WO2024010591A1

WO2024010591A1 - Alignment mechanism, vacuum chamber with an alignment mechanism and method of aligning a substrate in a vacuum chamber

Info

Publication number: WO2024010591A1
Application number: PCT/US2022/036532
Authority: WO
Inventors: Srinivasan Nagarajan; Brijesh RAJU; Sharath Poovanna PALANDIRA PONNAPPA
Original assignee: Applied Materials, Inc.
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2024-01-11

Abstract

An alignment mechanism for aligning a substrate in a vacuum chamber is provided. The alignment mechanism includes an actuator configured to be coupled to a chamber wall of the vacuum chamber, and a lever pivotably provided on a first pivot axis. The lever is actuatable by the actuator to pivot about the first pivot axis for alignment of the substrate. The alignment mechanism further includes a substrate contacting portion. The substrate contacting portion is configured for contacting the substrate. The substrate contacting portion is pivotably coupled to the lever and pivotable about a second pivot axis.

Description

ALIGNMENT MECHANISM, VACUUM CHAMBER WITH AN ALIGNMENT MECHANISM AND METHOD OF ALIGNING A SUBSTRATE IN A VACUUM CHAMBER

TECHNICAL FIELD

[0001] Embodiments of the present invention relate to substrate alignment in a vacuum chamber. Embodiments particularly relate to large area substrate alignment using levers contacting the substrate.

BACKGROUND

[0002] Modern displays typically are manufactured by processing substrates in a vacuum chamber, e.g. to apply various types of coatings, films, layers or patterns onto the substrate. For example, processing may include depositing organic or inorganic layers onto the substrate. Techniques for layer deposition on a substrate include, for example, sputter deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD) and thermal evaporation. The substrates generally include a transparent base material, such as glass, and often are rectangular. Due to the marketplace's acceptance of flat panel technology, the demand for larger displays, increased production and lower manufacturing costs have driven equipment manufacturers to develop new systems that accommodate larger size glass substrates for flat panel display fabricators.

[0003] For processing, the substrate is transferred into the vacuum chamber and disposed on a substrate support. The substrate is then aligned to the substrate support for further processing. Aligning the substrate often includes utilizing an alignment mechanism for urging the substrate into an aligned position.

[0004] With increasing substrate sizes, the size of vacuum chambers for processing the substrates increases accordingly. With increasing vacuum chamber size, a deformation of the vacuum chamber for processing large-area substrates becomes increasingly relevant, particularly since components of the alignment mechanism may be calibrated under pressurized conditions.

[0005] In view of the above, it is beneficial to provide an improved alignment mechanism, a vacuum chamber for processing a large area substrate including an alignment mechanism, and a method of aligning a substrate in a vacuum chamber.

SUMMARY

[0006] In light of the above, an alignment mechanism, a vacuum chamber and a method of aligning a substrate in a vacuum chamber according to the independent claims are provided. Further aspects, advantages and features of the present disclosure are apparent from the description and the accompanying drawings.

[0007] According to an embodiment, an alignment mechanism for aligning a substrate in a vacuum chamber is provided. The alignment mechanism includes an actuator configured to be coupled to a chamber wall of the vacuum chamber, and a lever pivotably provided on a first pivot axis. The lever is actuatable by the actuator to pivot about the first pivot axis for alignment of the substrate. The alignment mechanism further includes a substrate contacting portion. The substrate contacting portion is configured for contacting the substrate. The substrate contacting portion is pivotably coupled to the lever and pivotable about a second pivot axis.

[0008] According to an embodiment, a vacuum chamber for processing a large area substrate is provided. The vacuum chamber includes a chamber body with chamber walls, the chamber body defining a volume configured for holding a vacuum, and at least one alignment mechanism according to an embodiment described herein and adapted to align the substrate within the vacuum chamber, the actuator of the alignment mechanism being coupled to a chamber wall of the chamber walls. The vacuum chamber further includes a substrate support configured for providing a substrate thereon. The at least one alignment mechanism is configured for aligning the substrate on the substrate support.

[0009] According to an embodiment, a method of aligning a substrate in a vacuum chamber is provided. The method includes disposing a substrate on a substrate support, actuating a lever with an actuator coupled to a wall of the vacuum chamber to cause the lever to pivot about a first pivot axis, contacting the substrate with a substrate contacting portion mounted to a contacting portion support pivotably connected to the lever at a second pivot axis, and aligning the substrate by actuating the lever with the actuator until the substrate is aligned to the substrate support.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the manner in which the above recited features can be understood in detail, a more particular description, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments and are described in the following:

Fig. 1 shows a schematic top view of a vacuum chamber according to embodiments with a substrate being aligned therein;

Fig. 2 shows a schematic top view of an alignment mechanism according to embodiments;

Fig. 3 shows a schematic side-view of an alignment mechanism according to embodiments;

Fig. 4A shows a schematic view of a calibrated alignment mechanism during substrate alignment;

Fig. 4B shows a schematic view of an uncalibrated alignment mechanism during substrate alignment; Fig. 4C shows a schematic view of an alignment mechanism according to embodiments during substrate alignment;

Fig. 5 shows a schematic cross-sectional view of an alignment mechanism according to embodiments; and

Fig. 6 shows a method of aligning a substrate in a vacuum chamber according to embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

[0011] Reference will now be made in detail to the various embodiments, 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 and is not meant as a limitation. 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.

