Film forming device and method for manufacturing organic EL display device using the same

Abstract

The film forming device of the present invention includes a substrate holding unit and an electrostatic suction cup, wherein the substrate holding unit includes a supporting portion for supporting the peripheral portion of the substrate, the electrostatic suction cup is arranged above the supporting portion and is used to adsorb the substrate, and the supporting portion includes a first supporting component arranged in a first direction and a second supporting component arranged in the first direction in a manner opposite to the first supporting component, and the first supporting component and the second supporting component are respectively capable of being displaced in the direction of supporting the substrate on their respective substrate supporting surfaces.

Description

[0001] This application is a divisional case of an invention patent application filed on July 27, 2018, with application number 201810845796.9 and invention name “Film-forming device and method for manufacturing an organic EL display device using the same”. Technical Field

[0002] The present invention relates to a film forming apparatus, and more particularly to a substrate supporting portion for attaching a substrate flatly to an electrostatic chuck. Background Art

[0003] Organic EL displays (OLEDs) have recently attracted attention as flat-panel displays. These self-luminous displays boast superior response speed, viewing angle, and thinness compared to liquid crystal panels. They are rapidly replacing conventional LCDs in monitors, televisions, and various mobile devices, including smartphones. Their application is also expanding to automotive displays.

[0004] Organic EL display devices have a basic structure in which a light-emitting organic layer is formed between two opposing electrodes (a cathode and an anode). The organic layer and electrode layers of an organic EL display device are formed by depositing a vapor deposition material onto (the lower surface of) a substrate placed above a vacuum chamber through a mask with a pixel pattern formed on it. The vapor deposition material is evaporated by heating a vapor deposition source located below the vacuum chamber of a film-forming apparatus.

[0005] In the vacuum chamber of such an upward-facing vapor deposition system, the substrate is held by a substrate holder, with the peripheral edge of the substrate's lower surface supported by the support portion of the substrate holder to prevent damage to the organic layer and electrode layer formed on the substrate's lower surface. In this case, as the substrate size increases, the central portion of the substrate, which is not supported by the support portion of the substrate holder, deflects due to the substrate's own weight, significantly reducing vapor deposition accuracy.

[0006] As a method for reducing substrate deflection caused by the weight of the substrate, the use of an electrostatic chuck is under investigation. Specifically, by placing an electrostatic chuck on top of the substrate, the chuck attracts the top surface of the substrate supported by the support portion of the substrate holder. This pulls the center of the substrate by the electrostatic attraction of the chuck, reducing substrate deflection. Summary of the Invention

[0007] [Problems to be Solved by the Invention]

[0008] However, the support members that make up the support portion of a conventional substrate holder are arranged so that their substrate support surfaces are at the same height. A substrate placed on such a support portion deflects in its center due to its own weight. Consequently, the substrate supported by the support portion of the substrate holder is held in a state where its peripheral edge is closer to the electrostatic chuck than its center. In this state, if the flat-plate-shaped electrostatic chuck is lowered toward the substrate, the peripheral edge of the substrate supported by the support portion of the substrate holder is almost simultaneously attracted by the electrostatic attraction force from the electrostatic chuck, becoming attracted by the chuck, while the center of the substrate is attracted least slowly.

[0009] Specifically, the attraction of the substrate to the electrostatic chuck progresses from the periphery of the substrate toward the center of the substrate. Therefore, even if the electrostatic chuck is brought sufficiently close to the substrate, the substrate will not be flatly attracted to the chuck, and a gap will remain between the substrate and the chuck in the center of the substrate. In other words, in conventional film-forming apparatuses, even when an electrostatic chuck is used, a gap will still remain between the center of the substrate and the chuck, resulting in an inability to hold the substrate flatly. Furthermore, because the periphery of the substrate's lower surface is supported by the substrate holder's support with the strongest force, i.e., because the electrostatic attraction is strongest, the deflection of the central portion of the substrate, which is the last to be affected by the electrostatic attraction of the chuck, cannot be fully extended toward the periphery of the substrate, resulting in wrinkles.

[0010] An object of the present invention is to provide a film forming apparatus capable of adsorbing a substrate in a flat shape using an electrostatic chuck, and a method of manufacturing an electronic device using such a film forming apparatus.

[0011] [Methods of solving the problem]

[0012] A first embodiment of the present invention provides a film forming device including a substrate holding unit and an electrostatic suction cup, wherein the substrate holding unit includes a supporting portion for supporting a peripheral portion of a substrate, the electrostatic suction cup is arranged above the supporting portion and is used to adsorb the substrate, and the supporting portion includes a first supporting component arranged in a first direction and a second supporting component arranged in the first direction in a manner opposite to the first supporting component, wherein the first supporting component and the second supporting component are respectively capable of being displaced in the direction in which their respective substrate supporting surfaces support the substrate.

[0013] The second mode of the film forming method of the present invention includes: a process of carrying a substrate into the film forming device of the first mode of the present invention and placing the substrate on the support part of the substrate holding unit, a process of using an electrostatic suction cup to adsorb the upper surface of the substrate placed on the support part of the substrate holding unit, and a film forming process of depositing a vapor deposition material on the substrate through a mask.

[0014] A method for manufacturing an organic EL display device according to a third aspect of the present invention manufactures an organic EL display device using the film-forming method according to the second aspect of the present invention.

[0015] [Effects of the Invention]

[0016] According to the present invention, by configuring the support components of the substrate holding unit for supporting the peripheral portion of the lower surface of the substrate to have substrate support surfaces of different heights, when the substrate supported by the support components of the substrate holding unit is attracted by the electrostatic chuck, the two opposing sides of the substrate are not attracted by the electrostatic chuck simultaneously. Instead, the side supported by the support component with the higher substrate support surface is attracted by the electrostatic chuck first, and then the substrate is attracted by the electrostatic chuck in sequence toward the other sides. This allows the deflection of the central portion of the substrate to extend toward the other sides of the peripheral portion of the substrate, ensuring that even in the central portion of the substrate, the substrate and the electrostatic chuck are in close contact with each other without a gap, and the substrate is in close contact with the electrostatic chuck as a whole, flat and wrinkle-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of a portion of a production line for organic EL display devices.

