WO2019007515A1

WO2019007515A1 - Apparatus and method for holding a substrate

Info

Publication number: WO2019007515A1
Application number: PCT/EP2017/066979
Authority: WO
Inventors: Michael Rainer SCHULTHEIS; Andreas Lopp; Wolfgang Buschbeck; Jürgen Henrich; Stefan Bangert
Original assignee: Applied Materials, Inc.
Priority date: 2017-07-06
Filing date: 2017-07-06
Publication date: 2019-01-10
Also published as: CN109477201A; JP2019523818A; JP6670941B2; KR20190087969A

Abstract

The present disclosure provides an apparatus (100) for holding a substrate (10) or a mask in a vacuum deposition process. The apparatus (100) includes one or more first electrodes and one or more second electrodes connectable to a first power assembly (230) and one or more third electrodes arranged between the one or more first electrodes and the one or more second electrodes and connectable to a second power assembly (240).

Description

APPARATUS AND METHOD FOR HOLDING A SUBSTRATE

FIELD

[0001] Embodiments of the present disclosure relate to an apparatus for holding a substrate used in a vacuum deposition process, a system for layer deposition on a substrate, and a method for holding a substrate. Embodiments of the present disclosure particularly relate to an electrostatic chuck (E-chuck) for holding substrates in an essentially vertical orientation.

BACKGROUND

[0002] Techniques for layer deposition on a substrate include, for example, thermal evaporation, physical vapor deposition (PVD), 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 microelectronics, such as for organic light emitting diode (OLED) devices, substrates with TFTs, color filters or the like.

[0003] During a vacuum deposition process, the substrate can be supported by a substrate support using, for example, holding devices such as mechanical clamps, to hold the substrate and an optional mask at the substrate support. In the past, there has been a continuous increase in substrate sizes. The increasing size of substrates makes the handling, supporting and aligning of the substrates and masks, e.g. without sacrificing the throughput through substrate breakage, increasingly challenging. Moreover, the space available for holding a substrate inside a vacuum chamber can be limited. Accordingly, there is also a need for reducing the space used by supporting systems for holding a substrate inside a vacuum chamber. [0004] In view of the above, new apparatuses for holding a substrate used in a vacuum deposition process, systems for layer deposition on a substrate, and methods for holding a substrate, that overcome at least some of the problems in the art are beneficial. The present disclosure particularly aims at providing an apparatus, system and method for reliably holding a substrate and an optional mask e.g. during a vacuum deposition process.

SUMMARY

[0005] In light of the above, an apparatus for holding a substrate used in a vacuum deposition process, a system for layer deposition on a substrate, and a method for holding a substrate are provided. Further aspects, benefits, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings. [0006] According to an aspect of the present disclosure, an apparatus for holding a substrate or a mask used in a vacuum deposition process is provided. The apparatus includes one or more first electrodes and one or more second electrodes, and a first power assembly connected to the one or more first electrodes and a second power assembly connected to the one or more second electrodes, wherein at least one of the first power assembly and the second power assembly provides one or more redundant components.

[0007] According to an aspect of the present disclosure, an apparatus for holding a substrate or a mask used in a vacuum deposition process is provided. The apparatus includes one or more first electrodes and one or more second electrodes, and a first power assembly connected to the one or more first electrodes and a second power assembly connected to the one or more second electrodes.

[0008] According to another aspect of the present disclosure, an apparatus for holding a substrate or a mask used in a vacuum deposition process is provided. The apparatus includes one or more first electrodes and one or more second electrodes connectable to a first power assembly, and one or more third electrodes arranged between the one or more first electrodes and the one or more second electrodes and connectable to a second power assembly.

[0009] According to yet another aspect of the present disclosure, an apparatus for holding a substrate or a mask used in a vacuum deposition process is provided. The apparatus includes a first electrode arrangement having one or more first electrodes, a second electrode arrangement having one or more second electrodes, and a controller configured to ground at least one electrode of the one or more first electrodes and the one or more second electrodes when the at least one electrode is defective.

[0010] According to an aspect of the present disclosure, an apparatus for holding a substrate or a mask used in a vacuum deposition process is provided. The apparatus includes a main electrode arrangement and a redundant electrode arrangement, wherein each of the main electrode arrangement and the redundant electrode arrangement is configured to provide an attracting force sufficient to hold the at least one of the substrate and the mask at the support surface. [0011] According to a further aspect of the present disclosure, a system for layer deposition on a substrate is provided. The system includes a vacuum chamber, one or more deposition material sources in the vacuum chamber, and the apparatus for holding the substrate or a mask in a vacuum deposition process according to the embodiments described herein. [0012] According to a further aspect of the present disclosure, a method for holding a substrate or a mask is provided. The method includes operating one or more first electrodes using a first power assembly and one or more second electrodes using a second power assembly, and operating the one or more first electrodes using a component selected from the group consisting of a power supply, a high voltage generator and a controller of the second power assembly when it is determined that a failure in the first power assembly has occurred.

