Film deposition apparatus, film deposition method and method for manufacturing electronic device

Abstract

To provide a film deposition apparatus and film deposition method, capable of enhancing the positioning accuracy of a mask, and a method for manufacturing an electronic device.SOLUTION: A film deposition apparatus 1 forms a thin film on a substrate held by an electrostatic chuck through a mask 16 held on a mask frame 15 placed on a mask stand 33 by a film deposition material discharged from an evaporation source 5 in a chamber. Kinematic coupling fitting positions the mask stand 33 and the mask frame 15, and the mask 16 has a protrusion pressed when positioning the mask frame 15 on the mask stand 33.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film forming apparatus, a film forming method, and a method for manufacturing an electronic device.

Background Art

[0002] Organic EL display devices (organic EL displays) are widely used not only in smartphones, TVs, and automotive displays, but also in applications such as VR HMDs (Virtual Reality Head-Mounted Displays). In particular, displays used in VR HMDs are required to form pixel patterns with high precision, such as reducing user dizziness, and further higher resolution is demanded.

[0003] In the manufacture of an organic EL display device, when forming an organic light-emitting element (organic EL element; OLED) that constitutes the organic EL display device, a film-forming material emitted from a film-forming source is deposited on a substrate through a mask on which a pixel pattern is formed, thereby forming an organic layer or a metal layer.

[0004] In order to deposit the film-forming material emitted from an evaporation source installed on the lower surface of a vacuum chamber on a substrate through a mask, the film-forming material accumulates on the mask by repeating the film formation. Therefore, it is necessary to replace the mask every time a film is formed on the substrate a predetermined number of times. At this time, it is necessary to discharge the mask on which the film-forming material has accumulated from the vacuum chamber and accurately install a new mask at a predetermined position.

[0005] As a method for accurately positioning the mask, the kinematic coupling technique is known (see Patent Document 1). As the kinematic coupling technique, several methods are known. For example, by providing a kinematic coupling in which three V-grooves and a spherical seat are fitted to constrain six degrees of freedom, high-precision positioning can be performed.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 5-267116 [Summary of the Invention] [Problems to be Solved by the Invention]

[0007] A kinematic coupling enables high-precision positioning when multiple locations are properly fitted. However, if there are locations that are not properly fitted due to some influence, high-precision positioning cannot be achieved.

[0008] An object of the present invention is to provide a film-forming apparatus, a film-forming method, and a method for manufacturing an electronic device that can improve the positioning accuracy of a mask. [Means for Solving the Problems]

[0009] The film-forming apparatus of the present invention is a film-forming apparatus that forms a thin film on a substrate held by a substrate holding member through a mask held by a mask holding member placed on a mask stage by a film-forming material emitted from a film-forming source in a chamber, wherein the mask stage and the mask holding member are positioned by fitting a plurality of kinematic mounts, and any one of the mask, the mask holding member, the substrate, and the substrate holding member is provided with a convex portion that is pressed when the mask holding member is positioned on the mask stage. [Effects of the Invention]

[0010] As described above, according to the present invention, the positioning accuracy of the mask can be improved. [Brief Description of the Drawings]

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, with reference to the drawings, the mode for carrying out this invention will be exemplarily and specifically described based on examples. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this example are not intended to limit the scope of this invention only to these, unless otherwise specifically described.

[0013] (Example 1) With reference to FIGS. 1 to 4, a film forming apparatus, a film forming method, and a method for manufacturing an electronic device according to Embodiment 1 of the present invention will be described. Note that the XYZ axes are shown in FIGS. 1 to 3. The Z axis is an axis parallel to the vertical direction, and the XY axes are parallel to the horizontal direction and perpendicular to each other.

[0014] <Film forming apparatus> With reference to FIG. 1, the film forming apparatus 1 according to this embodiment will be described. FIG. 1 is a schematic configuration diagram of the film forming apparatus 1 according to Embodiment 1, schematically showing the configuration of the film forming apparatus 1 as viewed from the front. In FIG. 1, a magnetic levitation stage 2 as a stage is provided in the portion surrounded by the dotted line. The magnetic levitation stage 2 is fixed to the upper corner of the inner surface or the upper side surface of the vacuum chamber as a chamber by a stage support 6. The vacuum chamber is composed of a vacuum chamber side surface 3, a vacuum chamber bottom surface 32, and a vacuum chamber top plate 11, and generally has a hexahedral configuration as a whole. A thin film is formed on the substrate through a mask 16 by a film forming material released from an evaporation source 5 as a film forming source installed on the vacuum chamber bottom surface 32. The mask 16 has magnetism and is configured to be attracted by a suction magnet 18 as a magnet that can move up and down relative to the magnetic levitation stage 2. Note that the suction magnet 18 is configured to be able to move up and down by an elevating mechanism 18X. For the elevating mechanism 18X, various known techniques such as a ball screw mechanism and a rack and pinion mechanism can be adopted. The position of the magnetic levitation stage 2 is configured to be controllable based on the measurement result by a laser displacement meter 17 installed on a mask stage 33. Further, the film forming apparatus 1 is controlled It has a control unit 35. The control unit 35 has functions to control various mechanisms, the evaporation source 5, and film formation. The control unit 35 can be constituted by, for example, a computer having a processor, a memory, a storage, I / O, etc. In this case, the functions of the control unit 35 are realized by the processor executing a program stored in the memory or the 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, part or all of the functions of the control unit 35 may be constituted by a circuit such as an ASIC or an FPGA. Note that a control unit 35 may be provided for each film forming apparatus 1, or one control unit 35 may control a plurality of film forming apparatuses 1.

[0015] Next, the configuration of the vibration isolation table support part 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, so that the vibration transmitted from the vacuum chamber is suppressed. Further, the mask table 33 is supported in the vacuum chamber by the mask support columns 13a, 13b that move up and down by the mask guide mechanisms 12a, 12b provided on the support frame 8. The mask frame 15 as a mask holding member is carried into the apparatus by a robot hand (not shown) and placed on the mask table 33.