[0018] Figure 2 It is a schematic diagram of the film forming apparatus of the present invention.

[0019] Figure 3 This is a schematic diagram showing a support portion of a substrate holding unit used in a film forming apparatus according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram showing a support portion of a substrate holding unit used in a film forming apparatus according to another embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram showing the structure of a support portion of a substrate holding unit according to another embodiment of the present invention.

[0022] Figure 6 is a schematic diagram showing the structure of an organic EL display device. DETAILED DESCRIPTION

[0023] Preferred embodiments and examples of the present invention are described below with reference to the accompanying drawings. However, the following embodiments and examples merely illustrate preferred configurations of the present invention and are not intended to limit the scope of the present invention to these configurations. Furthermore, the hardware and software configurations, processing flow, manufacturing conditions, dimensions, materials, and shapes of the devices described below are not intended to limit the scope of the present invention unless otherwise specified.

[0024] The present invention can be preferably applied to a device for forming a patterned thin film (material layer) on the surface of a substrate by vacuum evaporation. As the material of the substrate, any material such as glass, a film of a polymer material, or a metal can be selected. In addition, as the evaporation material, any material such as an organic material, a metallic material (metal, metal oxide, etc.) can also be selected. The technology of the present invention can be specifically applied to manufacturing devices for organic electronic devices (such as organic EL display devices, thin-film solar cells), optical components, etc. Among them, in the manufacturing device of the organic EL display device, since the evaporation material is evaporated to form an organic EL display element, it is one of the preferred application examples of the present invention.

[0025] <Electronic device production line>

[0026] Figure 1 It is a plan view schematically showing a part of the structure of a production line for electronic devices. Figure 1 The production line is used, for example, to manufacture display panels for organic EL displays used in smartphones. In the case of smartphone display panels, the organic EL film is formed on a substrate measuring approximately 1800 mm x 1500 mm, and then the substrate is cut into multiple smaller panels.

[0027] like Figure 1 As shown, a production line for electronic devices generally has multiple film forming chambers 11 and 12 and a transfer chamber 13. A transfer robot 14 is provided in the transfer chamber 13 to hold and transfer the substrate 10. The transfer robot 14 is, for example, a robot having a multi-jointed arm with a substrate-holding robot arm mounted thereon, and carries the substrate 10 into and out of each film forming chamber.

[0028] A film forming apparatus (also called a vapor deposition apparatus) is installed in each of the film forming chambers 11 and 12. The film forming apparatus automatically performs a series of film forming processes, including transferring the substrate 10 to the transfer robot 14, adjusting (aligning) the relative position of the substrate 10 and the mask, securing the substrate 10 to the mask, and film formation (evaporation).

[0029] Next, the structure of the film forming apparatus in the film forming chamber will be described.

[0030] <Film Forming Equipment>

[0031] Figure 2 This is a cross-sectional view schematically illustrating the structure of film-forming apparatus 2. In the following description, an XYZ orthogonal coordinate system is used, with the vertical direction being the Z direction. Assuming that the substrate is fixed parallel to a horizontal plane (XY plane) during film formation, the direction parallel to the short side of the substrate is the X direction, and the direction parallel to the long side is the Y direction. The rotation angle about the Z axis is represented by θ.

[0032] The film forming apparatus 2 includes a vacuum chamber 20 defining a space in which a film forming process is performed. The interior of the vacuum chamber 20 is maintained in a vacuum atmosphere or an inert gas atmosphere such as nitrogen.

[0033] In the upper part of the vacuum chamber 20 of the film forming device 2, there are provided a substrate holding unit 21 for holding the substrate, a mask stage 22 for carrying the mask, an electrostatic suction cup 23 for adsorbing the substrate by electrostatic attraction, a magnet 24 for applying magnetic force to the metal mask, etc., and in the lower part of the vacuum chamber 20 of the film forming device, there is provided a vapor deposition source 25 for storing the vapor deposition material, etc.

[0034] The substrate holding unit 21 receives the substrate 10 from the transfer robot 14 in the transfer chamber 13, and holds and transports it. The substrate holding unit 21 is also called a substrate holder. The substrate holding unit 21 includes support portions 211 and 212 that support the peripheral portion of the lower surface of the substrate. A fluorine-coated pad (not shown) is provided on the support portion to prevent damage to the substrate. As described later, the support portion of the present invention includes a plurality of support members of different heights so that the substrate can be adsorbed flatly on the electrostatic chuck as a whole.

[0035] A frame-shaped mask stage 22 is provided below the substrate holding unit 21. A mask 221 having an opening pattern corresponding to the thin film pattern formed on the substrate 10 is placed on the mask stage 22. In particular, the mask used to manufacture organic EL elements for smartphones is a metal mask with a fine opening pattern, also known as an FMM (Fine Metal Mask).

[0036] An electrostatic chuck 23 is installed above the support portions 211 and 212 of the substrate holding unit 21. It is used to attract and secure the substrate using electrostatic attraction. The electrostatic chuck has a structure in which metal electrodes and other circuits are embedded within a ceramic base. When positive (+) and negative (-) voltages are applied to the metal electrodes, polarized charges are induced on the substrate through the ceramic base, and the electrostatic attraction between them attracts and secures the substrate to the electrostatic chuck 23. The electrostatic chuck can be divided into multiple modules based on the structure of the embedded circuits.

