Organic vapor deposition system, and organic thin film manufacturing method

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to the technical field of an organic vapor deposition apparatus, and particularly to a technique for cleaning a mask.

【0002】

[Conventional technology]

In recent years, an organic EL display device using an organic thin film has attracted attention. Reference numeral 201 in FIG. 5 is an example of an organic EL display device, in which 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 formed on a transparent glass substrate 211. Are stacked in this order.

【0003】

When a voltage is applied between the transparent electrode film 212 and the cathode electrode film 215, electrons and holes are combined in the organic thin film and emit light. The light passes through the glass substrate 211 and is radiated to the outside, and characters, figures, etc. are displayed.

【0004】

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 on the transparent electrode film that generate light of each of the three primary colors.

【0005】

Reference numeral 102 in FIG. 6 is a prior art organic vapor deposition apparatus, which is used to manufacture an organic EL display apparatus capable of color display.

【0006】

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

【0007】

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

【0008】

The organic vapor deposition source 155 has a container 121 and a heater 122 wound around the container 121, and the organic material 122 is arranged in advance in the container 121.

【0009】

When the heater 123 of the organic vapor deposition source 155 is energized to raise the temperature of the organic material 122, steam of the organic material 122 is generated and discharged into the vacuum chamber 103 from the opening portion of the container 121.

【0010】

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

【0011】

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

【0012】

When the vapor of the organic material 122 released into the vacuum chamber 103 passes through the holes 111 and reaches the surface of the transparent electrode film 109 on the glass substrate 108, the transparent electrode film 109 is in a field turn corresponding to the pattern of the holes 111. An organic thin film is formed on top.

【0013】

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

【0014】

The arrangement of the holes 111 on the mask 110 is shown in FIG. 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.

【0015】

As described above, in order to perform 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 the glass substrate 108 to form an organic thin film. As a result, an organic thin film is also formed on the shielding member 113 of the mask 110.

【0016】

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

【0017】

[Problems to be Solved by the Invention]

The present invention has been created to solve the inconveniences of the above-mentioned 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 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, an organic vapor deposition source arranged on the bottom wall side of the vacuum chamber, and the like. It has a mask arranged at a position between the substrate arranged in the substrate holder and the organic vapor deposition source, and a laser light generator so that the mask can be irradiated with the laser light emitted from the laser light generator. It is an organic vapor deposition apparatus configured in. The invention according to claim 2 is the organic thin-film deposition apparatus according to claim 1, which has a reflecting means arranged in the vacuum chamber, reflects the laser beam by the reflecting means, and irradiates the mask. It is an organic vapor deposition apparatus configured as described above. The invention according to claim 3 is the organic thin-film deposition apparatus according to claim 2, wherein the reflection means moving device for moving the reflection means in the vacuum chamber is provided. The invention according to claim 4 is the organic thin-film deposition apparatus according to any one of claims 1 to 3, wherein the organic vapor deposition apparatus is provided with a mask moving device for moving the mask in the vacuum chamber. is there. In the invention according to claim 5, a substrate is arranged in a vacuum chamber, and steam of an organic material is discharged from the organic vapor deposition source arranged in the vacuum chamber. This is an organic thin film manufacturing method in which an organic thin film is formed on the substrate by steam passing through the holes of the mask arranged at an intermediate position. The inside of the vacuum chamber is made into a vacuum atmosphere, and a laser is applied to the organic thin film adhering to the mask surface. This is an organic thin film manufacturing method including 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 organic thin film manufacturing method according to claim 5, wherein the mask cleaning step is an organic thin film manufacturing method in which the mask is irradiated with the laser beam while evacuating the inside of the vacuum chamber. is there.

【0019】

Generally, a mask having a large number of holes is used to form an organic EL display device capable of multicolor display, and this mask is a position between an organic evaporation source and a substrate and is a substrate surface. Is placed in contact with or close to the surface of the substrate.

【0020】

Then, when the vapor of the organic material is released from the organic evaporation source, the vapor of the organic material passes through the pores of the mask, and an organic thin film having a pattern according to the arrangement pattern of the pores is formed on the substrate.

【0021】

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

【0022】

The present invention is configured as described above, and the mask is cleaned by irradiating the mask with laser light to evaporate the organic thin film formed on the mask surface. Therefore, the diameter of the pores is not reduced by the organic thin film adhering to the mask surface, and the organic thin film does not peel off from the mask surface to become dust.

【0023】

In this case, if the laser beam is irradiated while moving the mask by the mask moving device, the laser beam can be irradiated to the desired position of the mask. Therefore, the surface of the effective region of the mask is irradiated with the laser beam with the small diameter laser beam. Can be done.

