TECHNICAL FIELD

[0001 ] Embodiments of the present disclosure relate to the deposition of an evaporated source material, e.g. an evaporated organic material, on a substrate in a vacuum chamber. Embodiments of the present disclosure further relate to an evaporation system for depositing an evaporated source material, e.g. an evaporated organic material, on a substrate. More specifically, embodiments described herein relate to an evaporation system including an evaporation source with one or more vapor outlets for directing an evaporated source material toward a substrate through a shielding device and through a mask. Particularly, embodiments relate to methods of operating an evaporation source in a vacuum chamber, an evaporation system, and a shield handling apparatus.

BACKGROUND

[0002] Evaporation sources are a tool for the production of organic light-emitting diodes (OLEDs). OLEDs are a special type of light-emitting diode in which the emissive layer includes a thin- film of certain organic compounds. Organic light emitting diodes are used in the manufacture of television screens, computer monitors, mobile phones and other hand-held devices for displaying information. OLEDs can also be used for general space illumination. The range of colors, brightness, and viewing angle possible with OLED displays is greater than that of traditional LCD displays because OLED pixels directly emit light and do not need a back light. Therefore, the energy consumption of OLED displays is considerably less than that of traditional LCD displays. Further, the fact that OLEDs can be manufactured onto flexible substrates results in further applications. A typical OLED display may include a layer of organic material situated between two electrodes that are deposited on a substrate in a manner to form a matrix display panel having individually energizable pixels. The OLED is generally placed between two glass panels, and the edges of the glass panels are sealed to encapsulate the OLED therein. Also other materials, such as metals, may be deposited by evaporation. [0003] There are many challenges encountered in the manufacture of display devices by evaporation. Typical displays include a stack of several materials, which are typically evaporated in a vacuum chamber. The evaporated materials may be deposited in a subsequent manner through shadow masks. For the fabrication of OLED stacks with high efficiency, the co-deposition or co-evaporation of two or more materials, e.g. host and dopant, leading to mixed/doped layers is beneficial.

[0004] For depositing the source material on a substrate, the source material is heated in a crucible until the source material evaporates. The evaporated source material is guided through a vapor distribution assembly toward a plurality of vapor outlets or vapor nozzles. The evaporated source material is directed by the plurality of vapor outlets or vapor nozzles toward a substrate through a mask that is arranged in front of the substrate. The mask may have a plurality of small openings for forming individual pixels on the substrate.

[0005] A shielding device may be arranged downstream of the plurality of vapor outlets and upstream of the mask and the substrate. The shielding device may shape the evaporated source material emanating from the plurality of vapor outlets. For example, the shielding device may be a shaping device configured to shape the plumes of evaporated source material emitted from the vapor nozzles, such that only vapor particles within a predetermined emission cone arrive at the substrate, whereas vapor particles emitted at large emission angles are blocked by the shaping device. Reducing the maximum vapor emission angle reduces the shadowing effect of the mask. The blocked evaporated source material may condense on the shielding device, such that the dimensions of the shielding device may change over time. The deposition accuracy may be negatively affected. Cleaning of the shielding device at regular intervals is possible, but time consuming.

[0006] In view of the above, it would be beneficial to provide an evaporation system that allows for a high up-time and a high deposition accuracy. More specifically, it would be beneficial to provide methods of operating an evaporation source and a corresponding evaporation system that allow for a reduction of idle times of the system and ensure a high deposition quality and accuracy. SUMMARY

[0007] In light of the above, methods of operating an evaporation source, evaporation systems, and shield exchange apparatuses are provided.

[0008] According to a first aspect of the present disclosure, a method of operating an evaporation source is provided, the evaporation source including a vapor distribution assembly with one or more vapor outlets, and a shielding device attached to the vapor distribution assembly. The method includes: emitting evaporated source material from the one or more vapor outlets, wherein at least a part of the evaporated source material emitted from the one or more vapor outlets is blocked by the shielding device; detaching the shielding device from the vapor distribution assembly in the vacuum chamber; and cleaning the shielding device.

[0009] The shielding device may be cleaned in a cleaning region of the vacuum chamber, particularly by heating the shielding device such that source material that has accumulated on the shielding device over time is re-evaporated.

[0010] After the cleaning, the shielding device may be re-attached to the vapor distribution assembly.

[0011] According to a second aspect of the present disclosure, an evaporation system is provided. The evaporation system includes a vacuum chamber and an evaporation source arranged in the vacuum chamber, the evaporation source including a vapor distribution assembly with one or more vapor outlets, and a shielding device attached to the vapor distribution assembly. The evaporation system further includes a shield handling apparatus configured to detach the shielding device from the vapor distribution assembly and to move the shielding device into a cleaning region of the vacuum chamber.

[0012] The shielding device may be cleaned in the cleaning region, particularly by heating, and be re-attached to the vapor distribution assembly. [0013] The shielding device may be exchangeably attached to the vapor distribution assembly, such that the shielding device can be detached by the shield handling apparatus and moved away from the vapor distribution assembly into the cleaning region.

[0014] According to a third aspect of the present disclosure, a shield handling apparatus for cleaning a shielding device of an evaporation source is provided. The shield handling apparatus includes a shield holding device with a shield holder configured for holding and releasing the shielding device, at least one drive configured to move the shield holding device to a cleaning position, and at least one heating device for directing heat toward the shielding device.

[0015] Optionally, the shield holding device may include at least a second shield holder configured for holding a second shielding device. The shield handling apparatus may be configured to hold a plurality of shielding devices at respective shield holders. The shield handling apparatus may be configured to exchange the detached shielding device with a second shielding device.

[0016] According to a fourth aspect of the present disclosure, an evaporation source is provided. The evaporation source includes a vapor distribution assembly with one or more vapor outlets for emitting an evaporated source material, and a shielding device for at least partially blocking the evaporated source material emitted from the one or more vapor outlets, wherein the shielding device is exchangeably held at the vapor distribution assembly.

[0017] In particular, the first shielding device is held at the vapor distribution assembly in an exchangeable manner, such that the first shielding device can be detached with the shield handling apparatus and moved to the cleaning region. In particular, the first shielding device is magnetically held at the vapor distribution assembly.