[0037] A magnet 24 is provided on the electrostatic chuck 23 to apply magnetic force to the metal mask 221 to prevent the mask from bending and to keep the mask 221 in close contact with the substrate 10. The magnet 24 can be a permanent magnet or an electromagnet and can be divided into a plurality of modules.

[0038] Although Figure 2 Although not shown in the figure, a cooling plate for cooling the substrate is provided between the electrostatic chuck 23 and the magnet 24. The cooling plate may be formed integrally with the magnet 24.

[0039] The evaporation source 25 includes a crucible (not shown) for storing the evaporation material to be formed on the substrate, a heater (not shown) for heating the crucible, and a baffle (not shown) for preventing the evaporation material from scattering toward the substrate until the evaporation rate from the evaporation source is constant. The evaporation source 25 can have various structures depending on the application, such as a point evaporation source, a linear evaporation source, or a rotary evaporation source.

[0040] Although Figure 2 Although not shown in the figure, the film forming apparatus 2 includes a film thickness monitor (not shown) and a film thickness calculation unit (not shown) for measuring the thickness of the film deposited on the substrate.

[0041] The outer upper surface of the vacuum chamber 20 of the film-forming apparatus 2 is provided with a drive mechanism for moving the substrate holding unit 21, electrostatic chuck 23, magnet 24, and the like in the vertical direction (Z direction). Furthermore, a drive mechanism for moving the electrostatic chuck 23 and substrate holding unit 21 parallel to the horizontal plane (X direction, Y direction, and θ direction) is provided to align the substrate with the mask. Furthermore, an alignment camera (not shown) is provided to capture images of alignment marks formed on the substrate and mask through a window provided in the ceiling of the vacuum chamber 20 to align the mask with the plate.

[0042] Hereinafter, the film forming process of the film forming apparatus of the present invention will be described.

[0043] The substrate is brought into the vacuum chamber 20 by the transfer robot 14 in the transfer chamber 13 and placed on the substrate holding unit 21. Next, an alignment process is performed to measure and adjust the relative position of the substrate 10 placed on the substrate holding unit 21 and the mask 221 placed on the mask stage. Once the alignment process is complete, the substrate holding unit 21 is lowered by the drive mechanism, and the substrate 10 is placed on the mask 221. The magnet 24 then descends, bringing the substrate 10 and mask 221 into close contact. During these alignment processes, the lowering process for placing the substrate on the mask, and the process of bringing the substrate and mask into close contact using magnets, the substrate is secured by the support portions 211 and 212 of the substrate holding unit 21 and the electrostatic chuck 23.

[0044] In this state, the shutter of the vapor deposition source 25 is opened, and the vapor deposition material evaporated from the crucible of the vapor deposition source 25 passes through the fine pattern openings of the mask and is vapor deposited on the substrate.

[0045] When the film thickness of the deposition material deposited on the substrate reaches a predetermined thickness, the shutter of the deposition source 25 is closed, and then the transfer robot 14 carries the substrate out of the vacuum chamber 20 to the transfer chamber 13 .

[0046] <Height of the Support Portion of the Substrate Holding Unit>

[0047] Below, refer to Figure 3 The structure of the substrate holding unit 21 , particularly the structure of the support portions 211 and 212 that hold the substrate together with the electrostatic chuck, will be described.

[0048] The substrate holding unit 21 is a mechanism that holds the peripheral edge of the substrate 10 using the support parts 211 and 212 and transports the substrate. Figure 3 In the illustrated first embodiment of the present invention, the support portions 211 and 212 are provided so as to support the peripheral edge portions of two opposing sides of the substrate.

[0049] The supporting parts 211 and 212 of the substrate holding unit 21 include a plurality of first supporting members 211 arranged along one of the two opposite sides of the substrate (the first side) and a plurality of second supporting members 212 arranged along the other side (the second side). For example, the plurality of first supporting members 211 are arranged along the long side direction (Y direction, first direction) of the substrate, and the plurality of second supporting members 212 are arranged in the long side direction (Y direction, first direction) of the substrate in a manner opposite to the plurality of first supporting members 211. Figure 3 The first supporting member 211 and the second supporting member 212 are each composed of a plurality of supporting members, but the present invention is not limited thereto. The first supporting member 211 and / or the second supporting member 212 may each be composed of a single supporting member extending long in the first direction. Figure 3 , the first supporting member 211 and the second supporting member 212 are shown as being arranged along the long sides of the substrate, but the present invention is not limited thereto, and the first supporting member 211 and the second supporting member 212 may also be arranged along the opposite short sides of the substrate.

[0050] like Figure 3 As shown in (a), the substrate supporting surface of the first supporting member 211 and the substrate supporting surface of the second supporting member 212 have different heights in the vertical direction (Z-axis direction). Figure 3 In the embodiment shown in (a), the substrate supporting surface of the first support member 211 is arranged to be higher than the substrate supporting surface of the second support member 212. For example, the height difference between the substrate supporting surface of the first support member 211 and the substrate supporting surface of the second support member 212 is set to be at least 0.1 mm and at most 1 mm. If the height difference is less than 0.1 mm, there is a possibility that the peripheral edge of the substrate supported by the first support member 211 and the peripheral edge of the substrate supported by the second support member 212 will be attracted by the electrostatic chuck 23 almost simultaneously. If the height difference is greater than 1 mm, there is a possibility that the tilt of the substrate before being attracted by the electrostatic chuck 23 will increase, and the substrate may tilt to one side.

