CARRIER

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to apparatus and methods for guiding of carriers in a transport system, particularly carriers used for carrying large-area substrates. More specifically, embodiments of the present disclosure relate to transport systems for transporting carriers, particularly in a vacuum chamber, and substrate processing systems including said transport systems.

BACKGROUND

[0002] Techniques for layer deposition on a substrate include, for example, sputter deposition, physical vapor deposition (PVD), such as thermal evaporation or sputtering, and chemical vapor deposition (CVD). Coated substrates may be used in several applications and in several technical fields. For instance, coated substrates may be used in the field of display devices. Display devices can be used for the manufacture of television screens, computer monitors, mobile phones, other hand held devices, and the like for displaying information. Typically, displays are produced by coating a substrate with a stack of layers of different materials.

[0003] Substrates are typically coated in a processing system, for example a vacuum deposition system, which may include a plurality of deposition sources and other substrate processing apparatuses. The substrates are typically transported through the processing system along a transport system, e.g. from a first deposition source to a second deposition source and to other substrate processing apparatuses. The substrates may be transported through the processing system in a substantially vertical orientation. [0004] A substrate is typically carried by a carrier, i.e. a carrying device for carrying the substrate. The carrier is typically transported through the processing system using a transport system. The transport system may be a roller system, in which the weight of the carrier is held by a plurality of rollers, or a magnetic levitation system, in which the weight of the carrier is held by magnetic forces. The transport system may be configured for conveying the carrier carrying the substrate along.

[0005] When transporting a carrier on a transport system, bridging a gap in the transport system is challenging. For instance, the transport system may be required to transport a carrier through a load lock chamber or through a door separating a process chamber from other areas of the processing system. At these points, a gap is provided in the transport system, and the carrier bridges the gap when being transported. However, magnetic attraction forces between the carrier and a magnetic guide which is guiding the carrier may cause collisions to occur between the carrier and an end of the magnetic guide.

[0006] Accordingly, it would be beneficial to provide an improved magnetic guide for guiding carriers across gaps in a transport system, which overcome at least some problems of the state of the art. Specifically, providing a magnetic guide for a transport system for transporting carriers carrying large-area substrates would be beneficial.

SUMMARY

[0007] In light of the above, a magnetic guide for guiding a carrier, a transport system for transporting a carrier, a processing system and a method for guiding a carrier are provided. Further aspects, advantages, and features are apparent from the dependent claims, the description, and the accompanying drawings.

[0008] According to one aspect of the present disclosure, a magnetic guide for guiding a carrier is provided. The magnetic guide comprises a housing comprising a first portion and a second portion arranged opposite from the first portion in a transverse direction, the first and second portions extending in a first direction being a transport direction; at least one first guiding magnet arranged on a surface of the first portion; and at least one second guiding magnet arranged on the surface of the second portion, wherein the at least one first guiding magnet extends in a second direction opposite to the transport direction past a first end of the first portion, the first end comprising a magnetic material, and the at least one second guiding magnet extends in the second direction opposite to the transport direction past a second end of the second portion, the second end comprising a magnetic material.

[0009] According to a further aspect, a magnetic guide for guiding a carrier is provided. The magnetic guide comprises a housing comprising a first portion and a second portion arranged opposite to the first portion in a transverse direction, the first and second portions extending in a first direction being a transport direction; at least one first guiding magnet arranged on the surface of the first portion; and at least one second guiding magnet arranged on the surface of the second portion, wherein the at least one first guiding magnet and the at least one second guiding magnet are arranged to shield a magnetic attraction of the carrier towards the housing.

[0010] According to a yet further aspect of the present disclosure, a transport system for transporting a carrier is provided. The transport system comprises a transporting means extending in the transport direction configured for supporting the carrier against the force of gravity and for moving the carrier in the transport direction; and a magnetic guide according to one of the above aspects.

[0011] According to a yet further aspect of the present disclosure, a substrate processing system is provided, comprising at least one processing chamber and the transport system according to the above aspect.