[0012] Fig. 1 shows a vacuum chamber for processing large area substrates, such as substrate 110. In the present disclosure, the term “large area substrate” refers to a substrate having a main surface area with an area of 0.5 m² or larger, particularly of 1 m² or larger. In some embodiments, a large area substrate can be GEN 4.5, which corresponds to about 0.67 m² of substrate (0.73 m x 0.92 m), GEN 5, which corresponds to about 1.4 m² of substrate (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m² of substrate (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7 m² of substrate (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m² of substrate (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can similarly be implemented. Further, the substrate thickness can be from 0.1 to 1.8 mm, particularly about 0.9 mm or below, such as 0.7 mm or 0.5 mm. [0013] Embodiments of the present invention provide an alignment mechanism 100, wherein a deformation of the vacuum chamber may have a reduced effect on the alignment mechanism calibration and reduce or avoid mechanical stresses during alignment of the substrate 110. For example, mechanical stress on a lever 102, which may by actuated to contact portions of the substrate 110 with a substrate contacting portion 104, may negatively affect substrate alignment, substrate quality and/or the lifetime of the alignment mechanism 100. According to one embodiment, an alignment mechanism 100 for aligning a substrate 110 in a vacuum chamber is provided. The alignment mechanism 100 includes an actuator configured to be coupled to a chamber wall 122 of the vacuum chamber, a lever 102 pivotably provided on a first pivot axis 106, wherein the lever 102 is actuatable by the actuator to pivot about the first pivot axis 106 for alignment of the substrate 110, and a substrate contacting portion 104, wherein the substrate contacting portion 104 is configured for contacting the substrate 110, wherein the substrate contacting portion 104 is mounted to a contacting portion support, and wherein the substrate contacting portion support is pivotably coupled to the lever 102 and pivotable about a second pivot axis 108.

[0014] As shown in Fig. 1 , the substrate 110 may be essentially rectangular. A square substrate 110 is considered rectangular. In particular, the substrate 110 may include corner portions 112, and an alignment may be performed by aligning the substrate to a substrate support, particularly by aligning the corner portions 112 of the substrate 110 to the substrate support. The substrate may be a transparent substrate, particularly a substrate for display manufacture. The substrate may comprise glass or polymer as a transparent base layer. The transparent base layer may be processed or is processable to include components of a display structure, such as, but not limited to, components of pixel structures, such as thin-film- transistor (TFT) pixel structures or organic light emitting diode (OLED) pixel structures, light emitting layers, color filters, or the like.

[0015] Fig. 1 shows a vacuum chamber having a chamber body 120 with chamber walls 122. The chamber body 120 defines a volume. Accordingly, the chamber walls 122 at least partially define the volume. The volume may hold a vacuum, particularly during processing of the substrate. The vacuum chamber may be a vacuum chamber of a substrate processing apparatus, such as a deposition chamber. The vacuum chamber may be connected to e.g. a load chamber, a load-lock chamber, a factory interface, and/or a transfer chamber for loading and unloading a substrate 110 to be processed (not shown). Beneficially, the vacuum chamber may be evacuated and remain evacuated during loading and unloading of the substrate, and substrate alignment, as described herein with reference to embodiments, may be performed under vacuum, i.e. while the vacuum chamber is evacuated. Accordingly, the vacuum chamber, particularly the volume defined by the chamber body, may be fluidly connected to a vacuum pump assembly configured for evacuating the vacuum chamber and/or maintaining a vacuum within the volume.

[0016] The vacuum chamber may include one or more deposition sources (not shown). The deposition sources may be arranged vertically, and may be configured for depositing a material vertically onto the substrate, e.g. after the substrate has been moved by an angle (e.g. rotated), e.g. by 90°, along a horizontal axis so that the substrate is in an essentially vertical position. Accordingly, the substrate support may be configured for rotating between an essentially horizontal and an essentially vertical position. Alternatively, deposition sources may be arranged horizontally above or below the substrate and deposit a material in an upward or downward fashion onto the substrate.

[0017] The vacuum chamber includes a substrate support. The substrate support may include a table and/or a table frame. In the embodiment shown in Fig. 1 , the substrate 110 rests in a horizontal position on the substrate support, and the substrate support and/or the table are provided below the substrate (not shown). The substrate support may include stoppers, such as the stoppers 410 shown in Fig. 4A-4C, provided in the corner portion of the substrate support. The substrate may rest, at least in part, on the stoppers, or the substrate may be provided on the substrate support without contacting the stoppers. The stoppers may define an aligned position, and alignment of the substrate 110 to the substrate support may include aligning the substrate 110 to the stoppers. The substrate support may include at least one stopper for limiting a movement of the lever. Accordingly, a stopper may be provided in a corner portion of the substrate support. A stopper may be provided in two or more corner portions of the substrate support, such as in each corner portion of the substrate support.