[0018] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed at methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus. Embodiments are also directed at methods of manufacturing the described apparatuses and systems. Further aspects, advantages and features of the present disclosure are apparent from the description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 present disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the present disclosure and are described in the following:

[0020] FIGS. 1A-1D show four subsequent stages of a method of operating an evaporation source in a vacuum chamber in accordance with methods described herein; [0021] FIG. 2 shows a schematic view of an evaporation system according to embodiments described herein;

[0022] FIGS. 3A-3C show subsequent stages of a method of operating an evaporation source according to embodiments described herein;

[0023] FIGS. 4A-4B show subsequent stages of a method of operating an evaporation source according to embodiments described herein;

[0024] FIGS. 5A-5B show subsequent stages of a method of operating an evaporation source according to embodiments described herein;

[0025] FIG. 6 shows a shielding device of an evaporation system according to embodiments described herein, the shielding device configured as a shaping device; [0026] FIG. 7 shows a shielding device of an evaporation system according to embodiments described herein, the shielding device configured as a shaping device;

[0027] FIG. 8 shows a shielding device of an evaporation system according to embodiments described herein, the shielding device configured as a shutter device;

[0028] FIG. 9 shows a shielding device of an evaporation system according to embodiments described herein, the shielding device configured as a shutter device;

[0029] FIG. 10 shows an evaporation source with several vapor distribution assemblies and shielding devices according to embodiments described herein; and

[0030] FIG. 11 is a flow diagram illustrating a method of operating an evaporation source according to embodiments described herein. DETAILED DESCRIPTION OF EMBODIMENTS

[0031] Reference will now be made in detail to the various embodiments of the present disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, 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 of the present disclosure. 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.

[0032] As used herein, the term “source material” may be understood as a material that is to be evaporated and deposited on a surface of a substrate. In embodiments described herein, a source material (e.g., an organic source material) is evaporated, and the evaporated source material is guided through a vapor distribution assembly and emitted by one or more vapor outlets or vapor nozzles toward a substrate. Before the evaporation, the source material may be in a solid state, e.g. a powder or granulate. After the evaporation, the source material is in a vapor state. Non-limiting examples of source materials include one or more of the following: organic materials, metals, ITO, NPD, Alq3, Quinacridone, Mg, Ag, starburst materials, and the like.

[0033] As used herein, the term “evaporation source” may be understood as an arrangement providing an evaporated source material to be deposited on a substrate. In particular, the evaporation source may be configured to direct an evaporated source material into a deposition area in a vacuum chamber where a substrate may be arranged. The evaporated source material may be directed toward the substrate by one or more vapor outlets, particularly by a plurality of vapor nozzles of the evaporation source. The vapor nozzles may be directed toward the deposition area and have a nozzle channel extending along an evaporation direction X, when the evaporation source is provided in a deposition position.

[0034] The evaporation source may include a crucible which evaporates the source material and a vapor distribution assembly in fluid communication with the crucible. The vapor distribution assembly is configured to transport the evaporated source material to the plurality vapor outlets for emitting the evaporated source material into the deposition area. The vapor distribution assembly may include a vapor distribution pipe extending in a first direction, e.g. an essentially vertical direction, and the plurality of vapor nozzles may extend through a front wall of the vapor distribution pipe. The evaporation source further includes a shielding device for shielding the evaporated source material emitted by the plurality of vapor outlets.

[0035] According to embodiments described herein, the vapor distribution pipe may be a linear distribution pipe extending in a first direction, particularly in an essentially vertical direction. “Essentially vertical” as used herein may be understood to include deviations of 10° or less from an exactly vertical direction. In some embodiments, the vapor distribution assembly may include a vapor distribution pipe having the cross-sectional shape of a cylinder or triangle. In some embodiments, the evaporation source may include two or three crucibles and two or three associated distribution pipes arranged next to each other on a common support which may be movable.

[0036] FIG. 1A shows a schematic view of an evaporation system 200 with an evaporation source 100 according to embodiments described herein. The evaporation source 100 is arranged in a vacuum chamber 11. The evaporation source 100 includes a vapor distribution assembly 130 with one or more vapor outlets 131, particularly with a plurality of vapor nozzles (e. g. , ten, thirty or more vapor nozzles), for directing an evaporated source material 15 toward a substrate 10. The evaporated source material propagates through an inner volume of the vapor distribution assembly 130 towards the one or more vapor outlets 131, and each of the one or more vapor outlets 131 emits a plume of evaporated source material in the emission direction X.

[0037] FIG. 1A shows the evaporation source 100 in a deposition state in which the evaporated source material 15 is emitted from the one or more vapor outlets 131, particularly from the plurality of vapor nozzles, toward the substrate 10. The plurality of vapor outlets may be arranged one above the other in a linear array. Only one vapor outlet is shown in the sectional view of FIG. 1A.

[0038] The evaporation source 100 further includes a first shielding device 120 (also referred to herein as “shielding device 120”) provided in front of the one or more vapor outlets 131 at the vapor distribution assembly 130. The first shielding device 120 may be attached to the vapor distribution assembly 130 on an emission side of the vapor distribution assembly where the one or more vapor outlets 131 are provided. The emission side is also referred to herein as the “front side” of the vapor distribution assembly. The one or more vapor outlets 131 or vapor nozzles may optionally at least partially protrude into the shielding device 120.

[0039] The shielding device 120 may be arranged downstream of the one or more vapor outlets 131 and upstream of the substrate 10, such that the shielding device can partially or completely block the evaporated source material 15 emitted from the one or more vapor outlets 131. In other words, the shielding device 120 constitutes a vapor shield that at least partially or entirely blocks the evaporated source material 15 emitted by the one or more vapor outlets 131. In particular, the shielding device 120 may be arranged between the vapor distribution assembly 130 and a mask 12 that defines a pixel pattern to be deposited on the substrate 10.

[0040] In some embodiments, the one or more vapor outlets 131 include a plurality of vapor outlets or vapor nozzles in a linear array (e.g., ten or more vapor outlets in a linear array), and the shielding device 120 includes a plurality of shielding portions in a linear array. In particular, each shielding portion of the plurality of shielding portions may include a circumferential shielding wall for an associated vapor outlet of the plurality of vapor outlets.

[0041] In some embodiments, the shielding device 120 is a shaping device configured to partially block the plumes of evaporated source material 15 emitted by the one or more vapor outlets 131, particularly for blocking only evaporated source material 15 emitted by the one or more vapor nozzles at an angle larger than a predetermined maximum emission angle, whereas evaporated source material 15 emitted at an angle smaller than the predetermined maximum emission angle may pass through the shaping device. Hence, the shielding device 120 improves the directionality of the emitted vapor plumes by blocking vapor particles emitted at large emission angles with respect to the emission direction X.