[0016] When the robot hand enters and exits the apparatus to carry the mask frame 15 and the substrate into the apparatus, the mask table 33 is lowered by the mask guide mechanisms 12a, 12b to a position that does not obstruct the movement of the robot hand. When the mask guide mechanisms 12a, 12b move up and down, the bellows 14a, 14b expand and contract. By these bellows 14a, 14b, the vacuum state in the chamber is maintained.

[0017] In addition, when the positioning accuracy by the robot hand or the misalignment during placement of the mask or the like is large, a rotation and translation mechanism may be required in addition to the vertical drive in order to place the mask or the like within the camera field of view. Since this is a known technique, its description will be omitted.

[0018] Also, the alignment cameras 7a and 7b are supported by the support frame 8. As a result, the vibration transmitted from the vacuum chamber to the alignment cameras 7a and 7b is suppressed, enabling high-precision measurement. An alignment measurement viewport is installed on the chamber top plate 11, allowing alignment measurement from the atmosphere side. Note that by using the transmitted light of the illuminations 24a and 24b installed on the lower surface of the mask stage 33, the alignment marks 102a, 102b, 102c, and 102d (see FIG. 4) are photographed by the alignment cameras 7a and 7b. Four alignment cameras and illuminations (including those not shown) are installed respectively, configured to detect the positions of the alignment marks formed on the substrate.

[0019] <Magnetic levitation stage> The magnetic levitation stage 2 will be described with reference to FIGS. 2 and 3. FIG. 2 is an enlarged view of the magnetic levitation stage 2 in FIG. 1, and FIG. 3 is a view of the magnetic levitation stage 2 seen from above. In FIG. 3, in order to clarify the positional relationship between the mover and the stator, etc., the stator provided on the stage support 6 and the suction magnet 18 are also shown.

[0020] The magnetic levitation stage 2 includes a stage frame 31, and self-weight compensation magnet movers 22a, 22b, 22c, 22d and linear motor movers 20a, 20b, 20c, 20d fixed to the stage frame 31. The self-weight compensation magnet movers 22a, 22b, 22c, 22d serve to support the magnetic levitation stage 2 in a non-contact state with respect to the stage support 6 in order to cancel the self-weight of the magnetic levitation stage 2. The linear motor movers 20a, 20b, 20c, 20d are in a non-contact state with respect to the stage support 6, and magnetically It plays a role in exerting a thrust force to move the levitation stage 2. Further, an electrostatic chuck 25 as a substrate holding member is fixed to the lower surface of the magnetic levitation stage 2. By this electrostatic chuck 25, the substrate 27 to be film-formed can be adsorbed in a face-down state.

[0021] On the lower surface of the stage support 6, self-weight compensation magnet stators 23a, 23b, 23c, 23d are fixed so as to face the above-described self-weight compensation magnet rotors 22a, 22b, 22c, 22d, respectively. A magnetic force corresponding to the self-weight of the magnetic levitation stage 2 is configured to be generated between the rotor and the stator of the self-weight compensation magnet, and the magnetic levitation stage 2 is supported by the stage support 6 in a non-contact state.

[0022] Also, on the lower surface of the stage support 6, linear motor stators 21a, 21b, 21c, 21d are fixed so as to face the above-described linear motor rotors 20a, 20b, 20c, 20d, respectively. A thrust force for moving the magnetic levitation stage 2 is generated by a change in the current value flowing through the coils built in these linear motor stators 21a, 21b, 21c, 21d. In the vertical direction, since the self-weight of the magnetic levitation stage 2 is canceled by the above-described self-weight compensation magnet, the thrust force generated by the linear motor can be made small. Therefore, since the amount of energization can be small, the amount of heat generated by energization is small, and problems such as deformation and breakage of each member due to heat generation do not occur. However, if necessary, each coil may be covered with a water-cooling jacket and a refrigerant may be flowed to actively cool it.

[0023] The linear motor movers 20a, 20b, 20c, and 20d are arranged at four corners on the upper surface of the stage frame 31. Thereby, the XY-direction translational drive and the rotational drive around the Z-axis of the magnetic levitation stage 2 are possible. Also, by arranging at least three or more linear motors (not shown) that generate thrust in the Z-axis direction, it is possible to move the magnetic levitation stage 2 with six degrees of freedom. In this embodiment, the magnetic levitation stage 2 is configured to be moved with six degrees of freedom by the linear motors arranged at a total of seven locations. Further, the self-weight compensation magnet movers 22a, 22b, 22c, and 22d are arranged symmetrically at four locations around the center of gravity of the magnetic levitation stage 2. Thereby, a moment force can be applied, so that the magnetic levitation stage 2 can be stably levitated.

[0024] <Alignment mechanism> The alignment mechanism (positioning mechanism) between the substrate 27 and the mask 16 will be described. The relative position of the magnetic levitation stage 2 with respect to the mask stage 33 is measured by the laser displacement meter 17. This laser displacement meter 17 is arranged at a total of six locations, such as two locations in the X direction, one location in the Y direction, and three locations in the Z direction. Geometric coordinate transformation is performed based on the information from the six laser displacement meters 17 arranged, and it is converted into the position with six degrees of freedom around the center of gravity of the magnetic levitation stage 2. Control calculation is performed based on the position information with six degrees of freedom, and a thrust command with six degrees of freedom is determined. Based on the thrust command with six degrees of freedom, current is passed through the coils of each of the seven linear motors arranged, and by moving the magnetic levitation stage 2, it is possible to position the magnetic levitation stage 2 with high precision with respect to the mask stage 33.

