JP2018527455A - Apparatus and method for transporting a carrier or substrate - Google Patents

Abstract

An apparatus for non-contact transfer of a deposition source is provided. The apparatus includes a deposition source assembly. The deposition source assembly includes a deposition source. The deposition source assembly includes a first active magnetic unit. The apparatus includes a guiding structure extending in the source transport direction. The deposition source assembly is movable along the guiding structure. The first active magnetic unit and the guiding structure are configured to provide a first magnetic buoyancy for levitating the deposition source assembly. [Selection] FIGS. 1A, 1B, and 1C

Description

  [0001] Embodiments of the present disclosure relate to an apparatus and method for transporting a carrier or substrate, more specifically, a carrier or substrate for layer deposition on a large area substrate.

  [0002] Several methods for depositing material on a substrate are known. As an example, the substrate can be coated by using a vapor deposition process, a physical vapor deposition (PVD) process such as a sputtering process or a spray process, or a chemical vapor deposition (CVD) process. The process can be performed in a processing chamber of a deposition apparatus in which a substrate to be coated is placed. Deposition material is provided in the treatment chamber. Multiple materials such as small molecules, metals, oxides, nitrides, and carbides can be used for deposition on the substrate. In addition, other processes such as etching, structuring, annealing, etc. can be performed in the processing chamber.

  [0003] For example, the coating process can be considered for large area substrates, for example, in display manufacturing technology. Coated substrates can be used in some applications and in several technical fields. For example, one application may be an organic light emitting diode (OLED) panel. Further applications include insulating panels, microelectronics such as semiconductor devices, substrates with thin film transistors (TFTs), color filters, and the like. An OLED is a solid-state device composed of a thin film of (organic) molecules that emit light when applied with electricity. As an example, an OLED display can provide a bright display of electronic devices and can reduce power consumption compared to, for example, a liquid crystal display (LCD). Within the processing chamber, organic molecules are generated (eg, evaporated, sputtered, or sprayed, etc.) and deposited as a layer on the substrate. To deposit material at a desired location on the substrate, for example to form an OLED pattern on the substrate, the particles may pass through a mask having, for example, a boundary or a specific pattern.

  [0004] The alignment of the substrate relative to the mask and the quality of the processed substrate (specifically the quality of the deposited layer) can be provided. As an example, the alignment should be accurate and stable in order to achieve good processing results. Systems used for substrate and mask alignment may be susceptible to external interference such as vibration. Furthermore, the alignment system can increase the cost of ownership.

  [0005] In view of the above, there is a need for an apparatus that can provide improved control of carrier or substrate transport during a layer deposition process.

  [0006] According to one embodiment, a method for non-contact alignment of a carrier assembly is provided. The method includes levitating the carrier assembly within a vacuum chamber and moving the carrier assembly while levitating to position the carrier assembly relative to a predetermined location, particularly a mask or mask carrier. Aligning the carrier assembly with respect to the mask or mask carrier in at least one direction selected from the group consisting of: substrate transport direction, vertical direction + -15 ° first direction, and combinations thereof. Including.

  [0007] According to another embodiment, a method of processing a substrate of a carrier assembly is provided. The method includes a method of non-contact alignment of a carrier assembly, wherein the mask or mask carrier is positioned in a vacuum chamber and the substrate is processed in the vacuum chamber. A method of non-contact alignment of a carrier assembly includes floating the carrier assembly in a vacuum chamber and floating the carrier assembly to position the carrier assembly relative to a predetermined position, particularly a mask or mask carrier. And the carrier with respect to the mask or the mask carrier in at least one direction selected from the group consisting of a substrate transport direction, a vertical direction of + -15 ° in the vertical direction, and combinations thereof. Aligning the assembly.

  [0008] According to another embodiment, an apparatus for non-contact alignment of a carrier assembly and a mask or mask carrier relative to each other within a vacuum chamber of a substrate processing system is provided. The apparatus includes an induction structure having a plurality of active magnetic units in the vacuum chamber, the induction structure configured to float the carrier assembly in the vacuum chamber, and a plurality of further in the vacuum chamber. A drive structure having an active magnetic unit, the drive structure configured to drive a carrier assembly along a transport direction without mechanical contact, and a mask, substrate, or in a vacuum chamber Two or more alignment actuators that contact the mask and the substrate, a guidance structure, a drive structure, and a controller connected to the two or more alignment actuators, the guidance structure and the drive structure Multiple pre-alignment and mechanical alignment using two or more alignment actuators. Configured to control the gas unit and a plurality of further active magnetic unit, and a controller, including.

  [0009] In order to provide a thorough understanding of the above features of the present disclosure, a more detailed description of the present disclosure, briefly summarized above, may be obtained by reference to embodiments. The accompanying drawings relate to embodiments of the present disclosure and are described below.

FIG. 4 shows a schematic side view of an apparatus for transporting a carrier assembly, such as a carrier loaded with a substrate on a surface, in a substrate processing system according to an embodiment of the present disclosure. 1B shows a top view of the device according to FIG. 1A. FIG. 1B shows another side view of the device according to FIG. 1A. 1 illustrates an apparatus, such as a substrate processing system, including an apparatus for transporting a carrier assembly according to an embodiment of the present disclosure. FIG. 5 shows a schematic side view of transport of a carrier assembly, such as a carrier loaded with a substrate on a surface, according to an embodiment of the present disclosure. FIG. 6 shows a schematic side view illustrating a method of aligning a substrate in a substrate processing system, according to an embodiment of the present disclosure. FIG. 6 shows a schematic diagram of a mask or mask configuration that may be utilized in combination with an apparatus for transporting a carrier assembly or within a substrate processing system, according to embodiments of the present disclosure. FIG. 6 shows a schematic diagram of a mask or mask configuration that may be utilized in combination with an apparatus for transporting a carrier assembly or within a substrate processing system, according to embodiments of the present disclosure. FIG. 3 shows a schematic diagram of a holding configuration for supporting a substrate carrier and a mask carrier during layer deposition in a processing chamber, according to embodiments described herein. FIG. 4 shows a cross-sectional view of a holding configuration for supporting a substrate carrier and a mask carrier during layer deposition in a processing chamber, according to embodiments described herein. FIG. 6 shows a schematic diagram of a holding configuration for supporting a substrate carrier and a mask carrier during layer deposition in a processing chamber, according to further embodiments described herein. FIG. 6 shows a flow diagram illustrating a method of aligning a carrier assembly and a mask with respect to each other according to an embodiment of the present disclosure.

