, the mask is irradiated with the laser beam while evacuating the vacuum chamber.