Alignment apparatus, alignment method, film deposition apparatus, and method for manufacturing electronic devices

Abstract

To provide an alignment device, an alignment method, and a deposition device that can improve the alignment accuracy between a substrate and a mask.SOLUTION: An alignment device comprises: a mask stand 33 that supports a mask 16; an electrostatic chuck 25 that supports a substrate 27; measuring means that measures the relative positional relationship between the substrate 27 and the mask 16; and a magnetic levitation stage 2 that drives the electrostatic chuck 25 to change the relative position between the substrate 27 and the mask 16 on the basis of a result of measurement performed by the measuring means. At least one of the mask 16 and the substrate 27 is provided with a projection, and with the projection in contact with the other, at least one of the measurement by the measuring means and the driving operation by the magnetic levitation stage 2 is performed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an alignment apparatus, an alignment method, and a film forming apparatus for aligning a substrate and a mask. [Background technology]

[0002] In a film forming apparatus for manufacturing an organic EL display device (organic EL display), how to improve the alignment accuracy between a substrate and a mask is important for the quality. For example, Patent Document 1 discloses a technique for improving the alignment accuracy between a substrate and a mask. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-83311 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in recent years, there has been an increasing demand for high-precision alignment between the substrate and the mask. For example, issues include how to improve the measurement accuracy of the positional relationship between the substrate and the mask, and how to suppress misalignment between the substrate and the mask that may occur when the substrate and the mask are brought into contact with each other entirely after the substrate and mask have been positioned.

[0005] An object of the present invention is to provide an alignment apparatus, an alignment method, and a film forming apparatus that can improve the alignment accuracy between a substrate and a mask. [Means for solving the problem]

[0006] The present invention employs the following means to solve the above problems.

[0007] The alignment device of the present invention comprises: A mask support means for supporting a mask; A substrate support means for supporting a substrate; a measuring means for measuring a relative positional relationship between the substrate and the mask; a driving means for driving at least one of the mask supporting means and the substrate supporting means so as to change the relative position between the substrate and the mask based on a measurement result of the measuring means; An alignment apparatus comprising: At least one of the mask and the substrate has a convex portion, and at least one of measurement by the measuring means and driving operation by the driving means is performed with the convex portion in contact with the other. Effect of the Invention

[0008] According to the present invention, the alignment accuracy between the substrate and the mask can be improved. [Brief description of the drawings]

[0009] [Figure 1] Schematic diagram of a film forming apparatus according to Example 1 [Diagram 2] Schematic configuration diagram of a magnetic levitation stage according to the first embodiment [Diagram 3] Schematic plan view of a magnetic levitation stage according to a first embodiment. [Figure 4] Schematic plan view of a substrate according to Example 1 [Diagram 5] Schematic plan view of a mask according to Example 1 [Figure 6] FIG. 1 is an explanatory diagram of alignment according to the first embodiment; [Figure 7] FIG. 1 is a flow chart of alignment according to the first embodiment. [Figure 8] FIG. 1 is an explanatory diagram of an alignment operation according to the first embodiment; [Figure 9] FIG. 1 is an explanatory diagram of a protrusion according to the first embodiment; [Figure 10] FIG. 13 is a flowchart of an alignment according to a modified example. [Figure 11] FIG. 11 is an explanatory diagram of an alignment operation according to the second embodiment; [Figure 12] Schematic configuration diagram of a magnetic levitation stage according to Example 3. [Figure 13] Schematic diagram of a magnetic levitation stage according to a fourth embodiment [Figure 14] Diagram of an organic EL display device DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described in the embodiment are not intended to limit the scope of the present invention unless otherwise specified.

[0011] Example 1 First Embodiment An alignment apparatus, an alignment method, and a film forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

[0012] <Film forming equipment> With reference to FIG. 1, a film forming apparatus 1 including an alignment device according to the present embodiment will be described. FIG. 1 is a schematic diagram of the film forming apparatus 1 according to the first embodiment, and shows the structure of the film forming apparatus 1 seen from the front. In FIG. 1, a magnetic levitation stage 2 is provided as a driving means in the area surrounded by a dotted line. The magnetic levitation stage 2 is fixed to the upper corners or upper side of the interior of the vacuum chamber by a stage support 6. The vacuum chamber is generally configured as a hexahedron as a whole, and is composed of a vacuum chamber side 3, a vacuum chamber bottom 32, and a vacuum chamber top plate 11. A thin film is formed on the substrate through a mask 16 by a film forming material discharged from an evaporation source 5 as a film forming source installed on the vacuum chamber bottom 32. The mask 16 is magnetic and is configured to be attracted by an attraction magnet 18 as an attraction means that can move up and down relative to the magnetic levitation stage 2. The attraction magnet 18 corresponds to a magnet that is movably provided on the opposite side of the mask 16 through the substrate, and the suction force that attracts the mask 16 changes with the movement of the attraction magnet 18. The magnetic levitation stage 2 is configured so that its position can be controlled based on the measurement results by the laser displacement meter 17 installed on the mask table 33 as a mask support means. The film forming apparatus 1 also has a control unit 35. The control unit 35 has a function of controlling various mechanisms, the evaporation source 5, and film formation. The control unit 35 can be configured, for example, by a computer having a processor, memory, storage, I / O, etc. In this case, the function of the control unit 35 is realized by the processor executing a program stored in the memory or storage. As the computer, a general-purpose personal computer may be used, or an embedded computer or a PLC (programmable logic controller) may be used. Alternatively, some or all of the functions of the control unit 35 may be configured by a circuit such as an ASIC or FPGA. Note that a control unit 35 may be provided for each film forming apparatus 1, or one control unit 35 may control multiple film forming apparatuses 1.

[0013] Next, the configuration of the vibration isolation table support section on the atmosphere side will be described. The vibration isolation tables 9a, 9b are disposed on the vacuum chamber top plate 11 via the vibration isolation table bases 10a, 10b. The support frame 8 is supported by the vibration isolation tables 9a, 9b, thereby suppressing vibrations transmitted from the vacuum chamber. Furthermore, the mask stage 33 is supported in the vacuum chamber by mask support columns 13a, 13b that are moved up and down by mask guide mechanisms 12a, 12b provided on the support frame 8. The mask frame 15 is carried into the apparatus by a robot hand (not shown) and placed on the mask stage 33 .