  [0010] Reference will now be made in detail to various embodiments of the disclosure. One or more examples of these embodiments are shown in the figures. In the following description of the drawings, the same reference numerals represent the same components. Only the differences will be described with respect to the individual embodiments. While examples are provided as illustrations of the present disclosure, the examples are not intended to limit the present disclosure. Moreover, features illustrated or described as part of one embodiment can be used in other embodiments or in combination with other embodiments to create additional embodiments. Is possible. It is intended that the specification include such modifications and variations.

  [0011] Embodiments described herein relate to non-contact levitation, transport, and / or alignment of a carrier or substrate. The present disclosure refers to a carrier assembly that includes one or more elements of the group consisting of a carrier supporting a substrate, a carrier without a substrate, a substrate, or a substrate supported by a support. May be included. The term “contactless” throughout this disclosure can be understood in the sense that the weight of the carrier and substrate, etc., is not held by mechanical contact or mechanical force, but is held by magnetic force. Specifically, the carrier assembly is held in a floating or floating state using magnetic force instead of mechanical force. As an example, the apparatus described herein may not have mechanical means, such as mechanical rails, that support the weight of the deposition source assembly. In some implementations, there may be no mechanical contact between the carrier assembly and the rest of the device while the carrier assembly is floating (eg, moving) in the system.

  [0012] According to an embodiment of the present disclosure, levitation or levitation represents a state of an object in which the object is floating without mechanical contact or support. Furthermore, the movement of the object represents providing a driving force (eg, a force in a direction different from buoyancy), and the object moves from one position to another position (eg, another lateral position). To do. For example, an object such as a carrier assembly may be levitated by a force that reacts with gravity, for example, and may move in a direction different from the direction parallel to gravity while levitating.

  [0013] Non-contact flotation, transport, and / or alignment of a carrier assembly according to embodiments described herein is an apparatus, such as a deposition source assembly and a mechanical rail, during transport or alignment of the carrier assembly. This is advantageous in that there is no generation of particles due to mechanical contact with these parts. Thus, in particular, the embodiments described herein provide for the purity and uniformity of layer deposition on the substrate, since particle generation is minimized using non-contact flotation, transport, and / or alignment. Bring improvement.

  [0014] A further advantage over mechanical means for guiding the carrier assembly is that the embodiments described herein reduce frictional contributions that affect the linearity and / or accuracy of carrier assembly movement. It is not to receive. Non-contact transfer of the carrier assembly allows frictionless movement of the carrier assembly, and the alignment of the carrier assembly with respect to the mask can be controlled and maintained with high accuracy. Still further, levitation allows for quick acceleration and deceleration of the carrier assembly speed and / or fine adjustment of the carrier assembly speed.

  [0015] Furthermore, the material of the mechanical rail typically undergoes deformations that can be caused by evacuation of the chamber and by temperature, use, wear, and the like. Such deformation affects the positioning of the carrier assembly and thus the quality of the deposited layer. In contrast, the embodiments described herein make it possible, for example, to compensate for deformations that may occur in the guiding structures described herein. In view of the non-contact manner in which the carrier assembly is lifted and transported, the embodiments described herein allow non-contact alignment of the carrier assembly. Therefore, the alignment of the substrate with respect to the mask can be improved and the efficiency can be improved.

  [0016] According to embodiments that may be combined with other embodiments described herein, the apparatus may be along a vertical direction (eg, y direction) and / or along one or more transverse directions (eg, x direction). In addition, it is configured to be suitable for non-contact translation of the carrier assembly.

  [0017] Embodiments described herein allow non-contact rotation of the carrier assembly relative to at least one axis of rotation, for example to angularly align the carrier assembly with respect to the mask. Within an angular range of 0.003 degrees to 3 degrees, the deposition source assembly can be rotated relative to the axis of rotation. [0017] Embodiments described herein provide additional mechanical rotation (ie, rotation with contact) of the carrier assembly relative to at least one axis of rotation, eg, to angularly align the carrier assembly with respect to the mask. Enable. Within an angular range of 0.0001 degrees to 3 degrees, mechanical rotation of the deposition source assembly relative to the axis of rotation can occur.

  [0018] In the present disclosure, the term "substantially parallel" direction may include a plurality of directions that form a small angle of up to 10 degrees or 15 degrees from each other. Further, the phrase “substantially perpendicular” direction may include a plurality of directions that are at an angle of less than 90 degrees (eg, at least 80 degrees, or at least 75 degrees) to each other. Similar considerations apply to concepts such as substantially parallel or perpendicular axes, planes, regions, etc.

  [0019] Some embodiments described herein involve the concept of “vertical direction”. The vertical direction is considered to be a direction substantially parallel to the direction along the extension of gravity. The vertical direction can deviate from, for example, an angle of up to 15 degrees, strict verticality (defined by gravity). For example, the y direction (shown as “Y” in the figure) described in this document is the vertical direction. In particular, the y-direction shown defines the direction of gravity.

  [0020] Embodiments described herein may further entail the concept of “transversal direction”. It should be understood that the transverse direction is different from the vertical direction. The transverse direction can be perpendicular or substantially perpendicular to the exact vertical direction defined by gravity. For example, the x-direction and z-direction (denoted as “X” and “Z” in the figure) described in this document are transverse directions.

[0021] Embodiments described herein can be utilized to coat large area substrates, for example, for display manufacturing. The substrate or substrate receiving area for which the apparatus and methods described herein are provided may be a large area substrate. For example, large area substrates or carrier, corresponds to GEN4.5 corresponds to about 0.67 m ² substrate (0.73 × 0.92 m), about 1.4 m ² substrate (1.1 m × 1.3 m) GEN5 corresponding to an approximately 4.29 m ² substrate (1.95 m × 2.2 m), GEN 8.5 corresponding to an approximately 5.7 m ² substrate (2.2 m × 2.5 m), or GEN10 corresponding to a substrate of about 8.7 m ² (2.85 m × 3.05 m). Larger generations, such as GEN11 and GEN12, and corresponding substrate areas can be implemented as well.

  [0022] As used herein, the term "substrate" can encompass a substantially non-flexible substrate, such as a wafer, a transparent crystal flake such as sapphire, or a glass plate, among others. However, the present disclosure is not limited thereto, and the term “substrate” can also include flexible substrates such as webs and foils. It is understood that the phrase “substantially inflexible” is different from “flexible”. Specifically, a substantially non-flexible substrate such as a glass plate having a thickness of 0.5 mm or less may have a certain degree of flexibility, and the flexibility of a substantially non-flexible substrate is , Lower than the flexible substrate.