[0012] According to a yet further aspect of the present disclosure, a method of guiding a carrier with a magnetic guide having a housing, at least one first guiding magnet and at least one second guiding magnet is provided. The method comprises shielding a magnetic attraction of the carrier towards the housing by the at least one first guiding magnet and the at least one second guiding magnet. [0013] The magnetic guide is configured for guiding a carrier such that a collision between the carrier and the housing is avoided. Particularly, the magnetic guide is configured for avoiding a magnetic attraction between the carrier and the housing from causing the carrier to collide with the housing. [0014] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed at methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

FIG. 1 shows a schematic bottom view of an existing magnetic guide; FIG. 2 shows a schematic bottom view of a magnetic guide according to embodiments described herein;

FIGS. 3a and 3b show schematic end views of the magnetic guide of FIG. 2 according to embodiments described herein; and

FIG. 4 shows a schematic side view of a transport system according to embodiments described herein. DETAILED DESCRIPTION OF EMBODIMENTS

[0016] Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. Only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

[0017] A processing system may comprise at least one processing chamber and a transport system for transporting carriers therebetween. For example, the processing system may include at least two chambers, which may include at least one of a deposition chamber, a load lock chamber, a transfer chamber or a storage chamber, among others, and at least one of the chambers may contain a vacuum. Adjacent chambers may contain different process environments which are separated, for example, by a sealing door or hatch. A transport system according to embodiments described in the present disclosure may be configured for transporting carriers from one chamber into another chamber through the sealing door or hatch, and is therefore provided with a gap where the sealing door or hatch is located.

[0018] A “carrier” as used herein may be understood as a carrying device configured for carrying an object, particularly a substrate that is to be coated, through a processing system. The carrier may include a carrier body and a holding device, e.g. a mechanical, electrostatic, or magnetic chucking device, configured for holding the substrate at a support surface of the carrier body.

[0019] The carrier may be configured to carry a large-area substrate, i.e. a substrate having a size of 1 m ² or more, particularly 5 m ² or more, more particularly 8 m ² or more or even 10 m ² or more. Accordingly, the carrier may be a large and heavy component, the carrier body having a substrate support surface of several square meters. For example, the carrier may have a weight of 200 kg or more, e.g. from 400 kg to 2000 kg, such as 1000 kg or more, and/or a length of several meters.

[0020] Transporting carriers over a gap in the transport system can be challenging. In typical operation, the carrier is guided with at least one guide rail. However, the guide rail is not present in a gap, and so the carrier bridges the gap with a reduced level of guidance. Such a gap in the transport system which is to be bridged by the transported carrier may be as large as 500 mm. The end of the gap, where the end of the guide rail is provided, is a problematic area as the partially unguided carrier may collide with the end of the guide rail. Such a collision may cause a carrier to be stuck, or may damage the carrier or the transport system.

[0021] Typically, a magnetic guide may be used in the transport system for guiding a carrier. A magnetic guide includes a number of magnets arranged on a housing made of magnetic material, such as iron or steel. The carrier being guided by the magnetic guide typically includes a carrier guiding magnet which is guided between the magnets of the magnetic guide. However, the problem where the carrier collides with the end of the guide rail becomes more prominent with magnetic guides, as there is a magnetic attraction force between the magnetic housing and the carrier guiding magnet, which causes the carrier to be attracted towards the housing.

[0022] The situation in which a carrier collides with the end of a magnetic guide is exemplarily shown in FIG. 1, which shows a schematic bottom view of an existing magnetic guide 100. Magnetic guide 100 includes a housing 10 in the form of a U- shaped channel having a first portion 11 and a second portion 12 joined by third portion 13. Provided on the first portion 11 is a first guiding magnet 21, and provided on the second portion 12 is a second guiding magnet 22. Carrier 30, which may include carrier guiding magnet 31, is aimed to be guided through magnetic guide 100 in a transport direction T. A magnetic repulsive force is provided between the carrier guiding magnet 31 and the first and second guiding magnets 21, 22 so as to maintain the carrier 30 in a stable position in the transverse direction 4.