[0014] When the robot hand enters or leaves the apparatus to carry the mask frame 15 or substrate into the apparatus, the mask guide mechanisms 12a and 12b lower the mask stage 33 to a position where it does not interfere with the movement of the robot hand. When the mask guide mechanisms 12a and 12b move up and down, the bellows 14a and 14b expand and contract. The bellows 14a and 14b maintain the vacuum state in the chamber.

[0015] In addition, when the positioning accuracy of the robot hand or the positional deviation when placing the mask, etc. is large, a rotation / translation mechanism may be required in addition to the vertical drive to bring the mask, etc. into the camera's field of view. This is a well-known technique, so a description thereof will be omitted.

[0016] The alignment cameras 7a and 7b are also supported by the support frame 8. This suppresses vibrations transmitted from the vacuum chamber to the alignment cameras 7a and 7b, enabling highly accurate measurements. A viewport for alignment measurement is installed on the chamber top plate 11, allowing alignment measurement from the atmospheric side. The alignment cameras 7a and 7b capture images of alignment marks (not shown) using transmitted light from lighting 24a and 24b installed on the underside of the mask table 33. Four alignment cameras and lighting are installed, including one not shown, and are configured to detect the positions of alignment marks formed on the substrate.

[0017] <Magnetic levitation stage> The magnetic levitation stage 2 as a driving means will be described with reference to Figures 2 and 3. Figure 2 is an enlarged view of the magnetic levitation stage 2 in Figure 1, and Figure 3 is a top view of the magnetic levitation stage 2. Note that in Figure 3, in order to clarify the positional relationship between the mover, the stator, etc., the stator provided on the stage support 6 and the attraction magnet 18 are also shown.

[0018] The magnetic levitation stage 2 includes a stage frame 31, and weight compensation magnet movers 22a, 22b, 22c, and 22d and linear motor movers 20a, 20b, 20c, and 20d fixed to the stage frame 31. The weight compensation magnet movers 22a, 22b, 22c, and 22d support the magnetic levitation stage 2 in a non-contact state with respect to the stage support 6 in order to cancel the weight of the magnetic levitation stage 2. The linear motor movers 20a, 20b, 20c, and 20d exert a thrust force to move the magnetic levitation stage 2 in a non-contact state with respect to the stage support 6. In addition, an electrostatic chuck 25 is fixed to the lower surface of the magnetic levitation stage 2 as a substrate support means. The electrostatic chuck 25 can adsorb a substrate 27, which is a film formation target, in a face-down state.

[0019] Weight compensation magnet stators 23a, 23b, 23c, and 23d are fixed to the underside of the stage support 6 so as to face the weight compensation magnet movers 22a, 22b, 22c, and 22d, respectively. A magnetic force equivalent to the weight of the magnetic levitation stage 2 is generated between the mover and stator of the weight compensation magnet, and the magnetic levitation stage 2 is supported by the stage support 6 in a non-contact state.

[0020] In addition, linear motor stators 21a, 21b, 21c, and 21d are fixed to the lower surface of the stage support 6 so as to face the linear motor movers 20a, 20b, 20c, and 20d, respectively. A thrust force for moving the magnetic levitation stage 2 is generated by a change in the value of the current flowing through the coils built into these linear motor stators 21a, 21b, 21c, and 21d. In the vertical direction, the weight of the magnetic levitation stage 2 is cancelled out by the weight compensation magnet, so the thrust generated by the linear motor is very small. Therefore, only a small amount of current is required, and the amount of heat generated by current is very small, so there is no problem with deformation or damage to the various components due to heat. However, if necessary, the coil can be covered with a water-cooled jacket and actively cooled by running a coolant through it.

[0021] The linear motor movers 20a, 20b, 20c, and 20d are arranged at four corners on the upper surface of the stage frame 31. This allows the magnetic levitation stage 2 to be driven in translation in the XY directions and in rotation around the Z axis. In addition, by arranging at least three or more linear motors (not shown) that generate thrust in the Z axis direction, the magnetic levitation stage 2 can be moved with six degrees of freedom. In this embodiment, the magnetic levitation stage 2 is configured to be moved with six degrees of freedom by linear motors arranged at a total of seven locations. In addition, the gravity compensation magnet movers 22a, 22b, 22c, and 22d are arranged at four locations symmetrically around the center of gravity of the magnetic levitation stage 2. This allows the magnetic levitation stage 2 to receive force even against moment forces, allowing the magnetic levitation stage 2 to levitate stably.

[0022] <Mask mounting part> The mask mounting portion will be described. The mask 16 is configured such that a plurality of through holes corresponding to the pixel pattern are provided at equal intervals, and the film-forming material passing through the through holes is formed on the surface of the substrate 27. The material of the mask 16 is, for example, a metal foil such as Invar that is resistant to thermal expansion, or a membrane film made by thinning a Si wafer. The mask 16 is fixed to the mask frame 15, and is transported together with the frame by a robot hand and placed on the mask table 33. The method of fixing the mask 16 and the mask frame 15 can employ various known techniques, such as a method of fixing by spot welding in a stretched state, a mechanical clamp, or fixing by adhesive. It is desirable to prevent the mask 16 from being distorted when fixed.

[0023] The substrate 27 is held by an electrostatic chuck 25 serving as a substrate support means. The attraction magnet 18 is configured to be able to approach the surface of the electrostatic chuck 25 opposite to the attraction surface in a non-contact range, and is configured to be able to generate a magnetic flux required to attract the mask 16. The electrostatic chuck 25 and the substrate 27 are non-magnetic, and the magnetic flux of the attraction magnet 18 can generate an attraction force that attracts the mask 16 vertically upward. This attraction force can bring the mask 16 into close contact with the substrate 27. By ensuring the close contact here, it is possible to prevent the film-forming material from wrapping around (shadowing) during film formation.