  [0023] The substrate may be made of any material suitable for material deposition. For example, the substrate consists of glass (eg, soda lime glass, borosilicate glass, etc.), metal, polymer, ceramic, composite material, carbon fiber material, or any other material or combination of materials that can be coated by a deposition process. It can be made of a material selected from the group.

  [0024] As shown in FIG. 1A, according to one embodiment, an apparatus 100 for non-contact transfer of a carrier assembly 110 and / or a substrate 120 is provided. The apparatus includes a carrier assembly 110. The carrier assembly 110 can include a substrate 120. The carrier assembly 110 includes a first passive magnetic unit 150. The apparatus includes a guiding structure 170 extending in the carrier assembly transport direction. The guidance structure includes a plurality of active magnetic units 175. The carrier assembly 110 is movable along the guide structure 170. A first passive magnetic unit 150, such as a rod of ferromagnetic material, and a plurality of active magnetic units of the guiding structure 170 are configured to provide a first magnetic buoyancy for levitating the carrier assembly 110. The levitation means described herein are, for example, means for providing a non-contact force that causes the carrier assembly to levitate.

  [0025] According to embodiments that may be combined with other embodiments described herein, the apparatus 100 may be disposed within a processing chamber. The processing chamber can be a vacuum chamber or a vacuum deposition chamber. In this document, the term “vacuum” can be understood to mean an industrial vacuum having a vacuum pressure of, for example, less than 10 mbar. The apparatus 100 may include one or more vacuum pumps, such as a turbo pump and / or a cryopump, connected to the vacuum chamber to generate a vacuum inside the vacuum chamber.

  [0026] FIG. 1A shows a side view of the device 100. FIG. The apparatus 100 includes a carrier assembly 110. In addition, the device includes a guiding structure 170. The apparatus can further include a drive structure 180. The drive structure includes a plurality of further active magnetic units. The carrier assembly may include a second passive magnetic unit 160 such as a rod of ferromagnetic material that interacts with a further active magnetic unit 185 of the drive structure 180. FIG. 1A shows a side view of the XY plane. FIG. 1B shows a top view of the device 100 of FIG. 1A. FIG. 1B shows the XZ plane. In FIG. 1B, a plurality of active magnetic units 175 are shown from an upper viewpoint. FIG. 1C shows another side view of the device 100. FIG. 1C shows the ZY plane. FIG. 1C shows one active magnetic unit 175 of the plurality of active magnetic units. The active magnetic unit 175 provides a magnetic force that interacts with the first passive magnetic unit 150 of the carrier assembly 110. For example, the first passive magnetic unit 150 may be a rod of ferromagnetic material. The rod can be a portion of the carrier assembly 110 that is connected to the support structure 112. Each of the rods or the first passive magnetic unit may be integrally formed with a support structure 112 for supporting the substrate 120. The carrier assembly 110 may further include a second passive magnetic unit 160 such as a further rod. Further rods can be connected to the carrier assembly 110. Each of the rods or second passive magnetic units may be integrally formed with the support structure 112.

  [0027] The term “passive” magnetic unit is used herein to distinguish from the concept of “active” magnetic unit. A passive magnetic unit may be an element having magnetic properties that are not affected by active control or regulation, at least except during operation of the device 100. For example, the magnetic properties of passive magnetic units, such as the carrier assembly rod or further rods, are typically not affected by active control during movement of the carrier assembly to the deposition or processing apparatus. According to some embodiments that may be combined with other embodiments described herein, the controller of apparatus 100 is not configured to control the passive magnetic unit of the deposition source assembly. The passive magnetic unit can be adapted to generate a magnetic field, such as a static magnetic field. The passive magnetic unit is not configured to generate an adjustable magnetic field. The passive magnetic unit can be a magnetic material, such as a ferromagnetic material, can be a permanent magnet, or can have permanent magnet properties.

  [0028] In view of the tunability and controllability of the magnetic field generated by the active magnetic unit, the active magnetic unit provides greater flexibility and accuracy compared to the passive magnetic unit. In accordance with the embodiments described herein, the magnetic field generated by the active magnetic unit can be controlled to align the carrier assembly 110. For example, by controlling the adjustable magnetic field, the magnetic buoyancy acting on the carrier assembly 110 can be controlled with high accuracy, and therefore, the active magnetic unit allows non-contact alignment of the carrier assembly and thus the substrate. Is possible.

  [0029] In accordance with the embodiments described herein, a plurality of active magnetic units 175 provide a magnetic force to the first passive magnetic unit 150 and thus the carrier assembly 110. The plurality of active magnetic units 175 causes the carrier assembly 110 to float. A further active magnetic unit 185 drives the carrier in the processing system, for example along the X direction, ie along the first direction which is the substrate transport direction. Thus, the plurality of additional active magnetic units 185 form a drive structure for moving the carrier assembly 110 while it is levitated by the plurality of active magnetic units 175. A further active magnetic unit 185 interacts with the second passive magnetic unit 160 to provide a force along the substrate transport direction. For example, the second passive magnetic unit 160 may include a plurality of permanent magnets that are arranged with alternating polarities. The resulting magnetic field of the second passive magnetic unit 160 can interact with a plurality of additional active magnetic units 185 to move the carrier assembly 110 while levitating.

  [0030] The active magnetic unit is adjustable to levitate the carrier assembly 110 using a plurality of active magnetic units 175 and / or move the carrier assembly 110 using a plurality of additional active magnetic units 185. It can be controlled to provide a magnetic field. The adjustable magnetic field can be a static or dynamic magnetic field. According to embodiments that may be combined with other embodiments described herein, the active magnetic unit is configured to generate a magnetic field to provide magnetic buoyancy extending along the vertical direction. According to other embodiments that may be combined with further embodiments described herein, the active magnetic unit may be configured to provide a magnetic force that extends along a transverse direction. The active magnetic unit described herein can be or include an element selected from the group consisting of an electromagnetic device, a solenoid, a coil, a superconducting magnet, or any combination thereof.