[0042] Providing the shaping device in close proximity to the vapor distribution assembly 130, particularly attaching the shaping device to the vapor distribution assembly, is beneficial because the shaping device is then arranged close to the one or more vapor outlets at a position where the plume diameters are small. Accordingly, vapor outlets of the vapor distribution assembly can be arranged in close proximity to each other, and the plumes of adjacent vapor outlets can still be individually shaped by the shaping device.

[0043] If a mask 12 is used for depositing the evaporated source material 15 on the substrate 10, the mask 12 may be a pixel mask with pixel openings having the size of 50 pm x 50 pm or below, such as pixel openings with a minimum dimension of 30 pm or less, or 20 pm or less. Considering the thickness of the mask and the size of the pixel openings, a shadowing effect may appear, where the walls of the pixel openings in the mask 12 shadow the pixel opening. This shadowing effect may lead to deposited pixels having a sloping edge, i.e. no sharp, well- defined edge. The first shielding device 120 may limit the maximum angle of impact of the evaporated source material 15 on the substrate 10 and reduce the shadowing effect, improving the deposition quality.

[0044] In other embodiments, the shielding device 120 is a shutter device configured to completely block the plumes of evaporated source material 15 emitted by the one or more vapor outlets 131. A shutter device may be placed in front of the one or more vapor outlets 131 in one or more of the following situations: (i) during idle times of the evaporation system, e.g. for maintenance and servicing of the evaporation source, where it is not desired to completely shut down the evaporation source; (ii) for substrate or mask exchange; (iii) for calibration or quality checks of the evaporation source; and/or (iv) for covering and protecting the one or more vapor outlets 131 or vapor nozzles. The emitted plumes of evaporated source material can simply be blocked by placing the shutter device on the front side of the vapor distribution assembly downstream of the one or more vapor outlets 131.

[0045] Attaching the shutter device to the vapor distribution assembly 130 is beneficial because the shutter device is then arranged close to the one or more vapor outlets at a position where the plume diameter is small. A stray coating of the vacuum chamber and/or of components arranged in the vacuum chamber can be effectively reduced or entirely prevented and the vapor outlets or vapor nozzles can be reliably covered and protected.

[0046] In FIG. 1A, the shielding device 120 is exemplarily depicted as a shaping device that blocks the evaporated source material 15 emitted by the one or more vapor outlets 131 at an emission angle larger than a predetermined maximum emission angle in at least one sectional plane. The predetermined maximum emission angle may be 60° or less, particularly 50% or less. The shielding device 120 improves the directionality of the plumes of evaporated material emitted by the one or more vapor nozzles. Alternatively, the shielding device 120 may be a shutter device (as exemplarily illustrated by reference numeral 402 in FIG. 1 A) that completely blocks the evaporated source material. [0047] The shielding device 120 is typically held at a temperature below the evaporation temperature of the evaporated source material during the evaporation, such that the evaporated source material that is blocked by the shielding device 120 condenses and remains on a wall of the shielding device 120. A re-emission of source material that is blocked by the shielding device 120 at an undefined emission angle can be reduced or prevented by holding the shielding device 120 at a temperature below the evaporation temperature, e.g. at a temperature of 250°C or less, or 150°C or less. Since evaporated source material condenses at the shielding device 120 during the operation of the evaporation system, there is a risk of clogging of the shielding device. It may be beneficial to clean the shielding device 120 at regular intervals, in order to make sure that the shaping or blocking effect of the shielding device is not negatively affected by source material accumulated thereon. However, cleaning of the shielding device 120 is time- consuming and may negatively affect the up-time of the evaporation system 200 if the evaporation source cannot be used otherwise during the cleaning of the shielding device. The up-time of the evaporation system 200 can be increased according to embodiments described herein.

[0048] According to embodiments described herein, the shielding device 120 is detached from the vapor distribution assembly 130 in the vacuum chamber 11 , and the detached shielding device is cleaned, particularly in a cleaning region 16 of the vacuum chamber.

[0049] In some embodiments, the shielding device 120, after the detaching, is moved from the vapor distribution assembly 130 to a cleaning position P in the vacuum chamber where the shielding device is cleaned.

[0050] In some embodiments, moving the shielding device 120 to the cleaning position P may include translating the shielding device 120 away from the vapor distribution assembly 130 into a cleaning region inside the vacuum chamber.

[0051] In some embodiments, which can be combined with other embodiments described herein, a shielding wall 150 (also referred to herein as an “idle shield”) is arranged between the vapor distribution assembly 130 and the cleaning region 16 in the vacuum chamber. Translating the shielding device 120 to the cleaning region 16 may include moving the shielding device through the shielding wall 150, particularly through a closable opening that is provided in the shielding wall 150. [0052] In some implementations, the shielding device 120 is at least locally heated at the cleaning position P for releasing attached source material from the shielding device.

[0053] In some implementations, the shielding device 120 at the cleaning position P faces toward a material collection wall 160 that is arranged in the vacuum chamber 11. The shielding device may be heated while the shielding device faces toward the material collection wall 160, such that the source material that has accumulated on the shielding device re-evaporates and propagates toward the material collection wall 160, where the re-evaporated source material may condense again. The material collection wall 160 may be a material collection box with an open side, as is schematically depicted in FIG. 1 A. The cleaning position P may be a position at the open side of the material collection box. The shielding device may be held at the open side of the material collection box during the cleaning, such that most or all of the re-evaporated material can be collected on an inner wall of the material collection box, and a stray coating of other components or of the vacuum chamber can be reduced or avoided.

[0054] In some embodiments, which can be combined with other embodiments described herein, moving the shielding device 120 to the cleaning position P may include rotating the shielding device around a rotating axis A, particularly around an essentially vertical rotation axis. In particular, the detached shielding device may be moved into the cleaning region by rotating the shielding device around an axis and/or by translating the shielding device along a linear translation path.

[0055] In some embodiments, which can be combined with other embodiments described herein, the shielding device 120 is detached from the vapor distribution assembly with a shield handling apparatus 180 including a shield holding device 182.