[0024] <Alignment mechanism> An alignment mechanism (positioning mechanism) between the substrate 27 and the mask 16 will be described. The position of the magnetic levitation stage 2 relative to the mask table 33 is measured by the laser displacement meter 17. The laser displacement meter 17 is arranged at six locations in total, including two locations in the X direction, one location in the Y direction, and three locations in the Z direction. Based on the information from the laser displacement meter 17 arranged at six locations, a geometric coordinate conversion is performed and converted into a position of six degrees of freedom around the center of gravity of the magnetic levitation stage 2. A control calculation is performed based on the position information of the six degrees of freedom, and a thrust command of six degrees of freedom is determined. Based on the thrust command of the six degrees of freedom, a current is passed through the coils of each linear motor arranged at seven locations to move the magnetic levitation stage 2, thereby making it possible to position the magnetic levitation stage 2 with high accuracy relative to the mask table 33.

[0025] The laser displacement meter 17 is fixed near the mask 16 on the mask table 33. This makes it possible to directly position the mask 16 and the substrate 27 in a vacuum environment without being affected by Abbe error or the like. Furthermore, the laser displacement meter 17 is protected from vibrations from the vacuum chamber by the vibration isolation tables 9a and 9b on which the support frame 8 is placed via the mask table 33. Since vibrations are suppressed, stable measurement is possible. Furthermore, the magnetic levitation stage 2 is supported by a non-contact, weight compensation magnet with low magnetic spring properties, and vibrations from the vacuum chamber are similarly suppressed. With the above configuration, the relative positions of the magnetic levitation stage 2 and the mask table 33 can be determined with high accuracy, and as a result, highly accurate alignment of the substrate 27 and the mask 16 is possible.

[0026] <Alignment of substrate and mask> The alignment between the substrate 27 and the mask 16 will be described. The alignment cameras 7a and 7b are used to measure the relative positional relationship between the mask 16 and the substrate 27. The substrate 27 is provided with substrate marks 28L and 28R as alignment marks (see FIG. 4), and the position of the substrate 27 is measured from the image data of the substrate marks 28L and 28R photographed by the alignment cameras 7a and 7b. The mask 16 is provided with mask marks 29L and 29R as alignment marks (see FIG. 5), and the position of the mask 16 is measured from the image data of the mask marks 29L and 29R photographed by the alignment cameras 7a and 7b. The substrate mark 28L and the mask mark 29L are photographed simultaneously by the alignment camera 7a, and the substrate mark 28R and the mask mark 29R are photographed simultaneously by the alignment camera 7b. Incidentally, the alignment cameras 7a, 7b and the control unit 35 that processes the data (image data) captured by the alignment cameras 7a, 7b constitute a measuring means for measuring the relative positional relationship between the substrate 27 and the mask 16. Incidentally, although the planar external shapes of the mask 16 and the substrate 27 are shown in Figures 4 and 5 as being circular, this is merely an example, and it goes without saying that, for example, a mask or a substrate having a rectangular external shape may be used.

[0027] FIG. 6(a) shows an example of the positional relationship between the substrate mark 28 and the mask mark 29 when the substrate 27 and the mask 16 have been transported into the film forming apparatus 1. In FIG. 6, the alignment marks on the substrate 27 and the mask 16 are enlarged. The mask mark 29 and the substrate mark 28 are photographed in the same field of view by the alignment camera 7, and the center (centroid) positions of the marks are extracted from the image data by image processing by the control unit 35. This processing is performed for both the substrate mark 28L and the mask mark 29L, and the substrate mark 28R and the mask mark 29R, so that the relative positional relationship between the substrate 27 and the mask 16 is measured. In addition, when the mask 16 and the substrate 27 are mounted, if there is a large installation error and they are out of the field of view of the camera, a process of retrying and bringing them into the field of view again is performed.

[0028] Based on the above measurement results, the magnetic levitation stage 2 is controlled to move so that the substrate mark 28L and the mask mark 29L, and the substrate mark 28R and the mask mark 29R coincide with each other, and thus the substrate 27 moves with respect to the mask 16. More specifically, the substrate 27 moves with respect to the mask 16 so that the distance between the center of the substrate mark 28L and the center of the mask mark 29L, and the distance between the center of the substrate mark 28R and the center of the mask mark 29R, are both equal to or less than a threshold value, and thus the alignment is completed. FIG. 6(b) shows an example of the positional relationship of each alignment mark after the alignment is completed. When the alignment is completed, the through hole of the mask 16 coincides with the position of the light-emitting circuit (TFT), and thus a film can be formed at a desired position on the substrate 27.

[0029] <Alignment operation> The alignment operation will be described with reference to Figures 7 and 8. Figure 7 is a flow chart of the alignment, and Figure 8 is a diagram showing the positional relationship between the substrate 27, mask 16, and attraction magnet 18 in each step shown in Figure 7.

[0030] <<Step S1>> When the alignment operation is started, the substrate 27 is lowered until the substrate 27 and the mask 16 are spaced apart by a predetermined distance. The predetermined distance is a distance that allows the mask 16 and the substrate 27 to come into close contact with each other in the effective deposition area when the suction magnet 18 is lowered to suction the mask 16 after the alignment is completed. In the following description, the mask 16 and the substrate 27 come into close contact with each other in the effective deposition area, and this may be expressed as "the mask 16 and the substrate 27 come into full contact with each other." The optimum value of the predetermined distance varies depending on the material and thickness of the mask 16, the configuration of the magnetic circuit of the suction magnet 18, and the distance to the mask 16. However, it has been found that the narrower the distance, the higher the alignment accuracy and the closer the substrate 27 and the mask 16 are to each other. Specifically, the above distance is preferably 0.1 mm or less. FIG. 8(a) shows the state in which the substrate 27 has been lowered to a predetermined position.

[0031] <<Step S2>> After the substrate 27 has been lowered to a predetermined position, an operation is performed in which a convex portion provided on at least one of the mask 16 and the substrate 27 is brought into contact with the other (see FIG. 8(b)). This operation is performed by at least one of an operation of lifting the mask 16 together with the mask stage 33 by the mask guide mechanisms 12a and 12b, and an operation of attracting the mask 16 by the attraction magnet 18. Although not shown in particular, a configuration in which the mask 16 is lifted by providing a mechanism capable of adjusting the position in six degrees of freedom while the mask stage 33 is magnetically levitated can also be adopted, similar to a magnetic levitation stage that adjusts the position of the substrate 27 in six degrees of freedom. In this case, rough adjustments can be performed by the mask guide mechanisms 12a and 12b, and fine adjustments can be performed by the above-mentioned mechanism not shown in the figures.