  [0031] FIG. 2 shows an apparatus 200 for processing a substrate in a vacuum chamber. The vacuum chamber 252 can have a chamber wall 253, for example. A gate valve 262 may be provided on the chamber wall 253. The gate valve can be opened to load the carrier assembly 110 into and out of the vacuum chamber 252. One or more guide structures 170 are provided. One or more inductive structures may include a plurality of active magnetic units 175. FIG. 2 shows an embodiment of the apparatus 200 having two gate valves 262 and two guide structures 170. Thus, the two carrier assemblies 110 can be loaded into and unloaded from the vacuum chamber 252, for example, alternately or simultaneously. To alternately load and unload the carrier assembly 110, another substrate of another carrier assembly is unloaded or loaded separately at the same time that a processing tool such as a deposition source processes the substrate of the carrier assembly. There is an advantage. Therefore, the throughput of the device 200 can be increased.

  [0032] As shown in FIG. 2, the apparatus 200 further includes a maintenance chamber 254, which may be, for example, a further vacuum chamber. The maintenance chamber 254 can be separated from the vacuum chamber 252 by a further gate valve 264. According to one embodiment that may be combined with other embodiments described herein, the apparatus 200 may be a deposition apparatus. Deposition source assembly 270 may move along track 272. The track 272 or a portion of the track 272 can extend into the maintenance chamber 254 to move the deposition source assembly from the vacuum chamber 252 to the maintenance chamber 254. Moving the deposition source assembly 270 into the maintenance chamber has the advantage that the deposition source assembly can be maintained outside the vacuum chamber 252. For example, after further gate valve 264 is closed, maintenance chamber 254 can be vented to have maintenance access to the deposition source assembly, while vacuum chamber 252 can remain evacuated. According to some embodiments, the first deposition source assembly 270 can be maintained in the maintenance chamber 254 while the second deposition source assembly 270 is operating in the vacuum chamber 252. Additionally or alternatively, the environment within the vacuum chamber 252 becomes cleaner as a result of the reduced number of times that the vacuum chamber 252 requires ventilation.

  [0033] According to some embodiments of the present disclosure that may be combined with other embodiments described herein, the deposition source assembly 270 may include a support 274. The support 274 can include a drive unit for moving the deposition source assembly 270 along the track 272. The support 274 can further include a magnetic unit to float the deposition source assembly. The deposition source assembly can include one or more deposition sources. As illustrated in FIG. 2, the support 274 supports three crucibles 276 for evaporating and depositing material on the substrate. The evaporated material can be directed into a vapor distribution element or vapor distribution line 278. The vapor distribution element or vapor distribution pipe can direct the vaporized material to a substrate mounted on the carrier of carrier assembly 110.

  [0034] FIG. 2 shows the deposition source assembly facing the substrate of the upper carrier assembly 110 of FIG. The deposition source assembly can move along a substrate mounted on the carrier of the carrier assembly. For example, the deposition source assembly can include one or more line sources. The combination of providing a line source and moving the deposition source assembly allows the material to be deposited on a rectangular substrate, such as a large area substrate for display manufacturing. According to a further alternative, the distribution source assembly distribution pipe may include one or more point sources that may move along the substrate surface.

  [0035] In addition to translation of the deposition source assembly, the deposition source assembly can also rotate the deposition source to direct the deposition source toward the substrate of the lower carrier assembly 110 shown in FIG. is there. Thus, while the carrier assembly 110 is loaded into and out of the vacuum chamber 252 at the first of the upper and lower positions shown in FIG. 2 can be processed at the other position corresponding to the upper position and the lower position shown in FIG. After this corresponding other substrate has been processed, the loading of a new substrate onto the carrier assembly 110 can be completed, for example. After one or more deposition sources of the deposition source assembly 270 have rotated, the substrate loaded into the first position of the upper and lower positions shown in FIG. 2 can be processed. Similarly, during processing (eg, layer deposition) of a substrate at a first location, unloading and loading of another substrate can be performed at the other location.

  [0036] According to an embodiment, the speed of the deposition source assembly along the source transport direction may be controlled to control the deposition rate. The speed of the deposition source assembly can be adjusted in real time under the control of the controller. Adjustments can be made to compensate for changes in the deposition rate. A speed profile can be defined. The speed profile can determine the speed of the deposition source assembly at various locations. The speed profile can be provided to the controller or stored in the controller. The controller can control the drive system such that the speed of the deposition source assembly follows the speed profile. Thus, real-time control and adjustment of the deposition rate can be performed so that layer uniformity can be further improved. The translation of the deposition source assembly along the source transport direction, considered to be according to the embodiments described herein, enables high coating accuracy, particularly high masking accuracy, in the coating process. This is because the substrate and the mask can remain stationary during the coating.

  [0037] A mask 212 may be provided between the deposition source assembly 270 and the substrate of the carrier assembly 110, as shown in FIG. FIG. 2 shows the first mask 212 in the upper position, ie, between the deposition source assembly and the upper carrier assembly 110, and the lower position, ie, the deposition source assembly and the lower carrier assembly 110. The second mask 212 is shown in the middle position.

  [0038] According to embodiments described in more detail in connection with FIGS. 5 and 6, the mask can be an edge exclusion mask or a mask for depositing a pattern on a substrate (Shadow mask). According to the embodiments described herein, the mask can be supported by a mask carrier. Accordingly, mask alignment, levitation, or mechanical contact with such a mask as referred to herein may also be made in connection with the mask carrier. Embodiments of the present disclosure refer to moving a carrier assembly that has floated within a processing apparatus. Movement of the levitated carrier assembly provides a more accurate positioning compared to movement of the carrier assembly which is mechanically supported, i.e. not supported without contact, e.g. mechanical contact with the substrate transport roller. to enable. In particular, the lifted carrier assembly movement allows for highly accurate substrate positioning in the transport direction and / or vertical direction, such as the X and Y directions of FIGS. 1A-1C. This positioning accuracy of the carrier assembly, according to the embodiments described herein, allows for improved alignment of the substrate supported by the carrier of the carrier assembly with respect to the mask 212. Alignment can be improved to provide the desired accuracy for some mask configurations, or improved to allow for reduced complexity of a separate alignment system for some other mask configurations. Can be done.

  [0039] Apparatus and methods according to the present disclosure may be used for vertical substrate processing. In such an apparatus and method, the substrate is oriented vertically during substrate processing. That is, the substrates are placed in parallel in the vertical direction described herein (ie, allowing deviations from the strict verticality that may occur). A small deviation from the strict verticality of the substrate orientation can be provided. This is because, for example, the substrate support is accompanied by such a shift, which can result in a more stable substrate position or a reduction in particle adhesion to the substrate surface. Basically vertical substrates can have a deviation of + -15 ° or less from the vertical orientation. Thus, embodiments of the present disclosure may refer to a vertical + -15 ° direction when reference is made to substrate orientation.