[0018] In the embodiment shown in Fig. 1 , the vacuum chamber includes four alignment mechanisms 100. Two alignment mechanisms 100 are shown in a position in which a substrate contacting portion 104 is contacting a corner portion 112 of the substrate 110. Two alignment mechanisms 100 are shown in a position in which the substrate contacting portion 104 is not in contact with the substrate.

[0019] According to embodiments, the vacuum chamber includes at least one alignment mechanism 100. According to embodiments, the vacuum chamber includes two alignment mechanisms 100. The two alignment mechanisms 100 may be provided at opposite chamber walls 122 and configured for engaging opposite corner portions 112 of the substrate 110. The vacuum chamber may include three alignment mechanisms 100. According to embodiments, such as in the embodiment shown in Fig. 1 , the vacuum chamber may include four alignment mechanisms 100, with an alignment mechanism provided for each corner portion 112 of the substrate 110.

[0020] As shown in Fig. 1 , for the top-left alignment mechanism 100, each alignment mechanism 100 includes a lever 102 pivotably provided on a first pivot axis 106. It should be noted that Fig. 1 includes reference signs only for the top-left alignment mechanism 100 for clarity, and the elements of the remaining alignment mechanisms 100 are essentially identical to the mechanisms described with respect to the top-left alignment mechanism 100.

[0021] The lever 102 is actuatable by an actuator. Actuators according to embodiments are described in further detail with reference to Fig. 2. The actuator is coupled to a chamber wall 122 of the vacuum chamber. The first pivot axis 106 may be mechanically coupled to the chamber wall 122, and the position of the first pivot axis may be defined by, be constant with respect to, and/or move together with the chamber wall 122, e.g. during chamber wall deformation. Accordingly, the position of the lever 102 may be defined, at least in part, by the position of the first pivot axis 106. The actuator may be mechanically coupled to the chamber wall 122 to exert and/or transfer forces between the alignment mechanism 100 and the chamber wall 122. Actuating the lever 102 with the actuator causes the lever to pivot about the first pivot axis 106, as indicated by the arched arrows in Fig. 1 .

[0022] As explained in further detail with reference to Fig. 3, the actuator may be provided outside the volume, i.e. outside the chamber body, and the substrate contacting portion 104 may be provided inside the volume, i.e. inside the chamber body. Accordingly, the lever 102, or at least portions of the lever 102, may be provided inside the volume. For example, the first pivot axis 106 may include a shaft and a bearing including a gasket, and/or may separate the inside of the volume from the outside of the volume, and/or may be configured for transferring a torque and/or rotary motion from the outside of the volume to the inside of the volume.

[0023] As indicated by the arrows 124, the chamber walls 122 of the vacuum chamber may deform when applying a vacuum to the vacuum chamber. For example, under pressurized conditions, such as conditions in which the outside pressure is essentially identical to the pressure within the volume, the chamber wall 122 may be describable as an essentially flat surface, while under vacuum, the chamber wall 122 may be slightly concave when observed from the outside of the chamber body 120. Accordingly, the position of the alignment mechanism 100, particularly the position of the substrate contacting portion 104, may change with respect to the substrate support when applying a vacuum.

[0024] The lever 102 of the alignment mechanism 100 may be in a disengaged position, such as the position of the alignment mechanisms 100 shown in the topright and bottom-left of Fig. 1 , during loading, unloading and/or processing of the substrate, and may be in an engaged position, i.e. a position in which the substrate is being contacted, such as the position of the alignment mechanisms 100 shown in the top-left and bottom-right of Fig. 1 , during alignment of the substrate. Actuating the lever 102 with the actuator may cause the lever 102 to change from an engaged position to an unengaged position, and vice versa. In the engaged position, the actuator may exert mechanical forces onto the lever 102, and the lever 102 may, via substrate contacting portion 104, transfer the mechanical forces onto the substrate 110 to urge the substrate 110 into an aligned position. It should be noted that in Fig. 1 , two alignment mechanisms 100 are shown in the engaged position and two alignment mechanisms 100 are shown in the disengaged position to provide a better explanation of the disclosure. According to embodiments, the alignment mechanisms 100 may operate essentially synchronously, i.e. all be in the engaged or unengaged position. Still pertaining to the aspect, additionally or alternatively, each alignment mechanism 100 may be operable independently.

[0025] The alignment mechanism 100 includes a substrate contacting portion 104. The substrate contacting portion 104 is configured for contacting the substrate 110, e.g. for engaging the substrate 110, exerting forces onto the substrate 110, and/or urging the substrate into an aligned position. Beneficially, the substrate contacting portion is configured for evenly distributing the forces exerted by the substrate contacting portion 104 onto the substrate 110, e.g. to allow accurate alignment, prevent mechanical strain onto, or even damage to the substrate 110. As shown in Fig. 1 , the substrate contacting portion 104 may be provided at an end of the lever 102. The end of the lever 102 may be an end adjacent to the substrate 110 when engaging the substrate 110. The end of the lever 102 may be an end opposite the first pivot axis 106. The end of the lever 102 having the substrate contacting portion 104 may be an end opposite the end of the lever 102 closest to the actuator.