[0032] Here, the configuration of the convex portion will be described with reference to FIG. 9. Here, the case where a plurality of convex portions 27a are provided on the substrate 27 will be described as an example. FIG. 9(a) is a schematic diagram of the state when the plurality of convex portions 27a provided on the substrate 27 contacts the mask 16, as viewed from the side. FIG. 9(b) is a plan view of the substrate 27. The many rectangles 27b in FIG. 9(b) indicate the portions on which a film is formed by the film forming process. Also, four rectangles 27c shown by two-dot chain lines in the figure indicate the portions cut out from the substrate 27 after the film forming process. That is, the portions of the rectangles 27c are the portions that become the products, and the other portions are the portions that are discarded. In the illustrated example, the rectangles 27c are provided in four places, but the portions cut out from the substrate 27 as the products may be either single or multiple. In addition, this figure shows an example of a substrate 27 having a rectangular planar outer shape, unlike the substrate 27 shown in Figure 4 above. However, even in the case of a substrate 27 having a circular outer shape, there are similarly provided portions on which multiple films are formed and portions which are cut out as products.

[0033] As shown in the figure, the plurality of protrusions 27a are provided outside the range to be cut out in the substrate 27. The height of the plurality of protrusions 27a is preferably as low as possible, and is preferably several tens of μm or less (approximately 1 μm if possible). In addition, the protrusions 27a are preferably made of a material with a low coefficient of friction so as to reduce frictional resistance. For example, the protrusions 27a can be provided by applying a thin film of fluorine-based resin to the substrate 27 or by resist patterning. This makes it possible to suppress the generation of particles when the substrate 27 and the mask 16 slide against each other. In addition, it is also preferable that the protrusions 27a have high wear resistance, and in some cases, a material with high wear resistance even if the friction coefficient is high can be adopted. The protrusions 27a can also be provided by a material used in semiconductor processes (such as a silicon oxide film or a silicon nitride film).

[0034] Furthermore, the protrusions 27a may be provided only near the edges of the substrate 27, or may be provided in the center of the substrate 27. Fig. 9(b) shows a configuration in which the protrusions 27a are also provided in the center. Note that if particles are unlikely to be generated even when the substrate 27 slides against the mask 16, or if particles are generated but do not impair quality, the location where the protrusions 27a are provided may not be restricted. Alternatively, the cutout portion 24 may be provided within the cutout area of ​​the substrate 27.

[0035] Here, the case where the substrate 27 is provided with a plurality of protrusions 27a has been shown, but a configuration in which protrusions are provided on the mask 16 can also be adopted. In this case, the height and material of the protrusions are as described above. In addition, when the mask 16 is provided with protrusions, it is preferable to provide the protrusions at a position of the mask 16 that contacts the outside of the range cut out of the substrate 27. However, as described above, if particles are unlikely to be generated even when the substrate 27 and the mask 16 slide against each other, or if particles are generated and do not impair the quality, the position at which the protrusions 27a are provided is not restricted. In addition, when the mask 16 is provided with protrusions, the mask frame 15 can also be provided with protrusions. Therefore, it can be said that the "mask" in the present invention also includes the mask frame. In addition, a configuration in which protrusions are provided on both the substrate 27 and the mask 16 can also be adopted. In this case, the protrusions provided on the substrate 27 and the protrusions provided on the mask 16 may be configured to contact each other.

[0036] In the case where the convex portion is provided only near the edge of the substrate or mask (including the case where it is provided only on the mask frame 15) and not in the center, the convex portion provided on at least one of the mask 16 and the substrate 27 can be brought into contact with the other only by the operation of lifting the mask stage 33 by the mask guide mechanisms 12a, 12b, etc., without performing the operation of attracting the mask 16 by the attraction magnet 18. Of course, even in this case, the operation of attracting the mask 16 by the attraction magnet 18 may be used in combination, or the convex portion provided on at least one of the mask 16 and the substrate 27 may be brought into contact with the other only by the operation of attracting the mask 16 by the attraction magnet 18. On the other hand, in the case where the convex portion is provided in the center of the substrate or mask, the operation of attracting the mask 16 by the attraction magnet 18 is necessary. In this case, the operation of lifting the mask stage 33 by the mask guide mechanisms 12a, 12b, etc. may be used in combination or not.

[0037] In the process of step S2 described above, in the region excluding the convex portions, the mask 16 and the substrate 27 are separated (a gap is formed). Therefore, in step S2, the suction force when the suction magnet 18 suctions the mask 16 is set to be smaller than the suction force in the following step S5.

[0038] Furthermore, when the magnetic levitation stage 2 moves while the mask 16 and the substrate 27 are in contact with each other, friction occurs at the contact portion between the mask 16 and the substrate 27, so it is better to make the movement amount of the magnetic levitation stage 2 as short as possible. Therefore, when adopting a configuration in which alignment is performed while the mask 16 and the substrate 27 are in contact with each other, as in this embodiment, it is desirable to perform a preliminary alignment before performing the alignment. This point will be described with reference to the alignment flowchart of the modified example shown in FIG. In this modified example, a process of step S12 is added between steps S1 and S2, but the other processes are the same as in this embodiment, so the description thereof will be omitted.

[0039] In this modified example, after the above-mentioned step S1, in a state where the mask 16 and the substrate 27 are not in contact with each other, the magnetic levitation stage 2 aligns the substrate 27 and the mask 16 (first alignment step) so that the positional deviation between the substrate 27 and the mask 16 is equal to or less than a first threshold value (step S12). That is, first, the alignment marks (mask mark 29 and substrate mark 28) are photographed by the alignment camera 7, the positions of the alignment marks are detected based on the image data, and the amount of movement of the magnetic levitation stage 2 is calculated. Then, based on the calculated result, the magnetic levitation stage 2 moves, and photographing is performed again by the alignment camera 7, and the amount of positional deviation (error) between the mask mark 29 and the substrate mark 28 is calculated. It is determined whether or not this amount of positional deviation is equal to or less than the first threshold value, and if it is equal to or less than the first threshold value, the above-mentioned step S2 is performed. The above operation is performed to detect the positional deviation. This is repeated until the amount is below the first threshold.

[0040] The first threshold is preferably set to, for example, 1 μm. The threshold (which can be called the “second threshold”) used when performing alignment in this embodiment (alignment performed with the substrate 27 and the mask 16 in contact with each other at their protruding portions) is set to a value smaller than the first threshold.