[0025] Further, the laser displacement meter 17 is fixed in the vicinity of the mask 16 on the mask stage 33. Thereby, in the vacuum environment, the positioning between the mask 16 and the substrate 27 can be directly performed without being affected by Abbe error or the like. Further, since the vibration from the vacuum chamber is suppressed by the vibration isolators 9a and 9b on which the support frame 8 is placed via the mask stage 33, stable measurement is possible for the laser displacement meter 17. Further, the magnetic levitation stage 2 is supported by non-contact and low magnetic spring characteristic self-weight compensation magnets, and the vibration from the vacuum chamber is similarly suppressed. With the configuration as described above, the relative position between the magnetic levitation stage 2 and the mask stage 33 can be positioned with high precision. As a result, high-precision alignment between the substrate 27 and the mask 16 becomes possible.

[0026] <Mask and Substrate> The mask 16 and the substrate 27 will be described in more detail. A plurality of through holes corresponding to pixel patterns are provided at equal intervals in a plurality of locations on the mask 16, and the film forming material passing through the through holes is configured to be formed on the surface of the substrate 27. The material of the mask 16 is made of, for example, a metal foil that is resistant to thermal expansion such as invar or a membrane film obtained by thinly processing a Si wafer. The mask 16 is fixed to a mask frame 15 as a mask holding member, and is transported by a robot hand together with the frame and placed on the mask stage 33. As a method for fixing the mask 16 and the mask frame 15, various known techniques such as a method of fixing by spot welding in a stretched state, a mechanical clamp, and fixing by adhesion can be adopted. When fixing, it is desirable to prevent the mask 16 from being distorted.

[0027] The substrate 27 is held by an electrostatic chuck 25 as a substrate holding member. And the suction magnet 18 is configured to be approachable in a non-contact range to the surface of the electrostatic chuck 25 on the side opposite to the adsorption surface, and is configured to be able to generate the magnetic flux necessary for suction of the mask 16. The electrostatic chuck 25 and the substrate 27 are non-magnetic bodies, and it is possible to generate an attractive force that sucks the mask 16 vertically upward by the magnetic flux of the suction magnet 18. By this attractive force, the mask 16 can be brought into close contact with the substrate 27. By ensuring the adhesion here, it becomes possible to prevent the intrusion (shadow) of the film-forming material during film formation.

[0028] <Mask positioning with respect to the mask stage> With reference to FIGS. 4 to 8, the positioning of the mask 16 with respect to the mask stage 33 will be described. FIG. 4 is a view showing the mask 16 and the mask frame 15 according to the present embodiment, where FIG. 4(a) is a side view of the mask 16 and the mask frame 15, FIG. 4(b) is a top view of the mask 16 and the mask frame 15, and FIG. 4(c) is a bottom view of the mask 16 and the mask frame 15.

[0029] On the lower surface of the mask frame 15, spherical seats 100 (100a, 100b, 100c) as hemispherical surface portions constituting a kinematic coupling are provided at a plurality of locations (specifically, three locations). These spherical seats 100a, 100b, 100c are desirably installed at an equal angle of 120° or at positions corresponding thereto, based on the center of gravity of the mask 16 (which coincides with the center of the mask 16 and the center of the mask frame (the centroid in the plan view) in the present embodiment). On the upper surface of the mask 16, convex portions 101 (101a, 101b, 101c) are provided. Also, alignment marks 102a, 102b, 102c, 102d are provided on the mask 16, and as described above, they are photographed by an alignment camera during alignment.

[0030] FIG. 5 is a diagram showing the mask stage 33 according to the present embodiment, where FIG. 5(a) is a side view of the mask stage 33 and FIG. 5(b) is a top view of the mask stage 33. On the top surface of the mask stage 33, a plurality of (specifically, three) groove portions constituting a kinematic coupling are provided. This groove portion is constituted by V-groove portions 110 (110a, 110b, 110c) having a pair of side surfaces whose distances from each other narrow as they approach the groove bottom.

[0031] As described above, in the present embodiment, the ball seats 100 constituting the kinematic coupling are provided on the lower surface of the mask frame 15, and the groove portions (V-groove portions 110) are provided on the upper surface of the mask stage 33. When the mask 16 is placed on the mask stage 33, the ball seats 100 are fitted into the V-groove portions 110, resulting in a kinematic coupling in which the relative positioning of the six degrees of freedom between the mask frame 15 and the mask stage 33 is achieved, and the positioning is performed with high precision. In the present embodiment, the ball seats 100 are provided on the mask frame 15, and the mask stage 33 shows a configuration in which groove portions are provided. However, a configuration in which ball seats constituting the kinematic coupling are provided on the mask stage 33 and groove portions constituting the kinematic coupling are provided on the mask frame 15 can also be adopted. Further, in the present embodiment, as the kinematic coupling, the configuration in the case of ball seats and V-groove portions is shown, but the kinematic coupling is not limited to these configurations, and other known techniques can also be adopted.

[0032] In the present embodiment, illuminations 24a, 24b, 24c, 24d are embedded in the mask stage 33. In the case of the present embodiment, the illuminations 24a, 24b, 24c, 24d irradiate the alignment marks 102a, 102b, 102c, 102d, and alignment is performed by photographing the transmitted light. Since the alignment method using alignment marks is a known technique, its description is omitted.

[0033] As described above, by repeatedly forming a film on the substrate 27, a film-forming material accumulates on the mask 16. Therefore, it is necessary to replace the mask 16 every time a film is formed on the substrate 27 a predetermined number of times. As described with reference to FIG. 1, by lowering the mask stage 33 together with the mask support columns 13a and 13b by the mask guide mechanisms 12a and 12b, the gap between the electrostatic chuck 25 holding the substrate 27 and the mask stage 33 is widened. In that state, a robot hand (not shown) enters the apparatus, the mask frame 15 is carried out from the mask stage 33, and a new mask frame 15 is placed on the mask stage 33.