[0023] First portion 11 and second portion 12 of housing 10 each have a respective first end 11a of first portion 11 and second end 12a of second portion 12. First end 11a and second end 12a include a magnetic material such as iron or steel, and a magnetic attractive force A is generated between first end 11a and/or second end 12a and the carrier guiding magnet 31. This magnetic attractive force A causes carrier 30 to be attracted towards housing 10, potentially causing a collision C between carrier 30 and housing 10.

[0024] According to embodiments of the present disclosure, a magnetic guide may be provided which is configured for avoiding collision of the carrier with the housing. As exemplarily shown in FIGS. 2 and 3 A, a magnetic guide 200 for guiding a carrier 30 is provided. FIG. 2 shows a schematic bottom view of the magnetic guide 200, while FIG. 3A shows a schematic end view of the magnetic guide 200. Magnetic guide 200 includes a housing 10 having a first portion 11 and a second portion 12 arranged opposite from the first portion 11 in a transverse direction 4, the first and second portions extending in a first direction 1 corresponding to a transport direction T. At least one first guiding magnet 21 is arranged on a surface of the first portion 11, and at least one second guiding magnet 22 is arranged on a surface of the second portion 12.

[0025] The at least one first and second guiding magnets 21, 22 are arranged to extend in a second direction 2 opposite to the transport direction T past a respective first end 11a of first portion 11 and second end 12a of second portion 12. As shown in FIG. 2, the at least one first and second guiding magnets 21, 22 extend past the respective first and second ends 1 la, 12a by a distance X. By arranging the first and second guiding magnets 21, 22 to extend past the housing, the magnetic attractive force A exhibited in the existing magnetic guide 100 of FIG. 1 is shielded by a magnetic repulsive force R between the first and second guiding magnets 21, 22 and the carrier guiding magnet 31. By preventing the magnetic attractive force A between carrier guiding magnet 31 and housing 10, the carrier 30 is not moved in the direction of the housing, and a collision between carrier 30 and housing 10 is avoided.

[0026] According to an embodiment, which may be combined with other embodiments described herein, the at least one first and second guiding magnets 21, 22 may extend in the second direction 2 past the first and second ends 11a, 12a of the respective first and second portions 11, 12, i.e. the distance X, by at least 5 mm, particularly by at least 10 mm, more particularly by at least 20 mm. The at least one first and second guiding magnets 21, 22 may alternatively extend in the second direction 2 such that the distance X is less than or equal to 50 mm. Particularly, the first and second guiding magnets 21, 22 may extend in the second direction 2 such that the distance X is in the range from 5 mm up to 50 mm, particularly from 10 mm up to 50 mm, more particularly from 20 mm up to 50 mm. The greater the distance X by which the first and second guiding magnets 21, 22 extend, the greater the amount of shielding of the magnetic attractive force A between the carrier guiding magnet 31 and the housing 10.

[0027] In the context of the present disclosure, housing 10 includes first portion 11 and second portion 12, both of which contain a magnetic material. Accordingly, first end 11a of first portion 11 and second portion 12a of second portion 12 also contain a magnetic material. Housing 10 may also include other portions which may contain a non-magnetic material. For example, housing 10 may include additional non-magnetic extension portions which extend beyond the first end 11a and the second end 12a so that housing 10 may extend further than the first and second guiding magnets 21, 22. Such non-magnetic extension portions may comprise an aluminium alloy or a plastic material, for example. However, the distance X by which the first and second guiding magnets 21, 22 extend past the first and second ends 11a, 12a remains as the distance X by which the first and second guiding magnets 21, 22 extend past a portion of housing 10 which contains a magnetic material.

