KR20130111181A - Film forming apparatus and film forming method - Google Patents

Abstract

PURPOSE: A film forming apparatus and a film forming method are provided to closely attach a mask to a substrate by changing the mask according to a substrate support plate. CONSTITUTION: A substrate support device vertically maintains a substrate (6). The surface of the substrate support device is convexly formed toward the substrate. A silicon rubber buffering sheet (98) is arranged between the substrate support device and the substrate. Silicon rubber buffering materials are arranged on the upper and lower surfaces of the substrate support device. A plurality of protrusions (91b) is arranged on the surface of the substrate support device near the substrate.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a film forming apparatus,

TECHNICAL FIELD The present invention relates to a film forming apparatus and a film forming method for forming a film in a vacuum chamber, and more particularly, to a film forming apparatus and a film forming method suitable for forming an organic EL device.

The manufacturing method of the conventional organic electroluminescent device is described in patent document 1. As shown in FIG. In the manufacturing method of the organic EL device described in this publication, in order to produce an organic EL device with low material loss and economically, N sheets (N is 2 or more) are accommodated in a vacuum chamber, and during deposition of the first substrate, The N-th board | substrate is carried in and the 1st board | substrate is carried out out of a vacuum chamber during the deposition of a 2nd board | substrate. Hereinafter, the efficiency of film formation is improved by repeating this procedure. Therefore, the vacuum chamber is divided into a plurality.

[Patent Document 1] Japanese Patent Publication No. 2010-86956

In the conventional method of manufacturing the organic EL described in Patent Document 1, since the vacuum chamber is divided into a plurality of operations and the operation in each of the divided chambers is different, the loading or unloading of the other substrate during the deposition is prevented. It becomes possible, and the efficiency of film-forming is improved. By the way, in the method of this publication, after setting a board | substrate perpendicularly with respect to the alignment of a board | substrate and a mask, it is described by the alignment camera to image the alignment mark provided in the mask and the board | substrate, and to align by moving a mask with an alignment mechanism. There is only enough degree of adhesion between the mask and the substrate in the actual alignment.

In general, a mask has a mask sheet having a thickness of several tens of micrometers in which fine holes are formed in a portion to be formed, and a rigid metal frame (mask frame) is provided on the outer circumference of the mask sheet to hold the mask sheet. The metal frame and the mask sheet are welded together, which is collectively referred to as a mask.

By the way, when forming an organic EL film etc., it becomes important how faithfully a vapor deposition film is formed in the hole of the mask arrange | positioned at the front surface of a board | substrate. Although the mask and the substrate are in close mechanical contact with each other, in practice, the substrate support plate and the mask frame for holding the substrate have warpage generated during component processing, and the entire surface of the substrate and the mask cannot be brought into close contact with each other. In this case, when the substrate surface after vacuum deposition is observed, a film having a substantially uniform thickness is formed after the hole formed in the mask, while a very thin inclined surface film is formed around the hole compared with the film thickness formed in the hole. Formed. The width | variety of this inclined surface film may be several tens of micrometers or more at maximum.

Since the organic molecules are sprayed from the evaporation source with a constant spray angle, the larger the gap between the mask and the substrate, the larger the film is formed, and the inclined surface film is formed in a wider range. Recently, high-definition display is required in a small screen, and the pixel per inch (PPI) density is increasing, and it is expected to increase to about 300PPI. On the other hand, since the area of the film to be formed is tended to be wide and high luminance is secured, for example, the interval between the R light emitting film and the G light emitting film is narrowed, and it is required to make the inclined plane film as small as possible.

In the case of the display, when the current is controlled to emit light of each color, the film thickness in the vicinity of the inclined surface film becomes thin, the luminance is uneven, and the deterioration speed is also high, and it cannot be used as an effective film. Accordingly, it is strongly demanded to make the formation of the inclined plane film as small as possible by bringing the mask into close contact with the substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art, and an object thereof is to eliminate the gap between the mask and the substrate so as to prevent unnecessary film formation of the inclined plane when the deposition film is formed in the film deposition apparatus and the film deposition method. It is to adhere | attach a board | substrate. Another object of the present invention is to bring a mask into contact with a substrate in an organic EL film forming apparatus and a film forming method.

A feature of the present invention for achieving the above object is a film supporting apparatus for depositing a vapor deposition material injected from an evaporation source through a mask on a substrate for an organic EL device carried in a vacuum chamber, wherein the substrate supporting means holds the substrate vertically. The surface facing the said board | substrate of is comprised by the curved surface which convex on the said board | substrate side.