[0056] Before the detaching, the shield holding device 182 may be moved toward the vapor distribution assembly. After the detaching, the shield holding device 182 may be moved away from the vapor distribution assembly toward the cleaning position P.

[0057] In some implementations, detaching the shielding device 120 from the vapor distribution assembly includes transferring the shielding device 120 from the vapor distribution assembly 130 to a first shield holder 184 (also referred to herein as “shield holder 184”) of the shield holding device 182. The transferring may include switching a first magnet device of the shield holder 184 to a holding state. In particular, the first magnet device may include an electropermanent magnet that is switchable between a holding state and a release state, particularly by applying an electric pulse to a coil of the electropermanent magnet.

[0058] The shielding device 120 may be heated with at least one heating device 185 in the cleaning region 16, particularly with at least one radiation heater. The at least one heating device may be integrated in the shield holding device 182. Alternatively or additionally, at least one heating device for heating the shielding device 120 may be provided at the material collection wall 160.

[0059] In some embodiments, which can be combined with other embodiments described herein, a second shielding device 121 may be attached to the vapor distribution assembly 130 after detaching the first shielding device 120 from the vapor distribution assembly. For example, a used first shielding device having attached source material thereon is replaced by a clean second shielding device, such that the evaporation process can immediately continue after the exchange without a substantial delay. The first shielding device 120 may be cleaned after the detachment, and the deposition procedure may continue with the second shielding device 121 being attached to the vapor distribution assembly, while the first shielding device 120 is being cleaned in the cleaning region 16. The cleaning of the shielding device may take 5 minutes or more, particularly 10 minutes or more. During the cleaning of the first shielding device, the evaporation source with the attached second shielding device can be used for the deposition process.

[0060] An exchange of the first shielding device 120 with the second shielding device 121 can be beneficial, e.g., in the following situations: (1) The first shielding device is a shaping device having a substantial amount of source material condensed thereon that is to be exchanged with the second shielding device being another shaping device for continuing with the deposition process. (2) The first shielding device is a shutter device that blocks the one or more vapor outlets of the vapor distribution assembly, e.g., for conducting a quality check of an adjacent vapor distribution assembly that is unblocked. After the quality check, the shutter device is to be replaced by the second shielding device being a shaping device for starting with the deposition process. (3) The evaporation source is to be switched from a deposition state to an idle state by blocking the plumes of evaporated material emitted by the one or more vapor outlets. Therefore, the first shielding device being a shaping device is replaced by the second shielding device being a shutter device. Other replacement situations are possible. [0061] According to embodiments, which can be combined with other embodiments described herein, the detaching of the first shielding device 120 from the vapor distribution assembly 130 includes transferring the first shielding device 120 from the vapor distribution assembly 130 to a first shield holder 184 of the shield holding device 182. The shield holding device 182 may be a movable part of a shield handling apparatus 180 that is arranged in the vacuum chamber 11 and is configured to conduct an exchange of shielding devices in the vacuum chamber.

[0062] According to embodiments, which can be combined with other embodiments described herein, the attaching of the second shielding device 121 at the vapor distribution assembly 130 includes transferring the second shielding device 121 from a second shield holder 186 of the shield holding device 182 to the vapor distribution assembly 130.

[0063] In some embodiments, the shield handling apparatus 180 is a robot with at least one robot arm configured for holding the first shielding device 120 and/or the second shielding device 121 thereon. In some implementations, the robot may have several robot arms, each robot arm configured for holding and releasing at least one shielding device. The robot may be configured to detach the first shielding device 120 from the vapor distribution assembly, to move the first shielding device 120 away from the vapor distribution assembly, to move the second shielding device 121 to the vapor distribution assembly, and to attach the second shielding device 121 at the vapor distribution assembly.

[0064] In some embodiments, which can be combined with other embodiments described herein, a cleaning station may be provided in the cleaning region 16. The shield handling apparatus 180, particularly the at least one robot arm, may be configured to move the shielding device into the cleaning region 16 and to hand the shielding device over to the cleaning station. In particular, the shield handling apparatus 180 may be configured to transport the shielding device between the vapor distribution assembly and the cleaning station. A used shielding device can be detached from the vapor distribution assembly and be transported to the cleaning station with the shield handling apparatus 180, where the used shielding device can be cleaned. A clean shielding device can be transported from the cleaning station to the vapor distribution assembly and be attached to the vapor distribution assembly with the shield handling apparatus, such that the clean shielding device can be used for the deposition process. [0065] The cleaning station may include a plurality of shield supports for supporting a respective shielding device during the cleaning. The shield supports can be configured to magnetically or mechanically hold a respective shielding device during the cleaning. Further, the cleaning station may include one or more heating devices for heating one or more shielding devices that are held at the shield supports. For example, the cleaning station may include a heating device for inductively or resistively heating one or more shielding devices, and/or for directing heat radiation toward one or more shielding devices for re-evaporating the accumulated material condensed thereon. In some implementations, the cleaning station includes a plurality of shield supports for holding a respective shielding device and at least one heating device for heating and cleaning the shielding devices that are held at the plurality of shield supports.

[0066] FIG. 1A schematically shows an exemplary embodiment of a shield handling apparatus 180 arranged inside the vacuum chamber 11. In some embodiments, the shield handling apparatus 180 is configured to detach the shielding device 120 from the vapor distribution assembly 130 and to move the shielding device 120 into the cleaning region 16 where the shielding device 120 can be cleaned.

[0067] The shield handling apparatus 180 may include a shield holding device 182 including a first shield holder 184 configured for holding and releasing the shielding device 120. The shield handling apparatus may further include at least one of a first drive for rotating the shield holding device around the rotation axis A and a second drive for translating the shield holding device 182 away from the vapor distribution assembly into the cleaning region 16.

[0068] The shield handling apparatus 180 may further include a second shield holder 186, both the first shield holder 184 and the second shield holder 186 being configured to hold a shielding device. In some embodiments, the first shield holder 184 is configured to hold and release the first shielding device 120, and the second shield holder 186 is configured to hold and release the second shielding device 121. The first shield holder 184 may be configured to detach the first shielding device 120 from the vapor distribution assembly, and the second shield holder 186 may be configured to attach the second shielding device 121 at the vapor distribution assembly. [0069] In particular, the shield handling apparatus may include two, three, four, six, eight, or more shield holders for holding a respective shielding device, each shield holder configured to attach and detach the respective shielding device to/from the vapor distribution assembly.