[0028] An extreme example of the above is the case where the first portion 11 and second portion 12 are infinitesimally small, and the housing 10 comprises non magnetic material on which the first and second guiding magnets 21, 22 are arranged. In this case, first and second portions 11, 12 of housing 10 are essentially replaced with a substantially non-magnetic housing. However, this example is beyond the scope of the present disclosure, as the challenge of the carrier guiding magnet 31 being attracted to housing 10 no longer exists. [0029] The effect of the first and second guiding magnets 21, 22 extending past the respective first and second ends 11a, 12a is that the magnetic attraction A of the carrier 30 towards the housing 10 is shielded. By shielding the magnetic attraction A of the carrier 30 towards the housing 10, a collision between the carrier 30 and the housing 10 is avoided. According to embodiments of the present disclosure, a magnetic guide 200 for guiding a carrier 30 is provided. The magnetic guide 200 includes a housing 10 having a first portion 11 and a second portion 12 arranged opposite from the first portion 11 in a transverse direction 4, the first and second portions 11, 12 extending in a first direction 1 being a transport direction T. The magnetic guide 200 further includes at least one first guiding magnet 21 arranged on a surface of the first portion 11, and at least one second guiding magnet 22 arranged on a surface of the second portion 12, wherein the at least one first guiding magnet 21 and the at least one second guiding magnet 22 are arranged to shield a magnetic attraction A of the carrier 30 towards the housing 10.

[0030] According to an embodiment, which may be combined with other embodiments described herein, the carrier 30 is oriented in a substantially vertical orientation. In other words, the carrier 30 may be oriented such that the main surface of the carrier 30 is substantially vertical (vertical +/- 10°) during transport of the carrier 30. The magnetic guide 200 may be provided as an upper guide which is provided for guiding an upper part of the carrier 30 that is configured to magnetically interact with the magnetic guide 200. Accordingly, magnetic guide 200 serves to maintain carrier 30 in a stable orientation in the transverse direction 4 as it is transported. The transport direction T may be an essentially horizontal direction. The transport direction T may correspond to a longitudinal direction of the carrier 30, along which the carrier 30 is moved.

[0031] According to an embodiment, which may be combined with other embodiments described herein, carrier 30 may include at least one carrier guiding magnet 31. The at least one carrier guiding magnet 31 is arranged to be guided between the at least one first guiding magnet 21 and the at least one second guiding magnet 22. Magnetic guide 200 does not specifically require a carrier guiding magnet 31 to be provided on carrier 30 in order to magnetically guide carrier 30, however providing carrier guiding magnet 31 on carrier 30 enhances guiding performance and stability. The at least one carrier guiding magnet 31 may include one carrier guiding magnet 31, or may alternatively include multiple carrier guiding magnets 31. In the case where multiple carrier guiding magnets 31 are provided, the carrier guiding magnets 31 may be offset from each other in the third direction 3 perpendicular to the transport direction T.

[0032] Carrier guiding magnet 31 may be arranged such that the magnetic poles of carrier guiding magnet 31 facing each respective first and second guiding magnet 21, 22 are the same polarity, such that a magnetic repulsive force is exerted on carrier guiding magnet 31 by the respective first and second guiding magnets 21, 22.

[0033] As exemplarily shown in FIG. 3A, magnetic guide 200 may include one first guiding magnet 21 and one second guiding magnet 22, such that magnetic repulsive forces are applied to the carrier guiding magnet 31 in the transverse direction 4. However, additional transport stability can be achieved by providing more than one guiding magnet on each side of the magnetic guide 200.

[0034] Referring now to FIG. 3B, an alternative arrangement of guiding magnets is shown. According to an embodiment, which may be combined with other embodiments described herein, the at least one first guiding magnet includes two first guiding magnets 21a, 21b and the at least one second guiding magnet includes two second guiding magnets 22a, 22b, and wherein the two first guiding magnets 21a, 21b are offset from each other in a third direction 3 perpendicular to the transport direction T, and the two second guiding magnets 22a, 22b are offset from each other in the third direction 3 perpendicular to the transport direction T.

[0035] Arranging two first guiding magnets 21a, 21b and two second guiding magnets 22a, 22b on each respective side of the magnetic guide 200 allows for the magnetic repulsive force between the first and second guiding magnets 21a, 21b, 22a, 22b to be directed not only in the transverse direction 4, but also in a third direction 3. In the case of a carrier 30 being transported in a substantially vertical orientation, the third direction 3 is in the vertical direction. Thus, a component of the magnetic repulsive force is directed in the transverse direction 4 and another component of the magnetic repulsive force is directed in the third direction 3.