In this aspect, a silicone rubber buffer sheet may be disposed between the substrate support means and the substrate, and a silicone rubber buffer material may be disposed at the upper end and the lower end of the substrate support means. It is also possible to arrange a plurality of projections at intervals on the substrate side surface of the substrate supporting means.

Another feature of the present invention for achieving the above object is to bring a substrate for an organic EL device into a horizontal state in a vacuum chamber, and then to keep the substrate in a vertical state, and to face an evaporation source of the substrate held in this vertical state. The substrate support plate which consists of the curved surface arrange | positioned at the back side which is a surface opposite to the surface made to press is pressed to the said board | substrate side, and the mask sheet of the mask arrange | positioned at the front surface side of the said board is made to conform to this board | substrate shape. .

In this aspect, it is preferable that the surface of the substrate side of the substrate support plate is a curved surface convex toward the substrate side, and the mask sheet conforms to the shape of the surface facing the mask sheet of the substrate.

According to the present invention, since the surface of the substrate support plate disposed on the back of the substrate is a smooth curved surface, in the film forming method and the film forming apparatus, the gap between the mask and the substrate is eliminated without generating an unnecessary inclined film when forming the vapor deposition film. The mask and the substrate are in close contact with each other. In addition, in the film-forming apparatus and film-forming method for organic EL, since a board | substrate and a mask deform | transform according to a board | substrate support plate, a mask and a board | substrate can be brought into close_contact | adherence.

1: is a front view (a) and the partial enlarged view (b) which show the detail of one Example of the board | substrate support plate used for the film-forming apparatus which concerns on this invention.
FIG. 2: is a figure explaining the operation | movement of the board | substrate support plate shown in FIG. 1, and is a longitudinal cross-sectional view.
3 is a longitudinal sectional view of an embodiment of a film forming apparatus according to the present invention incorporating the substrate supporting plate shown in FIG. 1.
4 is a perspective view of an essential part of the film forming apparatus shown in FIG. 3.
5 is a diagram illustrating an example of a mask used in the film forming apparatus according to the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of the film-forming apparatus which concerns on this invention is described using drawing. 1: is a front view (the same figure (a)) and the partial enlarged view (the same figure (b)) of an Example of the board | substrate support plate used for a film-forming apparatus. FIG. 2: is a figure explaining the operation | movement of the board | substrate support plate shown in FIG. 1, and is a longitudinal cross-sectional view. FIG. 3 is a longitudinal sectional view of an embodiment of the film forming apparatus incorporating the substrate support plate shown in FIG. 1, FIG. 4 is a perspective view of an essential part of the film forming apparatus, and FIG. 5 is a view showing an example of a mask used in the film forming apparatus. to be.

First, the outline | summary of the film-forming apparatus 100 which concerns on this invention is demonstrated using FIGS. In the following description, the film formation in the organic EL device will be described. However, the present invention is not limited to the organic EL device, but can also be applied to an ordinary EL device or the like. In addition, the board | substrate 6 demonstrated in a present Example is 5th-6th generation, and the size is 1500 mm x 800 mm.

The film forming apparatus 100 includes a vacuum chamber 1 vacuum-inhaled by a vacuum pump (not shown) and a gate valve that opens and closes the vacuum chamber 1 when carrying in and transporting the substrate 6 into the vacuum chamber 1. Has 10. During film formation with the film forming apparatus 100, the inside of the vacuum chamber 1 is partitioned by the gate valve 10 and maintained at a pressure of 10 ⁻⁵ Pa order.

The board | substrate 6 is guided to the vacuum chamber 1 in the horizontal state from the exterior using the conveyance means which is not shown in figure. And it mounts on the board | substrate holding means 90 provided so that a board | substrate can be mounted and it can rotate. The board | substrate holding means 90 is connected to the rotating mechanism 92 fixed in the vacuum chamber 1, and is rotatable 90 degree | times from a horizontal position to a vertical position by the rotating mechanism 92. As shown in FIG. The board | substrate holding means 90 hold | maintains the board | substrate 6, and has the board | substrate support plate 91 which forms a board | substrate mounting surface. In order to prevent the temperature of the board | substrate 6 from raising excessively at the time of film-forming, the board | substrate support plate 91 is provided with the cooling means, for example, a cooling flow path, and is also called CP (cooling plate). When the board | substrate 6 rotates and is located in a vertical direction, the alignment camera 86 is attached in the vicinity of the position which becomes the upper end part and the lower end part of the board | substrate support plate 91. As shown in FIG.

