WO2019174726A1

WO2019174726A1 - Method for processing a substrate, apparatus for vacuum processing and vacuum processing system

Info

Publication number: WO2019174726A1
Application number: PCT/EP2018/056415
Authority: WO
Inventors: Sebastian Gunther ZANG; Matthias HEYMANNS; Tommaso Vercesi; Stefan Bangert
Original assignee: Applied Materials, Inc.
Priority date: 2018-03-14
Filing date: 2018-03-14
Publication date: 2019-09-19
Also published as: KR20190109378A; CN110494587B; CN110494587A; KR102217879B1; JP2020514524A

Abstract

The present disclosure provides a method of processing a substrate. The method includes transporting a mask having a plurality of deposition openings (21) into a processing chamber, transporting a substrate having a backplane pattern (11) into the processing chamber, aligning (780) the substrate (10) with respect to the mask (20), and at least locally inspecting (790) an offset between the plurality of deposition openings (21) and the backplane pattern (11) with an optical inspection device (440).

Description

METHOD FOR PROCESSING A SUBSTRATE, APPARATUS FOR VACUUM PROCESSING AND VACUUM PROCESSING SYSTEM

FIEED

[0001] Embodiments of the present disclosure relate to methods, apparatuses and systems for processing a substrate, more specifically for processing a large area substrate coated with depositing material. Also, the embodiments of the present disclosure relate to apparatuses for vacuum processing of a substrate, and to vacuum processing systems. Specifically, embodiments of the present disclosure relate to inspecting an alignment of a mask and a substrate relative to each other, particularly inspecting an in-situ alignment.

BACKGROUND

[0002] Several methods are known for depositing a material on a substrate. As an example, substrates may be coated by using an evaporation process, a physical vapor deposition (PVD) process, such as a sputtering process, a spraying process, etc., or a chemical vapor deposition (CVD) process. The process can be performed in a processing chamber of a deposition apparatus, where the substrate to be coated is located. A deposition material is provided in the processing chamber. A plurality of materials, such as organic material, molecules, metals, oxides, nitrides, and carbides may be used for deposition on a substrate. Further, other processes like etching, structuring, annealing, or the like can be conducted in processing chambers.

[0003] For example, coating processes may be considered for large area substrates, e.g. in display manufacturing technology. Coated substrates can be used in several applications and in several technical fields. For instance, an application can be organic light emitting diode (OLED) panels. Further applications include insulating panels, microelectronics, such as semiconductor devices, substrates with thin film transistors (TFTs), color filters, or the like. OLEDs are solid-state devices composed of thin films of (organic) molecules that create light with the application of electricity. As an example, OLED displays can provide bright displays on electronic devices and use reduced power compared to, for example, liquid crystal displays (LCDs). In the processing chamber, the organic molecules are generated (e.g., evaporated, sputtered, or sprayed etc.) and deposited as layers on the substrates. The particles can for example pass through a mask having a boundary or a specific pattern to deposit material at desired positions on the substrate, e.g. to form an OLED pattern on the substrate.

[0004] An aspect related to the quality of the processed substrate, in particular of the deposited layer, is the alignment of the substrate with respect to a mask. As an example, the alignment should be accurate and steady in order to achieve good process results. Lor this purpose, reference points (fiducials) present on the substrate and on the mask are used to correctly align the mask with the substrate before the deposition process. However, the relation between these reference points can be susceptible to external interferences, such as vibrations, manufacturing tolerance, handling, deformation due to temperature and/or vacuum, transport of mask and substrate, etc.

[0005] When the substrate and the mask are maintained in an essentially vertical position during the deposition, gravity influences the alignment between the mask and the substrate, particularly for large area substrates for display manufacturing. However, the deposition process needs to be as accurate as possible to achieve the best possible results on the substrate.

[0006] In view of the above, there is a need for methods, apparatuses and systems which can provide for a more efficient inspection of alignments that saves time and material.

SUMMARY [0007] In light of the above, a method for processing a substrate, an apparatus for processing of a substrate, and a system for vacuum processing of a substrate, is provided. Further aspects, benefits, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings. [0008] According to an aspect of the present disclosure, a method of processing a substrate is provided. The method includes transporting a mask having a plurality of deposition openings into a processing chamber, transporting a substrate having a backplane pattern into the processing chamber, aligning the substrate with respect to the mask, and at least locally inspecting an offset between the plurality of deposition openings and the backplane pattern with an optical inspection device.

[0009] According to a further aspect of the present disclosure, an apparatus for vacuum processing of a substrate is provided. The apparatus includes an alignment device configured to align a substrate having a backplane pattern with respect to a mask having a plurality of deposition openings, an optical inspection device configured to at least locally determine an offset between the plurality of deposition openings and the backplane pattern, and a deposition source arranged on a front side of the mask and configured to deposit one or more materials on the substrate.

[0010] According to a further aspect of the present disclosure, a vacuum processing system is provided. The vacuum system includes an apparatus according to embodiments described herein, a substrate coupled to a first mount of the alignment device, and a mask coupled to a second mount of the alignment device.

BRIEF DESCRIPTION OF THE DRAWINGS [0011] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

FIG. 1 shows a schematic view of an apparatus for vacuum processing of a substrate according to embodiments described herein;

FIG. 2 shows a schematic view of a substrate and a mask according to embodiments described herein; FIG. 3A and 3B show schematic views of a holding arrangement according to embodiments described herein;

FIG. 4A, 4B and 4C show a schematic view of inspection arrangements according to embodiments described herein; FIG. 5 shows a schematic representation of a front view of an aligned mask and substrate arrangement as well as different features related to an optical inspection of a substrate according to embodiments described herein;

FIG. 6 shows a schematic representation of an inspection system for an optical inspection according to embodiments described herein;

FIG. 7 shows a flowchart for illustrating a method for processing a substrate according to embodiments described herein; and

FIG. 8 shows a schematic representation of a system for vacuum processing a substrate according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0012] 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.

[0013] In the production of OLED devices, there are technical challenges with respect to the deposition of evaporated materials in order to achieve high resolution OLED devices. In particular, a precise alignment of the substrate with respect to the mask is beneficial for achieving high quality processing results, e.g., for the production of high resolution OLED devices. Further, it is beneficial if the deposition process is time efficient and fast as well as providing a high throughput of OLED devices to be processed. [0014] Alignment of vertically oriented masks to vertically oriented substrates, for example, in a micron range is challenging. Mask pixels are affected by gravity and transportation of the mask in a substrate processing system may influence the mask. Accordingly, the final mask arrangement may be provided after transporting the substrate and the mask to the processing chamber and before starting the deposition process. In the processing chamber, the final alignment of mask and substrate with respect to each other takes place. At the same time, this process stage may be regarded as the stage where last changes may be applied to both the mask and/or the substrate as well as to the process, e.g. to the process parameters, particularly with regard to the alignment of mask and substrate. However, the inspection of the alignment is difficult, since the process has to be paused and corrective actions have to be undertaken for every single deposition process or every single mask.

[0015] The present disclosure relates to imaging technologies including, for example, camera and video. The embodiments of the present disclosure use one or more capturing devices to image one or more objects in a vacuum environment. Particularly, the methods, apparatuses and systems provided herein are intended for the automated optical inspection of an aligned mask and substrate arrangement before a deposition process is initiated.

[0016] Therefore, an optical inspection device is used to capture images of portions or inspection areas which include parts of the mask and the substrate arrangement. The inspection may be combined with the deposition process in a processing chamber. [0017] FIG. 1 shows a schematic view of an apparatus 100 for vacuum processing of a substrate according to embodiments described herein.

[0018] The apparatus 100 includes an alignment device configured to align a substrate having a backplane pattern with respect to a mask having a plurality of deposition openings, i.e. a fine metal mask. An optical inspection device is configured to at least locally determine an offset between the plurality of deposition openings and, for example, the backplane pattern. A deposition source is arranged on a front side of the aligned mask with respect to the substrate and configured to deposit one or more materials on the substrate.