[0013] According to a yet further aspect of the present disclosure, a method for holding a substrate or a mask is provided. The method includes applying a first voltage to one or more first electrodes and one or more second electrodes, applying a second voltage to one or more third electrodes arranged between the one or more first electrodes and the one or more second electrodes, and connecting at least one electrode of the one or more first electrodes, the one or more second electrodes, and the one or more third electrodes to ground. [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 have can be understood in detail part supply, such as, 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 view of an apparatus for holding a substrate in a vacuum deposition process according to embodiments described herein;

FIGs. 2A and B show schematic views of electrode configurations according to embodiments described herein; FIG. 3 shows a schematic view of an apparatus for holding a substrate in a vacuum deposition process according to further embodiments described herein;

FIG. 4 shows a schematic view of a system for layer deposition on a substrate according to embodiments described herein; and

FIG. 5 shows a flow chart of a method for holding a substrate 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. Generally, 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] In OLED coating systems, the substrate can be held during transport and deposition using a monopolar or bipolar electrostatic chuck (E-chuck). Electrostatic chucks can transport flat substrate materials, such as glass, wafers, plastic, and the like, through a process environment. The substrate can be supported using a chucking voltage and the design of the electrodes inside the electrostatic chuck. The environment in which the E- chuck is used may include warm/cold temperatures, atmosphere/overpressure/vacuum, dry/wet conditions, etc. A high voltage can generate an electrostatic field using the electrodes. The electrostatic field can collapse e.g. if there is a leakage current due to an error, such as a short circuit. In this case the substrate can drop from the electrostatic chuck.

[0018] The present disclosure provides an apparatus, such as an electrostatic chuck, having a fail-safe substrate support. Even if there is a problem with the electrostatic field, the substrate can be held at the substrate support. In particular, the present disclosure provides an apparatus with redundancy. One or more redundancy components are provided, such as a power supply, a high voltage (HV) generator, and/or a controller. The apparatus can further have one or more redundant electrodes, such as one or more redundant electrode pairs (cluster). Each electrode pair can have an own power assembly, which may include at least one of a power supply, a HV generator and a controller. Accordingly, if there is a problem with one electrode pair or the components used to operate the electrode pair, the other(s) continue(s) to support the substrate so the substrate does not fall of the apparatus. Such a system provides more process safety. An extensive cleaning due to broken substrates inside a manufacturing tool, which may be under vacuum, can be avoided. The embodiments of the present disclosure are particularly beneficial for applications in which the substrate is in an essentially vertical orientation.

[0019] FIG. 1 shows a schematic view of an apparatus 100 for holding a substrate 10 in a vacuum deposition process according to embodiments described herein. The apparatus 100 can be a substrate support, such as a carrier. In particular, the apparatus 100 according to the present disclosure can be an electrostatic chuck (E-chuck) providing an electrostatic force.

[0020] The apparatus 100 includes a support surface 112, an electrode arrangement 120 having a plurality of electrodes configured to provide an attracting force for holding at least one of the substrate 10 and a mask 20 at the support surface 112, and a controller 130. The controller 130 can be configured to selectively apply one or more voltages to the electrode arrangement 120. The electrode arrangement 120 may include a first electrode arrangement having at least one or more first electrodes and one or more second electrodes.

[0021] According to some embodiments, a first power assembly is connected to the one or more first electrodes and a second power assembly is connected to the one or more second electrodes. The second power assembly can provide one or more redundant components e.g. for the first power assembly, or vice versa. The one or more redundant components can be selected from the group including a power supply (e.g. a battery), a high voltage (HV) generator and a controller (e.g. the controller 130). For example, the first power assembly includes at least one of a first power supply, a first high voltage generator and a first controller. The second power assembly can include at least one of a second power supply, a second high voltage generator and a second controller. [0022] The at least one of the second power supply, the second high voltage generator and the second controller can be configured to substitute for a defective one of the first power supply, the first high voltage generator and the first controller. For example, the second power assembly provides one or more components adapted to replace a component of the first power assembly in case of failure of the component of the first power assembly. However, the present disclosure is not limited to a substitution of the defective component and the first power assembly and the second power assembly can be independent from each other.

[0023] In some implementations, the first power assembly and the second power assembly include the same components. In particular, the first power assembly can include the first power supply, the first high voltage generator and the first controller. The second power assembly can include the second power supply, the second high voltage generator and the second controller. In other words, the first power assembly and the second power assembly can be configured essentially identically. In some embodiments, if one component of a power assembly fails, the corresponding component of the other power assembly can take over. Full redundancy can be provided. In other embodiments, the first power supply and the second power supply are independent from each other and cannot substitute each other.

[0024] In further implementations, the first power assembly and the second power assembly can share one or more components selected from the group consisting of a power supply, a high voltage generator and a controller. The one or more redundant components can be non-shared components. For example, the first power assembly and the second power assembly can share a power supply. In other words, the first power assembly and the second power assembly can include (or use) the same power supply. Each of the first power assembly and the second power assembly can include a respective HV generator and controller. If a HV generator and/or a controller of one power assembly fails, the other HV generator and/or controller of the other power assembly can take over the function of the defective component. A partial redundancy can be provided. In other embodiments, the first power supply and the second power supply are independent from each other and cannot substitute each other. [0025] According to some embodiments, which can be combined with other embodiments described herein, the first power assembly and the second power assembly share the controller (common controller). In other words, the controller is provided once, i.e., not redundantly. The first power assembly can include the first power supply and/or the first HV generator and the second power assembly can include the second power supply and/or the second HV generator. In other words, the power supply and/or the HV generator is/are provided twice, i.e., redundantly. [0026] According to some embodiments, which can be combined with other embodiments described herein, the first power assembly and the second power assembly share the power supply (common power supply). In other words, the power supply is provided once, i.e., not redundantly. The first power assembly can include the first controller and/or the first HV generator and the second power assembly can include the second controller and/or the second HV generator. In other words, the controller and/or the HV generator is/are provided twice, i.e., redundantly.