  [0040] FIGS. 3A and 3B illustrate an alternative embodiment of an apparatus that provides a vertical substrate orientation, and small offsets having absolute values of 15 degrees or less may be provided. According to embodiments of the present disclosure, the substrate 120 supported by the support 112 may be slightly tilted downward. This reduces particle adhesion to the substrate surface during substrate processing. FIG. 3A shows a carrier assembly having a first passive magnetic unit 150 and a second passive magnetic unit. The support 112 for supporting the substrate 120 may be provided between the first passive magnetic unit and the second passive magnetic unit. FIG. 3A further shows the guide structure 170 and the drive structure 180. The carrier assembly shown in FIG. 3A is tilted by providing additional active magnetic units 370 or a plurality of additional active magnetic units 370 distributed along the length of the guiding structure 170, ie, from a vertical orientation. The second passive magnetic unit 160 is attracted to the further active magnetic unit 370. Thus, a floating carrier assembly is provided and the lower end of the carrier assembly is pulled laterally by a further active magnetic unit 370. Other elements for pulling the lower end of the carrier assembly laterally without mechanical contact can also be provided.

  [0041] According to yet further embodiments, deviations from vertical orientation can also be provided by passive magnetic units such as permanent magnets. For example, the carrier assembly may include a permanent magnet provided as (or adjacent to) the second passive magnetic unit 160 or in addition to the second passive magnetic unit 160. Further permanent magnets can be provided below the permanent magnets. Additional permanent magnets and permanent magnets can be provided with opposite polarities to attract each other. This attractive force can cause the carrier assembly to deflect from vertical orientation. Furthermore, guidance along the transport direction can be performed by attractive force. Still further pairs of permanent magnets can be provided to provide inductive force to the upper end of the carrier, which can be combined with other embodiments described herein, and further embodiments. Accordingly, one permanent magnet of the second pair of permanent magnets may be provided in the upper region of the carrier assembly, and the corresponding permanent magnet of the second pair of permanent magnets. Can be provided adjacent in the region of the guiding structure. Guidance along the transport direction can be performed by the attractive force between the second pair of permanent magnets.

  [0042] FIG. 3 illustrates another embodiment of the present disclosure having a first passive magnetic unit 150 and a second passive magnetic unit 160. While the support 112 is shaped to provide a substrate tilt to provide a substrate orientation of the substrate 120 that is tilted, ie, slightly offset from the vertical orientation (eg, by an absolute value of 15 ° or less), the carrier 112 The assembly is vertical.

  [0043] According to embodiments of the present disclosure, a carrier assembly, such as the carrier assembly 110 shown herein, may include one or more holding devices (not shown) configured to hold the substrate 120 in a plate or frame. . The one or more holding devices may comprise mechanical means, electrostatic means, electrokinetic (vander Waals) means, electromagnetic means, and / or magnetic means, such as mechanical clamps and / or magnetic clamps. , At least one.

  [0044] In some implementations, the carrier assembly includes an electrostatic chuck (E chuck) or is an E chuck. The E-chuck can have a support surface (eg, support 112 shown in FIGS. 1C, 3A, and 3B) for supporting the substrate 120 on the surface. In one embodiment, the E-chuck includes a dielectric body with electrodes embedded therein. The dielectric body can be made from a dielectric material, preferably a highly thermally conductive dielectric material such as pyrolytic boron nitride, aluminum nitride, silicon nitride, alumina, or equivalent material. The electrode may be coupled to a power source that provides power to the electrode to control the chucking force. The chucking force is an electrostatic force that acts on the substrate 120 to fix the substrate to the support surface of the support.

  [0045] In some implementations, the carrier assembly 110 includes or is an electrokinetic chuck or G-chuck. The G chuck may have a support surface for supporting the substrate on the surface. The chucking force can be an electromotive force acting on the substrate to fix the substrate to the support surface.

  [0046] FIGS. 4A and 4B illustrate an operating state of the apparatus 100 according to an embodiment that may be combined with other embodiments described herein. 4A and 4B show side views of the device 100. FIG. As shown, the guide structure 170 may extend along the transport direction of the carrier assembly, ie, the X direction in FIGS. 4A and 4B. The carrier assembly transport direction is the transverse direction described in this document. The guide structure 170 may have a linear shape extending along the transport direction. The length of the guide structure 170 along the source conveyance direction may be 1 to 30 m.

  [0047] In the embodiment shown in FIGS. 4A and 4B, the substrate 120 may be disposed substantially parallel to the plane of the drawing, for example with a +15 offset. During substrate processing, such as a layer deposition process, the substrate can be provided in a substrate receiving area. The substrate receiving area has dimensions such as length and width that are the same as or slightly larger (for example, 5 to 20%) than the corresponding substrate dimensions.

  [0048] During operation of the apparatus 100, the carrier assembly 110 may be translatable along the guiding structure 170 in a transport direction, such as the x-direction. 4A and 4B show the carrier assembly 110 in different positions along the x direction with respect to the guiding structure 170. FIG. A horizontal arrow 485 indicates the driving force of the driving structure 180. As a result, translation of the carrier assembly 110 from left to right along the guiding structure 170 occurs. A vertical arrow 475 indicates buoyancy acting on the carrier assembly.

  [0049] The first passive magnetic unit 150 may have magnetic properties substantially along the length of the first passive magnetic unit 150 in the transport direction. The magnetic field generated by the active magnetic unit 175 ′ interacts with the magnetic characteristics of the first passive magnetic unit 150 to provide a first magnetic buoyancy and a second magnetic buoyancy. Accordingly, non-contact levitation, transport and alignment of the carrier assembly 110 can be performed.

  [0050] As shown in FIG. 4A, the carrier assembly 110 is provided in a first position. In accordance with embodiments of the present disclosure, two or more active magnetic units 175 ′ (eg, two or three active magnetic units 175 ′) are activated by the controller 440 to generate a magnetic field for levitating the carrier assembly 110. generate. According to embodiments of the present disclosure, the carrier assembly floats below the guiding structure 170 without mechanical contact.