【0024】

Further, since the organic material forming the organic thin film is a powder or a liquid, the organic evaporation source containing the organic material inside must be placed below the vacuum chamber and the opening portion must be directed upward. Therefore, the substrate The holder should be located on the ceiling side in the vacuum chamber and above the organic evaporation source.

【0025】

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

【0026】

Therefore, in the present invention, the reflecting means is arranged in the vacuum chamber, the laser beam is reflected by the reflecting means, and the mask is irradiated. Therefore, even when the position of the mask is fixed. , The laser light generator can be arranged at a desired position.

【0027】

Further, if the reflecting means moving device is provided so that the reflecting means can be moved, the reflecting means does not get in the way when forming the organic thin film. It is also possible to move the reflecting means when irradiating the laser beam.

【0028】

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to FIG. 1, reference numeral 2 indicates an organic thin-film deposition apparatus according to an example of the present invention.

【0029】

The organic vapor deposition apparatus 2 has a vacuum chamber 3, and a plurality of organic vapor deposition sources are arranged on the bottom wall in the vacuum chamber 3. Here, the first to third organic vapor deposition sources 55₁~55₃And an organic thin-film deposition source (not shown) are arranged. 1st to 3rd organic vapor deposition sources 55₁~55₃Inside, there are three types of organic materials corresponding to each of the three primary colors 56₁~56₃Are arranged, and an organic vapor deposition material serving as a base material of the organic thin film is arranged in an organic vapor deposition source (not shown).

【0030】

A substrate holder 30 is arranged on the ceiling side in the vacuum chamber 3. The substrate holder 30 is a first to third organic vapor deposition source 55.₁~55₃And located on an organic vapor deposition source (not shown).

【0031】

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

【0032】

One end of the mask moving device 31 is attached to the ceiling of the vacuum chamber 3, and the mask suspension plate 32 and the substrate suspension plate 33 are attached to the other end in a horizontal state.

【0033】

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

【0034】

Hooks 35 and 36 are vertically attached to the four corners of the mask suspension plate 32 and the board suspension plate 33 so as to face downward. The lower ends of the hooks 35 and 36 are horizontal and are bent in the direction along the sides of the mask suspension plate 32 and the substrate suspension plate 33, and are plate-shaped on the bent portion. It is configured so that members can be placed on it.

【0035】

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, reference numeral 8 in the figure indicates a glass substrate in a state of being placed in the substrate holder 30 by the hook 36 of the substrate suspension plate 33.

【0036】

The lower end of the hook 35 attached to the mask suspension plate 32 is located below the lower end of the hook 36 attached to the board suspension plate 33, and the substrate 8 is located directly above the mask 10. It has become like.

【0037】

Further, the substrate 8 and the mask 10 are leveled by hooks 35 and 36, and the substrate 8 is arranged at a position close to the mask 10.

【0038】

When laminating organic thin films using the organic vapor deposition apparatus 2 as described above, each organic vapor deposition source 55 is used in advance.₁~55₃Organic vapor deposition material corresponding to the three primary colors 56₁~56₃Is arranged, the substrate 8 is not arranged on the substrate holder 30, and the vacuum exhaust device 52 connected to the vacuum chamber 3 is operated with the mask 10 attached to evacuate the inside of the vacuum chamber 3.

【0039】

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 patterned in advance is formed on the surface thereof. The substrate 8 is inserted into the substrate holder 30 with the surface on which the transparent conductive film is formed facing down, and is placed on the lower end portion of the hook 36 as described above.

【0040】

Reference numeral 34 is a holding plate, which is lowered from above the substrate 8 and brought into close contact with the surface of the substrate 8 to prevent the substrate 8 from moving on the hook 36.

【0041】

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

【0042】

After the alignment, first, the vapor of the organic material as the base material and the first organic vapor deposition source 55₁First color organic material placed inside 6₁And release.

【0043】

FIG. 3 shows the mask 3, the substrate 8, and the first organic vapor deposition source 55.₁It is a figure which showed the relative positional relationship with. Reference numeral 57 in the figure.₁Is the vapor of the organic compound used as the base material and the first organic material 56₁Shows the steam of.

【0044】

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

【0045】

Steam 57₁However, when it passes through the holes 11 of the mask 10 and reaches the substrate 8, a first organic thin film is formed on the surface of the transparent conductive film in the same pattern as the arrangement pattern of the holes 11.

【0046】

When forming the first organic thin film and the second and third organic thin films described later, the mask suspension plate 31 and the substrate suspension plate 21 are rotated together about the central axis 64. The substrate 8 and the mask 10 are rotated together in a relatively stationary state so that the vapor of the organic material reaches the surface of the substrate 8 uniformly.