[0027] According to some embodiments, which can be combined with other embodiments described herein, the first power assembly and the second power assembly share the HV generator (common HV generator). In other words, the HV generator is provided once, i.e., not redundantly. The first power assembly can include the first controller and/or the first power supply and the second power assembly can include the second controller and/or the second power supply. In other words, the controller and/or the power supply is/are provided twice, i.e., redundantly. [0028] In view of the above, at least one common component can be provided which is shared by the first power assembly and the second power assembly and optionally one or more further power assemblies. The at least one common component can be selected from the group consisting of a controller, a power supply, and a HV generator. At least one of the other components can be provided redundantly, i.e., at least twice. [0029] According to further embodiments, as illustrated in FIGs. 2A and B, the electrode arrangement 120 may include a first electrode arrangement having at least one or more first electrodes and one or more second electrodes and a second electrode arrangement having at least one or more third electrodes. According to some embodiments, the one or more first electrodes and the one or more second electrodes are connectable (or connected) to a first power assembly. The one or more third electrodes are arranged between the one or more first electrodes and the one or more second electrodes and are connectable (or connected) to a second power assembly. The first power assembly and the second power assembly may each include at least one of a power supply (e.g. a battery), a HF generator, and a controller. In some implementations, the first power assembly and the second power assembly may each include a respective battery integrated in the apparatus 100, wherein the batteries may be chargeable using an external power source. The second power assembly can provide one or more redundant components for the first power assembly and/or the first power assembly can provide one or more redundant components for the second power assembly. The first power assembly and the second power assembly can be configured as described above and can particularly provide the full or partial redundancy. [0030] Even if e.g. the one or more third electrodes and/or components of the second power assembly fail, the substrate 10 can be reliably held at the support surface 112. For example, both the first electrode arrangement and the second electrode arrangement are configured to provide an attracting force sufficient to hold the substrate 10 and/or the mask 20 at the support surface 112. The arrangement of the one or more third electrodes between the one or more first electrodes and the one or more second electrodes in combination with the respective connections to the individual power assembly can provide an improved distribution of the attracting force across the support surface 112. In particular, the occurrence of large areas without attracting force in the event of a failure can be avoided.

[0031] The electrode arrangement 120 can be configured to provide the attracting force, such as a chucking force. The attracting force can be a force acting on the substrate 10 and/or the mask 20 at a certain relative distance between the electrode arrangement 120 (or the support surface 112) and the substrate 10 and/or the mask 20. The attracting force can be an electrostatic force provided by the voltages applied to the electrodes of the electrode arrangement 120. A magnitude of the attracting force may be determined by a voltage polarity configuration and a voltage level. The attracting force can be changed by altering the voltage polarity configuration and/or by altering the voltage level.

[0032] The attracting force can be defined with respect to the entity on which the attracting force acts. For example, the attracting force acting on the substrate 10 can be referred to as "substrate attracting force 140". Likewise, the attracting force acting on the mask 20 can be referred to as "mask attracting force 142". Yet, the term "attracting force" shall embrace both the substrate attracting force and the mask attracting force.

[0033] The substrate 10 is attracted by the attracting force provided by the apparatus 100, which can be an E-chuck, towards the support surface 112 (e.g., in a direction 2, which can be a horizontal direction perpendicular to a vertical direction 1). The attracting force can be strong enough to hold the substrate 10 e.g. in a vertical position using factional forces. In particular, the attracting force, such as the substrate attracting force 140, can be configured to fix the substrate 10 on the support surface 112 essentially immoveably. For example, to hold a 0.5 mm glass substrate in a vertical position using friction forces, an attracting pressure of about 50 to 100 N/m² (Pa) can be used, depending on the friction coefficient. [0034] The apparatus 100 can include a body 110 providing the support surface 112, which can be an essentially flat surface configured for contacting e.g. a back surface of the substrate 10. In particular, the substrate 10 can have a front surface (also referred to as "processing surface") opposite the back surface and on which a layer is deposited during the vacuum deposition process. [0035] The electrode arrangement 120 can be embedded in the body 110, or can be provided, e.g., placed, on the body 110. According to some embodiments, which can be combined with other embodiments described herein, the body 110 is a dielectric body, such as a dielectric plate. The dielectric body can be fabricated from a dielectric material, preferably a high thermal conductivity dielectric material such as pyrolytic boron nitride, aluminum nitride, silicon nitride, alumina or an equivalent material, but may be made from such materials as polyimide. In some embodiments, the electrodes, such as a grid of fine metal strips, can be placed on the dielectric plate and covered with a thin dielectric layer.

[0036] According to some embodiments, which can be combined with other embodiments described herein, the apparatus 100 includes two or more voltage sources, such as the first power supply and/or the first HV generator of the first power assembly and the second power supply and/or the second HV generator of the second power assembly, configured to apply one or more voltages to the electrode arrangement 120. In some implementations, the two or more voltage sources are configured to ground at least one electrode of the electrode arrangement 120. For example, the two or more voltage sources can be configured to apply a first voltage having a first polarity, a second voltage having a second polarity, and/or ground to the electrode arrangement 120. Dashed squares in FIG. 1 indicate electrodes having e.g. the first polarity and open squares indicate electrodes having e.g. the second polarity. As used throughout the present disclosure, the term "polarity" refers to an electric polarity, i.e., negative (-) and positive (+). For example, the first polarity can be the negative polarity and the second polarity can be the positive polarity, or the first polarity can be the positive polarity and the second polarity can be the negative polarity.