[0026] The substrate contacting portion 104 is pivotably coupled to the lever 102 and pivotable about a second pivot axis 108. As described with reference to embodiments, the substrate contacting portion 104 can be mounted to a contacting portion support, and the contacting portion support may be pivotable about the second pivot axis 108. The substrate contacting portion 104 may be fixedly mounted to the contacting portion support and be pivotable about the second pivot axis due to the contacting portion support being pivotable about the second pivot axis 108. Being pivotable about the second pivot axis 108 may beneficially allow the substrate contacting portion 104 to evenly distribute the forces exerted onto the substrate 110. [0027] As shown in Fig. 1 , and pertaining to the aspect, the alignment mechanism 100 may be configured for urging the substrate contacting portion 104 against a corner portion 112 of the substrate 110. In particular, the substrate contacting portion 104 may be configured for contacting adjacent edges of the corner portion 112 of the substrate. If the forces exerted by the substrate contacting portion 104 onto one of the adjacent edges are larger than the forces exerted onto the other of the adjacent edges, the substrate contacting portion 104 may pivot about the second pivot axis 108 until the forces are essentially identical and/or at least in equilibrium. Beneficially, the substrate contacting portion 104 pivoting about the second pivot axis 108 may evenly distribute the forces exerted onto the substrate 110.

[0028] Pivoting, in the context of the disclosure, is to be understood as an at least partial rotation along an axis, however, a pivoting component is not required to be fully rotatable, i.e. the angular range of the lever and/or the contacting portion support may be limited. Accordingly, it should be noted that the pivoting movements shown in the figures may be exaggerated for a better understanding of the disclosure, and may be smaller in practical embodiments of the invention.

[0029] Referring now to Fig. 2 and Fig. 3, an alignment mechanism according to embodiments is described. The alignment mechanism is provided at a chamber wall 122 of the vacuum chamber. The chamber wall 122 is a barrier between the inside 222 of the vacuum chamber, i.e. the inside of the volume, and the outside 224 of the vacuum chamber, i.e. the outside of the volume.

[0030] The alignment mechanism 100 extends towards the inside 222 of the volume. The alignment mechanism 100 may be provided within and/or include a recess. The recess includes a housing for housing components of the alignment mechanism 100, such as the actuator 210 and the linkage 212. In the embodiment shown in Fig. 2, the actuator 210 is coupled to the chamber wall 122 through the housing. As for the chamber wall 122, the housing forms a barrier separating the inside 222 of the volume from the outside 224 of the volume. [0031] The actuator 210 may be a linear actuator. For example, the actuator 210 may include a hydraulic cylinder, particularly a pneumatic cylinder. According to embodiments, further types of actuators may be suitable, such as linear motors. The actuator 210 is connected to the lever 102 by a linkage 212. The linkage 212 may be configured for converting a linear motion of the actuator into an angular motion of the lever.

[0032] Alternatively, according to embodiments, the actuator 210 may be a rotary actuator, such as a rotary pneumatic actuator, a torque motor, a swivel motor or other known types of rotary actuators. For rotary actuators, the linkage 212 may be omitted, and/or substituted, e.g. by a gear assembly.

[0033] It is to be understood that the arrangement of the actuator and the linkage shown in Fig. 2 is exemplary, and further arrangements may be utilized without departing from the scope of the disclosure. For example, the actuator may be directly coupled to the chamber wall 122 outside the volume, and particularly outside the housing. An example for an alternative arrangement is provided in document US62103907A, which is incorporated herein to the extent of the description of the alignment mechanism disclosed therein. For example, the actuator may be provided at an angle other than 90°, such as at an angle of 30° to 60°, such as about 45°, relative to the chamber wall. For example, the actuator may be pivotably coupled to the housing or the chamber wall. Pivotably coupling the actuator 210 and/or providing the actuator at an angle other than 90° relative to the chamber wall may beneficially increase the range of motion of the lever 102 while maintaining a compact housing. Providing the actuator outside the housing may allow a compact housing.

[0034] As shown in Fig. 3, a shaft 310 connects the inside 222 of the volume and the outside 224 of the volume. The shaft 310 is configured for pivoting about the first pivot axis 106, and/or a rotation of the shaft may define the first pivot axis 106. The shaft 310 mechanically couples the lever 102 to the actuator 210. A rotation of the shaft 310, as effected by the actuator 210 and the linkage 212, causes the lever 102 to pivot about the first pivot axis 106. [0035] As shown in Fig. 3, the alignment mechanism 100 includes a seal provided about the first pivot axis for coupling the actuator to the lever 102 without vacuum leakage from the chamber body. The seal may include the gasket 312. In addition to the gasket 312, the seal may include additional components, such as additional gaskets, bushings for mechanically supporting the shaft 310, and/or retaining means, such as washers and retainer rings (not shown).

[0036] As shown in Fig. 2 and Fig. 3, the alignment mechanism 100 includes a substrate contacting portion 104. The substrate contacting portion 104 is mounted to a contacting portion support 304. The contacting portion support 304 is pivotably coupled to the lever 102 and pivotable about the second pivot axis 108. As shown in Fig. 3, the substrate contacting portion 104, together with the contacting portion support 304, can rotate relative to the lever about the plane 306.