[0041] <<Step S3>> After the convex portion provided on at least one of the mask 16 and the substrate 27 is brought into contact with the other (step S2), the alignment camera 7 photographs the alignment marks (mask mark 29 and substrate mark 28) of the mask 16 and the substrate 27. From the image data obtained by this photographing, the XY distance of the alignment marks is measured. In general, the mask mark 29 and the substrate mark 28 are photographed while being spaced apart in the Z direction, but since the alignment camera 7 that photographs has a subject depth, the smaller the separation distance, the smaller the measurement error. In the case of this embodiment, the alignment camera 7 photographs the mask 16 and the substrate 27 while the convex portion provided on at least one of the mask 16 and the substrate 27 is brought into contact with the other in step S2, so the separation distance is short and the measurement error can be reduced. In addition, when the mask 16 is then sucked to bring the mask 16 and the substrate 27 into full contact (contact), the positional deviation of the alignment mark can be suppressed.

[0042] <<Step S4>> Based on the calculation result (measurement result) obtained in step S3, the substrate 27 is moved by being driven by the magnetic levitation stage 2 (see FIG. 8(c)). After the substrate 27 has moved, the mask mark 29 of the mask 16 and the substrate mark 28 of the substrate 27 are photographed by the alignment camera 7. From the image data obtained by this photographing, the distance between the alignment marks (the distance between the center of the mask mark 29 and the center of the substrate mark 28) is measured (calculated). If this distance (error) is equal to or less than the threshold, the process proceeds to step S5. If it is not equal to or less than the threshold, the magnetic levitation stage 2 is moved again, and the same operation is repeated until the threshold is reached. As described above, when the modified example shown in FIG. 10 is adopted, this threshold corresponds to the second threshold.

[0043] <<Step S5>> In step S4, if the distance between the alignment marks is equal to or less than the threshold value, the suction magnet 18 is lowered to bring the mask 16 and the substrate 27 into full contact with each other (see FIG. 8(d)). In this way, in this embodiment, the suction force for attracting the mask 16 changes (increases) as the suction magnet 18 is lowered. As a result, a part of the mask 16 (the part where the convex portion is provided) contacts the substrate 27, and the other part changes from a state in which the other part is separated from the substrate 27 to a state in which the other part is also in contact with the substrate 27. In other words, the mask 16 and the substrate 27 are in full contact (close contact) with each other except for the vicinity of the periphery of the convex portion. Note that, as described above, when a configuration in which the convex portion is provided only on the mask frame 15 is adopted, the convex portion can be brought into contact with the substrate 27 only by the operation of raising the mask stage 33 by the mask guide mechanisms 12a, 12b, etc., and then the mask 16 can be attracted by the suction magnet 18 to bring the mask 16 and the substrate 27 into full contact with each other.

[0044] When the mask 16 and the substrate 27 are brought into close contact with each other over their entire surfaces, these misalignments may occur. That is, misalignments in the XY directions may occur between the alignment marks. However, in this embodiment, the mask 16 and the substrate 27 have already been brought into contact with each other at the convex portions in step S2. Therefore, even in the portions where a gap exists between the mask 16 and the substrate 27, the distance is small, and it is possible to reduce the amount of misalignment in the XY directions that occurs when the mask 16 and the substrate 27 are brought into close contact with each other over their entire surfaces.

[0045] <<Step S6>> After the mask 16 and the substrate 27 are brought into full contact with each other, the alignment camera 7 photographs the mask mark 29 of the mask 16 and the substrate mark 28 of the substrate 27. The distance between the alignment marks is measured (calculated) from the image data obtained by this photographing. If this distance (error) is equal to or less than the threshold, the alignment is completed, and film formation (deposition) is started. If a positional deviation in the XY directions occurs due to step S5 and is not equal to or less than the target threshold, the attraction magnet 18 is raised to release the full contact state between the mask 16 and the substrate 27, and the process returns to step S4, where the same operation is repeated until the target threshold is reached. The threshold here may be the same as the threshold in step S4, or may be a value slightly larger than that in step S4.

[0046] <Advantages of the alignment apparatus, alignment method, and film formation apparatus according to the present embodiment> According to this embodiment, at least one of the mask 16 and the substrate 27 is provided with a convex portion, and measurement is performed by the measuring means (alignment cameras 7a, 7b, and control unit 35) while the convex portion is in contact with the other. As a result, even in a portion where a gap occurs between the mask 16 and the substrate 27, the gap is short, so that the distance in the Z direction between the mask mark 29 and the substrate mark 28 is short, and measurement errors can be reduced. Also, in this embodiment, a driving operation (alignment operation between the mask 16 and the substrate 27) is performed by the magnetic levitation stage 2 as a driving means while the convex portion is in contact with the other. Therefore, when the mask 16 and the substrate 27 are brought into full contact (contact) thereafter, positional deviation between the mask 16 and the substrate 27 can be suppressed. Therefore, the alignment accuracy between the substrate 27 and the mask 16 is improved.

[0047] In this embodiment, the configuration is shown in which the measurement is performed by the measuring means and the driving operation is performed by the driving means in a state where the convex portion is in contact with the other. This can effectively improve the alignment accuracy between the substrate 27 and the mask 16. However, it is also possible to adopt a configuration in which the measurement is performed by the measuring means in a state where the convex portion is in contact with the other, and then the driving operation is performed by the driving means in a state where the convex portion is separated from the other. Even in this case, the alignment accuracy can be improved by improving the measurement accuracy. It is also possible to adopt a configuration in which the measurement is performed by the measuring means in a state where the convex portion is not in contact with the other, and then the driving operation is performed by the driving means in a state where the convex portion is in contact with the other. Even in this case, when the mask 16 and the substrate 27 are then brought into full contact (contact) with each other, the positional deviation between the mask 16 and the substrate 27 can be suppressed, and therefore the alignment accuracy between the substrate 27 and the mask 16 is improved.

[0048] In this embodiment, a configuration in which a magnetic levitation stage 2 that moves the substrate 27 is used as a driving means for changing the relative position between the substrate 27 and the mask 16 (performing an alignment operation). However, the driving means of the present invention is not limited to such a configuration, and it is sufficient to adopt a configuration that drives at least one of the mask support means and the substrate support means so as to change the relative position between the substrate and the mask. Therefore, a configuration may be adopted in which a means (mechanism) for moving the mask is provided without moving the substrate, or both a means (mechanism) for moving the substrate and a means (mechanism) for moving the mask may be adopted. The same applies to the following embodiments.