[0037] The controller 130 can be configured to control the two or more voltage sources for applying the one or more voltages and/or ground to the electrode arrangement 120. In some implementations, the controller 130 can be integrated into the one or more voltage sources, or vice versa. In further implementations, the controller 130 can be provided as a separate entity connected to the one or more voltage sources, for example, via a cable connection and/or a wireless connection.

[0038] According to some embodiments, which can be combined with other embodiments described herein, the apparatus 100 can be a unipolar apparatus, such as a unipolar E-chuck, a bipolar apparatus, such as a bipolar E-chuck, or a combined E-chuck switchable between the unipolar configuration and the bipolar configuration. In particular, the unipolar configuration includes polarities of only one kind, i.e., either the first polarity or the second polarity, and optionally includes one or more grounded electrodes. The bipolar configuration includes both kinds of polarities, i.e., the first polarity and the second polarity, and optionally includes one or more grounded electrodes.

[0039] The apparatus 100 can be configured for contactless levitation and/or contactless transportation in a vacuum chamber of a vacuum processing system, e.g., along one or more transportation paths in a transport direction. For example, the apparatus 100 may include a one or more passive magnetic elements. For example, the one or more passive magnetic elements can be bars or rods of a ferromagnetic material which can be a portion of the apparatus. Alternatively, the one or more passive magnetic elements may be integrally formed with the apparatus 100. The one or more passive magnetic elements can magnetically interact with a magnetic structure, such as a magnetic guiding and/or drive structure, in the vacuum chamber of the vacuum processing system for contactless levitation and/or contactless transportation of the apparatus 100 in the vacuum chamber.

[0040] The contactless levitation and/or transportation of the apparatus 100 is beneficial in that no particles are generated during transportation, for example due to mechanical contact with guide rails. An improved purity and uniformity of the layers deposited on the substrate can be provided, since particle generation is minimized when using the contactless levitation and/or transportation.

[0041] The term "contactless" can be understood in the sense that the weight of the apparatus, e.g. of the substrate carrier and/or mask carrier, is not held by a mechanical contact or mechanical forces but is held by a magnetic force. In particular, the carrier can be held in a levitating or floating state using magnetic forces instead of mechanical forces. For example, in some implementations, there can be no mechanical contact between the carrier and the transportation track, particularly during levitation, movement and positioning of the substrate carrier and/or mask carrier. [0042] According to some embodiments, which can be combined with other embodiments described herein, the apparatus 100 is configured to hold at least one of the substrate 10 and the mask 20 in an essentially vertical orientation (with respect to the vertical direction 1), and in particular during the vacuum deposition process. As used throughout the present disclosure, "substantially vertical" is understood particularly when referring to the substrate orientation, to allow for a deviation from the vertical direction or orientation of ±20° or below, e.g. of ±10° or below. This deviation can be provided for example because a substrate support with some deviation from the vertical orientation might result in a more stable substrate position. Further, fewer particles reach the substrate surface when the substrate is tilted forward. Yet, the substrate orientation, e.g., during the vacuum deposition process, is considered substantially vertical, which is considered different from the horizontal substrate orientation, which may be considered as horizontal ±20° or below.

[0043] The term "vertical direction" or "vertical orientation" is understood to distinguish over "horizontal direction" or "horizontal orientation". That is, the "vertical direction" or "vertical orientation" relates to a substantially vertical orientation e.g. of the carrier and the substrate, wherein a deviation of a few degrees, e.g. up to 10° or even up to 15°, from an exact vertical direction or vertical orientation is still considered as a " substantially vertical direction" or a "substantially vertical orientation". The vertical direction can be substantially parallel to the force of gravity. [0044] The embodiments described herein can be utilized for evaporation on large area substrates, e.g., for display manufacturing. Specifically, the substrates for which the structures and methods according to embodiments described herein are provided, are large area substrates. For instance, a large area substrate or carrier can be GEN 4.5, which corresponds to a surface area of about 0.67 m² (0.73 x 0.92m), GEN 5, which corresponds to a surface area of about 1.4 m² (1.1 m x 1.3 m), GEN 7.5, which corresponds to a surface area of about 4.29 m² (1.95 m x 2.2 m), GEN 8.5, which corresponds to a surface area of about 5.7m² (2.2 m x 2.5 m), or even GEN 10, which corresponds to a surface area of about 8.7 m² (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding surface areas can similarly be implemented. Half sizes of the Gen generations may also be provided in OLED display manufacturing.

[0045] According to some embodiments, which can be combined with other embodiments described herein, the substrate thickness can be from 0.1 to 1.8 mm. The substrate thickness can be about 0.9 mm or below, such as 0.5 mm. The term "substrate" as used herein may particularly embrace substantially inflexible substrates, e.g., a wafer, slices of transparent crystal such as sapphire or the like, or a glass plate. However, the present disclosure is not limited thereto and the term "substrate" may also embrace flexible substrates such as a web or a foil. The term "substantially inflexible" is understood to distinguish over "flexible". Specifically, a substantially inflexible substrate can have a certain degree of flexibility, e.g. a glass plate having a thickness of 0.9 mm or below, such as 0.5 mm or below, wherein the flexibility of the substantially inflexible substrate is small in comparison to the flexible substrates.