[0070] The shield handling apparatus 180 depicted in FIG. 1A includes four shield holders, each shield holder configured to move to the vapor distribution assembly and to detach a shielding device from the vapor distribution assembly and/or to attach a shielding device to the vapor distribution assembly. In some embodiments, the shield handling apparatus includes six or more shield holders or nine or more shield holders. For example, two or more shield holders may be adapted for holding a respective shaping device thereon and two or more shield holders may be adapted for holding a respective shutter device thereon. At least one shield holder may be adapted to hold a clean shielding device thereon and/or at least one shield holder may be adapted to hold a clean shutter device thereon during the operation of the evaporation source, such that a clean shutter device or a clean shaping device can always be quickly attached to the vapor distribution assembly, if needed. For example, three shield holders may be provided for holding clean shaping devices, three shield holders may be provided for holding used shaping devise that are to be cleaned, and three shield holders may be provided for holding shutter devices. All shield holders may be rotatable around a common rotation axis.

[0071] For conducting a shield device exchange, the shield holding device 182 of the shield handling apparatus 180 may be moved toward the vapor distribution assembly 130, e.g. along a linear movement path. Thereupon, the first shielding device 120 may be detached from the vapor distribution assembly and be transferred to the shield handling apparatus where the first shielding device 120 may be held by one of the shield holders.

[0072] After the detaching and before the attaching of the second shielding device, the shield holding device 182 may be moved, e.g. rotated around a rotation axis A, for moving the second shielding device 121 to a position in front of the vapor distribution assembly 130 for attaching the second shielding device 121 to the vapor distribution assembly.

[0073] After attaching the second shielding device 121 to the vapor distribution assembly, the shield holding device 182 may be moved away from the vapor distribution assembly, e.g. into the cleaning region of the vacuum chamber where the first shielding device 120 maybe cleaned. The first shielding device 120 may be rotated to a position where the first shielding device 120 faces toward the material collection wall 160. [0074] In some embodiments, which may be combined with other embodiments described herein, transferring the first shielding device 120 from the vapor distribution assembly 130 to the first shield holder 184 of the shield holding device 182 includes switching a first magnet device of the first shield holder to a holding state. In particular, the first shield holder 184 may include a first magnet device that is configured to magnetically hold the first shielding device thereon. Optionally, the first magnet device includes an electropermanent magnet.

[0075] The first magnet device may be configured to attract a shielding device to the first shield holder 184 when the first magnet device is in the holding state. The first magnet device may include an electropermanent magnet configured to switch between a holding state and a release state in which the shielding device is released from the first shield holder, particularly by applying an electric pulse to a coil of the electropermanent magnet.

[0076] In some embodiments, which may be combined with other embodiments described herein, transferring the second shielding device 121 from the second shield holder 186 to the vapor distribution assembly 130 includes switching a second magnet device of the second shield holder from a holding state to a release state. In particular, the second shield holder 186 may include a second magnet device that is configured to magnetically hold the second shielding device thereon. Optionally, the second magnet device includes an electropermanent magnet.

[0077] In some embodiments, the shield holding device 182 includes a plurality of shield holders, each shield holder including an electropermanent magnet configured to switch between a holding state and a release state, particularly by applying an electric pulse to a coil of the respective electropermanent magnet. An electropermanent magnet is advantageous as compared to an electromagnet because the electropermanent magnet does not need a continuous current supply for continuously generating an attractive magnetic force. Rather, the attractive magnetic force is generated by a permanent magnet. The electropermanent magnetic is advantageous as compared to a simple permanent magnet because the electropermanent magnet can switch to a release state in which the shielding device is released from the electropermanent magnet.

[0078] In some embodiments, which can be combined with other embodiments described herein, the first shielding device 120 is magnetically held at the vapor distribution assembly 130 before the detaching. For example, the first shielding device 120 may include a ferromagnetic material, such as a metal, that is magnetically attracted toward a magnet provided at the vapor distribution assembly.

[0079] In some embodiments, the second shielding device 121 is magnetically held at the vapor distribution assembly after the attaching. For example, the second shielding device 121 may include a ferromagnetic material, such as a metal, that is magnetically attracted toward the magnet that is provided at the vapor distribution assembly. The magnetic force generated by the electropermanent magnets of the shield holders in the holding state may be stronger than the magnetic force generated by the magnet of the vapor distribution assembly. Accordingly, a shielding device can be detached from the vapor distribution assembly simply by moving a shield holder toward the shield holding and switching the electropermanent magnet of the shield holder to the holding state.

[0080] FIG. 1 A shows the evaporation system 200 in a deposition state, in which evaporated source material 15 is directed toward the substrate 10 by the one or more vapor outlets 131 through the first shielding device 120 and through the mask 12. A part of the evaporated source material is blocked by and attaches to the first shielding device 120 because the first shielding device 120 has a temperature that is lower than the evaporation temperature of the evaporated source material. Accordingly, the blocked evaporated source material condenses on a wall of the first shielding device 120.

[0081 ] The shield handling apparatus 180 is arranged in the vacuum chamber 11 at a distance from the evaporation source 100, e.g. behind the shielding wall 150. The shield handling apparatus 180 is configured to detach the first shielding device 120 from the vapor distribution assembly 130 and to transport the first shielding device 120 to a cleaning region where the first shielding device can be cleaned. The shield handling apparatus 180 may include a movable shield holding device 182 with a first shield holder 184 configured to hold the first shielding device at the first shield holder 184 and a second shield holder 186 configured to hold the second shielding device 121 at the second shield holder 186. In FIG. 1A, no shielding device is held at the first shield holder 184, and the second shielding device 121 is held at the second shield holder 186.

[0082] In some embodiments, the shield handling apparatus 180 includes a first drive for moving the movable shield holding device 182 toward and away from the vapor distribution assembly 130 in the vacuum chamber, particularly along a linear translation path. In some embodiments, the shield handling apparatus 180 includes a second drive for rotating the movable shield holding device 182 around a rotation axis A.

[0083] As is schematically depicted in FIG. 1 A, the source material that accumulates on the first shielding device 120 may change the dimension of shaping apertures of the shielding device over time. It may therefore be reasonable to exchange the first shielding device 120 with a second shielding device 121 that is clean, such that the shaping apertures have a predetermined dimension.