[0034] FIG. 6 shows an example of a state in which the kinematic coupling is fitted (a state in which the spherical seat 100 and the V-groove portion 110 are fitted). When the V-groove portion 110 and the spherical seat 100 of the kinematic coupling are in contact with each other at two contact points 120a and 120b (see FIG. 6(a)), six-degree-of-freedom positioning is achieved, and the mask frame 15 and the mask 16 can be accurately positioned with respect to the mask stage 33. However, when the mask frame 15 is placed by the robot hand, depending on the positioning accuracy of the transfer robot, the V-groove portion 110 and the spherical seat 100 may be in a state of contacting at one contact point 120c as shown in FIG. 6(b). It is desirable to apply a coating for reducing the friction coefficient to the surfaces of the V-groove portion 110 and the spherical seat 100 so that the mask frame 15 slides due to its own weight from the one-point contact state shown in FIG. 6(b) to the two-point contact state shown in FIG. 6(a).

[0035] However, even if a coating is applied, due to wear of the coating or the like, it may sometimes enter the single-point contact state shown in Fig. 6(b). Therefore, in this embodiment, even when the mask frame 15 does not slide under its own weight and does not assume the state shown in Fig. 6(a), a method is adopted in which the kinematic coupling is properly fitted (the ball seat 100 and the V-groove portion 110 are properly fitted). That is, in this embodiment, when the mask frame 15 is positioned on the mask table 33, the convex portion 101 provided on the upper surface of the mask 16 is pressed, so that even if the mask frame 15 does not slide under its own weight, the configuration shown in Fig. 6(a) is adopted. Hereinafter, this point will be described in more detail.

[0036] Fig. 7 is a diagram for explaining the arrangement relationship between the kinematic coupling and the convex portion. (a) is a plan view of the mask and the like, and (b) is a side view of the mask and the like. In Fig. 4, the case where the outer shapes of the mask frame 15 and the mask 16 are substantially the same dimensional shape is shown, but in Fig. 7, the case where the outer dimension of the mask frame 15 is configured to be larger than the outer dimension of the mask 16 is shown. The convex portions 101 (101a, 101b, 101c) provided on the upper surface of the mask 16 are arranged at positions offset toward the center of gravity G of the mask 16 from the kinematic coupling (the ball seat 100 and the V-groove portion 110). More specifically, when viewed in the direction perpendicular to the surface of the mask 16, the convex portion 101 is arranged within a triangular region (see the grid-like hatched portion in Fig. 7(a)) connecting the center of gravity G and both ends on the center of gravity G side of the mask at both ends in the groove width direction of a pair of side surfaces in the V-groove portion 110.

[0037] If the convex portion 101S is arranged on the side opposite to the center of gravity G of the mask with respect to the kinematic coupling (see Fig. 8(a)), when a pressing force FS acts on the convex portion 101S toward the mask table 33, a moment MS in the direction in which the ball seat 100 moves away from the V-groove portion 110 acts. As a result, the fitting between the ball seat 100 and the V-groove portion 110 may become unstable. Therefore, it is desirable to arrange the convex portion 101 on the center of gravity G side of the mask rather than the kinematic coupling.

[0038] Also, even if the convex portion is arranged closer to the center of gravity G of the mask than the kinematic coupling, when the convex portion 101T is arranged outside the width direction R than the lattice-shaped hatching region shown in FIG. 7(a) (see FIG. 8(b)), when a pressing force FT acts on the convex portion 101T toward the mask table 33, a moment MT in the direction in which the spherical seat 100 moves away from the V-groove portion 110 acts. As a result, the fitting between the spherical seat 100 and the V-groove portion 110 may become unstable. Therefore, it is desirable to arrange the convex portion 101 within the range of the width direction R described above. Thereby, as shown in FIG. 8(b), when a pressing force F acts on the convex portion 101 toward the mask table 33, the spherical seat 100 can be moved toward the groove bottom of the V-groove portion 110.

[0039] As described above, it is desirable to arrange the convex portion 101 within the lattice-shaped hatching portion in FIG. 7(a). Further, in the present embodiment, as shown in FIG. 7(a), a configuration is adopted in which the center of gravity G of the mask 16 and the convex portion 101 are aligned on a straight line where a pair of side surfaces of the V-groove portion 110 intersect. Thereby, when a pressing force acts on the convex portion 101 toward the mask table 33, the spherical seat 100 can be more reliably moved toward the groove bottom of the V-groove portion 110. That is, the state can be more reliably shifted from the state shown in FIG. 6(b) to the state shown in FIG. 6(a).

[0040] In the present embodiment, the configuration in the case where the convex portion 101 is provided on the mask 16 has been shown. However, a configuration in which a convex portion that exhibits a similar function is provided on a member other than the mask 16 can also be adopted. For example, a configuration in which the convex portion 101 is provided on the mask frame 15, such as the convex portions 101ax, 101bx, 101cx shown in FIG. 7(a), can also be adopted. Also, a configuration in which the convex portion 101 is provided on the substrate 27, such as the convex portion 101by shown in FIG. 7(b), can also be adopted. Further, a configuration in which the convex portion 101 is provided on the electrostatic chuck 25, such as the convex portions 101az, 101cz shown in FIG. 7(c), can also be adopted. Of course, even when the convex portion 101 is provided on any of the mask frame 15, the substrate 27, and the electrostatic chuck 25, it is desirable that the convex portion 101 be arranged within the lattice-shaped hatching portion in FIG. 7(a).

[0041] As described above, in the film forming apparatus 1 according to this embodiment, the convex portion 101 is pressed when the mask frame 15 is positioned on the mask table 33. That is, the control unit 35 performs control to press the convex portion 101 when the mask frame 15 is positioned on the mask table 33. More specifically, the control unit 35 performs a tracing control for fitting the kinematic coupling by pressing the convex portion 101 when the mask frame 15 is positioned on the mask table 33 in accordance with the movement of the magnetic levitation stage 2. In addition, during this tracing control, the control unit 35 determines the fitting state of the kinematic coupling based on the position of the magnetic levitation stage 2, thereby making it possible for the ball seat 100 and the V-groove portion 110 to be more reliably fitted to each other.