[0019] The apparatus 100 may include a processing chamber including a side wall 101 and at least one deposition source 130. The deposition source 130 may be movable. The movable source may be movable past the substrate 10. For example, the deposition source can be a line source. The line source may be essentially vertically oriented. The apparatus may further include at least one track arrangement. Typically, the apparatus includes at least two track arrangements.

[0020] The processing chamber may be a vacuum chamber. The term“vacuum” as used throughout the present disclosure may be understood in the sense of a technical vacuum having a vacuum pressure of less than, for example, 10 mbar. The pressure in the vacuum chamber may be between 10 -5 mbar and about 10 -8 mbar, specifically between 10 -5 mbar and 10 ⁷ mbar, and more specifically between about 10 ⁶ mbar and about 10 ⁷ mbar. One or more vacuum pumps, such as turbo pumps and/or cryo-pumps, connected to the vacuum chamber for generation of the vacuum inside the vacuum chamber can be provided.

[0021] The apparatus 100 may include a substrate carrier 15 which can include a support structure or body providing a support surface 17, 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 processing, such as a vacuum deposition process. The front surface may be provided with a backplane pattern which is provided, e.g., by a previous processing tool and include, for example, electronic devices such as transistors or pixel electrodes. Pixels including an organic material are to be deposited on the backplane pattern in a predetermined pattern. According to some embodiments, which can be combined with other embodiments described herein, the substrate carrier 15 can be an electrostatic chuck (E-chuck, ESC) providing an electrostatic force for holding at least the substrate 10 at the substrate carrier 15, and particularly at the support surface 17. For example, the substrate carrier 15 includes an electrode arrangement (not shown) configured to provide an attracting force acting on the substrate 10. [0022] The term“essentially” may be understood as to describe that a particular feature may include deviations from an exact structure. For example,“essentially flat surface” is to be understood as a surface that may include small bulges and/or recesses but possesses an overall flat appearance.

[0023] The apparatus 100 may include a mask carrier which is to be understood as a carrier which is configured for holding a mask. For instance, the mask may be an edge exclusion mask or a shadow mask. An edge exclusion mask is a mask which is configured for masking one or more edge regions of the substrate, such that no material is deposited on the one or more edge regions during the coating of the substrate. A shadow mask or fine metal mask is a mask configured for masking a plurality of features which are to be deposited on the substrate. For instance, the shadow mask can include a plurality of small openings or deposition openings, e.g. a pattern of small openings. The fine metal mask has a plurality of openings, for example, sized in the micron range. The plurality of fine openings corresponds to a pixel pattern of a display, e.g. an OLED display.

[0024] An essentially vertical orientation of a deposition process on a large area substrate with a fine metal mask (FFM) is further unexpected in the sense that gravity acts along the surface of the fine metal mask in a vertical orientation. A pixel positioning and alignment in the micron range is more complicated for vertical orientation as compared to a horizontal orientation. Accordingly, concepts developed for horizontal vacuum deposition systems cannot be transferred to vertical vacuum deposition systems for large area systems, particularly vacuum deposition systems utilizing a FFM.

[0025] The apparatus 100 may include a first track arrangement 110 configured for transportation of a substrate carrier 15 and a second track arrangement 120 configured for transportation of the mask carrier 25. The first track arrangement 110 includes a first portion, such as a first track 112, configured to support the substrate carrier 15 at a first end of the substrate 10 and a second portion, such as a second track 114, configured to support the substrate carrier 15 at a second end of the substrate 10 opposite the first end of the substrate 10. The second track arrangement 120 includes a further first portion, such as a further first track 122, configured to support the mask carrier 25 at a first end of the mask 20 and a further second portion, such as a further second track 124, configured to support the mask carrier 25 at a second end of the mask 20 opposite the first end of the mask 20. [0026] The vacuum chamber may include the chamber wall. As exemplarily shown in FIG. 1, the first track arrangement 110 and the second track arrangement 120 can be arranged between the side wall 101 of the vacuum chamber and one or more movable deposition sources 130. The one or more deposition sources 130 can be configured as vapor sources for evaporating a deposition material. For example, an organic material may be deposited via the deposition source 130. Further, the deposition source may be rotatable and may include a first side that is provided with vapor nozzles and a second side, for example, an opposing side, that may include an optical inspection device attached to the deposition source.

[0027] As illustrated in FIGs. 3A and 3B, a first direction (y-direction), a second direction (z-direction) and a third direction (x-direction) can be utilized to describe a processing chamber. The first direction may be essentially vertical, i.e. parallel to gravity or with a small deviation of about +- 15°. As exemplarily shown in FIG. 1, according to some embodiments which can be combined with other embodiments described herein, the first track arrangement 110 and the second track arrangement 120 extend in the third direction (x-direction in FIGs. 3A and 3B), which can be an essentially horizontal direction. In some implementations, the first track arrangement 110 is configured for transportation of the substrate carrier 15 at least in the third direction. Likewise, the second track arrangement 120 can be configured for transportation of the mask carrier 25 at least in the third direction.

[0028] According to some embodiments, which can be combined with other embodiments described herein, the apparatus 100 can be configured for contactless levitation and/or contactless transportation of the substrate carrier 15 and/or the mask carrier 25. For example, the apparatus 100 can include a guiding structure configured for contactless levitation of the substrate carrier 15 and/or the mask carrier 25. The apparatus 100 can further include a drive structure configured for contactless transportation of the substrate carrier 15 and/or the mask carrier 25.

[0029] In the present disclosure, a track or track arrangement configured for contactless transportation is to be understood as a track or track arrangement which is configured for contactless transportation of a carrier, particularly a substrate carrier or a mask carrier. The term“contactless” can be understood in the sense that the weight of the carrier, e.g. of the substrate carrier 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.

[0030] 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. The contactless levitation and/or transportation of the carrier(s) 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 10 can be provided, since particle generation is minimized when using the contactless levitation and/or transportation.

[0031] One or more movable deposition sources 130 may be provided in the vacuum chamber. The substrate carrier 15 can be configured to hold the substrate 10 during a vacuum deposition process. The vacuum process can be configured for evaporation of e.g. an organic material for the manufacture of OLED devices. For example, the one or more deposition sources 130 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 material can be emitted from the one or more deposition sources 130 in an emission direction towards the deposition area in which the substrate 10 to be coated is located.

[0032] According to some embodiments, which can be combined with other embodiments described herein, the carriers are configured for holding or supporting the substrate and the mask in a substantially vertical orientation. As used throughout the present disclosure,“substantially vertical” is to be 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. [0033] The term“vertical orientation” or“vertical direction” is to be 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 substrate and the mask, wherein a deviation of a few degrees, e.g. up to 10° or even up to 20°, 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. The same is true for the terms “essentially vertical (direction)” and/or“essentially horizontal (direction)”.

[0034] The apparatus 100 further may include an alignment device (not shown in FIG. 1; an exemplary alignment device is illustrated in FIGs. 3 A and B) configured to align a mask arrangement (or mask 20) and a substrate arrangement (or substrate 10) with respect to each other, e.g. to obtain an aligned mask and substrate arrangement. The alignment device may be configured to align the mask 20 and the substrate 10 with respect to each other based on position information received. For example, an alignment device can perform a relative alignment based on position information received from a capturing device. The position information received may be extracted from analyzing reference markers, such as a fiducials, of the mask arrangement and/or the substrate arrangement which are aligned with respect to each other.

[0035] The apparatus 100 further includes an optical inspection device (not shown in FIG. 1). According to some embodiments of the present disclosure, the optical inspection device may be attached to the deposition source, particularly when the deposition source is movable past the substrate.

[0036] In some embodiments, the optical inspection device may be movably mounted. For example, the optical inspection device may be fixed to a movable or foldable arm provided between the deposition source and the mask or mask carrier.