【0047】

FIGS. 4 (a) and 4 (b) to (e) show the steps when three types of organic thin films are formed on the substrate 8, and as shown in FIG. 4 (a), the first organic thin film is shown. When 41 is formed to a predetermined film thickness, steam emission is temporarily stopped, and the mask 10 and the substrate 8 are relatively moved by a predetermined amount by the mask moving device 31 (FIG. 4 (b)), and then the base material and the base material are formed. Organic material vapor and second deposition source 55₂Second organic thin film material placed inside 56₂A second organic thin film 42 is formed at a position adjacent to the first organic thin film 41 (FIG. 4 (c)).

【0048】

After the formation of the second organic thin film 42, the mask 10 and the substrate 8 are similarly moved relative to each other by a predetermined amount (Fig. (D)), and the positions adjacent to the first and second organic thin films 41 and 42 are adjacent to each other. A third organic thin film 43 is formed in (Fig. 4 (e)).

【0049】

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

【0050】

As described above, when the patterned organic thin film is formed on the substrate 8 using the mask 10, the organic thin film also grows on the surface of the shielding member 13 of the mask 10. Reference numerals 14 in FIGS. 1 and 2 indicate an organic thin film on the shielding member 13.

【0051】

The organic vapor deposition apparatus 2 of the present invention includes a laser light generator 27 for removing the organic thin film 14 on the shielding member 13, a reflecting means 21, and a reflecting means moving device 24.

【0052】

The laser light generator 27 is arranged outside the vacuum chamber 3, so that the laser light emitted by the laser light generator 27 enters the vacuum chamber 3 through the window 26 provided in the vacuum chamber 3. It is configured in.

【0053】

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

【0054】

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

【0055】

The reflecting means 21 is attached to the reflecting means moving device 24 via the supporting member 23, and by operating the reflecting means moving device 24 and expanding and contracting the supporting member 23, the reflecting means 21 can move on the optical path of the laser beam. It is configured in.

【0056】

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

【0057】

Reference numeral 28 in FIG. 2 indicates the laser light emitted from the laser light generator 27 and reflected by the reflecting means 21. The vacuum exhaust device 52 is operated to create a vacuum atmosphere in the vacuum chamber 3, and the laser light 29 When the mask 10 is irradiated with light, the temperature of the mask 10 rises, and the organic thin film 14 formed on the surface of the mask 10 evaporates and is removed.

【0058】

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

【0059】

Further, while irradiating the laser beam 29, the organic vapor deposition source in which the organic material serving as the base material is arranged, and the first to third organic vapor deposition sources 55₁~55₃The shutter arranged in the opening portion of the vacuum chamber 3 is closed to prevent the vapor of the organic thin film 14 released into the vacuum chamber 3 from being mixed.

【0060】

The laser light 29 is irradiated as described above, but since the laser light generated by the laser light generator 27 has a width of about 5 mm, the mask moving device 31 and the reflecting means moving device 24 are used to make the reflecting means 21 When the mask 10 and the reflecting means 21 are moved while irradiating the laser beam, the laser beam 29 is completely irradiated in the effective region on the surface of the mask 10 and cleaning is performed.

【0061】

Reference numeral 22 in FIG. 2 is an accommodating member for accommodating the reflecting means 21, and when forming an organic thin film on the surface of the substrate 8, the reflecting means 21 is retracted from a position below the mask 10 and is housed in the accommodating member 22. It is preferable to store the organic vapor deposition material so that the reflecting means 21 does not interfere with the diffusion when the vapor of the organic vapor deposition material diffuses in the vacuum chamber 3.

【0062】

[Effect of the invention]

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

[Simple explanation of drawings]

[Figure 1]

An example of the organic vapor deposition apparatus of the present invention [Figure 2]

The figure for demonstrating the cleaning of the mask by this invention. [Fig. 3]

A diagram for explaining the relative positional relationship between the mask, the substrate, and the organic vapor deposition source. [Fig. 4]

(a) to (e): Diagram for explaining the formation process of the organic thin film [Fig. 5]

Diagram for explaining the structure of an organic EL display device [Fig. 6]

Conventional organic vapor deposition equipment [Fig. 7]

The figure for demonstrating the arrangement state of a hole on a mask [Explanation of symbols]

2 ...... Organic thin-film deposition equipment 3 ...... Vacuum tank 8 ...... Board 10 ...... Mask 11 ...... Hole 21 ...... Reflection means 24 ...... Reflective means moving device 29 ...... Laser light 31 ...... Mask moving device 41 ~ 43 ...... Organic thin film