[0042] <Operation flow> With reference to Fig. 9, an operation flow from when the substrate 27 is carried into the vacuum chamber and held by the electrostatic chuck 25 until film formation (deposition) is performed will be described. In the following description, the rotation axis around the X axis is the ωx axis, the rotation axis around the Y axis is the ωy axis, and the rotation axis around the Z axis is the ωz axis. In addition, in the flow shown in Fig. 9, impedance control is used as an example of tracking control. The following description will be given taking as an example a case where the above is adopted.

[0043] <<Step S1>> The mask table 33, which has been lowered for replacing the mask 16, is raised to a predetermined position.

[0044] <<Step S2>> The control mode of the magnetic levitation stage 2 is, for example, torque control for the Z axis and impedance control for the ωx and ωy axes. Then, the control is switched to dance control, and the substrate 27 is made to conform to the protrusions 101a, 101b, and 101c provided on the upper surface of the mask 16 and pressed against the mask 16 with a predetermined force (pressing step). This allows the substrate 27 to conform to all three protrusions on the upper surface of the mask 16.

[0045] <<Step S3>> When the substrate 27 is made to follow the convex portions 101a, 101b, and 101c, it is determined whether the coordinates of the Z-axis, ωx-axis, and ωy-axis of the magnetic levitation stage 2 are all within a predetermined range or outside the range. If all are within the range, it is determined that all three points of the kinematic coupling are in a two-point contact state (the state shown in FIG. 6(a)), and the process proceeds to step S5. If one or more are outside the range, it is determined that at least one of the kinematic couplings is in a one-point contact state (for example, the state shown in FIG. 6(b)), and the process proceeds to step S4. Thus, in step S3, during the following control, based on the position of the magnetic levitation stage 2, the fitting state of the kinematic coupling is determined.

[0046] <<Step S4>> The ωx-axis and ωy-axis are changed to the position control mode, and with the magnetic levitation stage 2 returned to horizontal, the pressing force of the Z-axis torque control is increased by a predetermined amount to press the mask. Then, the pressing force of the Z-axis torque control is returned to the initial set value, and the process returns to step S2 to perform the same operation again. In step S3, the same operation is repeated until it is determined that the coordinates of the Z-axis, ωx-axis, and ωy-axis of the magnetic levitation stage 2 are all within the predetermined range. Thereby, in all three points of the kinematic coupling, a two-point contact state can be achieved.

[0047] <<Step S5>> The coordinates of the Z-axis, ωx-axis, and ωy-axis of the magnetic levitation stage 2 when the substrate 27 is made to follow the convex portions 101a, 101b, and 101c are memorized. The Z-axis, ωx-axis, and ωy-axis are changed to the position control mode, the memorized coordinates of the ωx-axis and ωy-axis are held, and the Z-axis is moved to a position raised by a predetermined amount from the memorized coordinate. Thereby, regardless of the mechanical differences between the substrate 27 and the mask 16, a high-precision parallelism and gap between the substrate 27 and the mask 16 can be created, and alignment is performed in a non-contact state. By this alignment, the position adjustment between the mask 16 and the substrate 27 is performed in a direction parallel to the horizontal direction (X direction and Y direction) without rotation of the substrate 27 around the ωx-axis and ωy-axis.

[0048] <<Step S6>> The control mode of the magnetic levitation stage 2 is switched, for example, to torque control for the Z-axis and impedance control for the ωx and ωy axes, causing the substrate 27 to follow the convex portions 101a, 101b, and 101c provided on the upper surface of the mask 16 and performing alignment while pressing against them with a predetermined force. As a result, alignment is performed in a state where the gap between the substrate 27 and the mask 16 is narrower than in step S5, enabling higher-precision alignment. If the substrate 27 follows the convex portions 101a, 101b, and 101c, the substrate 27 and the mask 16 are parallel. Therefore, after changing the ωx and ωy axes to the position control mode while pressing the Z-axis against the substrate 27 with a predetermined force in the torque control state, alignment may be performed. After that, the ωx and ωy axes are changed to the position control mode, and alignment is performed while pressing the Z-axis against the substrate 27 with a predetermined force in the torque control state. It may be performed.

[0049] <<Step S7>> As described above, in this embodiment, alignment is performed between the substrate 27 and the mask 16 in a non-contact state (step S5), and then, more precise alignment is performed in a state where the substrate 27 and the mask 16 are slightly in contact (step S6). After that, in step S7, the suction magnet 18 is lowered, and film formation (deposition) is performed in a state where the substrate 27 and the mask 16 are in complete contact (film formation step).