[0046] According to embodiments described herein, the substrate may be made of any material suitable for material deposition. For instance, the substrate may be made of a material selected from the group consisting of glass (for instance soda-lime glass, borosilicate glass, and the like), metal, polymer, ceramic, compound materials, carbon fiber materials or any other material or combination of materials which can be coated by a deposition process.

[0047] The term "masking" may include reducing and/or hindering a deposition of material on one or more regions of the substrate 10. The masking may be useful, for instance, in order to define the area to be coated. In some applications, only parts of the substrate 10 are coated and the parts not to be coated are covered by the mask 20.

[0048] FIG. 2A shows a schematic view of electrode configurations according to embodiments described herein. [0049] The apparatus includes the first electrode arrangement having at least the one or more first electrodes 210 and the one or more second electrodes 212, and the second electrode arrangement having at least the one or more third electrodes 220. The first electrode arrangement, and particularly the one or more first electrodes 210 and the one or more second electrodes 212, are connected to the first power assembly 230. The second electrode arrangement, and particularly the one or more third electrodes 220, are connected to the second power assembly 240. The first power assembly 230 can include at least one of a first power supply, a first high voltage generator and a first controller. The second power assembly can include at least one of a second power supply, a second high voltage generator and a second controller. One or more of the aforementioned components can be configured as redundant components. For example, at least one of the second power supply, the second high voltage generator and the second controller can be configured to substitute for a defective one of the first power supply, the first high voltage generator and the first controller. Likewise, at least one of the first power supply, the first high voltage generator and the first controller can be configured to substitute for a defective one of the second power supply, the second high voltage generator and the second controller.

[0050] In some implementations, the first electrode arrangement can be a main electrode arrangement and the second electrode arrangement can be a redundant electrode arrangement. Each of the first electrode arrangement and the second electrode arrangement can generate an attracting force sufficient to hold the substrate at the apparatus 100. Even if e.g. the main electrode arrangement fails, the redundant electrode arrangement can hold the substrate at the apparatus, and particularly at the support surface.

[0051] According to some embodiments, which can be combined with other embodiments described herein, the first power assembly 230 is configured to apply at least one of a positive voltage and a negative voltage to the first electrode arrangement. Likewise, the second power supply can be configured to apply at least one of a positive voltage and a negative voltage to the second electrode arrangement. In the monopolar configuration, first power assembly 230 and the second power assembly 240 can be configured to apply either the positive voltage or the negative voltage to the first electrode arrangement and the second electrode arrangement, respectively. In the bipolar configuration, first power assembly 230 and the second power assembly 240 can be configured to apply both the positive voltage and the negative voltage to respective electrodes of the first electrode arrangement and the second electrode arrangement, respectively. An example of the bipolar case is illustrated in FIG. 3

[0052] Referring to FIG. 2B, the second electrode arrangement can include one or more fourth electrodes 222 connectable (or connected) to the second power assembly 240. The first power assembly 230 and the second power assembly 240 can be independent from each other. Accordingly, even if one power assembly or a component thereof fails, the other power assembly can continue to provide a voltage to the connected electrode arrangement to continue holding the substrate at the support surface of the apparatus. [0053] The one or more third electrodes 220 can be arranged between the one or more first electrodes 210 and the one or more second electrodes 212. Further, the one or more second electrodes 212 can be arranged between the one or more third electrodes 220 and the one or more fourth electrodes 222. The first electrode arrangement and the second electrode arrangement are thus interleaved. An improved distribution of the attracting force across the support surface can be achieved. In particular, the occurrence of large areas without attracting force in the event of a failure can be avoided.

[0054] According to some embodiments, which can be combined with other embodiments described herein, the apparatus includes at least one switch configured to open and close a connection between a power supply and an electrode arrangement. The at least one switch can be configured to open and close a connection between the power assembly and the electrode arrangement, such as the entire electrode arrangement. In further implementations, at least one switch can be configured to selectively open and close a connection between the power assembly and the one or more electrodes of the electrode arrangement. The at least one switch can disconnect e.g. defective electrodes from the respective power assembly and/or a defective power assembly from electrodes. [0055] As an example, the apparatus includes one or more first switches configured to open and close a connection between the first power assembly 230 and the first electrode arrangement. In some implementations, one first switch can be provided to open and close the connection between the first power assembly 230 and the first electrode arrangement, such as the entire first electrode arrangement. In further implementations, two or more first switches can be provided to selectively open and close the connection between the first power assembly 230 and one or more electrodes of the first electrode arrangement, such as the one or more first electrodes 210 and the one or more second electrodes 212. For example, one switch of the two or more first switches can be provided to open and close the connection between the first power assembly 230 and the one or more first electrodes 210. Another switch of the two or more first switches can be provided to open and close the connection between the first power assembly 230 and the one or more second electrodes 212.

[0056] Likewise, the apparatus can include one or more second switches configured to open and close a connection between the second power assembly 240 and the second electrode arrangement. In some implementations, one second switch can be provided to open and close the connection between the second power assembly 240 and the second electrode arrangement, such as the entire second electrode arrangement. In further implementations, two or more second switches can be provided to selectively open and close the connection between the second power assembly 240 and one or more electrodes of the second electrode arrangement, such as the one or more third electrodes 220 and the one or more fourth electrodes 222. For example, one switch of the two or more second switches can be provided to open and close the connection between the second power assembly 240 and the one or more third electrodes 220. Another switch of the two or more second switches can be provided to open and close the connection between the second power assembly 240 and the one or more fourth electrodes 222.