[0037] In some embodiments, the optical inspection device may be arranged and configured to capture an image from a side of a wall of the vacuum chamber. The image may be captured through at least one cut-out of a substrate carrier supporting the substrate. [0038] An optical inspection device may have cameras provided at one, two or three of the above-described positions.

[0039] Further, the optical inspection device may include one, two or more cameras. The optical inspection device is described in further detail with respect to FIGs. 4A to C and FIG. 6. It is further to be understood that the terms“inspection device” and“optical inspection device” are used synonymously throughout the present disclosure.

[0040] Throughout the present disclosure, the terms“front side” and“rear side” or“back side” when used with respect to the mask, the mask arrangement and/or the substrate, the substrate arrangement or mask and substrate arrangement are to be understood in relation to the deposition source. The term“front side” may be understood as the side facing the deposition source. The“front side” may correspond to the processing side. The“rear side” or“back side” may be understood as the side opposite the front side or the side facing away from the deposition source. Typically, the rear or back side is the side facing a wall of the vacuum chamber.

[0041] With respect to the deposition source, the“front side” may be understood as the side where the deposition takes place. Thus, the front side may be understood as the side where the nozzles for depositing material are placed. The front side may also be called “first side” throughout the present disclosure. The“rear side” or“back side” of the deposition source may be regarded as the side opposite the front side of the deposition source. The rear or back side of the deposition source may be understood as a side of the deposition source where no deposition takes place. The rear or back side may thus be understood as the side opposite the front side. The rear or back side may also be called “second side” throughout the present disclosure.

[0042] According to embodiments, the apparatus 100 may include at least one control unit. The control unit may be used e.g. to control the alignment of a mask 20 and a substrate 10 (and/or their respective carriers). Thus, the control unit may be configured for controlling the alignment device. Further, the control unit may be configured for controlling an inspection device which is described with respect to FIGs. 4A-C and FIG. 6. For example, the control unit may be configured to determine and/or to control the position of the inspection device. Further, the control unit may be configured for processing data. For example, the control unit may be capable of processing images and calculating offset values. In other words, the control unit may be configured to determine an offset value based on at least one image captured by the optical inspection device and for sending a re- alignment value to the alignment device based on the offset value. [0043] FIG. 2 shows a schematic view of a substrate and a mask according to embodiments described herein.

[0044] For manufacturing OLEDs, organic molecules can be generated by the deposition source 130 (e.g., evaporated, sputtered, sprayed etc.) and deposited on the substrate 10. The mask arrangement including the mask 20 is positioned between the substrate 10 and the movable deposition source 130. The mask 20 includes a pattern, e.g., provided by a plurality of deposition openings 21, so that organic molecules pass through the deposition openings 21 (e.g., along a path 32) to deposit a layer or film of an organic compound on the substrate 10. The pattern of the deposition openings may not be limited to the pattern shown in FIG. 2. The mask may be part of a mask arrangement, wherein the mask arrangement may include a mask carrier which carries the mask.

[0045] A plurality of layers or films can be deposited on the substrate 10 using different masks, e.g., to generate pixels with different color properties. As an example, a first material can be deposited to generate red pixels, a second material can be deposited to generate green pixels, and a third material can be deposited to generate blue pixels. The materials e.g., organic materials, can be arranged between two electrodes, such as an anode and a cathode (not shown). At least one electrode of the two electrodes can be transparent. The mask may include millions of deposition openings for the generation of millions of pixels. For example, 100 million deposition openings or more may be present on the mask. Typically, the mask may be a fine metal mask having more than 100.000 deposition openings.

[0046] The substrate 10 and the mask 20 can be arranged in a vertical orientation during the deposition process. In FIG. 2, arrows indicate a vertical direction (y-direction) and a horizontal direction (x-direction) as described above. [0047] The embodiments described herein can be e.g. utilized for providing large area coated substrates, e.g., for manufactured displays. The substrates or substrate receiving areas for which the apparatuses and methods described herein are configured can be large area substrates having a size of e.g. 1 m² or above. For example, a large area substrate or carrier can be GEN 4.5, which corresponds to about 0.67 m² substrates (0.73x0.92m), GEN 5, which corresponds to about 1.4 m² substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m² substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7m² substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m² substrates (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. For example, for OLED display manufacturing, half sizes of the above mentioned substrate generations, including GEN 6, can be coated by evaporation of an apparatus for evaporating material. The half sizes of the substrate generation may result from some processes running on a full substrate size, and subsequent processes running on half of a substrate previously processed.

[0048] 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 to substantially inflexible substrates, and the term“substrate” may 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 0.5 mm or below, wherein the flexibility of the substantially inflexible substrate is small in comparison to the flexible substrates.

[0049] A 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 etc.), metal, polymer, ceramic, compound materials, carbon fiber materials, metal or any other material or combination of materials which can be coated by a deposition process. The substrate may be transparent.

[0050] The substrate 10 may include a backplane pattern 11. A backplane pattern 11 as used herein may define predetermined positions where the deposition material is to be deposited on the substrate. The backplane pattern may thus determine the position of e.g. the pixels including the deposited material. The success of the deposition process may be dependent on how well the mask arrangement and the substrate arrangement may be aligned. The substrate may be part of a substrate arrangement and/or part of a mask and substrate arrangement.

[0051] As shown in FIG. 2, the mask 20 and the substrate may further be provided with reference markers 547 at the comers. For example, reference markers may be fiducials. Reference markers may be used in order to align the substrate 10 relative to the mask 20. The alignment utilizing the fiducials is carried out before the deposition.

[0052] FIGs. 3A and 3B show schematic views of a holding arrangement 300 according to embodiments described herein. The holding arrangement may be used for supporting the substrate carrier 15 and a mask carrier 25 during layer deposition in a vacuum chamber that can be used in systems and apparatuses according to embodiments described herein. FIG. 3B shows a front view of the holding arrangement 300 shown in Fig. 3A.

[0053] In some implementations, the apparatus and/or the system for vacuum processing of the present disclosure may include a holding arrangement 300 for holding the substrate carrier 15 and the mask carrier 25, particularly during an alignment and deposition process. The holding arrangement 300 may include one or more holding devices, such as one or more first holding devices 326 configured for holding the mask carrier 25 and/or one or more second holding devices 316 configured for holding the substrate carrier 15. The one or more holding devices can be configured to be movable in a moving direction being different from a substrate transport direction. For instance, the one or more holding devices can be configured to be movable in a direction substantially perpendicular to a plane of the substrate surface, e.g., in the first direction and the second direction. In FIG. 3 A, a moving direction of the one or more holding devices is indicated by the double sided arrow depicted on the one or more holding devices.

[0054] In some implementations, the mask carrier 25 can be transported on the second track arrangement to a predetermined position at which the holding arrangement 300 is provided. The one or more first holding devices 326 can move towards the mask carrier 25 in order to hold the mask carrier 25 in a predetermined position e.g. by chucking the mask carrier 25 using a chucking force, such as a magnetic or electromagnetic force. Thereafter, the substrate carrier 15 can be transported on the first track arrangement to a predetermined position corresponding to the mask carrier 25. At least one holding device of the one or more second holding devices 316 can move towards the substrate carrier 15 in order to hold the substrate carrier 15 in the predetermined position e.g. by chucking the substrate carrier 15 using a chucking force, such as a magnetic or electromagnetic force. Then, the substrate carrier 15 can be aligned with respect to the mask carrier 25, or vice versa.

[0055] According to some embodiments, an extension (e.g., a length) of the substrate carrier 15 in the x direction and an extension (e.g., a length) of the mask carrier 25 in the x direction are different. In particular, the substrate carrier 15 and the mask carrier 25 can have the same heights but different lengths. In particular, the length of the substrate carrier 15 can be less than the length of the mask carrier 25. The length difference can be selected such that the one or more first holding devices 412, which can be mounted on the side wall of the vacuum chamber, can pass by the edges of the substrate carrier 15 to grab and hold the mask carrier 25. In particular, the one or more first holding devices 412 can pass the substrate carrier 15 without interfering with the substrate carrier 15.