[0036] By applying the magnetic repulsive force also in the third direction 3, increased stability is provided to the transported carrier in a direction perpendicular to the transport direction T. In the case of a carrier 30 being transported in a substantially vertical orientation, additional stability is provided in the vertical direction such that enhanced guiding of the carrier 30 is provided.

[0037] According to an embodiment, which may be combined with other embodiments described herein, the at least one carrier guiding magnet 31 may be arranged to be guided at a point in the third direction 3 between the two first guiding magnets 21a, 21b and at a point in the third direction 3 between the two second guiding magnets 22a, 22b. More particularly, the at least one carrier guiding magnet 31 may be arranged at the magnetic equilibrium point between the two first guiding magnets 21a, 21b and the two second guiding magnets 22a, 22b.

[0038] Alternative arrangements of the first and second guiding magnets and the carrier guiding magnets may also provide the additional stability advantages discussed above. For example, providing one first guiding magnet 21 and one second guiding magnet 22, and providing two carrier guiding magnets 31 offset from each other in the third direction 3 would also provide additional vertical stability to the transported carrier. Alternatively, providing three or more first guiding magnets 21 and three or more second guiding magnets 22, and providing two carrier guiding magnets 31 offset from each other in the third direction 3 also provides additional vertical stability. Particularly, the additional stability may be provided when the numbers of first and second guiding magnets are equal to the number of carrier guiding magnets plus or minus one.

[0039] According to embodiments of the present disclosure, a transport system for transporting a carrier is provided. Reference will now be made to FIG. 4, which shows a schematic side view of a transport system 300 for transporting a carrier 30 in the transport direction T. The transport system 300 includes a transporting means 40 extending in the transport direction T configured for supporting the carrier 30 against the force of gravity and for moving the carrier 30 in the transport direction T, and a magnetic guide 200 according to embodiments described in the present disclosure.

[0040] Due to transporting means 40 providing support to the carrier 30 against the force of gravity, magnetic guide 200 is primarily configured to provide guidance in the transverse direction. Carrier 30 may be provided with a carrier guiding magnet

31 on one edge, and a guiding structure 32 on an opposite edge. Carrier guiding magnet 31 is provided for interacting with magnetic guide 200, and guiding structure

32 is provided for interacting with transporting means 40. Further, according to embodiments, the carrier 30 is oriented in a substantially vertical orientation.

[0041] FIG. 4 schematically shows an example of where a gap G is provided in transport system 300. In the present example, a sealing door 50 may be provided between two processing chambers. Transport system 300 transports carrier 30 such that gap G is bridged. The gap G between each end of the respective magnetic guides 200 may be up to 500 mm, and may be different between the gap between each end of the respective transporting means 40. According to embodiments described herein, first and second guiding magnets 21, 22 of each respective magnetic guide 200 extend from the housing 10 so as to shield a magnetic attraction force between the carrier guiding magnet 31 and the housing 10, such that a collision between the carrier 30 and the housing 10 is avoided.

[0042] The transport system as exemplarily shown in FIG. 4 is provided for transporting the carrier 30 in a substantially vertical orientation. As exemplarily shown, the magnetic guide 200 is provided at the upper side of carrier 30 so as to provide guidance in the transverse direction by interacting with the upper edge of the carrier 30. Accordingly, transporting means 40 is provided at the lower side of carrier 30 so as to support and transport the carrier 30 by interacting with the lower edge of the carrier 30. According to an embodiment, which may be combined with other embodiments described herein, the magnetic guide 200 is an upper guide. The transport system 300 of this embodiment can be thought of as a “standing” system, whereby the carrier 30 is supported at its lower edge and “stands” on transporting means 40 in a substantially vertical orientation. Accordingly, carrier 30 may be provided with a carrier guiding magnet 31 at its upper edge which is guided between first and second guiding magnets 21, 22 of the magnetic guide 200.