[0037] According to embodiments, as shown e.g. in Fig. 3, the first pivot axis 106 and the second pivot axis 108 are essentially parallel to each other. Accordingly, a pivoting of the substrate contacting portion 104 about the second pivot axis does not result in a tilting of the substrate contacting portion 104, i.e. the plane 306 remains orthogonal to the first pivot axis 106.

[0038] According to embodiments, the second pivot axis 108 is located along a length of the lever 102. Accordingly, the second pivot axis 108 moves together with the lever 102, particularly when the lever 102 is actuated by the actuator 210.

[0039] According to embodiments, the first pivot axis 106 is orthogonal to a surface of a substrate to be aligned by the alignment mechanism 100, such as the substrate 110 to be aligned by the alignment mechanism 100 shown in Fig. 1. Accordingly, the plane 306 is essentially parallel to the surface of the substrate, and the second pivot axis 108 is orthogonal to the surface of the substrate.

[0040] Referring now to Fig. 4A, 4B, and 4C, aspects of the substrate contacting portion are described in further detail. The substrate contacting portion of the alignment mechanism 40 shown in Fig. 4A and Fig. 4B is a substrate contacting portion with no second pivot axis, i.e. the substrate contacting portion is fixedly coupled to the lever 402. The substrate contacting portion 104 shown in Fig. 4C, mounted to a contacting portion support 304, is a substrate contacting portion according to embodiments of the disclosure.

[0041] According to an aspect, Fig. 4A and Fig. 4B serve as an example for the understanding of a typical alignment operation and the underlying technical problem. In Fig. 4A, a substrate 110 is shown in an aligned position. The substrate contacting portion of the alignment mechanism 40 has two contacting elements 404a and 404b, which, when the lever 402 is actuated by the actuator, push against the corner portion of the substrate 110 and urge the substrate along the direction of movement of the lever. A stopper 410 is provided, e.g. fixedly installed on a substrate support or a table, defining an aligned position and/or a target position. Once the substrate reaches the aligned position, the contacting elements 404a, 404b rest against the stopper so that the substrate 110 is not urged further, i.e. out of the aligned position. An aligned position may be a position in which the substrate is positioned within a margin of ± 1 mm, ± 0.5 mm, ± 0.3 mm, or even within ± 0.2 mm of a target position, as defined by the stopper. In Fig. 4A, both contacting elements 404a and 404b are calibrated, e.g. by adjusting the position of the substrate contacting portion with respect to the lever, to contact the stopper 410 and/or the substrate 110 in the aligned position on both adjacent edges of the corner portion of the substrate 110, and/or with essentially equal forces.

[0042] According to embodiments, which can be combined with other embodiments described herein, the substrate contacting portion 104 includes rollers. For example, the first contacting element 404a may be a first roller, and the second contacting element 404b may be a second roller. Further examples for a substrate contacting portion having rollers are given in embodiments described with reference to Fig. 5. The rollers are configured for contacting different adjacent edges of the corner portion of the substrate 110. The number of rollers is not limited to two, i.e. a higher number of rollers may be provided, such as two or more rollers for contacting a first edge of the adjacent edges, and two or more rollers for contacting a second edge of the adjacent edges of the corner portion of the substrate. [0043] According to embodiments, which can be combined with other embodiments described herein, the rollers each comprise a cylindrically shaped portion extending along an axis, the axis being essentially parallel to the first pivot axis. Accordingly, the axis may be essentially parallel to the second pivot axis. In the examples shown in Fig. 4A to 4C, the rollers extend essentially orthogonally to the drawing plane.

[0044] Referring now to Fig. 4B, an exemplary situation is described in which a deformation of a chamber wall along the direction indicated by arrow 424 has occurred. The deformation may be caused by applying a vacuum to a volume of a vacuum chamber. The deformation may affect the position of the alignment mechanism 40 being coupled, directly or indirectly, to the chamber wall. In particular, the alignment mechanism may shift according to the deformation of the chamber wall. The deformation of the vacuum chamber causes the alignment mechanism to move relative to the substrate support.

[0045] As shown in Fig. 4B, the deformation causes the substrate contacting portion to be uncalibrated and/or misaligned to the substrate 110 and/or the stopper 410. The misalignment causes the contacting element 404a to contact the stopper 410, and being stopped by the stopper 410, before the contacting element 404b comes into contact with the stopper 410. As a result of the misalignment, a gap 420 is present between the stopper 410 and the substrate 110 and the contacting element 404b. The gap 420 may negatively affect the alignment operation, e.g. by not fully aligning the substrate 110 to the stopper 410 along the direction at which the gap is present. It should be noted that the misalignment shown in Fig. 4B is exaggerated for clarity. Accordingly, even when the alignment mechanism 40 is misaligned, the alignment mechanism 40 may be suitable for fully aligning the substrate, e.g. when components of the alignment mechanism 40, such as the contacting element 404a, 404b, and/or the lever 402 flex due to stresses during alignment. However, such stresses, particularly unevenly distributed stresses, may negatively affect substrate quality, processing quality, lead to contamination of the vacuum chamber, reduce longevity of the alignment mechanism 40 or the processing apparatus including the vacuum chamber, and/or even cause other errors not directly related to the alignment of the substrate. To overcome the stated negative effects, extensive calibration of the alignment mechanism 40 may be required, taking into account the deformation of the vacuum chamber wall. Such calibration may be cumbersome and require extensive and repeated maintenance. The stated negative effects are overcome, at least in part, by an alignment mechanism according to an embodiment, such as the alignment mechanism 100 shown in Fig. 4C.