[0056] According to some embodiments, the holding arrangement 300 can include the alignment device configured for aligning the substrate arrangement (or substrate carrier 15) relative to the mask arrangement (or mask carrier 25) or vice versa. In particular, the alignment device can be configured to adjust the position of the substrate carrier 15 with respect to the mask carrier 25 or vice versa. For instance, the alignment device can be configured for aligning the substrate carrier 15 holding the substrate 10 relative to the mask carrier 25 holding the mask 20 in order to provide for a proper alignment between the substrate 10 and the mask 20 during material deposition, e.g. of the organic material.

[0057] In some implementations, the alignment device includes one or more alignment actuators for positioning the substrate carrier 15 and the mask carrier 25 with respect to each other. For example, the two or more alignment actuators can be piezoelectric actuators for positioning the substrate carrier 15 and the mask carrier 25 with respect to each other. However, the present disclosure is not limited to piezoelectric actuators. For example, the two or more alignment actuators can be electric or pneumatic actuators. The two or more alignment actuators can be linear alignment actuators. In some implementations, the two or more alignment actuators can include at least one actuator selected from the group consisting of a stepper actuator, a brushless actuator, a DC (direct current) actuator, a voice coil actuator, a piezoelectric actuator, and any combination thereof.

[0058] According to some embodiments, the one or more alignment actuators can be provided between the first track arrangement and the second track arrangement. In particular, the one or more alignment actuators can be provided between the substrate carrier 15 and the mask carrier 25. The one or more alignment actuators can be implemented in a space-saving manner, reducing a footprint of the apparatus.

[0059] The alignment device can be configured for a relative alignment in at least two directions defining a plane, which is essentially parallel to the plane of the substrate and the plane of the mask. For example, an alignment can at least be conducted in an x- direction and a y-direction, i.e. two Cartesian directions defining the above-described parallel plane. Typically, the mask and the substrate can be essentially parallel to each other. Specifically, the alignment can further be conducted in a direction essentially perpendicular to the plane of the substrate and the plane of the mask. Thus, an alignment unit is configured at least for an x-y-alignment, and specifically for an x-y-z-alignment of the mask and the substrate relative to each other. One specific example, which can be combined with other embodiments described herein, is to align the substrate in an x- direction, y-direction and z-direction to a mask, which can be held stationary in the vacuum processing chamber.

[0060] According to embodiments, the alignment of the mask and the substrate or the mask carrier and the substrate carrier may be performed by using the reference markers or fiducials provided on the mask and/or the substrate. For example, a visualization device may be used to inspect the reference markers 547 on the mask 20 and the substrate 10. The visualization device may for example be an optical inspection device. The visualization device may pass the reference markers, such as fiducials, on the mask and/or the substrate and may determine the position of said reference markers to perform the alignment of the mask with respect to the substrate as described above.

[0061] According to embodiments that can be combined with other embodiments described herein, an optical inspection of the alignment of the mask with respect to the substrate may be performed. This way of checking the alignment may be performed directly after the alignment of the mask with respect to the substrate and before the start of the deposition. The checking may be performed by an optical inspection device. The optical inspection device may capture images of the mask arranged in front of the substrate. The arrangement of the optical inspection device is described with respect to FIGs. 4A to C.

[0062] For example, the optical inspection can be carried out on a substrate 10 in a vacuum processing chamber before the deposition starts. In particular, the inspection device may be configured for the optical inspection of a substrate 10 in an essentially vertical position. The inspection device may detect an offset value, said offset value corresponding to the relative position of the substrate 10 with respect to a mask 20. According to some embodiments, which can be combined with other embodiments described herein, the offset value can be provided by detection of images of an aligned mask-substrate-assembly. For example, a mask-substrate alignment is provided, e.g. based on fiducials in the processing chamber. After the alignment based on the fiducials, the alignment may be checked with an inspection method described herein, e.g. by detecting an offset value with the inspection device, based on a relative positioning of the plurality of deposition openings and the backplane pattern of the substrate.

[0063] The fiducials are typically not provided adjacent to the backplane pattern on which the material is actually deposited, but on an edge area of the substrate and/or of the mask. Accordingly, the alignment via the fiducials may not be sufficiently accurate, e.g. due to local temperature variations of the substrate in an area between the fiducials and the backplane pattern. According to embodiments described herein, the alignment is checked by inspecting a relative positioning of the backplane pattern and the deposition openings. In other words, the alignment of the substrate -mask-arrangement is checked at positions where the deposition actually takes place. It can be accurately detected whether the alignment is accurate and whether the substrate-mask arrangement is ready for deposition.

[0064] The inspection device may include a light source for illuminating the substrate 10 and/or one or more image capturing devices for taking one or more images of at least a portion of the substrate 10, and a processing device for processing the captured images which is further described with respect to FIG. 6. [0065] FIGS. 4A, B and C show a schematic view of inspection arrangements 400, 400’ and 400” according to embodiments described herein.

[0066] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, an optical inspection device 440 can be positioned to inspect the substrate 10 being maintained under vacuum conditions. The optical inspection may be performed statically or dynamically.

[0067] According to an embodiment, the inspection arrangement 400 includes an inspection device 440. The inspection device 440 may be attached to the movable deposition source 130. [0068] The deposition source may have a first side that is provided with vapor nozzles and a second side different from the first side, wherein the optical inspection device may be attached to the second side of the movable deposition source. For example, the second side may be opposite the first side. For example, the inspection device 440 may be mounted on the rear side of the deposition source. The rear side of the deposition source may be understood as the side of the deposition source where no material is deposited. In other words, the rear side of the deposition source is a side neighboring the material deposition side.

[0069] According to a further embodiment, which can be combined with other embodiments described herein, two mask and substrate arrangements may be provided in the processing chamber. A“mask and substrate arrangement” as used herein may be understood as a mask arrangement and substrate arrangement being aligned with respect to each other. In other words, a“mask and substrate arrangement” may describe the combination of a mask 20 and a substrate 10, a mask and substrate aligned with respect to each other and/or the respective mask carrier 25 and substrate carrier 15 aligned with respect to each other. For example, two mask and substrate arrangements can oppose each other. The support surface 17 of the substrate carrier may be directed in the direction of the deposition source.

[0070] According to an embodiment that can be combined with other embodiments, the deposition source 130 may be movable. Typically, the deposition source may be provided at a source support 831. The source support 831 may be configured for the translational movement of the deposition source 130 along a linear guide. The movement of the deposition source may further include a rotational movement. The deposition source may rotate around a rotation axis. The rotation may include a 360° degree rotation. It is to be understood that the rotation may include every rotation angle of 0 to 360° degrees. In other words, the deposition source may be rotatable and linearly movable. The rotation may be halted at every of said angles. For example, the movable deposition source may deposit material on a first substrate and mask arrangement.

[0071] For example, when the deposition process is finished, the deposition source can perform e.g. a 180° degree turn and perform a further deposition process at the second mask and substrate arrangement opposite the first mask and substrate arrangement. The deposition source may further be translationally moved via the source support 831. In other words, the movable deposition source may move along a source track or support provided between a second substrate (or second substrate arrangement or second mask and substrate arrangement) and the first substrate (or first substrate arrangement or first mask and substrate arrangement), wherein the first substrate may be coated by the deposition source while an offset may be inspected (at the second substrate).

[0072] Thus, according to an embodiment, the movable deposition source may have a first side that may be provided with vapor nozzles and a second side opposite the first side, wherein the optical inspection device 440 may be attached to the second side of the movable deposition source.

[0073] According to a further embodiment, the optical inspection device may inspect the second mask and substrate arrangement while the deposition source deposits material on the first mask and substrate arrangement. The optical inspection device may be configured to perform the optical inspection from the front side of the mask and substrate arrangement (i.e. from the side, where the deposition source is arranged). Thus, the inspection device may adopt an inspection position at the front of the aligned mask and substrate arrangement.