Opposite the position where the substrate 6 is rotated to be in a vertical state, the mask 81, which will be described later, is held vertically by holding means fixed to the vacuum chamber 1. That is, the mask 81 is fixedly held by the mask holder 89 at its peripheral side (the opposite side of the side opposite to the substrate 6). The upper part of the mask holder 89 is connected to the alignment drive part 83 in which the motor was mounted in the outer side of this vacuum chamber 1.

The evaporation source 71 which extends in the left-right direction (Y direction in drawing) is arrange | positioned at the distance from the mask 81 slightly. The evaporation source 71 is able to move in the vertical direction. The movement of the evaporation source 71 in the vertical direction and the adjustment of the alignment of the mask 81 are performed in accordance with the instruction of the controller 200.

Here, the detail of the alignment is demonstrated using FIG. On the other hand, although FIG. 4 shows the case where two board | substrates 6 can be mounted to right and left, the following description applies similarly to the case where only one board | substrate 6 can be mounted. It is a case where the board | substrate 6 of the right side is aligned. The substrate 6 conveyed in the vacuum chamber 1 is initially in a horizontal state. Since it is held by the board | substrate support plate 91, the board | substrate 6 stands vertically, without flowing down using the rotation mechanism 92. As shown in FIG.

A window (opening) 85 as an alignment mark is formed at the corner of the mask 81, and the alignment mark provided on the substrate 6 and the window 85 are imaged by the alignment camera 86 to perform alignment. The alignment driver 83 adjusts the position of the mask 81 based on this imaging, and positioning of the mask 81 and the substrate 6 is performed. When the positioning is completed, the evaporation source 71 is moved to perform vapor deposition.

In the deposition mask 81 for producing the substrate 6 having a high PPI, a rectangular hole is drilled. Many of these holes are formed by etching or the like. The mask sheet 81a in which many holes were formed is welded and fixed to the mask frame 81b by applying tension. On the other hand, since the size of the board | substrate 6 reaches about 1500 mm x 800 mm in the 5th-6th generation, the mask frame 81b is sized according to the board | substrate 6. As shown to FIG. Therefore, deformations of several hundred micrometers are generated due to processing errors in the manufacturing process. At the time of vapor deposition, the mask frame 81b was pressed against the mask holding plate of the apparatus, but it was difficult to completely control the deformation generated during the manufacturing process.

By the way, although the contact | adherence of the mask of an organic substrate and a thin plate has been fully examined conventionally, when the board | substrate after film-forming is irradiated, the film of inclined surface shape is formed in many cases. One of the causes of this is that very fine gaps are formed between the organic substrate 6 and the mask 81 of the thin plate, and the present inventors considered that the gaps should be as zero as possible.

In FIG. 1 and FIG. 2, the board | substrate support plate 91 part is shown in detail. FIG. 1: (a) is a front view and a longitudinal cross-sectional view of the board | substrate support plate 91, and FIG. 1 (b) is a detailed top view and the longitudinal cross-sectional view of part A of FIG. In addition, FIG.2 (a) is a figure which showed the state before the alignment of the board | substrate 6 and the mask 81, and FIG.2 (b) shows the state after the alignment of the board | substrate 6 and the mask 81 with a longitudinal cross section, respectively. .

The board | substrate support plate 91 arrange | positioned at the back side of the board | substrate 6 acts to press the board | substrate 6 to the mask sheet 81 from the back side at the time of the said alignment. Thus, the mask sheet 81a is slightly deformed to conform to the substrate 6. Since the substrate 6 is made of glass, it is kept vertical with some deformation.

The board | substrate side surface of the board | substrate support plate 91 can be made into the curved surface which convex toward the board | substrate 6 side as a whole. Here, on the surface of the board | substrate support plate 91, the countless protrusion 91b of width W and height h is conventionally formed in the space | interval c. This protrusion 91b prevents the resistance from increasing when the substrate 6 is brought into close contact with the substrate support plate 91 and the substrate 6 is peeled off when the substrate 6 is moved to the other vacuum chamber 1. And to prevent electrification when the substrate 6 is peeled off.

By making the shape of this protrusion 91b into a curved surface as a whole, it can be brought into close contact with the organic substrate 6 of the substrate support plate 91. In this embodiment, the mask 81 and the substrate 6 are brought into close contact with each other in the longitudinal direction of the hole having the curvature. The curvature of the projection 91b is preferably selected so that the tension is applied to the mask sheet 81a when the mask 81 is brought along the substrate support plate 91. For example, what is necessary is just to select so that the change of the protrusion height which arises when the mask 81 follows the board | substrate support plate 91 may be about 500 micrometers. That is, the radius of curvature is about 560m.