  [0051] In FIG. 4A, two active magnetic units 175 'provide the magnetic force indicated by arrow 475. The magnetic force contacts the gravity so as to lift the carrier assembly. The controller 440 controls the two active magnetic units 175 '(specifically, controls the two active magnetic units individually) to keep the carrier assembly floating. In addition, one or more additional active magnetic units 185 ′ are controlled by the controller 440. A further active magnetic unit interacts with a second passive magnetic unit 160, such as a pair of alternating polarity permanent magnets, to generate the driving force indicated by arrow 485. The driving force moves a substrate such as the substrate supported by the support of the carrier assembly along the transport direction. As shown in FIG. 4A, the transport direction may be the X direction. According to some embodiments of the present disclosure that may be combined with other embodiments described herein, the number of additional active magnetic units 185 ′ that are simultaneously controlled to provide driving force is 1-3. It is. According to other embodiments, further control of the active magnetic unit 185 'may be performed by a second controller that is different from the controller 440 that controls the active magnetic unit 175'.

  [0052] The movement of the carrier assembly moves the substrate along a transport direction, such as the X direction. Thus, the substrate is positioned below the first group of active magnetic units 175 'in the first position and below another further group of active magnetic units 175' in yet another position. The controller 440 controls which active magnetic unit 175 'provides buoyancy for each position and controls each active magnetic unit to levitate the carrier assembly. For example, buoyancy can be provided by the immediate active magnetic unit while the substrate is moving. According to the embodiments described herein, the carrier assembly is passed from one set of active magnetic units to another set of active magnetic units.

  [0053] FIG. 4B shows the carrier assembly in the second position. The position shown in FIG. 4B corresponds to a processing position where the substrate is processed. In this processing position, the carrier assembly can be moved to a desired position. The substrate is aligned with respect to the mask using the non-contact transfer system described in this disclosure.

  [0054] In the second position illustrated in FIG. 4B, the two active magnetic units 175 'provide a first magnetic force indicated by arrow 494 and a second magnetic force indicated by arrow 496. The controller 440 controls the two active magnetic units 175 'to perform alignment in a vertical direction such as the Y direction in FIG. 4B. Additionally or alternatively, the controller 440 controls the two active magnetic units 175 'for alignment and the carrier assembly rotates in the XY plane. Both alignment movements can be exemplarily seen in FIG. 4B by comparing the position of the dotted carrier assembly 410 with the position of the carrier assembly 110 drawn in solid lines.

  [0055] The controller may be configured to control the active magnetic unit 175 'to translate and align the carrier assembly in the vertical direction. By controlling the active magnetic unit, the carrier assembly 110 can be positioned in the vertical position of the target. The carrier assembly 110 can be maintained in the vertical position of the target under the control of the controller 440. According to embodiments that may be combined with other embodiments described herein, the controller may have a first rotation axis (eg, a rotation axis perpendicular to the main substrate surface, ie, a rotation axis extending in the Z direction in the present disclosure). Is configured to control the active magnetic unit 175 'to angularly align the deposition source with respect to.

  [0056] According to embodiments of the present disclosure, alignment of the carrier assembly in the vertical direction (Y direction), particularly non-contact alignment, may be performed in an alignment range of 0.1 mm to 3 mm. Furthermore, the alignment accuracy in the vertical direction, particularly the non-contact type alignment accuracy, may be 1 μm to 10 μm, for example 5 μm or less, such as 50 μm or less. According to an embodiment of the present disclosure, the rotational alignment accuracy, particularly the non-contact alignment accuracy, may be 3 ° or less.

  [0057] According to embodiments of the present disclosure, one or more additional active magnetic units 185 'may provide a driving force as indicated by arrow 498. The controller controls one or more additional active magnetic units 185 'to perform alignment in a transverse direction, such as the X direction of FIG. 4B. According to embodiments of the present disclosure, alignment of the transverse (X-direction) carrier assembly may be performed in an alignment range that extends along the length of the guide structure. Further, the alignment accuracy in the transverse direction, particularly the non-contact type alignment accuracy may be 50 μm or less, such as 5 μm to 30 μm.

  [0058] FIG. 5 illustrates one embodiment of mask alignment that may be combined with other embodiments of the present disclosure. A mask 512 shown in FIG. 5 is an edge exclusion mask. This edge exclusion mask covers a portion of the edge of the substrate 120 by providing an edge 514 of the mask 512. For example, the width 516 of the covered portion of the substrate 120 can be 10 mm or less, such as 5 mm or less. An open area (or opening 518) is provided by edge 514. That is, the opening 518 is surrounded by the edge 514. A partition wall may optionally be provided in the center of the edge exclusion mask 512 such that two or more openings 518 are surrounded by corresponding edges. However, the openings are not configured to define pattern features. The opening is configured to define an area of the substrate. For example, the area of the opening 518 shown in FIG. 5 is at least 80% of the area of the substrate. For embodiments having more than one opening, each opening has an area of at least 0.1% of the substrate area.

  [0059] FIG. 5 shows a carrier assembly 110 supporting a substrate 120 on a surface. The carrier assembly 110, and thus the substrate 120, can be aligned with the mask 512 and thus the edge 514 of the mask. The alignment of the carrier assembly and the mask according to embodiments of the present disclosure can be controlled by control of an active magnetic unit, such as the active magnetic unit 175 ′ of the guidance structure 170 and / or a further active magnetic unit 185 ′ of the drive structure 180. Executed. According to some embodiments, especially for masks that are edge exclusion masks, the alignment accuracy utilizing alignment by the active magnetic unit may be sufficient for the desired accuracy of substrate processing. Thus, according to some embodiments of the present disclosure that may be combined with other embodiments described herein, the alignment of the substrate and mask relative to each other causes the substrate to float, such as a substrate transport system without mechanical contact. This is done by the active magnetic unit of the transport system.

  [0060] For example, display manufacturing, such as manufacturing an OLED display, includes a metallization process in which a conductive layer is provided over a large area on a substrate, such as an area corresponding to one or more openings 518 in FIG. May be included. The metallization process may be performed using an edge exclusion mask 512. The alignment of the substrate and the mask with respect to each other can be performed by the active magnetic unit of the guiding structure and / or the active magnetic unit of the driving structure. The accuracy of alignment using an active magnetic unit (eg, accuracy of 50 μm or less) may be sufficient for the metallization process.