[0046] Referring now to Fig. 4C, an alignment mechanism 100 according to an embodiment is shown. The alignment mechanism 100 differs from the alignment mechanism 40 in that the substrate contacting portion 104 having contacting elements 404a, 404b is not directly affixed to the lever 102, but is provided pivotably about a second pivot axis 108 on a contacting portion support 304. Being provided pivotably about the second pivot axis 108 allows the substrate contacting portion, e.g. the contacting elements 404a, 404b, to pivot about a pivot angle 430. The pivot angle may allow a rotation with respect to the lever 102. Beneficially, the pivot angle 430 may allow a rotation of ± 0.5 ⁰ with respect to the lever 402, or ± 1 °, or even ± 2°, such as 1.2°. It should be noted that the pivot angle 430 shown in Fig. 4C is exaggerated for clarity. According to embodiments, the pivot angle 430 may be limited, e.g. to the above-stated values.

[0047] As shown in Fig. 4C, in a situation such as the situation described with reference to Fig. 4B, in which the alignment mechanism 100 is misaligned and/or uncalibrated, moving the alignment mechanism 100 may cause the contacting portion support 304 to pivot about the second pivot axis. In particular, one of the contacting elements 404a, 404b, such as the contacting element 404a, may come into contact with the substrate 110 and/or the stopper 410 during a substrate alignment operation. Further rotation of the lever 102 along the first pivot axis (not shown) will cause the substrate contacting portion and the contacting portion support 304 to rotate until the second contacting element, such as the contacting element 404b, comes into contact with the substrate 110 and/or the stopper 410. Once both contacting elements 404a, 404b are in contact with the substrate 110 and/or the stopper 410, the forces exerted onto the substrate 110 and/or the stopper 410 are essentially equally distributed across the substrate contacting portion.

[0048] According to embodiments, urging the substrate contacting portion, e.g. the contacting elements 404a, 404b, against the substrate 110 causes the contacting portion support 304 to pivot until forces exerted by the substrate contacting portion onto the substrate 110 are essentially equally distributed.

[0049] According to embodiments in which the substrate contacting portion includes rollers, such as embodiments in which the contacting elements 404a, 404b are rollers, urging the rollers against the contacting adjacent edges of the corner portion of the substrate 110 causes the contacting portion support 304 to pivot about the second pivot axis 108 until forces exerted by the rollers onto the substrate 110 are substantially equally distributed between each roller.

[0050] Referring now to Fig. 5, an embodiment of the alignment mechanism 100, particularly the substrate contacting portion 104 and the contacting portion support 304 is described. The substrate contacting portion 104 includes two rollers 504a, 504b. The rollers are essentially cylindrical, i.e. include an essentially cylindrical outer surface. An axis of the cylinder extends along an axis parallel to the second pivot axis 108. Accordingly, the axis of the cylinder may be parallel to the first pivot axis (not shown). The lever 102 may be pivotable about a plane. The plane may be defined by, i.e. orthogonal to the first pivot axis, and/or the plane may be orthogonal to the second pivot axis. The plane may be essentially parallel to a surface of a substrate to be aligned, such as the substrate 110 described herein. The rollers may comprise and/or be made of a polymer suitable for exposure to vacuum conditions in a substrate processing apparatus, such as polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), or nylon.

[0051] As shown in Fig. 5, the rollers 504a, 504b have a bore for receiving a fastener 514a, 514b. The bore may be provided essentially along an axis of the cylindrical portion of the rollers 504a, 504b. The rollers 504a, 504b are fixedly mounted to the contacting portion support 304 with fasteners 514a, 514b. Accordingly, in embodiments utilizing rollers such as the rollers 504a, 504b as a substrate contacting portion 104, the contacting portion support 304 may be a roller support. According to embodiments, the rollers 504a, 504b being fixedly mounted to the contacting portion support 304 may be understood as the rollers being mounted so that no translation and/or no tilting of the rollers with respect to the contacting portion support is provided. Accordingly, and still pertaining to the aspect, the rollers 504a, 504b may be provided rotatably about the axis of the cylindrical portion of the rollers 504a, 504b, a rotation beneficially reducing friction between the rollers 504a, 504b and the corner portion 112 of the substrate 110.

[0052] As shown in Fig. 5, the contacting portion support 304 is pivotably mounted to the lever 102 so that the contacting portion support 304, together with the substrate contacting portion 104 having rollers 504a, 504b, may pivot about the second pivot axis 108. The second pivot axis is defined by the mounting means, which, in the embodiment shown in Fig. 5, include a fastener 510 being provided through a through-hole provided along the lever 102, and held by a nut 512. The nut 512 may be a flat nut. The nut 512 may include an essentially rectangular portion, and may be secured inside a slot 540 within the lever. In Fig. 5, the nut 512 is shown as a single component. The mounting means, alternatively or in addition to the nut 512, may include further components, such as washers, sliders, sleeves or bushing components, allowing the contacting portion support to freely pivot about the second pivot axis 108. For example, a polymer bushing, such as a PEEK, PTFE or nylon bushing, may be provided between the nut 512 and at least a portion of the fastener 510 to allow the fastener 510 and/or the nut to glide inside and/or about the bushing. The pivot angle 530, i.e. the angle at which the contacting portion support may rotate about the second pivot axis with respect to the lever 102, may be ± 0.5 °, ± 1 °, or even ± 2°, such as ± 1.2°. The pivot angle 530 may be defined by the mounting means, i.e. the mounting means may allow free rotation in the above-defined margins, and prevent further rotation outside the above-defined margins.