[0051] In the first embodiment of the present invention, the plurality of first support members 211 disposed along the first side of the substrate all have the same height, and the plurality of second support members 212 disposed along the second side of the substrate all have the same height. However, the present invention is not limited to this embodiment. The substrate supporting surfaces of the support portions of the plurality of first support members 211 or the plurality of second support members 212 may also have different heights. For example, the substrate supporting surface of a support member 211 disposed along a first side (e.g., a long side) of the substrate near one of the two corners of the first side may be higher than the substrate supporting surfaces of the other first support members 211. For the plurality of second support members 212, the substrate supporting surface of a support member 212 disposed along one of the two corners of the second side (e.g., a long side) may also be higher than the substrate supporting surfaces of the other second support members 212. In this case, the substrate supporting surface of the support member adjacent to one of the two corners on a diagonal line of the quadrilateral substrate is higher than the substrate supporting surface of the support member adjacent to the other corner on the diagonal line.

[0052] The supporting parts 211 and 212 of the peripheral portion of the lower surface of the supporting substrate are arranged in such a manner that the substrate supporting surface thereof can move in the vertical direction (Z direction) relative to the substrate holding unit 21. For this purpose, the supporting part may include an elastic member. For example, the elastic member of the supporting part may be an elastic member such as a spring or silicone rubber, but is not limited thereto. In this regard, refer to Figure 5 Described later.

[0053] Electrostatic chuck 23, which embeds an electrostatic circuit (not shown), is flatly positioned above the substrate. Therefore, at the moment electrostatic chuck 23 is turned on (voltage is applied to the embedded electrostatic circuit), the distance between electrostatic chuck 23 and the substrate supporting surface of first support member 211 (the peripheral edge of the substrate supported by the substrate supporting surface) is shorter than the distance between electrostatic chuck 23 and the substrate supporting surface of second support member 212 (the peripheral edge of the substrate supported by the substrate supporting surface).

[0054] In this state, if the electrostatic chuck 23 is lowered in the vertical direction (Z-axis direction), Figure 3 As shown in FIG. 2( a ), the lower surface of the electrostatic chuck first contacts the peripheral portion along the first side of the substrate 10 supported by the first support member 211. The height of the second support member 212 supporting the peripheral portion of the second side of the substrate is lower than that of the first support member 211. Therefore, the peripheral portion along the second side of the substrate does not contact the electrostatic chuck 23, and a gap exists between the substrate and the electrostatic chuck 23.

[0055] In this state, if the electrostatic chuck 23 is further lowered in the vertical direction, it will attract the substrate from the peripheral portion along the first side toward the center of the substrate in the direction of arrow A. When the electrostatic chuck 23 descends to the height of the second support member 212, it will attract the substrate from the center toward the peripheral portion along the second side, and finally the peripheral portion along the second side of the substrate will be attracted by the electrostatic chuck 23. When the electrostatic chuck 23 descends to the height of the second support member 212, the substrate supporting surface of the first support member 211 of the substrate holding unit 21 and the substrate supporting surface of the second support member 212 will be at the same height.

[0056] Thus, in this embodiment, by making the heights of the substrate supporting surface of the first supporting component 211 and the substrate supporting surface of the second supporting component 212 of the substrate holding unit 21 different from each other (that is, by making the distances from the substrate supporting surface of the supporting component to the electrostatic suction cup different from each other), the adsorption to the electrostatic suction cup 23 is successively promoted from the peripheral portion along the first side of the substrate supported by the first supporting component 211 through the central portion of the substrate to the peripheral portion along the second side of the substrate, and the deflection of the central portion of the substrate caused by the self-weight of the substrate stretches toward the second side while making the entire substrate flat and tightly attached to the electrostatic suction cup 23 without gaps and wrinkles. That is, unlike the previous supporting portion, the distances from the substrate supporting surfaces of the supporting components on the two opposite sides of the supporting substrate to the electrostatic suction cup are different. Therefore, the electrostatic suction cup 23 descends toward the substrate 10, and the part that initially contacts the substrate is not the peripheral portions of the two opposite sides, but only the peripheral portion of one side (the first side). As the electrostatic suction cup 23 continues to descend, it passes through the central portion of the substrate and the peripheral portions of the other side (the second side) are finally adsorbed by the electrostatic suction cup. Therefore, the deflection of the central portion of the substrate can be extended toward the other side (the second side).

[0057] In this embodiment, it is described that the descent toward the substrate begins when a voltage is applied to the electrostatic chuck 23 to turn it on, but the present invention is not limited to this. For example, the substrate can be adsorbed by applying a voltage to the electrostatic chuck 23 to turn it on while the electrostatic chuck 23 is lowered toward the substrate in an off state and is in contact with the substrate locally (for example, with the peripheral portion of the substrate along the first side supported by the first support member 211). Alternatively, after the electrostatic chuck 23 starts to descend, the electrostatic chuck 23 can be turned on without being in contact with the substrate. In such a case, the above-mentioned effects of the present invention can also be achieved.

[0058] Below, refer to Figure 4 Other embodiments (second to sixth embodiments) of the present invention will be described. Figure 4In the illustrated embodiment, the substrate holding unit 21 includes not only a first support member 211 and a second support member 212 that support the periphery of a first side (e.g., a long side) and a periphery of a second side (e.g., a long side) of the substrate 10, but also a plurality of third support members 213 and a plurality of fourth support members 214 arranged along the remaining two opposing sides (the third side and the fourth side). For example, the plurality of third support members 213 and the plurality of fourth support members 214 are arranged along the short side direction (the X direction, a second direction intersecting the first direction) of the substrate.

[0059] In the second embodiment of the present invention ( Figure 4 (b)) and the third embodiment ( Figure 4 In (c), the substrate supporting surfaces of the third supporting member 213 and the fourth supporting member 214 of the substrate holding unit 21 are higher than the substrate supporting surface of the second supporting member 212. Figure 4 (b) and Figure 4 As shown in (c), the substrate supporting surface of the second supporting member 212 supporting the peripheral portion of the second side of one of the four sides of the substrate is set lower than the substrate supporting surfaces of the supporting members 211, 213, and 214 supporting the peripheral portions of the remaining three sides. Figure 4 As shown in (b), the substrate supporting surfaces of the plurality of third supporting members 213 and the plurality of fourth supporting members 214 may also have the same height as the substrate supporting surface of the first supporting member 211 (second embodiment), as shown in FIG. Figure 4 As shown in (c), the heights can also be varied in stages (e.g., the heights can be gradually reduced) from the first support member 211 toward the second support member 212 (third embodiment). This allows the substrate to be deflected or wrinkled to be released to the second side of the substrate supported by the second support member 212, where the substrate support surface is the lowest.