[0074] For example, the optical inspection device may be fixed to the deposition source. The movable deposition source may be moved past the substrate and the inspection device may capture images of the substrate. After depositing material at the first mask and substrate arrangement, the first substrate may be transported away from the processing chamber. A new substrate may be transported into the processing chamber and may be aligned with the mask. Optionally, the mask may also be exchanged. [0075] According to embodiments which can be combined with other embodiments described herein, the optical inspection device 440 may be movable. For example, the optical inspection device may be mounted so that the device may be moved in different directions towards a mask and substrate arrangement and/or a mask arrangement and/or substrate arrangement. Additionally or alternatively, the deposition source may be configured to adapt the position of the optical inspection device with regard to the mask and substrate arrangement and/or a mask arrangement and/or substrate arrangement. For example, the position of the deposition source may be changed with regard to the position of the inspection device.

[0076] The inspection and deposition described herein provides several advantages. The inspection and deposition process is accelerated. Thus, a more efficient deposition process may be realized. Further, the process is also optimized with regard to energy consumption and costs.

[0077] FIG. 4B shows an inspection arrangement 400’ according to embodiments described herein similar to the embodiment depicted in FIG. 4A. [0078] According to embodiments that can be combined with other embodiments described herein, the inspection arrangement 400’ may include a movable and/or foldable mount 442. The mount 442 may e.g. be an“arm” or any movable mount configured to reach different positions in the x-, y- and z- directions (of a Cartesian coordinate system). The mount or arm may be controlled by a control unit. The optical inspection device may thus be movably mounted, particularly the optical inspection device may be fixed to the movable or foldable arm which may be provided on the front side of the mask or mask and substrate arrangement. The inspection device may be additionally or alternatively configured to perform the optical inspection from the front side and/or from a rear side of the alignment device and/or the substrate. [0079] The mount may be directly or indirectly attached to the processing chamber, e.g. to a top wall 402. However, it is to be understood that the mount 442 may alternatively be attached to another wall of the processing chamber. The control unit of the mount 442 may be provided outside the processing chamber. [0080] Additionally or alternatively, the inspection device may be attached to the deposition source. Thus, a movement of the inspection device which is described with respect to FIG. 4A may be possible.

[0081] According to embodiments, the inspection device 440 may be fixed to the mount 442. Additionally or alternatively, the inspection device may be fixed to the arm such that the optical inspection device may be moved independently from the arm. In other words, the optical inspection device may be movably fixed to the arm. For example, the inspection device may be rotatable around a rotation axis in a horizontal plane (rotation in an x-direction).

[0082] FIG. 4C shows an inspection arrangement 400” according to embodiments described herein which is similar to the embodiments depicted in FIG. 4A and FIG. 4B.

[0083] According to embodiments which can be combined with other embodiments described herein, the optical inspection device may be configured to perform the optical inspection from a rear side of the mask and substrate arrangement, i.e. for example, from behind the substrate carrier. The optical inspection device 440 may be mounted at a side wall 101 of the processing chamber that is behind the substrate carrier 15. The side wall 101 may be at a rear side of the mask and substrate arrangement.

[0084] According to embodiments, the inspection device 440 may be movably mounted to the processing chamber. For example, the inspection device may be mounted to a mount 442 (not shown in FIG. 4C). The mount may be connected to the processing chamber. Similarly to what is described with respect to FIG. 4B, the inspection device may be moved in x-, y- and/or z- directions (of a Cartesian coordinate system).

[0085] According to embodiments, the substrate carrier may be transparent or may have transparent areas or portions. In particular, the substrate carrier may be transparent to light. Transparency may be achieved by different ways, e.g. by omitting parts of the substrate carrier and/or by using a transparent material for the substrate carrier. For example, the substrate carrier may include at least one cut-out such that the optical inspection device may capture at least one image from the rear side of the substrate through the at least one cut-out. Further, the substrate carrier may be attached to the substrate only at the comers of the substrate enabling the capturing of images between the respective attachment areas. The inspection device may be mounted such that the view of the inspection device may be capable of passing the substrate carrier from the rear side to capture images of the substrate and the mask that is aligned with respect to the substrate.

[0086] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, the inspection arrangements 400, 400’, 400” can provide an in-situ inspection system. An in- situ inspection system allows the inspection within the processing chamber. As compared to an inline inspection between two processing chambers, the alignment may be checked directly before the respective processing or deposition. This may result in an improved yield of the processing system. Further, material which is used during processing may be saved and/or used more efficiently. Additionally, the optical inspection as well as the deposition process is accelerated.

[0087] FIG. 5 shows a schematic representation of a front view of an aligned mask and substrate arrangement as well as different features related to an optical inspection of a substrate according to embodiments described herein.

[0088] According to embodiments, the mask arrangement and the substrate arrangement (and thus the mask and the substrate) may be aligned with respect to each other. The alignment of the mask with respect to the substrate may be checked after the alignment and before the deposition process starts.

[0089] Exemplarily, FIG. 5 shows a substrate 10 aligned with a mask 20. For example, the mask and the substrate are aligned for the deposition of an organic material in order to form devices having e.g. pixels with different positions employed in apparatuses and systems according to the present disclosure. According to embodiments, the different areas or portions, also referred to as inspection areas, of the mask and substrate arrangement may be inspected by the inspection device described above. [0090] As further shown in FIG. 5, the mask 20 and/or the substrate may be provided with reference markers 547 e.g. at the respective comers. For example, reference markers may be fiducials. Fiducials may be used in order to align the substrate 10 to the mask 20 before the deposition process.

[0091] The term“fiducials” as used herein may be understood as pattern recognition markers that may e.g. be openings or markings on the substrate and/or on the mask, e.g., with a round bare copper in the center. In particular, the fiducials may be etched and/or electroformed in an edge region of the mask and/or of the substrate. For example, fiducials can be located near edges of the substrate/mask. The fiducials may be detected using a visualization device and/or inspection device that may compare the detected images, for example, with stored information data. By obtaining data about the location of the mask fiducials relative to the substrate fiducials - stored for example in a system’s memory - it is possible to compute the degree to which parts, e.g. the mask, is to be moved relative to the substrate to ensure an accurate placement.

[0092] According to embodiments, the aligned mask and substrate arrangement may be divided into inspection areas 545 (dashed lines in FIG. 5). For example, inspection areas 545 may be located at the comers of the aligned mask and substrate arrangement and/or in the center of said arrangement. Inspection areas may be distributed over the surface of the mask. For example, an array of 4x6 or 8x10 inspection areas may be provided. However, the locations of the inspection areas 545 are not limited to those shown in FIG. 5.

[0093] The term“inspection area” may be understood as an area where the optical inspection device may be arranged to capture an image of the mask and substrate arrangement. An inspection area may include a local inspection of the alignment. The number and locations of the areas may be adapted according to the mask and/or substrate used. The area may thus be defined by two-dimensional coordinates (in a Cartesian coordinate system). The inspection areas may be understood as the areas upon which the calculation of an offset value is based.

[0094] According to an embodiment, the inspection device 440 may capture at least one image from at least one inspection area 545. Typically, more than one image is captured from one inspection area. Typically, the optical inspection device may include one, two or more cameras. According to an embodiment, the optical inspection device may capture images of at least four comer regions of the substrate.

[0095] In embodiments, an offset between the plurality of deposition openings of the mask and the backplane pattern of the substrate is locally inspected by capturing an image of at least one inspection area.

[0096] According to embodiments, for performing an adjustment of the position of the mask 20 relative to the substrate 10, an optical inspection may be performed in order to check possible variances or deviations relative to a correct alignment. Fiducial reference markers may be taken into account for this purpose.

[0097] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, the inspection device 440 may be configured for detecting an offset mask value, said offset mask value corresponding to the relative position of the substrate 10 with respect to a mask 20. The offset value may be determined from the image captured with the inspection device.