Conventionally, the board | substrate 6 and the mask 81 were hold | maintained perpendicularly, and the board | substrate 6 and the mask 81 were made to adhere uniformly. As a result, attempts have been made to bring both the substrate 6 and the mask 81 as close to zero flatness as possible. However, it is practical to make the flatness of both the substrate and the mask 81 zero. According to this embodiment, even if the recessed portion is locally present on the curved substrate support plate 91, the substrate 6 forms a shape having no recessed portion due to its rigidity. In addition, since the mask 81 has only a stiffness much smaller than that of the substrate 6, the mask 81 can be made to follow the mask 81 to the substrate 6. Furthermore, since the mask 81 is made to follow the mask 6 to the substrate 6, The board | substrate 6 and the mask 81 can be brought into close contact with the whole surface, without using a precision component or apparatus.

In order to make the board | substrate support plate 91 into a curved shape, and to follow the board | substrate 6 and the mask 81 to this curved surface, the hole long side direction (up-down direction of FIG. 5) of the mask 81 is a mask 81 and a board | substrate. The adhesion of (6) is improved. However, at the upper end and the lower end of the mask 81, there is a fear that the influence of deformation due to processing error, assembly error, etc. in the width direction (left and right direction in FIG. 5) of the mask frame 81b may remain.

Therefore, the silicone rubber or the tetrafluoroethylene resin buffer sheet 98 is arrange | positioned in the whole surface, the upper end part, and the lower end part of the board | substrate support plate 91. FIG. By pressing the upper end and the lower end of the substrate 6 with the buffer sheet 98, the substrate 6 can be made to conform to the mask frame 81b also in the width direction (left and right direction in FIG. 5) of the mask 81. Become.

In addition, when the buffer sheet 98 is also provided at the center of the mask 81, the repulsive force of the buffer sheet 98 may increase the tension of the mask 81, but at the upper and lower ends of the substrate 6, the buffer sheet ( The high rigidity mask frame 81b receives the repulsive force of 98, so that the tension is not increased. Moreover, since the mask 81 is made to conform to the shape of the board | substrate 6, even if it presses the width direction (left-right direction of FIG. 5) of the mask 81 using the buffer sheet 98, the effect which improves adhesiveness is Not damaged.

In addition, in the Example shown in FIG. 2, the cross-sectional shape of the surface protrusion part of the board | substrate support plate 91 is made convex toward the organic substrate 6 side, The radius of curvature is the press-in amount which makes the mask sheet 81a follow. And the correlation of the size of the mask can be determined. In the case where the adhesion is prioritized, the shape of the curved surface may be a spherical surface, an elliptic sphere surface, or an oval shape. However, it is preferable that there is no concave surface. In addition, as for the thickness of the buffer sheet 98, about 5 mm is preferable. In addition, although the curved surface of the board | substrate support plate 91 should not only be a curved surface which convex toward the organic substrate side not only in a vertical direction but also in the left-right direction, the effect of this invention is acquired also by the curved surface of an up-down direction only.

1: vacuum chamber
6: substrate
10: gate valve
71: evaporation source
81: mask
81a: mask sheet
81b: mask frame
83: alignment drive unit
84: alignment mark
85: windows
86: alignment camera
89: mask holder
91: substrate support plate
91b: turning
92: rotary mechanism
98: cushioning sheet
100: film forming apparatus
200: controller.

Claims (6)

A film forming apparatus for depositing a vapor deposition material sprayed from an evaporation source through a mask onto a substrate for an organic EL device carried in a vacuum chamber, wherein the surface opposite to the substrate of the substrate supporting means for holding the substrate vertically is convex toward the substrate. A film forming apparatus comprising a curved surface. The method of claim 1,
A film forming apparatus, wherein a buffer sheet made of silicone rubber is disposed between the substrate supporting means and the substrate. The method of claim 1,
A film forming apparatus, wherein a silicon rubber buffer is disposed between the substrate supporting means and the substrate, and at the upper end and the lower end of the substrate supporting means. 3. The method according to claim 1 or 2,
A film forming apparatus, wherein a plurality of projections are arranged at intervals on the substrate side surface of the substrate supporting means. A substrate for an organic EL device is loaded into a vacuum chamber in a horizontal state, and then the substrate is held in a vertical state, and is disposed on a back side that is a surface opposite to a surface facing the evaporation source of the substrate held in this vertical state, A substrate supporting plate composed of curved surfaces is pressed to the substrate side, and the mask sheet of the mask disposed on the front surface side of the substrate is made to conform to the substrate shape. The method of claim 5,
The film-forming method of making the said board | substrate side surface of the said board | substrate support plate into the curved surface which convexed to this board | substrate side, and making the said mask sheet conform to the shape of the surface which opposes the mask sheet of the said board | substrate.

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