[0060] In other embodiments of the present invention, the substrate supporting surface of the third support member 213 and the substrate supporting surface of the fourth support member 214 of the substrate holding unit 21 may be set lower than the substrate supporting surface of the first support member 211. That is, the first support member 211 supporting the first side of any one of the four sides of the substrate may be set higher than the support members 212, 213, and 214 supporting the remaining three sides. In this case, Figure 4 As shown in (d), the substrate supporting surfaces of the third supporting member 213 and the fourth supporting member 214 may have the same height as the substrate supporting surface of the second supporting member 212 (fourth embodiment).

[0061] In another embodiment of the present invention, the height of the substrate support surface of the support member on one side of the diagonal line of the quadrilateral substrate (or on one side of the diagonal line of the support portion where the support member is arranged in a quadrilateral shape as a whole) is higher than the height of the substrate support surface of the support member on the opposite side of the diagonal line. Figure 4 As shown in (e), the substrate supporting surfaces of the support members 211 and 213 supporting two adjacent sides are higher than the substrate supporting surfaces of the support members 212 and 214 supporting the other two opposing sides (fifth embodiment).

[0062] In a sixth embodiment of the present invention, Figure 4 As shown in (f), the substrate supporting surface of the support members around one of the two diagonal corners of the supporting portion supporting the quadrilateral substrate (around one of the two diagonal corners of the supporting portion where the support members are arranged in a quadrilateral) is higher than the substrate supporting surface of the support members around the corner on the opposite side of the diagonal (around the corner on the opposite side of the two diagonal corners of the supporting portion where the support members are arranged in a quadrilateral). The remaining support members on the peripheral edge of the supporting substrate can be arranged in such a manner that the substrate supporting surface thereof gradually decreases as the substrate moves from the one corner toward the corner on the opposite side of the diagonal.

[0063] In the above-mentioned embodiment of the present invention, the description is based on the premise that the substrate has a quadrilateral, but the present invention is not limited to this. Even if the substrate is not a quadrilateral, the effect of the present invention can be achieved as long as the relative parts of the substrate are supported by supporting components with substrate supporting surfaces of different heights.

[0064] In the above-mentioned embodiment of the present invention, the electrostatic suction cup 23 is described as descending and adsorbing the substrate supported by the supporting parts 211, 212, 213, and 214 of the substrate holding unit 21, but the present invention is not limited to this. The substrate holding unit 21 can also be raised to adsorb the substrate to the electrostatic suction cup 23.

[0065] In the above-mentioned embodiment of the present invention, the situation in which the substrate is clamped and fixed by the supporting parts 211 and 212 of the substrate holding unit 21 and the electrostatic suction cup 23 provided on the substrate is described, but the present invention is not limited to this, and another clamping mechanism (substrate clamp) composed of a supporting part and a pressure part may be added.

[0066] In the above-mentioned embodiment of the present invention, the structure in which the electrostatic chuck is a flat plate and the supporting parts of the supporting substrate have different heights is mainly described, but the present invention is not limited to this. A structure in which the electrostatic chuck has steps and the supporting parts of the supporting substrate have the same height can also be adopted.

[0067] Thus, in the present invention, by setting the substrate supporting surface of the supporting component supporting the peripheral portion of any one side or one corner side in the supporting portion of the substrate holding unit 21 that supports the peripheral portion (4 sides) of the lower surface of the substrate to have a different height from the substrate supporting surface of the supporting component supporting the peripheral portion of other opposite sides or the corner side on the opposite side on the diagonal, when adsorbed to the electrostatic suction cup 23, the peripheral portion of the lower surface of the substrate will not be adsorbed to the electrostatic suction cup 23 at the same time, but will be adsorbed in sequence from one side to the other side opposite thereto, so that the deflection or wrinkles caused by the weight of the substrate can be effectively removed.

[0068] <Elastic Supporting Portion of Substrate Holding Unit>

[0069] The supporting portion of the substrate holding unit 21 of the present invention is configured to include an elastic body. Figure 5 As shown in (a), the plurality of support members 211, 212, 213, and 214 of the support portion each include a substrate support surface portion 30 and an elastic portion 31. The substrate support surface portion 30 supports the peripheral portion of the lower surface of the substrate, and the elastic portion 31 supports the substrate support surface portion 30 so as to be elastically displaceable.

[0070] As the elastic body used for the elastic body portion 31 , a coil spring, a leaf spring, silicone rubber, etc. can be used, but the present invention is not limited thereto and can include other structures as long as it can elastically displaceably support the substrate support surface portion of the support member.

[0071] In the present invention, among the plurality of support members 211, 212, 213, and 214, the first support member 211 provided at a position corresponding to the peripheral edge portion along one side (first side) of the substrate has a higher substrate support surface portion 30 than the other support members. Figure 5 As shown in (a), the length of the elastic portion 31 of the first supporting member 211 is longer than the length of the elastic portion 31 of the second supporting member 212 .

[0072] Through such a structure, when the substrate is placed on the supporting part of the substrate holding unit 21, when the substrate 10 contacts the electrostatic suction cup 23 by the rise of the substrate holding unit 21 or the lowering of the electrostatic suction cup 23, the peripheral edge of the first side of the substrate supported by the high first supporting part 211 of the substrate supporting surface part 30 first contacts the lower surface of the electrostatic suction cup 23 and is adsorbed.