[0043] Alternatively, the transport system 300 may be arranged opposite to the arrangement shown exemplarily in FIG. 4. In other words, the magnetic guide 200 may be provided at the lower side of carrier 30 so as to provide guidance in the transverse direction by interacting with the lower edge of the carrier 30. Accordingly, transporting means 40 is provided on the upper side of carrier 30 so as to support and transport the carrier 30 by interacting with the upper edge of the carrier 30. According to an embodiment, which may be combined with other embodiments described herein, the magnetic guide 200 is a lower guide. The transport system 300 of this embodiment can be thought of as a “hanging” system, whereby the carrier 30 is supported at its upper edge and “hangs” from transporting means 40 in a substantially vertical orientation.

[0044] According to an embodiment, which may be combined with other embodiments described herein, the transport system 300 is configured for operating in a vacuum. Transport system 300 may be configured for transporting carrier 30 into or out of a processing chamber which is maintained in a vacuum condition or a reduced pressure condition. In the present disclosure, the term “vacuum” may refer to a partial vacuum, whereby the internal pressure of a processing chamber is lower than the ambient pressure outside of the processing chamber. Accordingly, components of the transport system 300 may be configured so as to withstand a vacuum environment, or configured so as to not contaminate a vacuum environment.

[0045] Transporting means 40 may support and transport carrier 30 using contactless means, for example, using magnetic levitation. According to an embodiment, which may be combined with other embodiments described herein, transporting means 40 comprises a plurality of active magnetic bearings configured for supporting and moving the carrier 30 by magnetic levitation. The plurality of active magnetic bearings may be controlled in a manner such that the plurality of active magnetic bearings forms a linear motor. Accordingly, guiding structure 32 of carrier 30 may include a magnetic material component having a surface that is directed toward the active magnetic bearings of the transport means 40 during transport of the carrier 30 in the transport direction T.

[0046] Transporting means 40 may be configured to hold at least a part of the weight of the carrier 30 or the whole weight of the carrier 30 by magnetic forces. For example, the carrier 30 may be held in a contactless manner or in an essentially contactless manner with respect to transporting means 40 during the transport along the transport system 300. The magnetic levitation system may include a plurality of levitation magnets for levitating the carrier relative to the transporting means 40, e.g. active and/or passive levitation magnets, such as a plurality of active magnetic bearings. Magnetic levitation of carrier 30 along transport system 300 has the advantage of frictionless transport, such that the generation of particles resulting from friction between a carrier and the transport system 300 is reduced. Reducing particles generated in the processing system allows for higher quality material deposition on a substrate in, for example, a deposition chamber.

[0047] Alternatively, transporting means 40 may support and transport carrier 30 using non-contactless means. According to an embodiment, which may be combined with other embodiments described herein, transporting means 40 may include a plurality of rollers. For example, a plurality of rollers may be provided in the transport direction T upon which the carrier 30 is supported. Rotation of at least some of the plurality of rollers in a particular direction causes the carrier 30 to be transported in the transport direction T. Guiding structure 32 of carrier 30 may have the form of a cylindrical bar or rod extending in the transport direction. Accordingly, the plurality of rollers may have a circumferential groove formed therein, which is provided for accepting the guiding structure 32 of carrier 30.

[0048] According to an embodiment of the present disclosure, a method of guiding a carrier with a magnetic guide is provided. The magnetic guide includes a housing, at least one first guiding magnet, and at least one second guiding magnet. The method includes shielding a magnetic attraction of the carrier towards the housing by the at least one first guiding magnet and the at least one second guiding magnet. By shielding the magnetic attraction of the carrier towards the housing, a collision between the carrier and the housing is avoided. Particularly, the shielding of the magnetic attraction of the carrier towards the housing may be provided by a magnetic guide according to any of the embodiments described in the present disclosure.

[0049] While the foregoing is directed to embodiments, other and further embodiments may be devised without departing from the basic scope, and the scope is determined by the claims that follow.