  [0061] FIG. 6 illustrates a further embodiment of mask alignment. FIG. 6 shows a shadow mask 612 that includes a plurality of small openings 614. For example, the area of these openings, ie the area of one feature of the pattern to be generated, can be less than 0.01% of the substrate area. FIG. 6 shows the carrier assembly 110 supporting the substrate 120 on the surface. Pre-alignment may be performed by control of an active magnetic unit, such as active magnetic unit 175 ′ of guidance structure 170 and / or further active magnetic unit 185 ′ of drive structure 180. In accordance with some embodiments of the present disclosure that may be combined with other embodiments described herein, substrate transport in which pre-alignment of the substrate and mask to each other causes the substrate to float, such as a substrate transport system without mechanical contact. This is done by the active magnetic element of the system. The pre-alignment can have an accuracy of 50 μm or less. This accuracy of pre-alignment allows the use of alignment actuators 630 (eg, piezoelectric actuators such as piezoelectric alignment actuators), which reduces the complexity of the alignment unit or alignment system. According to some embodiments of the present disclosure, the alignment unit or alignment system may include two or more (eg, four) alignment actuators. The alignment actuator can be less complex than a typical alignment actuator that is utilized without the pre-alignment accuracy described above. In view of the above, alignment using active magnetic elements of a substrate transport system according to embodiments of the present disclosure can reduce the cost of ownership of the processing system. A low complexity alignment unit or alignment system is described below in connection with FIGS.

  [0062] FIGS. 7 and 8 illustrate a holding configuration 700 for supporting the substrate carrier 111 and mask carrier 740 of the carrier assembly 110 during layer deposition in a processing chamber, according to embodiments described herein. A schematic diagram is shown. FIG. 8 illustrates a cross-sectional view of a holding configuration 700 for supporting a substrate carrier 111 and mask carrier 740 during layer deposition in a processing chamber, according to embodiments described herein. FIG. 9 shows a schematic diagram of a holding configuration having four alignment actuators.

  [0063] The alignment system used in the vertically operating tool can function from outside the processing chamber (ie, from the atmospheric side). The alignment system can be connected to the substrate carrier and mask carrier using, for example, rigid arms that extend through the walls of the processing chamber. A long mechanical path between the mask carrier or mask and the substrate carrier or substrate makes the system susceptible to external interference (vibration, heating, etc.) and tolerances.

  [0064] In some embodiments, the present disclosure provides a holding configuration having two or more alignment actuators that provide a short connection path between the mask carrier and the substrate carrier. The holding arrangement according to the embodiments described herein is less susceptible to external interference and can improve the quality of the deposited layer.

  [0065] The holding configuration 700 includes two or more alignment actuators connectable to at least one of the substrate carrier 111 and the mask carrier 740, the holding configuration 700 holding the substrate carrier 111 in a first plane or in a first plane. A first alignment actuator 710 of two or more alignment actuators configured to support parallel to a plane moves the carrier assembly and mask carrier 740 relative to each other at least in a first direction Y. The second alignment actuator 720 of the two or more alignment actuators is configured such that the carrier assembly and the mask carrier 740 are at least in the first direction Y and the second direction different from the first direction Y. Configured to move relative to each other in a first direction Y and a second Direction X is in a first plane. Two or more alignment actuators are also referred to as “alignment blocks”.

  [0066] According to some embodiments described herein, which may be combined with other embodiments described herein, the mask 725 may be attached to the mask carrier 740. In some embodiments, the retention structure 700 is configured to support at least one of the substrate carrier 111 and the mask carrier 740 in a substantially vertical orientation, particularly during layer deposition.

  [0067] By using two or more alignment actuators to move the carrier assembly and mask carrier 740 relative to each other in at least a first direction Y and a second direction X, the substrate 120 is 740 or mask 725 can be aligned and the quality of the deposited layer can be improved.

  [0068] Two or more alignment actuators may be connectable to at least one of the carrier assembly and the mask carrier 140. As an example, two or more alignment actuators can be connected to the carrier assembly or substrate carrier 111 and are configured to move the substrate carrier 130 relative to the mask carrier 140. The mask carrier 140 can be in a fixed position or a stationary position. In other examples, two or more alignment actuators can be connected to the mask carrier 140 and configured to move the mask carrier 140 relative to the substrate carrier 111. The substrate carrier 111 can be in a fixed position or a stationary position.

  [0069] In the holding configuration of FIG. 9, the two or more alignment actuators include at least one of a third alignment actuator 930 and a fourth alignment actuator 940. According to some embodiments that may be combined with other embodiments described herein, the two or more alignment actuators may move the carrier assembly or substrate carrier 111, or mask carrier 140, in the first plane or in the first plane. In parallel (e.g., in the x and y directions), and the angular position of the substrate carrier 130 or mask carrier 140 is in the first plane or parallel to the first plane. Configured to adjust or change.

  [0070] In some implementations, at least one of the two or more alignment actuators is configured to move the substrate 120 and the mask carrier 140 relative to each other in the third direction Z. In particular, the third direction is substantially perpendicular to the first plane and / or the substrate surface 711. As an example, the first alignment actuator 710 and the second alignment actuator 720 are configured to move the substrate carrier 111 or the mask carrier 140 in the third direction Z. In some implementations, the distance between the substrate 120 and the mask 725 may be adjusted by moving the carrier assembly or substrate carrier 111 or the mask carrier 140 in the third direction Z. As an example, the distance between the substrate 120 or substrate carrier 111 and the mask 725 can be adjusted to be substantially constant in the region of the substrate surface 711 configured to deposit a layer on the surface. According to some embodiments, this distance may be less than 1 mm, specifically less than 500 micrometers, and more specifically less than 50 micrometers.

  [0071] In some embodiments that may be combined with other embodiments described herein, the first alignment actuator 710 is floating in the second direction X. The term “floating” means that the first alignment actuator 710 allows the substrate carrier 130 to move in the second direction X (eg, driven by the second alignment actuator 720). It can be understood that there is.

  [0072] The substrate carrier 111 may have a first edge portion 732 and a second edge portion 734. The first edge portion and the second edge portion may be disposed on both sides of the substrate carrier 111. A substrate region of the substrate carrier on which the substrate 120 may be disposed may be provided between the first edge portion 732 and the second edge portion 734. As an example, the first edge portion 732 can be the upper edge portion or the upper edge portion of the substrate carrier. The second edge portion 734 can be a lower edge portion or a bottom edge portion of the substrate carrier.