[0073] Next, as the distance between the electrostatic chuck 23 and the substrate 10 further decreases, for example, the elastic portion 31 of the first support member 211 is elastically compressed by the pressure from the electrostatic chuck 23. As a result, the substrate supporting surface portion 30 of the first support member 211 is displaced, i.e., lowered. As the elastic portion 31 of the first support member 211 is elastically compressed, the height difference between the substrate supporting surface portion 30 of the first support member 211 and the substrate supporting surface portion 30 of the second support member 212 decreases, and the substrate is attracted to the electrostatic chuck 23 from the periphery of the first side of the substrate toward the center of the substrate. As the distance between the electrostatic chuck 23 and the substrate 10 further decreases, the substrate is attracted from the center of the substrate toward the periphery of the second side of the substrate.

[0074] If the electrostatic suction cup 23 approaches the height of the substrate supporting surface 30 of the second supporting member 212, the peripheral portion of the second side of the substrate supported by the second supporting member 212 is adsorbed by the electrostatic suction cup 23. At this time, the height of the substrate supporting surface 30 of the first supporting member 211 is the same as the height of the substrate supporting surface 30 of the second supporting member 212, and the substrate as a whole is adsorbed on the electrostatic suction cup 23 in a flat state.

[0075] exist Figure 5 In (a), the figure shows a case where the displacement axis of the substrate support surface portion 30 of the support member coincides with the displacement axis of the elastic body portion 31, but the present invention is not limited thereto, and the displacement axis of the substrate support surface portion 30 and the displacement axis of the elastic body portion 31 may be formed in a manner different from each other. Figure 5 As shown in (b), the displacement axis of the substrate support surface portion 30 and the displacement axis of the elastic body portion 31 may be separated from each other in a direction parallel to the substrate surface (i.e., the two displacement axes may be formed to be parallel to each other). In such a structure, the support member of the substrate holding unit 21 may further include a guide portion 32 for guiding the displacement of the substrate support surface portion 30. Figure 5 As shown in (b), the elastic body portion 31 can be configured not only to be compressed and displaced by the contact between the substrate and the electrostatic chuck 23, but also to be tensile and displaced.

[0076] In this embodiment, by configuring the supporting component to include an elastomer portion 31, the substrate supported by the substrate supporting surface portion 30 can be prevented from being damaged when the substrate is subjected to pressure from the electrostatic suction cup. Even if the heights of the substrate supporting surface portions 30 of the supporting components are different due to manufacturing errors, the elastic displacement of the elastomer portion 31 can reduce the impact on the function of the overall supporting portion.

[0077] <Substrate Supporting Force of the Supporting Portion of the Substrate Holding Unit>

[0078] The support portion of the substrate holding unit 21 of the present invention is configured to support the peripheral edge of the lower surface of the substrate. In this case, the multiple support members 211 and 212 of the support portion can be configured so that the supporting force of the substrate varies depending on the support member. Specifically, the support portion of the substrate holding unit 21 is configured so that the supporting force of the first support member 211 supporting one of two opposing sides of the substrate, namely the first side, differs from the supporting force of the second support member 212 supporting the other side, namely the second side. For example, the supporting force of the first support member 211 supporting the substrate is configured to be greater than the supporting force of the second support member 212 supporting the substrate.

[0079] Therefore, if Figure 5 As shown in (c), the elastic modulus of the elastic portion 31 of the first supporting member 211 is made greater than the elastic modulus of the elastic portion 31 of the second supporting member 212, or the length of the elastic portion 31 of the first supporting member 211 is made longer than the length of the elastic portion 31 of the second supporting member 212. If the length of the elastic portion 31 of the first supporting member 211 is longer, the distance over which the elastic portion 31 of the first supporting member 211 is elastically displaced (tensilely or compressively) by the pressure from the electrostatic chuck 23 is longer than the distance over which the elastic portion 31 of the second supporting member 212 is elastically displaced. As a result, the supporting force exerted by the first supporting member 211 on the substrate can be greater than the supporting force exerted by the second supporting member 212 on the substrate.

[0080] Thus, by making the supporting force of the first supporting member 211 greater than the supporting force of the second supporting member 212 , the deflection of the central portion of the substrate can be extended toward the second supporting member 212 having a smaller supporting force, thereby allowing the entire substrate to be flatly adsorbed on the electrostatic chuck 23 .

[0081] In the present invention, as long as the supporting force of the first supporting member 211 is greater than the supporting force of the second supporting member 212 , the elastic modulus and length of the elastic body portion can be combined in various other ways.

[0082] For example, Figure 5As shown in (c), the elastic modulus and length of the elastic portion 31 of the first supporting member 211 can be greater than and longer than those of the elastic portion 31 of the second supporting member 212. Alternatively, the elastic modulus of the elastic portion 31 of the first supporting member 211 and the elastic portion 31 of the second supporting member 212 can be made the same, while the length of the elastic portion 31 of the first supporting member 211 is made longer than that of the second supporting member 212. Even if the elastic modulus of the elastic portion of the first supporting member 211 and the elastic portion of the second supporting member 212 are the same, if the length of the elastic portion 31 of the first supporting member 211 is longer than that of the second supporting member 212 as described above, the supporting force of the first supporting member 211 can be greater than that of the second supporting member 212.

[0083] Furthermore, even if the elastic modulus of the elastic portion of the first support member 211 is smaller than that of the elastic portion of the second support member 212, if the length of the elastic portion 31 of the first support member 211 is sufficiently longer than that of the elastic portion 31 of the second support member 212, the supporting force of the first support member 211 can be greater than that of the second support member 212. Furthermore, even if the elastic portions of the first support member 211 and the second support member 212 have the same length, a difference in supporting force can be imparted by having different elastic moduli.