[0084] FIG. IB schematically shows a subsequent stage of a method of operating an evaporation source according to embodiments described herein. Optionally, the evaporation source 100 may be moved from the deposition position that is depicted in FIG. 1A to an idle position that is depicted in FIG. IB, e.g. by rotating the evaporation source 100 around an axis. The evaporation source may be rotated by an angle of 60° or more and 120° or less, particularly by an angle of about 90° to the idle position. In the idle position, the one or more vapor outlets 131 may be directed toward the shielding wall 150.

[0085] For removing the first shielding device 120 from the vapor distribution assembly 130, the shield holding device 182 of the shield handling apparatus 180 may be moved toward the vapor distribution assembly, e.g. along a linear translation path. In particular, the first shield holder 184 may be moved toward the first shielding device 120 that is held at the vapor distribution assembly 130, and the first shielding device 120 may be transferred from the vapor distribution assembly 130 to the first shield holder 184, e.g. by switching a first magnet assembly of the first shield holder 184 to a holding state.

[0086] As is schematically depicted in FIG. IB, the shield holding device 182 of the shield handling apparatus 180 may be moved to the vapor distribution assembly 130 through the shielding wall 150, particularly through a closable opening in the shielding wall 150.

[0087] As is schematically depicted in FIG. 1C, the shield holding device 182 of the shield handling apparatus 180 may be rotated around an axis after the transferal of the first shielding device 120 to the first shield holder 184. For example, the shield holding device 182 may be rotated around an axis until the second shield holder 186 that holds the second shielding device 121 is directed toward the vapor distribution assembly 130 and/or until the first shielding device 120 is directed toward the material collection wall 160. In the exemplary embodiment of FIG. 1C, the shield holding device 182 is rotated by an angle of 60° or more and 300° or less, particularly by an angle of about 180°.

[0088] As is schematically depicted in FIG. ID, the second shielding device 121 may be transferred to the vapor distribution assembly 130 from the second shield holder 186, particularly by switching a second magnet device of the second shield holder 186 from a holding state to a release state for releasing the second shielding device 121 from the second shield holder. Specifically, the released second shielding device 121 may be magnetically attracted toward a magnet that is provided at the vapor distribution assembly 130, such that the second shielding device 121 can be magnetically held at the vapor distribution assembly.

[0089] After attaching the second shielding device 121 to the vapor distribution assembly 130, the shield holding device 182 may be moved away from the vapor distribution assembly 130, particularly along the linear translation path. In the embodiment depicted in FIG. ID, the shield holding device 182 is moved through the shielding wall 150, particularly through a closable opening of the shielding wall 150 into a cleaning region 16, where the detached first shielding device 120 can be cleaned.

[0090] In some embodiments, which may be combined with other embodiments described herein, the detached shielding device may be cleaned inside the vacuum chamber 11, particularly in a cleaning region 16 of the vacuum chamber. In particular, the detached shielding device may be moved from the vapor distribution assembly to a cleaning position P in the vacuum chamber 11 , where the shielding device can be at least locally heated for releasing attached source material from the shielding device. The vapor distribution assembly 130 and the cleaning region 16 may be separated by the shielding wall 150. Accordingly, the cleaning of the shielding device in the cleaning region 16 does not negatively affect the deposition process that may continue in the deposition area of the vacuum chamber.

[0091] For cleaning the shielding device 120, the shielding device 120 may be arranged at the cleaning position P at the open side of the material collection box. An unwanted stray coating of the vacuum chamber or of other components arranged in the vacuum chamber can be reduced or avoided by cleaning the shielding device 120 while the shielding device 120 faces toward the material collection wall 160. Further, the deposition process in the deposition area of the vacuum chamber can continue without being negatively affected by the cleaning process in the cleaning region. The up-time of the evaporation system can be increased. [0092] In the exemplary embodiment of figures 1A-1D, both the first shielding device 120 and the second shielding device 121 are shaping devices. As will be apparent to the skilled person, at least one or both of the first and second shielding devices may be a shutter device that completely blocks the evaporated source material emitted by the one or more vapor outlets.

[0093] FIG. 2 is a schematic view of an evaporation system 200 according to embodiments described herein. The evaporation system 200 includes a vacuum chamber 11 , an evaporation source 100 arranged in the vacuum chamber 11, and a shield handling apparatus 180 arranged in the vacuum chamber 11. The evaporation source 100 includes a vapor distribution assembly with one or more vapor outlets, particularly with a plurality of vapor nozzles. The vapor distribution assembly may include a crucible 136 in fluid communication with a vapor distribution pipe 132. The plurality of vapor nozzles may be provided in a front wall of the vapor distribution pipe 132. Two, three or more crucibles and vapor distribution pipes may be supported on a common source support that may be movable past a substrate 10 in the vacuum chamber. A shielding device 120 is provided at each of the vapor distribution pipes and is configured to shield the plumes of evaporated source material emitted by the plurality of vapor nozzles.

[0094] As is schematically depicted in FIG. 2, the evaporation source 100 can move past the substrate 10 that is arranged in a first deposition area for depositing the evaporated source material on the substrate 10 through a mask 12, particularly along a linear source path. Thereupon, the vapor distribution assembly can rotate, e.g. by an angle of about 180°, until the one or more vapor outlets are directed toward a second substrate 10’ that is arranged in a second deposition area on an opposite side of the evaporation source 100. The evaporation source 100 can then move past the second substrate 10’ for depositing the evaporated source material on the second substrate 10’ through a second mask 12’, particularly along a linear source path.

[0095] In some embodiments, a shielding wall 150 may be provided in the vacuum chamber for blocking the evaporated source material during a rotation of the evaporation source from the first deposition area to the second deposition area. The shielding wall 150 maybe supported on the same movable support as the vapor distribution pipes and may move together with the evaporation source past the substrate.

[0096] The shield handling apparatus 180 is configured for exchanging shielding devices of the evaporation source and includes a movable shield holding device 182 with a plurality of shield holders. In particular, a first shield holder 184 of the movable shield holding device 182 may be configured for holding and releasing a first shielding device, and a second shield holder 186 may be configured for holding and releasing a second shielding device.