[0098] An offset or offset value as used herein may be understood as a direct or indirect measurement of the deviation and/or variance of the alignment of the mask with respect to the substrate. Thus, the offset value may be understood as direct measurement of the shift of the deposition opening 21 with respect to the backplane pattern 11 of the substrate (hatched circles in FIG. 5). The direct offset value may thus illustrate a distance. For example, an offset value may be provided for each inspection area. Additionally or alternatively, the offset may also describe an indirect measurement of said shift. An indirect measurement may be understood with respect to several images that may be captured for determining the offset. Thus, the offset value may be a value that combines several single direct values that were measured independently of each other. Thus, the offset value may be understood as an average or median value. The inspection device may be configured to determine direct and/or indirect offset values.

[0099] By detecting the offset value on the substrate 10 using the inspection device 440 according to the present disclosure, it is possible to control the alignment of the mask 20 relative to the substrate 10 before deposition may start. The captured images may be processed in order to determine the offset value. The offset values may be calculated from the processed images. The offset values may adopt different values. A misalignment may result in offset values which exceed or are lower than predetermined tolerance values. The tolerance values may e.g. be determined based on the respective deposition process. It is possible to calculate one offset value for one mask-substrate-arrangement or one offset value for each inspection area and/or fiducial used. An overall offset value may e.g. be the median or average of several determined offset values.

[00100] According to an embodiment, which can be combined with other embodiments described herein, the offset value may be used to realign the mask with respect to the substrate (or the mask arrangement with respect to the substrate arrangement, respectively). For example, the offset value is calculated and exceeds a predetermined tolerance value or range. Then, the offset may be retranslated into e.g. the position coordinates of the mask with respect to the substrate. By acting on the alignment device and/or the alignment actuators respectively, the substrate may be realigned with respect to the mask by the offset value or by an alignment value determined therefrom. The offset may thus be compensated after the inspection. For example, the control unit may be configured to determine an offset value based on at least one image captured by the optical inspection device. The control unit may further be configured for sending a re-alignment value to the alignment device based on the offset value. A re-alignment value may be understood as a correction value of which e.g. the mask has to be shifted with respect to the substrate to compensate the previously determined offset.

[00101] The predetermined tolerance values may be set such that the detected offset value can still be considered acceptable for the final product or such that the offset value is not acceptable for the final product. In both cases the alignment device may act on the substrate carrier or on the mask carrier present in the processing chamber. The carriers may e.g. be actuated (via the alignment device) to compensate the detected offset.

[00102] In this way, it is possible to directly act on the alignment actuators of the mask 20 and/or substrate 10 on a real time basis in order to fine-adjust or re-adjust the alignment of the mask and the substrate arrangement. [00103] According to embodiments which can be combined with other embodiments described herein, the inspection device may capture pictures from different inspection areas. For example, the pictures show several deposition openings 21 and the backplane pattern 11 of the substrate as shown in FIG. 5. The realignment may be dependent on the offset between the deposition openings and the respective backplane pattern.

[00104] According to an example, the backplane pattern may be completely visible. No or only little offset between the deposition opening and the backplane pattern may be detectable by the inspection device. A realignment may be redundant.

[00105] According to a further example, the backplane pattern may be visible but an offset between the deposition openings and the backplane pattern may be detected. An offset value of 10 pm or less, particularly of 5 pm or less, more particularly of 3 pm or less, may be considered as acceptable. A realignment may be redundant.

[00106] According to a yet further example, the backplane pattern may be only partly visible and an offset between the deposition openings and the respective backplane pattern may be detected. For example, the offset value may be 10 pm or more, particularly 20 pm or more. A realignment of the substrate with respect to the mask may be performed depending on the detected offset value.

[00107] Advantageously, the results of the optical inspection may be used in real time to adjust, for example, deposition parameters, such as alignment parameters, before deposition of material may start. Thus, the alignment of mask and substrate may be readjusted before deposition is eventually carried out, resulting in a reduced process time with less rejects.

[00108] The term“in real time” as used herein is intended to describe that the optical inspection may be carried out after the alignment of the substrate with respect to the mask and before deposition on the substrate. Consequently, the re-alignment values of the mask offset may be directly transferred to, for example, the corresponding alignment actuators. Also, the feedback may refer to a specific mask in e.g. one specific chamber.

[00109] FIG. 6 shows a schematic representation of an inspection system 600 for an optical inspection according to embodiments described herein. The inspection system 600 can be configured to optically inspect a substrate 10. The inspection system 600 can include an inspection device arrangement for performing an optical inspection as described e.g. with respect to FIGs. 4A to 4C.

[00110] The inspection system 600 includes an inspection device 440 e.g. for optically inspecting the relative position of the mask 20 with respect to the substrate 10, the mask 20 being used for processing the substrate 10 in a processing chamber. The mask and the substrate may be aligned with respect to each other.

[00111] According to an embodiment, where the substrate 10 is maintained under vacuum conditions, some components of the inspection device 440, such as for example the light source 644 and the image capturing device 646, may be located in a separate space in normal air pressure conditions or lower vacuum conditions. Advantageously, the maintenance procedures of these components of the inspection device 440 may be facilitated.

[00112] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, the inspection device 440 may include a light source 644 for illuminating the substrate 10 or the mask 20 respectively, one or more image capturing devices 646 for taking one or more images of at least a portion of the substrate 10 and the mask 20, and/or a processing device 650 for processing the captured images. [00113] The light source 644 and/or the image capturing device 646 may be located according to (pre-)determined positions to correctly illuminate and to capture the images of the portion of the substrate 10 to be investigated. Additionally or alternatively, the incident light and the measured light signal can be guided to and from the substrate by an optical fiber. [00114] The image capturing device 646 can be a photo camera or a video camera configured for scanning over portions of the mask and substrate arrangement. The inspection device 440 may include a single-camera system, having a single image capturing device, or a multiple-camera system, having a plurality of image capturing devices 646. Particularly, the inspection device 440 according to one embodiment of the present disclosure may include four image capturing devices 646. In other words, the optical inspection device may include one, two or more capturing devices, in particular one, two or more cameras.

[00115] The processing device 650 processes and/or analyzes the images captured by the image capturing device 646 and/or controls the illumination conditions of the light source 644. Therefore, the processing device 650 may include a processing unit, such as a CPU, connected to the light source as well as to the image capturing device 646. Specifically, the processing device 650 may compare the captured images with stored data or another captured image to obtain information data on the quality of alignment of the mask 20 with respect to the substrate 10, e.g. through the offset value. In other words, the processing device 650 may be configured for calculating the offset value from one image or from a plurality of captured images.

[00116] The processing device 650 may provide the obtained information data for a re- alignment of the mask with respect to the substrate. The information may have an impact on the alignment device. In this regard, the alignment device is provided with a dedicated control unit that receives the information data from the inspection device 440. The control unit may directly control the alignment device on the substrate carrier and/or the mask carrier for adjusting the position of the mask 20 relative to the substrate 10. It is noted that the control unit may be located outside the processing chamber. [00117] FIG. 7 shows a flowchart for illustrating a method 700 for processing a substrate according to embodiments described herein. The method 700 can utilize the arrangements, apparatuses and systems according to the embodiments described herein. Likewise, the apparatuses and systems can utilize the method 700.

[00118] The method may for example be performed to deposit a material on a substrate. A deposition source may perform the material deposition. The material may be deposited to defined areas on the substrate. Typically, organic material may be deposited on the substrate. The organic material may e.g. be used to form pixels. The pixels may include different colors. The method 700 may therefore be performed several times on a substrate. For example, the material for one colored deposition (red, green or blue) is deposited on the substrate in one processing chamber. The material for other colored depositions (red, green or blue) may then be deposited on the substrate in different processing chambers.