[0057] FIG. 3 shows a schematic view of an apparatus for holding a substrate in a vacuum deposition process according to further embodiments described herein. The exemplary apparatus is a bipolar E-chuck. [0058] The apparatus includes the first electrode arrangement connected to the first power supply and the second electrode arrangement connected to the second power supply. The first electrode arrangement includes the one or more first electrodes 310 and the one or more second electrodes 320. The second electrode arrangement includes the one or more third electrodes 330 and the one or more fourth electrodes 340. The first electrode arrangement and the second electrode arrangement are interleaved. [0059] According to some embodiments, which can be combined with other embodiments described herein, at least one of the one or more first electrodes 310, the one or more second electrodes 320, the one or more third electrodes 330, and the one or more fourth electrodes 340 can include sub-electrodes of different polarity. The sub-electrodes of different polarity can be interleaved. [0060] For example, the one or more first electrodes 310 include one or more sub- electrodes of a first polarity (one or more first sub-electrodes 312 or first electrode pattern) and one or more sub-electrodes of a second polarity (one or more second sub-electrodes 314 or second electrode pattern) opposite the first polarity. The one or more second electrodes 320 can include one or more sub-electrodes of the first polarity (one or more third sub-electrodes 322 or third electrode pattern) and one or more sub-electrodes of the second polarity (one or more fourth sub-electrodes 324 or fourth electrode pattern). The one or more third electrodes 330 can include one or more sub-electrodes of the first polarity (one or more fifth sub-electrodes 332 or fifth electrode pattern) and one or more sub-electrodes of the second polarity (one or more sixth sub-electrodes 334 or sixth electrode pattern). The one or more fourth electrodes 340 can include one or more sub- electrodes of the first polarity (one or more seventh sub-electrodes 342 or seventh electrode pattern) and one or more sub-electrodes of the second polarity (one or more eight sub-electrodes 344 or eighth electrode pattern).

[0061] In some implementations, the one or more sub-electrodes of the first polarity and the one or more sub-electrodes of the second polarity are interleaved. In other words, the sub-electrodes can be alternately arranged. In particular, a sub-electrode of one polarity can be provided between two adjacent sub-electrodes of the other polarity. For example, the one or more first sub-electrodes 312 and the one or more second sub-electrodes 314 can be interleaved. Likewise, the one or more third sub-electrodes 322 and the one or more fourth sub-electrodes 324 can be interleaved, the one or more fifth sub-electrodes 332 and the one or more sixth sub-electrodes 334 can be interleaved, and the one or more seventh sub- electrodes 342 and the one or more eight sub-electrodes 344 can be interleaved.

[0062] According to some embodiments, which can be combined with other embodiments described herein, the electrodes or sub-electrodes are arranged as a grid. For example, the electrodes or sub-electrodes can be wires, lines or strips of a conductive material. The conductive material can be selected from the group consisting of a metal, copper, aluminum, and any combination thereof. The electrodes or sub-electrodes can extend essentially parallel to each other in a first direction. The first direction can correspond to a length extension of the wires, lines or strips. The electrodes or sub- electrodes can be spaced apart from each other in a second direction perpendicular to the first direction. The distance between adjacent electrodes or sub-electrodes in the second direction can be between 0.1 mm and 5 mm, specifically between 0.1 and 2 mm, and more specifically between 0.5 and 1 mm. According to some embodiments, which can be combined with other embodiments described herein, the sub-electrodes have a width in the second direction. For example, the width can be between 0.1 mm and 5 mm, specifically between 0.1 and 2 mm, and more specifically between 0.5 and 1 mm.

[0063] According to some embodiments, which can be combined with other embodiments described herein, the apparatus has two or more power terminals, such as two or more contacts. The two or more power terminals can provide a connection between the first power assembly and the first electrode arrangement and can provide a connection between the second power assembly and the second electrode arrangement. In some implementations, the apparatus can include the power supplies, such as chargeable batteries. For example, the power supplies can be integrated in the apparatus such that no connection to an external power supply has to be provided during the use of the apparatus in a vacuum processing system. The at least one switch described with respect to FIGs. 2 A and B can be provided at the two or more power terminals.

[0064] The first power assembly can be configured to apply at least one of a positive voltage and a negative voltage to the first electrode arrangement, and the second power assembly can be configured to apply at least one of a positive voltage and a negative voltage to the second electrode arrangement. In the example of FIG. 3, the first power assembly supplies a first voltage of a first polarity to the one or more first sub-electrodes 312 and the one or more third sub-electrodes 322 e.g. via a first power terminal 350. The first power assembly supplies a second voltage of a second polarity opposite the first polarity to the one or more second sub-electrodes 314 and the one or more fourth sub- electrodes 324 e.g. via a second power terminal 354. The second power assembly supplies a third voltage of the first polarity to the one or more fifth sub-electrodes 332 and the one or more seventh sub-electrodes 342 e.g. via a third power terminal 352. The second power assembly supplies a fourth voltage of the second polarity to the one or more sixth sub- electrodes 334 and the one or more eighth sub-electrodes 344 e.g. via a fourth power terminal 356. The first polarity can be a negative polarity and the second polarity can be a positive polarity, or the first polarity can be a positive polarity and the second polarity can be a negative polarity.