[0049] As described above, it is also preferable to perform the first alignment step and the second alignment step according to the flowchart of the alignment according to the modified example shown in FIG. 10. The first alignment is an alignment for making the amount of misalignment between the substrate 27 and the mask 16 by the magnetic levitation stage 2 equal to or less than the first threshold value when the substrate 27 and the mask 16 are not in contact with each other. The second alignment is an alignment for making the amount of misalignment between the substrate 27 and the mask 16 by the magnetic levitation stage 2 equal to or less than the first threshold value when the convex portion is in contact with the other. This is an alignment for making the thickness of the mask 16 and the substrate 27 equal to or less than the threshold value of 2. By adopting such a process, even if the mask 16 and the substrate 27 are positioned in a state where they are in contact with each other, the amount of relative movement between them can be shortened. This makes it possible to suppress the occurrence of damage due to friction.

[0050] Example 2 Fig. 11 shows a second embodiment of the present invention. In this embodiment, the configuration of the attraction magnet 18 as the attraction means is different from that of the first embodiment. Since the other configurations and functions are the same as those of the first embodiment, the same components are given the same reference numerals and the description thereof will be omitted as appropriate.

[0051] Fig. 11 is a diagram showing the positional relationship between the substrate 27, mask 16, and attraction magnet 18 in the alignment operation according to this embodiment. The alignment flow in this embodiment differs from the flow chart shown in Fig. 7 described in the first embodiment or the flow chart shown in Fig. 10 only in the operations of steps S2 and S5. Therefore, these flow charts will also be used for the explanation.

[0052] In this embodiment, the attraction magnet 18 as the attraction means has a first attraction means for bringing the substrate 27 and the mask 16 into contact with each other by the convex portion in step S2, and a second attraction means for bringing another portion of the mask 16 into contact with the substrate 27 in step S5. More specifically, the first attraction means is a first magnet 181 movably provided on the opposite side of the substrate 27 to the mask 16, and the second attraction means is a second magnet 182 movably provided on the opposite side of the substrate 27 to the mask 16. The second magnet 182 is configured to be movable independently of the first magnet 181.

[0053] In this embodiment, after the substrate 27 is lowered to a predetermined position by step S1 shown in FIG. 7 or FIG. 10 (see FIG. 11(a)), the first magnet 181 is lowered. As a result, a part of the mask 16 (near the convex portion) is attracted to the attraction magnet 18, and similarly to the first embodiment, the part of the mask 16 (the part where the convex portion is provided) comes into contact with the substrate 27, and the other part of the mask 16 is separated from the substrate 27 (see FIG. 11(b)). Thereafter, up to step S4, the same as in the first embodiment, the substrate 27 is moved by the driving of the magnetic levitation stage 2, and the substrate 27 and the mask 16 are positioned (see FIG. 11(c)).

[0054] Then, in step S5, the first magnet 181 remains in its current state while the second magnet 182 descends, thereby attracting other parts of the mask 16. As a result, the mask 16 and the substrate 27 are brought into full contact with each other (see FIG. 11(d)). The other steps are as described in the first embodiment above.

[0055] As described above, the present embodiment can also provide the same effects as those of the first embodiment. Furthermore, in the case of the present embodiment, the divided regions of the attraction magnet 18 (regions divided by the first magnet 181 and the second magnet 182) can be set appropriately. That is, the first magnet 181 may be provided at a position corresponding to the portion where the convex portion is provided, and the second magnet 182 may be provided at a position away from the convex portion. This makes it possible to more reliably bring only the convex portion into contact with the other in step S2, as compared to the first embodiment.

[0056] Example 3 12 shows a third embodiment of the present invention. In this embodiment, the suction means is an electrostatic chuck. The other configurations and functions are the same as those of the first embodiment, so the same components are given the same reference numerals and the description thereof is omitted as appropriate.

[0057] 12 is a schematic diagram of a magnetic levitation stage according to a third embodiment of the present invention. In the first embodiment, the attraction means is an attraction magnet 18, whereas in the present embodiment, the attraction means is an electrostatic chuck 25 for attracting the substrate 27 and the mask 16 by electrostatic attraction force, which is the only difference from the first embodiment.

[0058] The electrostatic adsorption force changes depending on the change in the voltage applied to electrostatic chuck 25. Therefore, by controlling the applied voltage, it is possible to achieve a state in which only substrate 27 is attracted to electrostatic chuck 25, a state in which substrate 27 and mask 16 are in contact with each other at the protruding portions in addition to substrate 27, and a state in which both are attracted entirely and substrate 27 and mask 16 are in close contact with each other entirely.

[0059] The alignment flow in this embodiment differs from the flow chart shown in Fig. 7 described in the first embodiment or the flow chart shown in Fig. 10 only in the operations of steps S2 and S5. Therefore, the alignment flow according to this embodiment will be described using these flow charts.

[0060] 7 or 10, after the substrate 27 has been lowered to a predetermined position, the voltage applied to the electrostatic chuck 25 is increased to a value higher than the voltage for attracting only the substrate 27. As a result, the mask 16 is attracted to the electrostatic chuck 25 while the substrate 27 remains attracted to the electrostatic chuck 25. As a result, similar to the first embodiment, the mask 16 and the substrate 27 come into contact with each other at the protruding portions, and the other portions of the mask 16 are separated from the substrate 27. Thereafter, the process up to step S4 is similar to the first embodiment, and the substrate 27 is moved by the driving force of the magnetic levitation stage 2, and the substrate 27 and the mask 16 are positioned relative to each other.

[0061] Then, in step S5, the voltage applied to the electrostatic chuck 25 is further increased, so that the mask 16 is attracted with a stronger force, and the mask 16 and the substrate 27 are brought into full contact with each other. The other steps are as described in the above embodiment 1. As described above, in this embodiment as well, the same effects as those in the above embodiment 1 can be obtained.