[00119] The method 700 includes in box 760 transporting a mask having a plurality of deposition openings into a processing chamber. [00120] The mask may include deposition openings which may be arranged in a respective pattern. Typically, the mask may be a fine metal mask having more than 100.000 deposition openings.

[00121] The method 700 further includes in box 770 transporting a substrate having a backplane pattern into the processing chamber. [00122] The mask and the substrate may be transported via the respective mask and/or substrate carrier. Thus, the mask arrangement as well as the substrate arrangement may be transported into the processing chamber. The mask arrangement and/or the substrate arrangement may be transported to the processing chamber via the track arrangement described with respect to FIG. 1. For example, the substrate 10 may be transported to the processing chamber via the first track arrangement. The mask 20 may be transported to the same processing chamber via the second track arrangement.

[00123] As described above, the track arrangement may also be used to transport the substrate and/or the mask into and out of the processing chamber. Particularly, the substrate may be subsequently transported to first, second and/or third processing chambers. The substrate and/or the mask may be transported in a vertical orientation. Alternatively, the substrate and the mask may also be transported in a horizontal orientation.

[00124] The method 700 further includes a box 780 aligning the substrate with respect to the mask. [00125] The mask arrangement and the substrate arrangement or the mask and substrate arrangement may be aligned with respect to each other. For example, the substrate may be aligned with respect to the mask. [00126] The mask and the substrate may be held in place before and/or during the alignment by a holding arrangement according to the description with respect to FIGs. 3A and B. Reference markers, particularly fiducial markers that may be provided on at least one of the mask and the substrate may be used as points of reference for the aligning. The alignment may thus be performed based on the fiducials at the comers of the mask and/or the substrate. The alignment may be performed by the alignment device. The holding arrangement may include the alignment device. The alignment device may include alignment actuators that may change the positions of the mask and/or the substrate with respect to each other. The mask and substrate arrangement may be particularly aligned in a vertical orientation.

[00127] The method 700 further includes a box 790 of at least locally inspecting an offset between the plurality of deposition openings and the backplane pattern with an optical inspection device.

[00128] For inspecting an offset between the mask and the substrate, the inspection device may adopt several configurations. Additionally or alternatively, the inspection device may be moved within the processing chamber. The optical inspection device may be movably mounted. The optical inspection device may for example be attached to the processing chamber, and may particularly be mounted to the top wall or the side wall 101 of the processing chamber.

[00129] According to an embodiment, the optical inspection device may be attached to a movable mount. A movable mount may include a movable or foldable arm as described with respect to FIG. 4B. The optical inspection device may be fixed to the movable mount. The movable mount may be attached to the processing chamber. The movable mount may be movable on the front side of a mask and substrate arrangement. Alternatively, the mount may be attached elsewhere in the chamber, e.g. at the deposition source or at a side wall of the processing chamber.

[00130] According to an embodiment, the inspection device may be attached to the movable deposition source. For example, the optical inspection device may be mounted to the back side of the movable deposition source, where no deposition material is released. The optical inspection device may be directly or indirectly movably attached or movably fixed to the deposition source. Being fixed indirectly to the deposition source may include being movably fixed to a movable arm which is movably fixed to the deposition source. Typically, the optical inspection device may be fixed to the movable deposition source. The method may thus further include moving the movable deposition source past the substrate and capturing images of the substrate with the optical inspection device.

[00131] According to an embodiment which can be combined with other embodiments described herein, the optical inspection device may be moved to an inspection position on a front side of the substrate and may capture at least one image showing portions of the backplane pattern behind the plurality of deposition openings. For example, the inspection device may be fixed to the deposition source and the deposition source may be arranged on the front side of the mask and substrate arrangement. Thus, at least one image may be captured that may include a“mask-substrate” or“deposition opening-backplane pattern” perspective.

[00132] According to an embodiment, the inspection device may be attached to a rear side of the substrate carrier as described with respect to FIG. 4C. The substrate carrier may be provided with at least one cut-out such that the optical inspection device may capture at least one image from the rear side of the substrate through the at least one cut-out. The substrate may be at least partially transparent. Thus, the optical inspection device may capture images with a“substrate -mask” and/or“backplane pattern-deposition openings” perspective.

[00133] The method 700 may further include the optical inspection device capturing images of one or more portions of the substrate aligned with respect to the mask or vice versa and processing the captured images for determining at least one offset value as described with respect to FIG. 5. Processing the captured images may be performed by a control unit. By processing the captured images, it is possible to obtain data including an offset mask value(s), said offset mask value(s) corresponding to the relative position of the substrate 10 with respect to a mask 20.

[00134] The calculated offset mask value can be used as feedback data for re-adjusting the alignment of the mask 20 relative to the substrate 10 before the deposition of the organic layer in the processing chamber starts. [00135] The method 700 may further include re-aligning the substrate with respect to the mask based on the at least one offset value. Thus, the aligning of the mask with respect to the substrate may be checked and/or surveilled. Depositing of material may be initiated after having checked the alignment. [00136] According to an embodiment, the method 700 may further include illuminating the mask and substrate arrangement, capturing images of at least a portion, e.g. the inspection area of the substrate, in particular the mask and substrate arrangement, and processing the images of the mask and substrate arrangement taken at different lighting conditions. [00137] The method 700 may further include the mask and the substrate being essentially vertically oriented during at least one of transporting, aligning, and inspecting. Further, the mask and the substrate may be essentially vertically oriented during depositing of material. Typically, one or more materials may be deposited on the substrate through the plurality of deposition openings. Thus, a specific pattern may be achieved. [00138] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, the method 700 may further include calculating an offset value by averaging the information data from captured images taken by a plurality of image capturing devices and for a plurality of portions of the substrate and mask arrangement or the respective mask and substrate. In this way, it is possible to obtain more precise data regarding the alignment of the mask and the substrate.

[00139] Using a plurality of image capturing devices 646 may lead to the advantage of collecting images of different portions of the substrate 10 at the same time, e.g. with the same point of view. This can be obtained, for example, if the image capturing devices 646 are located at the same distance from the substrate 10 with the same field of view. Alternatively, the plurality of image capturing devices 646 may be located at different distances from the substrate 10 with different fields of view in order to capture the substrate 10, or portion of the substrate 10, from different viewpoints. Similar results may be obtained with a single image capturing device that is movable through for example a mechanical arm on the substrate 10. [00140] The method described includes the advantages that are also associated with the apparatus and arrangements described with respect to FIGs. 1 to 6, since the method may utilize respective embodiments.

[00141] FIG. 8 shows a schematic representation of a system 800 for vacuum processing a substrate according to embodiments described herein.

[00142] The arrangements, apparatuses, systems, and the methods according to the present disclosure may be part of the system 800 or a similar manufacturing system.

[00143] The system 800 may generally include the apparatus as described herein. The substrate may be coupled to a first mount of the alignment device and the mask may be coupled to a second mount of the alignment device. The mounts may be part of the holding arrangement which is described with respect to FIGs. 3A and B. Further, the alignment device may be the alignment device described with respect to FIGs. 3A and B.

[00144] According to some embodiments, which can be combined with any other embodiments described herein, the system 800 includes the vacuum chamber (e.g. a vacuum processing chamber 805) having the inspection device and the alignment device according to embodiments described herein. The system 800 may include at least one further chamber 802 having a track arrangement described with respect to FIG. 1. The at least one further chamber 802 can be a rotation module, a transit module, or a combination thereof. In the rotation module, the track arrangement and the carrier(s) arranged thereon can be rotated around a rotational axis, such as a vertical rotation axis. For example, the carrier(s) can be transferred from the left side of the system 800 to the right side of the system 800, or vice versa. The transit module can include crossing tracks such that carrier(s) can be transferred through the transit module in different directions, e.g., directions perpendicular to each other. [00145] The vacuum processing chamber 805 can be configured for depositing organic materials. A deposition source 130, particularly an evaporation source, can be provided in the vacuum processing chamber 805. The deposition source 130 can be provided on a track or linear guide 438, as exemplarily shown in FIG. 8. The linear guide 438 may be configured for the translational movement of the deposition source 130. Further, a drive for providing a translational movement of deposition source 130 can be provided. In particular, a transportation apparatus for contactless transportation of the deposition source 130 may be provided.