[0084] The support portion of the substrate holding unit 21 of the present invention may include, in addition to a plurality of first support members 211 configured to support the periphery of a first side of the substrate and a plurality of second support members 212 configured to support the periphery of the substrate on a second side opposite the first side, a plurality of third support members 213 and a plurality of fourth support members 214 configured to support the periphery of the substrate on a third side and a fourth side connecting the first and second sides. In this case, the elastic modulus and length of the elastic portions 31 of the third and fourth support members 213 and 214 are preferably set so that the supporting force of the third and fourth support members 213 and 214 supporting the periphery of the substrate on the third and fourth sides is less than the supporting force of the first support members 211. More preferably, the elastic modulus and / or length are set so that the supporting force of the third and fourth support members 213 and 214 is greater than the supporting force of the second support member 212. In this way, by adjusting the supporting force of the supporting component, when the substrate 10 is adsorbed by the electrostatic suction cup 23, it can be adsorbed in sequence from the peripheral portion of the substrate on the first side (for example, one of the two opposite long sides) through the central portion of the substrate toward the second side (for example, the other of the two opposite long sides), and the substrate can be adsorbed flatly on the electrostatic suction cup.

[0085] <Method for Manufacturing Electronic Device>

[0086] Next, an example of a method for manufacturing an electronic device using the film-forming apparatus of this embodiment will be described. Hereinafter, as an example of an electronic device, the structure and manufacturing method of an organic EL display device will be described.

[0087] First, the manufactured organic EL display device will be described. Figure 6 (a) shows an overall view of an organic EL display device 60, Figure 6 (b) shows the cross-sectional structure of one pixel.

[0088] like Figure 6 As shown in (a), in the display area 61 of the organic EL display device 60, a plurality of pixels 62 each having a plurality of light-emitting elements are arranged in a matrix. The details will be described later, and the light-emitting elements each have a structure having an organic layer sandwiched by a pair of electrodes. In addition, the pixel mentioned here refers to the minimum unit that can display the desired color in the display area 61. In the case of the organic EL display device of this embodiment, the pixel 62 is formed by a combination of a first light-emitting element 62R, a second light-emitting element 62G, and a third light-emitting element 62B that emit different light. The pixel 62 is mostly composed of a combination of a red light-emitting element, a green light-emitting element, and a blue light-emitting element, but it can also be a combination of a yellow light-emitting element, a cyan light-emitting element, and a white light-emitting element. There is no particular limitation as long as it is at least one color.

[0089] Figure 6 (b) Yes Figure 6(a) is a partial cross-sectional schematic diagram of the AB line. The pixel 62 has an organic EL element having a first electrode (anode) 64, a hole transport layer 65, any one of the light-emitting layers 66R, 66G, and 66B, an electron transport layer 67, and a second electrode (cathode) 68 on a substrate 63. Among them, the hole transport layer 65, the light-emitting layers 66R, 66G, 66B, and the electron transport layer 67 are equivalent to organic layers. In addition, in this embodiment, the light-emitting layer 66R is an organic EL layer that emits red, the light-emitting layer 66G is an organic EL layer that emits green, and the light-emitting layer 66B is an organic EL layer that emits blue. The light-emitting layers 66R, 66G, and 66B are respectively formed into patterns corresponding to light-emitting elements (sometimes also described as organic EL elements) that emit red, green, and blue. In addition, the first electrode 64 is formed separately for each light-emitting element. The hole transport layer 65, electron transport layer 67, and second electrode 68 may be formed commonly across the plurality of light-emitting elements 62R, 62G, and 62B, or may be formed for each light-emitting element. Furthermore, an insulating layer 69 is provided between the first electrode 64 to prevent short circuits between the first electrode 64 and the second electrode 68 due to foreign matter. Furthermore, a protective layer 70 is provided to protect the organic EL element from moisture and oxygen, as the organic EL layer degrades due to moisture and oxygen.

[0090] exist Figure 6 In (b), the hole transport layer 65 and electron transport layer 67 are shown as a single layer. However, depending on the structure of the organic EL display element, they can also be formed from multiple layers including a hole blocking layer and an electron blocking layer. Alternatively, a hole injection layer having an energy band structure that facilitates hole injection from the first electrode 64 to the hole transport layer 65 can be formed between the first electrode 64 and the hole transport layer 65. Similarly, an electron injection layer can be formed between the second electrode 68 and the electron transport layer 67.

[0091] Next, an example of a method for manufacturing an organic EL display device will be described in detail.

[0092] First, a substrate 63 on which a circuit (not shown) for driving the organic EL display device and the first electrode 64 are formed is prepared.

[0093] On the substrate 63 having the first electrode 64 formed thereon, an acrylic resin is spin-coated and then patterned using photolithography to form an opening in the portion where the first electrode 64 is formed, thereby forming an insulating layer 69. This opening corresponds to the light-emitting region where the light-emitting element actually emits light.

[0094] After the insulating layer 69 has been patterned, the substrate 63 is loaded into the first organic material film-forming apparatus. The substrate is held by an electrostatic chuck and a substrate holding unit, and a hole transport layer 65 is formed as a common layer on the first electrode 64 in the display area. The hole transport layer 65 is formed by vacuum evaporation. In practice, the hole transport layer 65 is formed larger than the display area 61, eliminating the need for a high-definition mask.

[0095] Next, substrate 63, with hole transport layer 65 formed, is loaded into a second organic material film-forming apparatus and held by an electrostatic chuck and substrate holding unit. Alignment between the substrate and the mask is performed, and the substrate is placed on the mask. A red light-emitting layer 66R is formed on the portion of substrate 63 where the red light-emitting elements are located.