[0050] In this embodiment, while changing the torque of the Z-axis of the magnetic levitation stage 2 according to the position of the suction magnet 18, the suction magnet 18 is lowered, the mask 16 is suctioned and brought into close contact with the substrate 27, and then deposition is performed. The reason for changing the torque of the Z-axis will be described below. When the suction magnet 18 descends and suctions the mask 16, the magnetic levitation stage 2 receives a force from the mask 16 and is pushed back. An example of the relationship between the position of the suction magnet 18 and the force received by the magnetic levitation stage 2 from the mask 16 is shown in Fig. 10(a). Fig. 10(b) is an explanatory diagram of the force received by the magnetic levitation stage 2 from the mask 16 and is a diagram schematically showing the magnetic levitation stage 2 and the like. As can be seen from these figures, since the suction magnet 18 suctions the mask 16 upward, depending on the position of the suction magnet 18, the force F received by the magnetic levitation stage 2 from the mask 16 MIt changes. And the force F with which the magnetic levitation stage 2 presses against the mask frame 15 weakens from the Z-axis torque Fz of the stage as shown in the following formula (1). F = Fz - F M (1) The force F that the magnetic levitation stage 2 receives from the mask 16 M When the force F that the magnetic levitation stage 2 receives from the mask 16 becomes larger than the Z-axis torque Fz of the stage, the magnetic levitation stage 2 may move away from the mask frame 15. Therefore, it is desirable to change the Z-axis torque of the magnetic levitation stage 2. Thus, a relational expression between the position of the suction magnet 18 and the force that the magnetic levitation stage 2 receives from the mask 16 (corresponding to the contact force between the substrate 27 and the mask 16), or a table thereof, is stored in advance in a memory or the like, and it is desirable for the control unit 35 to change the Z-axis torque of the magnetic levitation stage 2 according to the position of the suction magnet 18. That is, the relationship between the position of the suction magnet 18 and the contact force between the substrate 27 and the mask 16 is stored in advance, and in the control unit 35, based on this relationship, it is desirable to change the Z-axis torque Fz so that the force F for bringing the substrate 27 and the mask frame 15 into contact by the magnetic levitation stage 2 becomes constant. Also, when the alignment between the substrate 27 and the mask 16 is misaligned during the process of the suction magnet 18 descending, if it is before the mask adheres tightly to the substrate 27, alignment may be performed at the position where the suction magnet 18 is descending during its descent.

[0051] As described above, in the flow shown in FIG. 9, the case where impedance control is adopted as the imitation control is shown. However, for the imitation control, controls other than impedance control can also be adopted. Hereinafter, with reference to FIGS. 11 to 13, other examples in the imitation control will be described. Here, an example of performing a thrust command based on the speed of the magnetic levitation stage 2 and performing feedback control for adding a predetermined force to the thrust command will be described. FIG. 11 shows the control block of the magnetic levitation stage 2. The output of the six-degree-of-freedom controller is coordinate-transformed into the thrust of each linear motor, the magnetic levitation stage 2 is given thrust, and the position detected by the laser displacement meter is coordinate-transformed into a six-degree-of-freedom position and fed back, thereby performing position control of the magnetic levitation stage 2. FIG. 12 shows the configuration of the controller for each axis. The controller for each axis is a PID control composed of the sum of a value obtained by multiplying the proportional gain Kp of the position, a value obtained by multiplying the integral gain Ki by the integral value of the position, and a value obtained by multiplying the differential gain Kd by the differential value of the position, and the torque command shown in FIG. 12 can be added only to the Z axis. When making the substrate 27 follow the convex portions 101a, 101b, 101c of the mask 16, the proportional gain Kp and the integral gain Ki of the Z axis, ωx, and ωy axes are set to zero. By doing so, it becomes a feedback control mode of differentiating the position, that is, the speed. FIG. 13 shows the concept of the force action during the imitation control. When the torque command F is added so that the Z axis descends, initially, as shown in FIG. 13(a), the speed is zero and only the downward force F is applied. After that, the magnetic levitation stage 2 starts to move downward. If the speed command is set to zero, as shown in FIG. 13(b) a force Fr acts in the reverse direction (upward) of the speed, and after the force in this reverse direction balances the torque command, it descends at an inertial speed v. When the substrate 27 and the mask 16 come into contact, the speed becomes zero again. Therefore, as shown in FIG. 13(c), only the torque command F can be applied to the mask 16. Since no torque command is given to the ωx and ωy axes, the ωx and ωy axes are tilted so that an equal force is applied to the convex portions 101a, 101b, 101c of the mask 16, and an imitation operation is performed.

[0052] As described above, according to the film forming apparatus 1 and the film forming method according to this embodiment, the positioning accuracy of the mask frame 15 and the mask 16 with respect to the mask stage 33 can be improved. Along with this, the film forming accuracy on the substrate 27 can be improved.

[0053] (Example 2) Examples 2 of the present invention are shown in FIGS. 14 and 15. In Example 1, a configuration in which convex portions are provided on the mask was shown. In contrast, in the present embodiment, a configuration is shown in which convex portions are provided on the mask frame, and an opening is provided in the mask so that the convex portions can be inserted. Since the other configurations and operations are the same as those in Example 1, the description of the same components will be omitted as appropriate.

[0054] FIG. 14 is a diagram showing a mask and a mask frame according to Example 2, FIG. 14(a) is a plan view thereof, and FIG. 14(b) is a side view thereof. FIG. 15 is a side view of a substrate, a mask, and a mask frame according to Example 2, and shows a state in which the mask is attracted by a magnet.

[0055] Also in the present embodiment, a mask 403 is fixed to a mask frame 401 as a mask holding member. In the present embodiment, the outer peripheral portions of the mask frame 401 and the mask 403 are fixed by a joint portion 404. Also in the present embodiment, spherical seats 402 (402a, 402b, 402c) as hemispherical portions constituting a kinematic coupling are provided at a plurality of locations (specifically, three locations) on the lower surface of the mask frame 401.

[0056] In this embodiment, convex portions 405 (405a, 405b, 405c) are provided on the upper surface of the mask frame 401. And the mask 403 is provided with openings 406 (406a, 406b, 406c) which do not contact the convex portions 405 and are configured such that the convex portions 405 can be inserted therein. The openings 406 are sized to ensure sufficient clearance so that the mask 403 and the convex portions 405 maintain non-contact. The convex portions 405 are arranged closer to the center of the mask than the joint portion 404 provided on the outer periphery of the mask, and the openings 406 are provided in accordance with the arrangement of the convex portions 405.