[00146] A source support 831 configured for the translational movement of the deposition source 130 along the linear guide 438 may be provided. The source support 831 can support an evaporation crucible 834 and a distribution assembly 836 provided over the evaporation crucible 834. Accordingly, the vapor generated in the evaporation crucible can move upwardly and out of the one or more outlets of the distribution assembly. The distribution assembly 836 is configured for providing evaporated organic material, particularly a plume of evaporated source material, from the distribution assembly to the substrate.

[00147] As exemplarily shown in FIG. 8, the vacuum processing chamber 805 may have gate valves 807 via which the vacuum process chamber 805 can be connected to an adjacent further chamber 802, e.g. a routing module or an adjacent service module. In particular, the gate valves 807 allow for a vacuum seal to the adjacent further chamber and can be opened and closed for moving a substrate and/or a mask into or out of the vacuum processing chamber 805.

[00148] With exemplary reference to FIG. 8, according to embodiments which can be combined with any other embodiment described herein, two substrates, e.g. a first substrate 10A and a second substrate 10B, can be supported on respective transportation tracks, such as respective first track arrangements 110 as described herein. Further, two tracks, e.g. two second track arrangements 120 as described herein, for providing mask carriers 25 thereon can be provided. In some embodiments, coating of the substrates may include masking the substrates using the respective masks, e.g. using an edge exclusion mask or a shadow mask. According to some embodiments, the masks, e.g. a first mask 20A corresponding to the first substrate 10A and a second mask 20B corresponding to the second substrate 10B, are provided in a mask carrier 25 to hold the mask in a predetermined and aligned position.

[00149] According to some embodiments, which can be combined with other embodiments described herein, the substrate is supported by the substrate carrier, which can be connected to a holding arrangement 828. The holding arrangement 828 can be configured as described with respect to FIGs. 3A and B. In particular, the holding arrangement 828 can include the alignment device configured for adjusting the position of the substrate with respect to the mask. It is to be understood that the substrate can be moved relative to the mask in order to provide for a proper alignment between the substrate and the mask before and/or during deposition of the organic material. According to further embodiments, which can be combined with other embodiments described herein, alternatively or additionally the mask carrier 25 holding the mask can be connected to the holding arrangement 828. Accordingly, either the mask can be positioned relative to the substrate or the mask and the substrate can both be positioned relative to each other. An alignment system as described herein may allow for a proper alignment of the masking during the deposition process, which is beneficial for high quality OLED display manufacturing.

[00150] Although one single vacuum processing chamber is illustrated in FIG. 8, it is to be understood that the system can include two or more vacuum processing chambers. Different vacuum processing chambers can be configured for deposition of different materials or material layers on the substrate.

[00151] For example, a plurality of layers or films may be deposited on the substrate using different masks or positions of the mask with respect to the substrate, e.g., to generate pixels, for example, with different color properties. As an example, a first layer or film can be deposited to generate red pixels, a second layer or film can be deposited to generate green pixels, and a third layer or film can be deposited to generate blue pixels.

[00152] The deposition of each of the colored pixels may be carried out in different vacuum chambers. The substrate may be transported via the track arrangements between or to the respective chamber. Thus, it may happen that either a plain substrate or an already coated substrate is aligned with respect to a mask or vice versa. The inspection arrangement of the present disclosure can improve such alignment in the different vacuum processing chambers such that also a relative alignment of multiple layers deposited on the substrate can be improved.

[00153] For example, the embodiments of the present disclosure can provide an alignment accuracy of at least ±3 pm. [00154] The embodiments according to the present disclosure have several advantages including the possibility to check the alignment between a mask, such as a fine metal mask, and a substrate in an efficient way, particularly before the deposition of an organic layer by using an automated optical inspection on a substrate maintained in an essentially vertical position.

[00155] Furthermore, the embodiments according to the present disclosure have the advantage of performing the optical inspection of the aligned mask and substrate without interrupting the production line and under the same conditions (for example substrate orientation and pressure) present during the deposition of the organic layer. [00156] In addition, the embodiments according to the present disclosure have the advantage of enabling the re-alignment of the mask with respect to the substrate before the deposition process starts, resulting in saving materials for the deposition process. This is possible, since the results of the optical inspection may be used in real time. Thus, the alignment of mask and substrate may be readjusted before deposition is carried out resulting in a reduced process time.

[00157] 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. Method for processing a substrate, comprising:

transporting (760) a mask having a plurality of deposition openings (21) into a processing chamber;

transporting (770) a substrate having a backplane pattern (11) into the processing chamber; aligning (780) the substrate (10) with respect to the mask (20); and

at least locally inspecting (790) an offset between the plurality of deposition openings (21) and the backplane pattern (11) with an optical inspection device (440).

2. Method of claim 1, further comprising: depositing one or more materials on the substrate (10) through the plurality of deposition openings (21 ).

3. Method of any of claims 1 or 2, wherein the optical inspection device (440) captures images of one or more portions of the substrate (10) aligned with respect to the mask (20) and processes the captured images for determining at least one offset value.

4. Method according to claim 3, further comprising: re-aligning the substrate (10) with respect to the mask (20) based on the at least one offset value.

5. Method of any of claims 1 to 4, wherein the optical inspection device (440) is moved to an inspection position on a front side of the substrate (10) and captures at least one image showing portions of the backplane pattern (11) behind the plurality of deposition openings (21).

6. Method of any of claims 1 to 5, wherein the optical inspection device (440) is fixed to a movable deposition source (130), the method comprising: moving the movable deposition source (130) past the substrate (10) and capturing images of the substrate with the optical inspection device (440).

7. Method of any of claims 1 to 5, wherein the substrate (10) is supported on a substrate carrier (15) that is provided with at least one cut-out, wherein the optical inspection device captures at least one image from a rear side of the substrate (10) through the at least one cut-out.

8. Method of any of claims 1 to 7, wherein the mask (20) and the substrate are essentially vertically oriented during at least one of transporting, aligning, and inspecting.

9. Method of any of claims 1 to 8, wherein reference markers (547), particularly fiducial markers, provided on at least one of the mask (20) and the substrate (10) are used as points of reference for the aligning.

10. Apparatus (100) for vacuum processing of a substrate, comprising: an alignment device configured to align a substrate (10) having a backplane pattern (11) with respect to a mask (20) having a plurality of deposition openings (21); an optical inspection device (440) configured to at least locally determine an offset between the plurality of deposition openings (21) and the backplane pattern (11); and a deposition source (130) arranged on a front side of the mask and configured to deposit one or more materials on the substrate (10).

11. Apparatus (100) according to claim 10, wherein the optical inspection device (440) is attached to the deposition source (130), particularly wherein the deposition source is movable past the substrate.

12. Apparatus (100) according to claim 10 or 11, wherein the optical inspection device (440) is movably mounted, particularly wherein the optical inspection device is fixed to a movable or foldable arm (442) provided on the front side of the mask.

13. Apparatus (100) according to any of claims 10 to 12, wherein the optical inspection device (440) is arranged on a rear side of the alignment device and configured to capture an image of a portion (545) of the substrate (10) aligned with respect to the mask (20) through at least one cut-out of a substrate carrier (15) supporting the substrate and/or wherein the optical inspection device (440) comprises one, two or more cameras.

14. Apparatus (100) according to any of claims 10 to 13, further comprising a control unit configured to determine an offset value based on at least one image captured by the optical inspection device (440) and for sending a re-alignment value to the alignment device based on the offset value.

15. V acuum processing system, comprising :

an apparatus (100) of any of claims 10 to 14;

a substrate (10) coupled to a first mount of the alignment device; and a mask (20) coupled to a second mount of the alignment device.