[0065] In some implementations, the one or more first sub-electrodes 312, the one or more third sub-electrodes 322, the one or more fifth sub-electrodes 332, and the one or more seventh sub-electrodes 342 can be referred to as "first cluster electrodes". In the example of FIG. 3 the first cluster electrodes are negative cluster electrodes. Likewise, the one or more second sub-electrodes 314, the one or more fourth sub-electrodes 324, the one or more sixth sub-electrodes 334, and the one or more eighth sub-electrodes 344 can be referred to as "second cluster electrodes". In the example of FIG. 3 the second cluster electrodes are positive cluster electrodes. [0066] According to some embodiments, which can be combined with other embodiments described herein, the first power assembly and/or the second power assembly are configured to selectively and/or individually apply at least one of the first to fourth voltages to the first electrode arrangement and the second electrode arrangement, respectively. For example, the at least one switch can be used to selectively and/or individually apply at least one of the first to fourth voltages to the first electrode arrangement and the second electrode arrangement.

[0067] In some implementations, the apparatus is configured to connect at least one electrode of the first electrode arrangement and the second electrode arrangement to ground. For example, a defective electrode can be connected to ground such that it does not disturb the operation of the remaining electrodes providing the chucking force for holding the substrate at the support surface. In particular, the controller can be configured to ground at least one electrode e.g. of the one or more first electrodes and/or the one or more second electrodes when the at least one electrode is defective.

[0068] According to some embodiments, the apparatus includes the at least one switch, as described with respect to FIGs. 2A and B. The at least one switch can be connected to ground and at least one of the one or more first electrodes, the one or more second electrodes, the one or more third electrodes, and the one or more fourth electrodes. For example, the at least one switch can be configured to connect the two or more power terminals to ground. In some implementations, each power terminal has one corresponding switch to connect the respective power terminal to ground. [0069] According to some embodiments, which can be combined with other embodiments described herein, an (entire) defective electrode arrangement or individual defective electrodes can be disconnected from the respective power assembly using for instance the at least one switch. It is noted that the fails-safe system of the present disclosure is not limited to defective electrodes or defective electrode arrangements. For example, the at least one switch can be configured to disconnect the electrode arrangement from the respective power supply if there is a failure e.g. in the power supply and/or the controller.

[0070] FIG. 4 shows a schematic view of a system 400 for layer deposition on a substrate 10 according to embodiments described herein. [0071] The system 400 includes a vacuum chamber 402, one or more material deposition sources 480 in the vacuum chamber 402, and the apparatus 100 for holding the substrate 10 in a vacuum deposition process according to the embodiments described herein. The apparatus 100 is configured to hold the substrate 10 e.g. during the vacuum deposition process. The system 400 can be configured for evaporation of e.g. an organic material for the manufacture of OLED devices. In another example, the system can be configured for CVD or PVD, such as sputter deposition.

[0072] In some implementations, the one or more material deposition sources 480 can be evaporation sources, particularly evaporation sources for depositing one or more organic materials on a substrate to form a layer of an OLED device. The apparatus 100, which can be a substrate support or carrier, for supporting the substrate 10 e.g. during a layer deposition process can be transported into and through the vacuum chamber 402, and in particular through a deposition area, along a transportation path, such as a linear transportation path. [0073] As indicated in FIG. 4, further chambers can be provided adjacent to the vacuum chamber 402. The vacuum chamber 402 can be separated from adjacent chambers by a valve having a valve housing 404 and a valve unit 406. After the apparatus 100 with the substrate 10 thereon is inserted into the vacuum chamber 402 as indicated by the arrow, the valve unit 406 can be closed. The atmosphere in the vacuum chamber 402 can be individually controlled by generating a technical vacuum, for example with vacuum pumps connected to the vacuum chamber 402.

[0074] According to some embodiments, the apparatus 100 and the substrate 10 are static or dynamic during deposition of the deposition material. According to some embodiments described herein, a dynamic deposition process can be provided, e.g., for the manufacture of OLED devices.

[0075] In some implementations, the system 400 can include one or more transportation paths extending through the vacuum chamber 402. The apparatus 100 can have a transport arrangement configured for transportation of the apparatus 100 along the one or more transportation paths, for example, past the one or more material deposition sources 480. Although in FIG. 4 one transportation path is exemplarily indicated by the arrow, it is to be understood that the present disclosure is not limited thereto and that two or more transportation paths can be provided. For example, at least two transportation paths can be arranged substantially parallel to each other for transportation of respective carriers. The one or more material deposition sources 480 can be arranged between the two transportation paths.

[0076] The transport arrangement can be configured for contactless levitation and/or contactless transportation of the apparatus 100, such as a carrier, in the vacuum chamber 402, e.g., along the one or more transportation paths in a transport direction. As an example, the system 400, and particularly the transport arrangement, can include a guiding structure configured for contactless levitation of the apparatus 100. Likewise, the system 400, and particularly the transport arrangement, can include a drive structure configured for contactless transportation of the apparatus 100.

[0077] The contactless levitation and/or transportation of the carrier is beneficial in that no particles are generated during transportation, for example due to mechanical contact with guide rails. An improved purity and uniformity of the layers deposited on the substrate can be provided, since particle generation is minimized when using the contactless levitation and/or transportation.