  [0073] According to some embodiments that may be combined with other embodiments described herein, the first alignment actuator 710 and the second alignment actuator 720 are provided on the first edge portion 732 or the second edge portion 734. Is done. In some implementations, the first alignment actuator 710 and the second alignment actuator 720 are corners or corner regions of the substrate carrier 111 (eg, corners or corner regions of the first edge portion 732 or the second edge portion 734). Can be provided.

  [0074] According to some embodiments that may be combined with other embodiments described herein, the two or more alignment actuators may be electric actuators or pneumatic actuators. The two or more alignment actuators can be, for example, a linear alignment actuator. In some implementations, the two or more alignment actuators can include at least one actuator selected from the group consisting of a stepper actuator, a brushless actuator, a DC (direct current) actuator, a voice coil actuator, and a piezoelectric actuator. . The term “actuator” can refer to a motor, such as a stepper motor. The two or more alignment actuators can be configured to move or position the carrier assembly or substrate carrier 111 (and thus the substrate) with an accuracy of less than plus or minus about 1 micrometer. As an example, the two or more alignment actuators may have plus or minus about 0.5 micrometers in at least one of the first direction Y, the second direction X, and the third direction Z, specifically The substrate carrier 111 can be configured to move or position with an accuracy of about 0.1 micrometers.

  [0075] In some implementations, the substrate is moved in at least one of a first direction, a second direction, and a third direction by driving two or more alignment actuators simultaneously or sequentially. Can be implemented.

  [0076] FIG. 10 shows a flow diagram illustrating a method of non-contact alignment of a carrier assembly, according to an embodiment of the present disclosure. As shown in block 902, the carrier assembly floats. For example, the active magnetic unit 175 'is activated and / or controlled by the controller 440, and two provide a magnetic force that counteracts gravity. The magnetic force plays a role of floating the carrier assembly. Block 904 illustrates moving the carrier assembly to position the carrier assembly relative to the mask. According to the embodiments described herein, moving the carrier assembly or moving the carrier assembly is performed while the carrier assembly is levitated. Block 906 indicates aligning the carrier assembly with respect to the mask. Thus, the movement of the carrier assembly is controlled to position, ie align, the carrier assembly with sufficient accuracy relative to the mask.

  [0077] According to some embodiments of the present disclosure, optionally, the carrier assembly and / or mask may be mechanically contacted, eg, to an alignment actuator, for further mechanical alignment. In such cases, the alignment shown in block 906 may be considered pre-alignment.

  [0078] According to embodiments of the present disclosure, the carrier assembly transport system or holding device is configured to align, or at least pre-align. The method described herein provides for movement of the carrier assembly without mechanical contact, for example, while floating, and the non-contact transport system is supported by and / or part of the carrier assembly. Allows sufficient accuracy to align a substrate, such as a substrate, and a mask with respect to each other. For example, the accuracy can be less than 100 μm, such as 50 μm or less.

  [0079] The present disclosure includes several advantages, including avoiding separate alignment actuators for some applications, or at least reducing the complexity of multiple alignment actuators for multiple applications. There is. Improved alignment and / or increased efficiency of the substrate relative to the mask may be provided. Thus, the cost of ownership of the processing system can be reduced. Furthermore, some embodiments of the present disclosure allow for increased throughput. Further advantages include, among other things, reducing particle generation in processing systems such as, for example, deposition systems for large area substrates utilized in OLED display manufacturing. For example, improved purity and uniformity of the deposited layer on the substrate can be provided.

[0080] While the above description is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure. The scope of the disclosure is determined by the following claims.

Claims (15)

A method for non-contact alignment of a carrier assembly, comprising:
Floating the carrier assembly in a vacuum chamber;
Moving the carrier assembly while levitating to position the carrier assembly relative to a predetermined position, in particular a mask or mask carrier;
Aligning the carrier assembly with respect to the mask or the mask carrier in at least one direction selected from the group consisting of a substrate transport direction, a first direction of + -15 ° to the vertical direction, and combinations thereof; Including a method.   The method of claim 1, further comprising guiding the carrier assembly along the substrate transport direction, wherein the guiding is performed simultaneously with floating and moving.   The method of claim 1 or 2, wherein the carrier assembly does not involve mechanical contact during alignment.   The method according to claim 1, wherein the alignment is performed with an accuracy of 50 μm or less.   The method further comprises further aligning the carrier assembly relative to the mask or the mask carrier by rotating the carrier assembly in a plane provided by the substrate transport direction and the first direction. The method according to any one of 1 to 4.   The method of claim 5, wherein the further alignment is performed with an accuracy of 3 ° or less.   The method further comprises contacting the mask or the mask carrier, the carrier assembly, or the mask or the mask carrier and the carrier assembly with two or more alignment actuators to perform mechanical alignment. Item 7. The method according to any one of Items 1 to 6.   The method according to claim 7, wherein the mechanical alignment is performed with an accuracy of 5 μm or less. A method for processing a substrate of a carrier assembly comprising:
The method of non-contact alignment of the carrier assembly according to any one of claims 1 to 7, wherein the mask or the mask carrier is positioned in the vacuum chamber;
Processing the substrate in the vacuum chamber.   The method of claim 9, further comprising opening the gate valve of the vacuum chamber and moving the carrier assembly out of the vacuum chamber while the carrier assembly is floating.   The method of claim 9 or 10, wherein processing the substrate in the vacuum chamber comprises depositing a layer on the substrate.   The method of claim 11, wherein the depositing includes moving a deposition source assembly along the substrate. An apparatus (100) for non-contact alignment of a carrier assembly and a mask or mask carrier with respect to each other within a vacuum chamber of a substrate processing system comprising:
An induction structure (170) having a plurality of active magnetic units (175) in the vacuum chamber, the induction structure (170) configured to float the carrier assembly in the vacuum chamber;
A drive structure (180) having a plurality of further active magnetic units in the vacuum chamber, the drive structure configured to drive the carrier assembly along a transport direction without mechanical contact A body (180);
Two or more alignment actuators in contact with the mask or the mask carrier, the carrier assembly, or the mask or the mask carrier and the carrier assembly in the vacuum chamber;
A controller connected to the guiding structure, the driving structure, and the two or more alignment actuators, performing pre-alignment using the guiding structure and the driving structure; and And a controller configured to control the plurality of active magnetic units and the plurality of further active magnetic units to perform mechanical alignment using one or more alignment actuators.   The apparatus of claim 13, wherein the two or more alignment actuators are piezoelectric actuators. The apparatus of claim 14, further comprising at least one additional piezoelectric actuator.

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