[0053] According to embodiments, the through-hole may be a round hole, essentially defining a standard position of the substrate contacting portion. [0054] According to further embodiments, the substrate contacting portion may be mountable at various positions along the slot 540. For example, according to embodiments, the nut 512, such as a flat nut having a PEEK bushing, may be floating. Positioning the substrate contacting portion may include a calibration of the alignment mechanism 100, particularly a coarse calibration, e.g. during the setup of a processing apparatus with a vacuum chamber including the alignment mechanism 100. For example, coarse calibration may include positioning the substrate contacting portion so that the substrate contacting portion is essentially aligned with the lever 102 when contacting a substrate and/or a stopper, such as the substrate 110 or the stopper 410, while the vacuum chamber is pressurized, i.e. the pivot angle may be essentially 0° after coarse calibration. A deformation of a wall of the vacuum chamber after evacuating the vacuum chamber may then, during substrate alignment, cause the substrate contacting portion to pivot about the second pivot axis 108 and result in a pivot angle 530 other than 0°, e.g. as described with reference to the embodiment shown in Fig. 4C.

[0055] Referring now to Fig. 6, a method 600 of aligning a substrate in a vacuum chamber is described. The method 600 may be performed for any vacuum chamber including an alignment mechanism described herein, such as the alignment mechanism 100. Embodiments of the vacuum chamber described herein, and/or embodiments of an alignment mechanism described herein and provided within a vacuum chamber, such as alignment mechanism 100, may be suitable for performing the method 600 at least in part.

[0056] In operation 602, a substrate is disposed on a substrate support. The substrate may be a large area substrate, particularly a transparent large area substrate for display manufacture, as described herein. The operation may include loading and/or transferring the substrate into the vacuum chamber. The substrate may be disposed on the substrate support in an unaligned manner, i.e. the substrate, after being transferred into the vacuum chamber and disposed on the substrate support, may require alignment. [0057] In operation 604, a lever is actuated with an actuator coupled to a wall of the vacuum chamber to cause the lever to pivot about a first pivot axis.

[0058] In operation 606, the substrate is contacted with a substrate contacting portion mounted to a contacting portion support pivotably connected to the lever at a second pivot axis. The substrate may be contacted as a result of the lever being actuated to pivot about the first pivot axis. Contacting the substrate may include exerting forces onto the substrate, and may further include urging the substrate to move, particularly into an aligned position, according to the exerted forces.

[0059] In operation 608, the substrate is aligned by actuating the lever with the actuator until the substrate is aligned to the substrate support. For example, as described herein with reference to Fig. 4, the lever may be actuated until the substrate contacting portion comes into contact with a stopper, the stopper defining the aligned position.

[0060] According to embodiments, aligning the substrate in operation 608 may include aligning the substrate comprising urging the substrate contacting portion against the substrate to move the substrate until the substrate contacting portion contacts a stopper.

[0061] According to embodiments, the method 600 may include a calibration operation. The calibration operation may be a coarse calibration, such as a coarse calibration as described with reference to Fig. 5. The calibration operation may be performed e.g. during the setup or maintenance of a processing apparatus including the vacuum chamber and an alignment mechanism with the lever and the substrate contacting portion. The calibration operation may include aligning the substrate contacting portion to a substrate until forces exerted by the substrate contacting portion onto the substrate are essentially equally distributed while a volume of the vacuum chamber is pressurized. The substrate may be a substrate not intended for production, such as a calibration substrate. The substrate may even be optional, e.g. in embodiments having stoppers, alignment of the substrate contacting portion to a substrate may include aligning the substrate contacting portion to a stopper. [0062] According to embodiments, aligning the substrate contacting portion may include positioning the contacting portion support relative to the lever to define the second pivot axis, particularly to define a position of the second pivot axis along the lever. As described with reference to Fig. 5, the substrate contacting portion support may be mountable to the lever with a fastener, and the position of the fastener may be variable, e.g. by the fastener and the nut being floatingly mounted to the arm. Accordingly, aligning the substrate contacting portion may include shifting the contacting portion support along the through-hole until the substrate contacting portion is aligned, and fixing the contacting portion support to the lever with a fastener in the aligned position.

[0063] According to embodiments, the method may include providing a vacuum within the volume after the calibration operation. Providing a vacuum within the volume may cause a deformation of the chamber walls of the vacuum chamber. Beneficially, the deformation may be mitigated by providing a substrate contacting portion mounted to a contacting portion support pivotably connected to the lever at a second pivot axis.