[0062] Example 4 13 shows a fourth embodiment of the present invention. In this embodiment, the configuration of the electrostatic chuck 25 as the suction means is different from that of the third embodiment. Since the other configurations and functions are the same as those of the first embodiment, the same components are denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0063] 13 is a schematic diagram of a magnetic levitation stage according to a fourth embodiment of the present invention. In the first embodiment, the attraction means is an attraction magnet 18, whereas in the present embodiment, as in the third embodiment, the attraction means is an electrostatic chuck 25 for attracting the substrate 27 and the mask 16 by electrostatic attraction force, which is the only difference from the first embodiment.

[0064] In this embodiment, the electrostatic chuck 25 as the suction means has a first suction means for bringing the substrate 27 and the mask 16 into contact with each other by the convex portion in step S2, and a second suction means for bringing another portion of the mask 16 into contact with the substrate 27 in step S5. More specifically, the first suction means is a first electrostatic chuck 251 for attracting the substrate 27 and the mask 16 by electrostatic attraction force. The second suction means is a second electrostatic chuck 252, the voltage applied to which is controlled independently of the first electrostatic chuck 251, for attracting the substrate 27 and the mask 16 by electrostatic attraction force.

[0065] The alignment flow in this embodiment is different from the flow chart shown in FIG. 7 described in the first embodiment or the flow chart shown in FIG. 10 only in the operations of steps S2 and S5. Therefore, using these flow charts, The flow of alignment related to the above will be described.

[0066] In this embodiment, after the substrate 27 is lowered to a predetermined position by step S1 shown in FIG. 7 or FIG. 10, the voltage applied to the first electrostatic chuck 251 is increased to a voltage higher than the voltage for attracting only the substrate 27. As a result, a part of the mask 16 (near the convex portion) is attracted to the first electrostatic chuck 251 while the substrate 27 is still attracted to the electrostatic chuck 25 (the first electrostatic chuck 251 and the second electrostatic chuck 252). As a result, as in the first embodiment, a part of the mask 16 (near the convex portion) comes into contact with the substrate 27, and the other part of the mask 16 is separated from the substrate 27. Thereafter, up to step S4, the process is the same as in the first embodiment, and the substrate 27 is moved by the driving of the magnetic levitation stage 2, and the substrate 27 and the mask 16 are positioned.

[0067] Then, in step S5, the voltage applied to the second electrostatic chuck 252 is increased to a value higher than the voltage for attracting only the substrate 27. As a result, other portions of the mask 16 are also attracted, resulting in a state in which the mask 16 and the substrate 27 are in close contact with each other over their entire surfaces. The other steps are as described in the first embodiment above.

[0068] As described above, the present embodiment can also provide the same effects as those of the above-described first embodiment. Moreover, in the present embodiment, the divided regions of the electrostatic chuck 25 (regions divided by the first electrostatic chuck 251 and the second electrostatic chuck 252) can be appropriately set. That is, the first electrostatic chuck 251 may be provided at a position corresponding to the portion where the convex portion is provided, and the second electrostatic chuck 252 may be provided at a position away from the convex portion. This makes it possible to more reliably bring only the convex portion into contact with the other in step S2, as compared to the first embodiment.

[0069] (Electronic device manufacturing method) An example of an apparatus and method for manufacturing an electronic device using the film forming apparatus according to the above embodiment will be described below. As an example of an electronic device, the configuration and manufacturing method of an organic EL display device will be illustrated below. First, the organic EL display device to be manufactured will be described. Fig. 14(a) shows an overall view of an organic EL display device 50, and Fig. 14(b) shows the cross-sectional structure of one pixel.

[0070] As shown in FIG. 14(a), a plurality of pixels 52 each including a plurality of light-emitting elements are arranged in a matrix in a display area 51 of an organic EL display device 50. Although details will be described later, each light-emitting element has a structure including an organic layer sandwiched between a pair of electrodes. Note that the pixel here refers to the smallest unit that allows a desired color to be displayed in the display area 51. In the case of the organic EL display device according to this embodiment, the pixel 52 is configured by a combination of a first light-emitting element 52R, a second light-emitting element 52G, and a third light-emitting element 52B that emit light different from each other. The pixel 52 is often configured by a combination of a red light-emitting element, a green light-emitting element, and a blue light-emitting element, but may also be a combination of a yellow light-emitting element, a cyan light-emitting element, and a white light-emitting element, and is not particularly limited as long as it is at least one color.

[0071] Fig. 14(b) is a schematic partial cross-sectional view taken along the line AB in Fig. 14(a). The pixel 52 has an organic EL element including a first electrode (anode) 54, a hole transport layer 55, light-emitting layers 56R, 56G, and 56B, an electron transport layer 57, and a second electrode (cathode) 58 on a substrate 53. Among these, the hole transport layer 55, the light-emitting layers 56R, 56G, and 56B, and the electron transport layer 57 correspond to organic layers. In this embodiment, the light-emitting layer 56R is an organic EL layer that emits red light, the light-emitting layer 56G is an organic EL layer that emits green light, and the light-emitting layer 56B is an organic EL layer that emits blue light. The light-emitting layers 56R, 56G, and 56B are formed in patterns corresponding to light-emitting elements (sometimes referred to as organic EL elements) that emit red, green, and blue lights, respectively. The first electrode 54 is formed separately for each light-emitting element. The hole transport layer 55, the electron transport layer 57, and the second electrode 58 may be formed in common with the plurality of light emitting elements 52R, 52G, and 52B, or may be formed separately for each of the light emitting elements 52R, 52G, and 52B. Alternatively, an insulating layer 59 may be formed for each optical element. In order to prevent the first electrode 54 and the second electrode 58 from shorting due to foreign matter, an insulating layer 59 is provided between the first electrodes 54. Furthermore, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer 60 is provided to protect the organic EL element from moisture and oxygen.

[0072] 14(b), the hole transport layer 55 and the electron transport layer 57 are shown as a single layer, but they may be formed of multiple layers including a hole blocking layer and an electron blocking layer depending on the structure of the organic EL display element. In addition, a hole injection layer having an energy band structure that can smoothly inject holes from the first electrode 54 to the hole transport layer 55 can be formed between the first electrode 54 and the hole transport layer 55. Similarly, an electron injection layer can be formed between the second electrode 58 and the electron transport layer 57.

[0073] Next, an example of a method for manufacturing an organic EL display device will be specifically described.