[0096] Similar to the film formation of the light-emitting layer 66R, the green light-emitting layer 66G is formed using the third organic material film-forming apparatus, and the blue light-emitting layer 66B is further formed using the fourth organic material film-forming apparatus. After the film formation of the light-emitting layers 66R, 66G, and 66B is completed, the electron transport layer 67 is formed over the entire display area 61 using the fifth film-forming apparatus. The electron transport layer 67 is formed as a layer common to the three-color light-emitting layers 66R, 66G, and 66B.

[0097] The second electrode 68 is formed by moving the substrate on which the electron transport layer 67 has been formed using a metallic vapor deposition material film forming apparatus.

[0098] According to the present invention, when a variety of organic materials and metallic materials are vapor-deposited on a substrate in order to manufacture an organic EL display element, the supporting parts 211, 212, 213, and 214 of the substrate holding unit supporting the substrate have different heights or supporting forces from each other. Therefore, when the substrate supported by the supporting part of the substrate holding unit is adsorbed by the electrostatic suction cup, the substrate is adsorbed more flatly, which can improve the accuracy of the vapor deposition process as a whole.

[0099] Thereafter, the process moves to a plasma CVD apparatus to form a protective layer 70 , thereby completing the organic EL display device 60 .

[0100] From the time the substrate 63, after patterning the insulating layer 69, is loaded into the film forming apparatus until the formation of the protective layer 70 is completed, exposure to an atmosphere containing moisture or oxygen may cause degradation of the light-emitting layer composed of the organic EL material. Therefore, in this example, loading and unloading of substrates between film forming apparatuses is performed in a vacuum atmosphere or an inert gas atmosphere.

[0101] The above-described embodiment is an example of the present invention. The present invention is not limited to the configuration of the above-described embodiment, and can be modified appropriately within the scope of the technical concept.

[0102] Description of Reference Numerals

[0103] 21: Substrate holding unit

[0104] 22: Mask stage

[0105] 23: Electrostatic chuck

[0106] 24: Magnet

[0107] 30: Substrate support surface

[0108] 31: Elastic body

[0109] 32: Guidance

[0110] 211: First supporting member

[0111] 212: Second supporting member

[0112] 213: Third supporting member

[0113] 214: Fourth supporting member

Claims

1. A film forming apparatus for forming a film on a substrate via a mask, wherein: Include: a substrate holding unit including a first supporting member for supporting a peripheral edge portion of a first side of the substrate and a second supporting member for supporting a peripheral edge portion of a second side of the substrate opposite to the first side; an electrostatic chuck, the electrostatic chuck being arranged above the substrate and being used for adsorbing the substrate; as well as a driving unit for driving the substrate holding unit and the electrostatic chuck, The first supporting member and the second supporting member each include a substrate supporting surface portion and a shaft portion, wherein the shaft portion is connected to the substrate supporting surface portion via an elastic portion. The substrate supporting surface portions of the first supporting member and the second supporting member are elastically displaced relative to the shaft portion in a direction intersecting the attraction surface of the electrostatic chuck due to elastic deformation of the leaf spring constituting the elastic body portion. The displacement axis of the substrate supporting surface portion and the displacement axis of the elastic portion of each of the first supporting member and the second supporting member are separated from each other in a direction parallel to the substrate surface. The first supporting member and the second supporting member each include a guide portion for guiding displacement of a substrate supporting surface portion.

2. The film forming apparatus according to claim 1, wherein: The height of each of the substrate supporting surface portions of the first supporting member and the second supporting member varies.

3. The film forming apparatus according to claim 1 or 2, wherein: The elastic portion is elastically displaced in the direction by pressure from the electrostatic chuck.

4. The film forming apparatus according to claim 1 or 2, wherein: The length of the elastic portion of the first supporting member is longer than the length of the elastic portion of the second supporting member.

5. The film forming apparatus according to claim 1 or 2, wherein: The elastic modulus of the elastic body portion of the first supporting member is greater than the elastic modulus of the elastic body portion of the second supporting member.

6. The film forming apparatus according to claim 1 or 2, wherein: The first supporting member includes a plurality of supporting members arranged along the first side, and the second supporting member includes a plurality of supporting members arranged along the second side.

7. The film forming apparatus according to claim 1 or 2, wherein: The support portion further includes a third support member for supporting a peripheral portion of a third side of the substrate intersecting the first side and the second side, and a fourth support member for supporting a peripheral portion of a fourth side of the substrate opposite to the third side. The substrate supporting surfaces of the third supporting member and the fourth supporting member are respectively displaceable in the direction.

8. The film forming apparatus according to claim 7, wherein: The third supporting member includes a plurality of supporting members arranged along the third side, and the fourth supporting member includes a plurality of supporting members arranged along the fourth side.

9. The film forming apparatus according to claim 8, wherein: The elastic modulus of the elastic body portion of the third support member and the fourth support member is larger than that of the elastic body portion of the second support member, and smaller than that of the elastic body portion of the first support member.

10. The film forming apparatus according to claim 8 or 9, wherein: The lengths of the elastic portions of the third support member and the fourth support member are longer than the length of the elastic portion of the second support member, and shorter than the length of the elastic portion of the first support member.

11. The film forming apparatus according to claim 1 or 2, wherein: The mask is made of metal, The film forming device further comprises: a mask stage provided below the substrate holding unit in order to hold the mask; and A magnet is provided above the electrostatic chuck and applies a magnetic force to the mask to bring the substrate and the mask into close contact.

12. A film forming method for forming a film on a substrate via a mask, wherein: Include: a step of carrying a substrate into the film forming apparatus according to any one of claims 1 to 11 and placing the substrate on a support portion of a substrate holding unit; a step of sucking the upper surface of the substrate placed on the support portion of the substrate holding unit using an electrostatic chuck; and A film forming step of depositing a vapor deposition material on the substrate through a mask.

13. A method for manufacturing an organic EL display device, wherein: An organic EL display device is manufactured using the film forming method according to claim 12.

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