[0057] FIG. 15 shows a state in which the convex portion 405 provided on the mask frame 401 is in contact with the substrate 407 held by the electrostatic chuck 408 as a substrate holding member. In the state shown in FIG. 14(b), when the convex portion 405 is in contact with the substrate 407, the gap between the substrate 407 and the upper surface of the mask frame 401 is controlled by the convex portion 405. In that state, by lowering a suction magnet (not shown), the mask 403 is suctioned and brought into close contact with the substrate 407, resulting in the state shown in FIG. 15. In the case of this embodiment, by providing the convex portion 405 on the mask frame 401 which is easier to ensure rigidity and flatness than the mask 403, it becomes easy to control the relative height accuracy of the convex portion 405, and the gap amount between the substrate 407 and the mask 403 can be controlled with higher precision. Further, by providing the openings 406 in the mask 403, the convex portion 405 does not contact the mask 403, so that deformation of the mask 403 is not inhibited. Thereby, the mask 403 can be adsorbed to the substrate 407 without impairing the alignment accuracy between the mask 403 and the substrate 407 performed before suctioning the mask 403.

[0058] In this embodiment, the configuration in the case where the convex portion is provided on the mask frame 401 is shown. However, a configuration in which the convex portion is provided on the substrate 407 or the electrostatic chuck 408 can also be adopted. Also in this case, the mask 403 may be provided with an opening that does not come into contact with the convex portion and is configured such that the convex portion can be inserted. By adopting such a configuration, the convex portion contacts the mask frame 401 without contacting the mask 403. Even when the above configuration is adopted, the same effects as those of this embodiment can be obtained.

[0059] In addition, in the first and second embodiments, by setting the number of convex portions to three, the contact points between the substrate and the mask frame are reproduced on one plane. Thereby, the gap amount between the substrate and the mask can be managed with high precision. However, in the case where a configuration with a large deformation due to the self-weights of the substrate and the mask frame is adopted, it is not necessarily required to have three convex portions, and the flatness of the substrate and the mask frame due to self-weight deformation may be suppressed by providing four or more convex portions.

[0060] <Method for manufacturing an electronic device> An example of a method for manufacturing an electronic device using the film forming apparatus 1 according to each of the above embodiments will be described. Hereinafter, the configuration and manufacturing method of an organic EL display device will be exemplified as an example of the electronic device. First, the organic EL display device to be manufactured will be described. FIG. 16(a) is an overall view of the organic EL display device 560, and FIG. 16(b) shows a cross-sectional structure of one pixel.

[0061] As shown in Fig. 16(a), in the display area 561 of the organic EL display device 560, a plurality of pixels 562 each including a plurality of light-emitting elements are arranged in a matrix. Although details will be described later, each of the light-emitting elements has a structure including an organic layer sandwiched between a pair of electrodes. Here, the pixel refers to the minimum unit capable of displaying a desired color in the display area 561. In the case of the organic EL display device according to this embodiment, the pixel 562 is constituted by a combination of a first light-emitting element 562R, a second light-emitting element 562G, and a third light-emitting element 562B that exhibit different emissions. The pixel 562 is often constituted 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 or more.

[0062] Fig. 16(b) is a partial cross-sectional schematic view taken along line A-B in Fig. 16(a). The pixel 562 has an organic EL element including a first electrode (anode) 564, a hole transport layer 565, one of light-emitting layers 566R, 566G, 566B, an electron transport layer 567, and a second electrode (cathode) 568 on a substrate 563. Among these, the hole transport layer 565, the light-emitting layers 566R, 566G, 566B, and the electron transport layer 567 correspond to the organic layer. In this embodiment, the light-emitting layer 566R is an organic EL layer that emits red light, the light-emitting layer 566G is an organic EL layer that emits green light, and the light-emitting layer 566B is an organic EL layer that emits blue light. The light-emitting layers 566R, 566G, 566B are formed in patterns corresponding to light-emitting elements (sometimes described as organic EL elements) that emit red, green, and blue light, respectively. The first electrode 564 is formed separately for each light-emitting element. The hole transport layer 565, the electron transport layer 567, and the second electrode 568 may be formed in common with a plurality of light-emitting elements 562R, 562G, 562B, or may be formed for each light-emitting element. In order to prevent the first electrode 564 and the second electrode 568 from being short-circuited by foreign matter, an insulating layer 569 is provided between the first electrodes 564. Further, since the organic EL layer deteriorates due to moisture and oxygen, a protective layer 570 for protecting the organic EL element from moisture and oxygen is provided.

[0063] In FIG. 16(b), the hole transport layer 565 and the electron transport layer 567 are shown as a single layer, but depending on the structure of the organic EL display element, it may be formed of a plurality of layers including a hole blocking layer and an electron blocking layer. Also, between the first electrode 564 and the hole transport layer 565, a hole injection layer having an energy band structure can be formed. Similarly, an electron injection layer can also be formed between the second electrode 568 and the electron transport layer 567.

[0064] Next, an example of a method for manufacturing an organic EL display device will be specifically described. First, a substrate 563 on which a circuit (not shown) for driving the organic EL display device and a first electrode 564 are formed is prepared.

[0065] An acrylic resin is spin-coated on the substrate 563 on which the first electrode 564 is formed, and the acrylic resin is patterned by a lithography method so that an opening is formed in the portion where the first electrode 564 is formed to form an insulating layer 569. This opening corresponds to the light-emitting region where the light-emitting element actually emits light.

[0066] The substrate 563 on which the insulating layer 569 is patterned is carried into a first film-forming apparatus, the substrate is held by a substrate support unit, and the hole transport layer 565 is formed as a common layer on the first electrode 564 in the display region. The hole transport layer 565 is formed by vacuum evaporation. Actually, since the hole transport layer 565 is formed in a size larger than the display region 561, a high-definition mask is not required.

[0067] Next, the substrate 563 on which the hole transport layer 565 is formed is carried into a second film-forming apparatus and held by a substrate support unit. Alignment (first alignment and second alignment) between the substrate and the mask is performed, the substrate is placed on the mask, and a light-emitting layer 566R that emits red light is formed in the portion where the element that emits red light of the substrate 563 is arranged.