[0078] FIG. 5 shows a flow chart of a method 500 for holding a substrate according to embodiments described herein. The method 500 can utilize the apparatuses and systems according to the present disclosure.

[0079] The 500 includes in block 510 applying a first voltage to one or more first electrodes and one or more second electrodes, in block 520 applying a second voltage to one or more third electrodes arranged between the one or more first electrodes and the one or more second electrodes, and in block 530 connecting at least one electrode of the one or more first electrodes, the one or more second electrodes, and the one or more third electrodes to ground if it is determined that a failure has occurred.

[0080] The failure can be related to the at least one electrode. For example, the failure can be selected from the group consisting of a failure in the at least one electrode (e.g., due to a flashover), a failure in a power assembly connected to the at least one electrode, such as a failure in a controller controlling e.g. the power assembly, the power supply (e.g. the battery) and the HV generator, and a failure in the connection between the at least one electrode and the power assembly. According to some embodiments, the method can further include holding at least one of the substrate and a mask in an essentially vertical orientation. [0081] According to another aspect of the present disclosure, a method for holding a substrate includes operating one or more first electrodes using a first power assembly and one or more second electrodes using a second power assembly, and operating the one or more first electrodes using a component selected from the group consisting of a power supply, a high voltage generator and a controller of the second power assembly when it is determined that a failure in the first power assembly has occurred.

[0082] According to embodiments described herein, the method for holding a substrate can be conducted using computer programs, software, computer software products and the interrelated controllers, which can have a CPU, a memory, a user interface, and input and output devices being in communication with the corresponding components of the apparatus.

[0083] E-chucks can be used in a vacuum deposition system. A voltage loss, such as a flashover, can lead to a collapse of the electric field. If the electric field does not recover fast enough the substrate drops. According to the present disclosure, redundancy is provided such that substrates can be supported e.g. by more than one pair of (positively and negatively charged) electrodes. So the electrostatic chuck contains more than one redundant holding areas (clusters). For example, the pairs of electrodes can build up one cluster. Each cluster can have a contact point, HV-generator and power supply, to create a redundant system. A fail-safe system can compensate for a voltage loss of one or more clusters with the other clusters. The system takes into account that the chucking force for each cluster is strong enough.

[0084] While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. An apparatus for holding a substrate or a mask used in a vacuum deposition process, comprising: one or more first electrodes and one or more second electrodes; a first power assembly connected to the one or more first electrodes; and a second power assembly connected to the one or more second electrodes and providing one or more redundant components for the first power assembly.

2. The apparatus of claim 1, wherein the one or more redundant components are selected from the group consisting of a power supply, a high voltage generator and a controller.

3. The apparatus of claim 1, wherein the first power assembly includes at least one of a first power supply, a first high voltage generator and a first controller, wherein the second power assembly includes at least one of a second power supply, a second high voltage generator and a second controller, and wherein the at least one of the second power supply, the second high voltage generator and the second controller is configured to substitute for a defective one of the first power supply, the first high voltage generator and the first controller.

4. An apparatus for holding a substrate or a mask used in a vacuum deposition process, comprising: one or more first electrodes and one or more second electrodes connectable to a first power assembly; and one or more third electrodes arranged between the one or more first electrodes and the one or more second electrodes and connectable to a second power assembly.

5. The apparatus of claim 4, further including one or more fourth electrodes connectable to the second power assembly, wherein the one or more second electrodes are arranged between the one or more third electrodes and the one or more fourth electrodes.

6. The apparatus of claim 4 or 5, wherein the second power assembly provides one or more redundant components for the first power assembly.

7. The apparatus of any one of claims 1 to 6, further comprising at least one switch connected to ground and at least one of the one or more first electrodes and the one or more second electrodes.

8. The apparatus of any one of claims 4 to 6, further comprising at least one switch connected to ground and at least one of the one or more first electrodes, the one or more second electrodes, and the one or more third electrodes.

9. The apparatus of any one of claims 1 to 8, wherein the first power assembly and the second power assembly share one or more components selected from the group consisting of a power supply, a high voltage generator and a controller, and wherein the one or more redundant components are non- shared components.

10. The apparatus of any one of the preceding claims, wherein the apparatus is configured to hold at least one of the substrate and the mask in an essentially vertical orientation.

11. An apparatus for holding a substrate or a mask used in a vacuum deposition process, comprising: a first electrode arrangement having one or more first electrodes; a second electrode arrangement having one or more second electrodes; and a controller configured to ground at least one electrode of the one or more first electrodes and the one or more second electrodes when the at least one electrode is defective.

12. The apparatus of claim 1, 4 or 11, wherein the first power assembly and the second power assembly are independent from each other.

13. A system for layer deposition on a substrate, including: a vacuum chamber; one or more deposition material sources in the vacuum chamber; and the apparatus of any one of claims 1 to 12 in the vacuum chamber.

14. A method for holding a substrate or a mask, comprising: applying a first voltage to one or more first electrodes and one or more second electrodes; applying a second voltage to one or more third electrodes arranged between the one or more first electrodes and the one or more second electrodes; and connecting at least one electrode of the one or more first electrodes, the one or more second electrodes, and the one or more third electrodes to ground.

15. The method of claim 14, further including: holding at least one of the substrate and the mask in an essentially vertical orientation.