[0097] The movable shield holding device 182 can be moved toward the vapor distribution assembly via a first drive 191, e.g. along a linear translation path. In particular, the movable shield holding device 182 can be moved through a closable opening of the shielding wall 150 toward the first shielding device 120 that is held at the vapor distribution assembly. The first shield holder 184 may be configured to detach the first shielding device 120 from the vapor distribution assembly and to hold the first shielding device 120 thereon. For example, the first shield holder 184 may include a first magnet device configured to magnetically hold the first shielding device 120 at the first shield holder. Alternatively, the first shield holder may be configured to mechanically, hydraulically, or electrostatically hold the first shielding device thereon, e.g. via a clamp or a hook device or via an electrostatic chuck or a Gecko chuck. The holding mechanism of the first shield holder 184 is not restricted to a magnetic holder and another type of holder may be provided.

[0098] A shield holder configured for magnetically holding the first shield device is beneficial because a magnetic holding force can reliably be generated and maintained under vacuum. Further, if the shielding device includes a ferromagnetic material, particularly a metal, the shielding device can be magnetically held at both the first shield holder and at the vapor distribution assembly. In some embodiments, the first magnet device includes an electropermanent magnet for holding and releasing the first shielding device. The second shield holder and further shield holders of the shield holding device 182 may be configured in a corresponding way.

[0099] In some embodiments, a second drive 192 may be provided for rotating the shield holding device 182 around an axis. For example, the shield holding device 182 may be rotated from a first rotation position in which the first shield holder is directed toward the vapor distribution assembly to a second rotation position in which the first shield holder is directed toward the material collection wall 160 via the second drive 192. A quick and easy transport of the shielding device from the vapor distribution assembly to the cleaning position P is possible.

[00100] FIGS. 3A-3C show subsequent stages of a method of operating an evaporation source 100 according to embodiments described herein. The evaporation source 100 depicted in FIG. 3 A and the shield handling apparatus 180 depicted in FIG. 3B may include any of the features of the previously described evaporation sources and shield handling apparatuses, such that reference can be made to the above explanations, which are not repeated here.

[00101] FIG. 3 A shows an evaporation source 100 in a deposition state in which evaporated source material 15 is emitted by a plurality of vapor outlets 131 toward a substrate 10. A part of the evaporated source material 15 having an emission angle larger than a predetermined maximum emission angle is blocked by the shielding device 120 that is held on a front side of the vapor distribution assembly 130.

[00102] The vapor distribution assembly 130 includes a plurality of vapor outlets 131 in a linear array, and the shielding device 120 is a shaping device with a plurality of shielding portions in a linear array. Each shielding portion may include a circumferential shielding wall for shaping a plume of evaporated source material emitted by an associated vapor outlet of the plurality of vapor outlets 131. A perspective view of the shielding device is shown in FIG. 6.

[00103] In particular, the shielding device 120 includes a plurality of shaping apertures respectively configured to individually shape a plume of evaporated source material emitted from one associated vapor nozzle. The plurality of vapor outlets 131 may be provided in a linear array, particularly one above the other in a vertical array of nozzles, and the shielding device 120 may include a plurality of shaping apertures in a corresponding linear array.

[00104] More specifically, the plurality of vapor outlets 131 may be provided in a linear array extending in the first direction V, particularly in an essentially vertical direction, and the shielding device includes a plurality of shielding apertures, each shielding aperture associated to one of the vapor outlets. The shielding apertures may be holes or apertures which are provided in an elongated body of the shaping device. In particular, the shielding device may be configured as an elongated bar element with a plurality of round or cylindrical shaping apertures provided therein in a linear array, as is schematically depicted in FIG. 6.

[00105] In some embodiments, which can be combined with other embodiments described herein, the vapor distribution assembly 130 includes a vapor distribution pipe 132 with a front wall 133 through which the plurality of vapor outlets 131 extend. The vapor distribution pipe 132 may extend in an essentially vertical direction, and the plurality of vapor outlets 131 may be arranged in a linear array one above the other. [00106] In some embodiments, an isolation element, particularly an isolation plate 134 made of a thermally isolating material, is arranged in front of the front wall 133, particularly between the front wall 133 and the shielding device 120. The isolation plate 134 may include a ceramic isolator. Accordingly, the shielding device 120 can be held at a temperature which is lower than the temperature of the vapor distribution assembly 130, such that evaporated source material condenses on a wall of the shielding device 120. The vapor distribution assembly 130 is typically heated to a temperature above the evaporation temperature of the evaporated source material, such that the evaporated source material remains in a vapor state when propagating therein and through the plurality of vapor outlets.

[00107] In some embodiments, a first magnet element 135 is provided in front of the front wall 133 of the vapor distribution pipe 132 for magnetically holding the shielding device 120 at the first magnet element 135. The first magnet element may be a permanent magnet, particularly a permanent magnetic plate which may be provided in front of the isolation plate

134 at the vapor distribution assembly 130. For example, the first magnet element 135 may be made of a permanent magnet, such as AlNiCo or FeNb. In particular, the first magnet element may be an AlNiCo plate or a NeNb plate. The first magnet element 135 may be connected to the front wall 133 of the vapor distribution pipe 132 and held spaced-apart therefrom, such that the thermal conduction between the vapor distribution pipe 132 and the first magnet element

135 is reduced. Accordingly, the first magnet element 135 may have a lower temperature than the front wall 133 of the vapor distribution pipe 132, e.g. a temperature of 30°C or more below the temperature of the front wall. Hence, the shielding device 120 that is attached to the vapor distribution assembly 130 is thermally decoupled from the vapor distribution assembly.

[00108] In some embodiments, which can be combined with other embodiments described herein, the plurality of vapor outlets 131 are vapor nozzles protruding at least partially into the shielding device 120, particularly into shaping apertures or material collection cavities of the shielding device. An unwanted stray coating of surfaces other than the surfaces of the shielding device 120 can be reduced or prevented, and the material plumes can be shaped directly after emission from the vapor outlets. This allows adjacent vapor outlets to be arranged closely next to each other.

[00109] As is schematically depicted in FIG. 3 A, a plurality of vapor nozzles may protrude at least partially through the isolation plate 134 and/or through the first magnet element 135 into the shielding device 120. [00110] The shielding device 120 may be made of or include a magnetic material, e.g. ametal, that can be magnetically held at the first magnet element 135. For example, the shielding device may include a ferromagnetic material, such as nickel, iron, or an iron-nickel alloy, particularly Invar. Alternatively or additionally, a second magnet element may be integrated into the shielding device 120, particularly a ferromagnetic element or a permanent magnetic element. A shielding device having a permanent magnetic element integrated therein can be magnetically held at a ferromagnetic or permanent magnetic element of the vapor distribution assembly.