[0068] Similar to the formation of the light-emitting layer 566R, a light-emitting layer 566G that emits green light is formed by a third film-forming apparatus, and further, a light-emitting layer 566B that emits blue light is formed by a fourth film-forming apparatus. After the formation of the light-emitting layers 566R, 566G, and 566B is completed, an electron transport layer 567 is formed over the entire display region 561 by a fifth film-forming apparatus. The electron transport layer 567 is formed as a layer common to the three-color light-emitting layers 566R, 566G, and 566B.

[0069] The substrate on which up to the electron transport layer 567 is formed is transferred to a sputtering apparatus to form the second electrode 568, and then transferred to a plasma CVD apparatus to form the protective layer 570, completing the organic EL display device 560.

[0070] From the time when the substrate 563 on which the insulating layer 569 is patterned is loaded into the film-forming apparatus until the formation of the protective layer 570 is completed, if exposed to an atmosphere containing moisture or oxygen, the light-emitting layer made of an organic EL material may be deteriorated by moisture or oxygen. Therefore, in this example, the loading and unloading of the substrate between the film-forming apparatuses are performed under a vacuum atmosphere or an inert gas atmosphere.

Explanation of Reference Numerals

[0071] 1: Film-forming apparatus 2: Magnetic levitation stage 5: Evaporation source 6: Stage support 15: Mask frame 16: Mask 18: Suction magnet 18X: Lifting mechanism 25: Electrostatic chuck 27: Substrate 31: Stage frame 33: Mask table 35: Control unit 100: Ball seat 101: Convex portion 110: V-groove portion 401: Mask frame 402: Ball seat 403: Mask 405: Convex portion 406: Opening 407: Substrate 408: Electrostatic chuck G: Center of gravity

Claims

1. A film forming apparatus for forming a thin film on a substrate held by a substrate holding member through a mask held by a mask holding member placed on a mask stage by a film forming material emitted from a film forming source in a chamber, wherein the mask stage and the mask holding member are positioned by fitting a kinematic coupling, and a convex portion that is pressed when the mask holding member is positioned on the mask stage is provided on any one of the mask, the mask holding member, the substrate, and the substrate holding member. A film forming apparatus characterized by that.

2. A stage for moving the substrate holding member to perform relative position adjustment between the substrate and the mask is provided, With the movement of the stage, following control for fitting the kinematic coupling is performed by pressing the convex portion. The film forming apparatus according to claim 1, characterized by that.

3. The film forming apparatus according to claim 2, characterized in that the fitting state of the kinematic coupling is determined based on the position of the stage during the following control.

4. In the following control, a thrust command based on the speed of the stage is performed, and feedback control for adding a predetermined force to the thrust command is performed. The film forming apparatus according to claim 2, characterized by that.

5. A magnet for sucking the mask through the substrate, A lifting mechanism for lifting and lowering the magnet, is provided, When sucking the mask with the magnet, the force for bringing the substrate and the mask into contact with each other by the stage is changed according to the position of the magnet lifted and lowered by the lifting mechanism. The film forming apparatus according to claim 2, characterized by that.

6. The relationship between the position of the magnet and the contact force between the substrate and the mask is stored in advance, and based on the relationship, the force for bringing the substrate and the mask into contact with each other by the stage is changed. The film forming apparatus according to claim 5, characterized by that.

7. The convex portion is arranged at a position offset toward the center of gravity side of the mask from the fitting portion of the kinematic coupling. The film forming apparatus according to claim 1, characterized by that.

8. The fitting portion of the kinematic coupling is provided on one of the mask stage and the mask holding member, and is composed of a groove portion having a pair of side surfaces whose distances from each other narrow as they go toward the groove bottom, and a hemispherical portion provided on the other, and When viewed in a direction perpendicular to the surface of the mask, the convex portion is disposed within a triangular region connecting both ends on the center-of-gravity side of the mask at both ends in the groove width direction of the pair of side surfaces and the center of gravity, according to the film forming apparatus of claim 1.

9. The film forming apparatus according to claim 8, wherein the center of gravity of the mask and the convex portion are aligned on a straight line where the pair of side surfaces intersect.

10. The convex portion is provided on any one of the mask holding member, the substrate, and the substrate holding member, and The mask is provided with an opening that does not come into contact with the convex portion and is configured such that the convex portion can be inserted, according to the film forming apparatus of claim 1.

11. A film forming method for forming a thin film on a substrate held by a substrate holding member through a mask held by a mask holding member placed on a mask stage with a film forming material emitted from a film forming source in a chamber, comprising: The mask stage and the mask holding member are configured to be positionable by fitting of a kinematic coupling, A pressing step of pressing a convex portion provided on any one of the mask, the mask holding member, the substrate, and the substrate holding member when the mask holding member is positioned on the mask stage; A film forming step of forming a thin film on the substrate through the mask; A film forming method characterized by including the above steps.

12. The film forming method according to claim 11, wherein when positioning the mask holding member on the mask stage by moving a stage for relatively adjusting the position of the substrate and the mask, the convex portion is pressed to perform imitation control for fitting the kinematic coupling.

13. The film forming method according to claim 12, wherein during the imitation control, the fitting state of the kinematic coupling is determined based on the position of the stage.

14. The film forming method according to claim 12, wherein in the imitation control, a thrust command based on the speed of the stage is performed, and feedback control of adding a predetermined force to the thrust command is performed.

15. Using a magnet for sucking the mask through the substrate and an elevating mechanism for elevating the magnet, When sucking the mask with the magnet, the method of forming a film according to claim 12, characterized in that the force for bringing the substrate and the mask into contact with each other by the stage is changed according to the position of the magnet lifted and lowered by the lifting mechanism.

16. A method for manufacturing an electronic device, characterized by manufacturing an electronic device using the method of forming a film according to any one of claims 11 to 15.

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