[0064] Embodiments of the present disclosure may be particularly suitable for aligning a large area substrate in a processing apparatus including a vacuum chamber suitable for processing the large area substrate. With increasing vacuum chamber sizes, deformation of the vacuum chamber may increase according to the size of the chamber. The present disclosure beneficially allows a certain degree of deformation. Accordingly, embodiments of the present disclosure may simplify calibration of an alignment mechanism, may reduce maintenance requirements, increase longevity of the alignment mechanism, improve substrate quality and/or substrate alignment quality, and/or may reduce the cost of the vacuum chamber, since less rigid chamber walls may be provided.

[0065] While the foregoing is directed to some embodiments, other and further embodiments may be devised without departing from the basic scope, and the scope is determined by the claims that follow.

Claims

1. An alignment mechanism for aligning a substrate in a vacuum chamber, comprising: an actuator configured to be coupled to a chamber wall of the vacuum chamber; a lever pivotably provided on a first pivot axis, wherein the lever is actuatable by the actuator to pivot about the first pivot axis for alignment of the substrate; and a substrate contacting portion, wherein the substrate contacting portion is configured for contacting the substrate, wherein the substrate contacting portion is pivotably coupled to the lever and pivotable about a second pivot axis.

2. The alignment mechanism according to claim 1, wherein the substrate contacting portion is mounted to a contacting portion support; and wherein the contacting portion support is pivotably coupled to the lever and pivotable about the second pivot axis.

3. The alignment mechanism according to claim 1 or 2, wherein the substrate contacting portion is configured for contacting adjacent edges of a corner portion of the substrate.

4. The alignment mechanism according to any one of the preceding claims, wherein the second pivot axis is essentially parallel to the first pivot axis.

5. The alignment mechanism according to any one of the preceding claims, wherein the substrate contacting portion comprises rollers, wherein at least two rollers are configured for contacting different adjacent edges of the corner portion of the substrate.

6. The alignment mechanism according to claim 5, wherein the rollers each comprise a cylindrically shaped portion extending along an axis, the axis being essentially parallel to the first pivot axis.

7. The alignment mechanism according to any one of the preceding claims, wherein the second pivot axis is located along a length of the lever.

8. The alignment mechanism according to any one of the preceding claims, wherein the first pivot axis is essentially orthogonal to a surface of the substrate.

9. The alignment mechanism according to any one of the preceding claims, wherein urging the substrate contacting portion against the substrate causes the substrate contacting portion to pivot until forces exerted by the substrate contacting portion onto the substrate are essentially equally distributed.

10. The alignment mechanism according to any one of the claims 5 to 9, wherein urging the rollers against the contacting adjacent edges of the corner portion of the substrate causes the contacting portion support to pivot about the second pivot axis until forces exerted by the rollers onto the substrate are substantially equally distributed between each roller.

11. A vacuum chamber for processing a large area substrate, comprising: a chamber body comprising chamber walls, the chamber body defining a volume configured for holding a vacuum; at least one alignment mechanism according to any one of the claims 1 to 10 adapted to align the substrate within the vacuum chamber, the actuator of the alignment mechanism being coupled to a chamber wall of the chamber walls; a substrate support configured for providing a substrate thereon; wherein the at least one alignment mechanism is configured for aligning the substrate on the substrate support.

12. The vacuum chamber according to claim 11 , wherein the substrate support comprises at least one stopper for limiting a movement of the lever.

13. The vacuum chamber according to claim 11 or 12, wherein a deformation of the vacuum chamber causes the alignment mechanism to move relative to the substrate support, and wherein the moving of the alignment mechanism causes the substrate contacting portion to pivot about the second pivot axis.

14. The vacuum chamber according to any one of the claims 11 to 13, wherein the actuator is provided outside the volume, and wherein the substrate contacting portion is provided inside the volume.

15. The vacuum chamber according to any one of the claims 11 to 14, comprising a seal provided about the first pivot axis for coupling the actuator to the lever without vacuum leakage from the chamber body.

16. The vacuum chamber according to any one of the claims 11 to 15, comprising at least two alignment mechanisms according to any of the claims 1 to 10, two alignment mechanisms of the at least two alignment mechanisms being provided at opposite chamber walls and configured for engaging opposite corner portions of the substrate.

17. A method of aligning a substrate in a vacuum chamber, comprising: disposing a substrate on a substrate support; actuating a lever with an actuator coupled to a wall of the vacuum chamber to cause the lever to pivot about a first pivot axis; contacting the substrate with a substrate contacting portion mounted to a contacting portion support pivotably connected to the lever at a second pivot axis; and aligning the substrate by actuating the lever with the actuator until the substrate is aligned to the substrate support.

18. The method according to claim 17, comprising: while a volume of the vacuum chamber is pressurized, aligning the substrate contacting portion to the substrate until forces exerted by the substrate contacting portion onto the substrate are essentially equally distributed; providing a vacuum within the volume, wherein providing a vacuum within the volume causes a deformation of the chamber walls of the vacuum chamber.

19. The method according to claim 18, wherein aligning the substrate contacting portion comprises positioning the contacting portion support relative to the lever to define the second pivot axis.

20. The method according to any one of claims 17 to 19, wherein aligning the substrate comprises urging the substrate contacting portion against the substrate to move the substrate until the substrate contacting portion contacts a stopper.