[0074] First, a substrate 53 on which a circuit (not shown) for driving the organic EL display device and a first electrode 54 are formed is prepared.

[0075] An acrylic resin is formed by spin coating on the substrate 53 on which the first electrode 54 is formed, and the acrylic resin is patterned by lithography so as to form an opening in the portion where the first electrode 54 is formed, thereby forming an insulating layer 59. This opening corresponds to the light-emitting region where the light-emitting element actually emits light.

[0076] The substrate 53 on which the insulating layer 59 has been patterned is carried into a film forming apparatus, and the substrate is supported by a substrate supporting means, and a hole transport layer 55 is formed as a common layer on the first electrodes 54 in the display area. The hole transport layer 55 is formed by vacuum deposition. In practice, the hole transport layer 55 is formed to be larger than the display area 51, so that a high-definition mask is not required.

[0077] Next, the substrate 53 on which the hole transport layer 55 has been formed is carried into another film forming apparatus and supported by a substrate support means. The substrate and the mask are aligned, the substrate is placed on the mask, and a red light emitting layer 56R is formed on the portion of the substrate 53 where the red light emitting element is to be disposed. In the same manner as the formation of the light emitting layer 56R, a green light emitting layer 56G is formed by another film forming apparatus, and a blue light emitting layer 56B is formed by another film forming apparatus. After the formation of the light emitting layers 56R, 56G, and 56B is completed, an electron transport layer 57 is formed on the entire display area 51 by yet another film forming apparatus. The electron transport layer 57 is formed as a layer common to the three light emitting layers 56R, 56G, and 56B.

[0078] The substrate on which the electron transport layer 57 has been formed is transferred to a sputtering device, where the second electrode 58 is formed, and then transferred to a plasma CVD device where the protective layer 60 is formed, thereby completing the organic EL display device 50.

[0079] If the substrate 53 on which the insulating layer 59 is patterned is exposed to an atmosphere containing moisture or oxygen from the time when it is carried into the film forming apparatus until the formation of the protective layer 60 is completed, the light emitting layer made of an organic EL material may be deteriorated by moisture or oxygen. Therefore, in this example, the substrate is carried in and out of the film forming apparatus in a vacuum atmosphere or an inert gas atmosphere. [Explanation of symbols]

[0080] 1: Film forming device 2: Magnetic levitation stage 5: Evaporation source 6: Stage support 7, 7a, 7b: Alignment camera 8: Support frame 9a, 9b: Vibration isolation table 10a, 10b: Vibration isolation table base 12a, 12b: Mask guide mechanism 13a, 13b: Mask support column 15: Mask frame 16: Mask 17: Laser displacement meter 18: Attractive magnet 25 :Electrostatic chuck 27: Substrate 27a: Convex portion 28, 28L, 28R: Substrate mark 29, 29L, 29R: Mask mark 31: Stage frame 33: Mask table 181: First magnet 182: Second magnet 251: First electrostatic chuck 252: Second electrostatic chuck

Claims

1. A mask support means for supporting a mask, A substrate support means for supporting the substrate, A measuring means for measuring the relative positional relationship between the substrate and the mask, A driving means drives at least one of the mask support means and the substrate support means to change the relative position of the substrate and the mask based on the measurement results of the measuring means, An alignment device comprising, An alignment device characterized in that at least one of the mask and the substrate is provided with a protrusion, and at least one of measurement by the measuring means and driving operation by the driving means is performed with the protrusion in contact with the other.

2. The alignment apparatus according to claim 1, characterized in that in the region excluding the convex portion, at least one of measurement by the measuring means and driving operation by the driving means is performed with the mask and the substrate separated.

3. The alignment apparatus according to claim 1 or 2, characterized in that, after the driving operation by the driving means is performed, an operation is performed to bring the substrate and the mask into full contact.

4. The alignment apparatus according to claim 1 or 2, further comprising a suction means for drawing the mask toward the substrate.

5. The alignment device according to claim 4, wherein the suction means is a magnet that is movable on the opposite side of the mask via the substrate, and the suction force that attracts the mask changes as the magnet moves.

6. The alignment apparatus according to claim 4, wherein the suction means is an electrostatic chuck for adsorbing the substrate and the mask by electrostatic adsorption force, and the suction force for adsorbing the mask changes depending on the voltage applied to the electrostatic chuck.

7. The aforementioned suction means is A first suction means for bringing the protrusion into contact with the other, A second suction means for bringing the substrate and the mask into full contact, The alignment device according to claim 4, characterized by having the following:

8. The first suction means is a first magnet that is movably mounted on the substrate on the side opposite to the mask, The alignment device according to claim 7, characterized in that the second suction means is a second magnet that is movably provided on the opposite side of the mask via the substrate and is movably provided independently of the first magnet.

9. The first suction means is a first electrostatic chuck for adsorbing the substrate and the mask by electrostatic adsorption force, The alignment apparatus according to claim 7, characterized in that the second suction means is a second electrostatic chuck whose applied voltage is controlled independently of the first electrostatic chuck, and which is used to attract the substrate and the mask by electrostatic attraction force.

10. An alignment method characterized by performing alignment between the substrate and the mask using the alignment apparatus described in claim 1 or 2.

11. A first alignment step in which, without the substrate and the mask being in contact, the driving means is used to align the substrate and the mask so that the amount of misalignment between the substrate and the mask is less than or equal to a first threshold, A second alignment step is performed by aligning the substrate and the mask using the driving means, with the convex portion in contact with the other, such that the amount of misalignment between the substrate and the mask is less than or equal to a second threshold value smaller than the first threshold, The alignment method according to claim 10, characterized by having the following:

12. The alignment device according to claim 1 or 2, A film deposition source for forming a thin film on the aforementioned substrate, A film deposition apparatus characterized by comprising the following features.

13. The film deposition apparatus according to claim 12, wherein the substrate is cut out after a thin film is formed by the film deposition source, and the protrusions are provided outside the cut-out area of ​​the substrate.

14. The film deposition apparatus according to claim 12, wherein the substrate is cut out after a thin film is formed by the film deposition source, and the protrusions are provided at a position in the mask that contacts an area outside the range in which the substrate is cut out.

15. A method for manufacturing an electronic device, characterized by manufacturing an electronic device using the film deposition apparatus described in Claim 12.

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