[00111] For detaching the shielding device 120 from the vapor distribution assembly 130, a first shield holder 184 of the shield handling apparatus 180 is moved toward the vapor distribution assembly 130, and the shielding device 120 is detached from the vapor distribution assembly 130. For example, a first magnet device 189 of the first shield holder 184 is brought into contact with the shielding device 120 and is switched from a release state to a holding state for activating a magnetic field attracting the shielding device 120 to the first shield holder 184. The first magnet device 189 may include an electropermanent magnet that is switchable between a release state and a holding state. The first magnet device 189 can generate a magnetic force that is stronger than the magnetic force generated by the first magnet element 135, such that the shielding device 120 can be pulled away from the vapor distribution assembly 130 by activating the first magnet device 189.

[00112] FIG. 3B shows the shielding device 120 that is held at the first shield holder 184 of the shield handling apparatus 180. The first shield holder 184 can move away from the vapor distribution assembly 130, e.g. for transporting the detached shielding device into a cleaning region inside the vacuum chamber.

[00113] FIG. 3C shows the shielding device 120 that is held at the first shield holder 184 after the transport to a cleaning position in the cleaning region. The shielding device 120 is at least partially heated up at the cleaning position, particularly by the at least one heating device 185. The at least one heating device 185 may be a radiation heater configured to direct heat toward the shielding device 120 held at the first shield holder 184. In some embodiments, the at least one heating device 185 is provided at the shield handling apparatus. Alternatively or additionally, at least one heating device may be provided at the material collection wall 160. In some embodiments, the at least one heating device 185 may include at least one of an infrared heater, resistance heater, laser, UV heater or another type of heater. In the embodiment depicted in FIG. 3C, the at least one heating device 185 is mounted at the shield handling apparatus 180. [00114] Optionally, at least one cooling device 188 may be provided for cooling down the shielding device after the cleaning. In this case, the cleaned shielding device can more quickly be re-used at the vapor distribution assembly.

[00115] Optionally, at least one heat shield 187 may be provided at the shield handling apparatus for protecting delicate components of the shield handling apparatus from heat of the at least one heating device 185. For example, at least one heat shield 187 may be provided for protecting the first magnet device 189. The at least one heat shield 187 may be a thermal shield or a heat reflector. The durability of the shield handling apparatus, particularly of the magnet units, can be increased.

[00116] In some embodiments, a material collection wall 160, particularly a material collection box having a bottom wall and side walls, may be provided in the cleaning region of the vacuum chamber. During the heating and cleaning of the shielding device 120, the shielding device 120 may face toward the material collection wall 160, such that the source material that is re-evaporated from the shielding device during the cleaning accumulates on the material collection wall 160. An unwanted stray coating of inner walls of the vacuum chamber can be reduced or avoided. The shield handling apparatus 180 may be configured to move the shielding device from the vapor distribution assembly to the cleaning position in front of the material collection wall 160. In some embodiments, the material collection wall is a material collection box having an open side.

[00117] After the removal of the shielding device 120 from the vapor distribution assembly 130 in FIG. 3B, a second shielding device, e.g. another shaping device or a shutter device, can be attached to the vapor distribution assembly, particularly with a second shield holder of the shield handling apparatus. The deposition process can continue after a short break, and the up time of the evaporation system can be increased.

[00118] FIGS . 4A-4B show subsequent stages of a method of operating an evaporation source according to embodiments described herein. The method essentially corresponds to the method depicted in FIGS. 3A-3C, such that reference can be made to the above explanations, which are not repeated here.

[00119] Instead of a shielding device including an elongated bar element with a plurality of shaping apertures arranged therein, the shielding device 120 depicted in FIGS. 4 A and 4B includes a plurality of separate shielding units which are separately held at the first magnet element 135 of the vapor distribution assembly 130. In particular, the shielding device 120 may include a plurality of tube cylinders which may be cylindrical, wherein each tube cylinder may be detachably held at the first magnet element 135 of the vapor distribution assembly 130. For example, the shielding device 120 may be comprised of ten or more tube cylinders which are respectively magnetically held at a permanent magnetic plate that is fixed at the vapor distribution assembly.

[00120] As is schematically depicted in FIG. 4 A, the permanent magnetic plate constituting the first magnet element 135 may include a plurality of ring grooves or annular steps for ensuring a correct positioning of the plurality of tube cylinders. Each ring groove or annular step may surround one of the plurality of vapor outlets and may be centered with respect to said vapor outlet.

[00121] The plurality of separate tube cylinders may include a magnetic material. Accordingly, the plurality of separate tube cylinders can be detached from the vapor distribution assembly 130 by a first shield holder 184 of the shield handling apparatus that includes a first magnet device 189.

[00122] FIG. 4B shows the shielding device 120 including the plurality of separate tube cylinders after the removal from the vapor distribution assembly 130. The shielding device 120 may be cleaned in the vacuum chamber or unloaded from the vacuum chamber for cleaning.

[00123] FIGS. 5A-5B show subsequent stages of a method of operating an evaporation source according to embodiments described herein. The method essentially corresponds to the method depicted in FIGS. 3A-3C, such that reference can be made to the above explanations, which are not repeated here.

[00124] Instead of a shielding device including an elongated bar element with a plurality of shaping apertures arranged therein, the shielding device 120 depicted in FIGS. 5 A and 5B is a shutter device 302 that is configured for completely blocking the plumes of evaporated source material emitted by the plurality of vapor outlets. In some embodiments, the shutter device 302 includes a plurality of material collection cavities with a circumferential side wall and a front wall that closes the circumferential side wall. The evaporated source material emitted by the plurality of vapor outlets can be collected in the material collection cavities. [00125] As is schematically depicted in FIG. 5A, each vapor outlet or vapor nozzle may at least partially protrude into an associated vapor collection cavity of the shielding device. The shutter device 302 depicted in FIG. 5A includes an elongated bar element with a plurality of blind holes provided therein. The shutter device 302 is illustrated in more detail in FIG. 8. The blind holes may be round or essentially cylindrical.

[00126] Alternatively, the shutter device may include a bar element with an elongated material collection cavity for blocking several plumes of evaporated material. In other words, the evaporated source material emitted by several vapor outlets may be blocked by the side walls and front wall of one elongated cavity of the shutter device. This embodiment of a shutter device is illustrated in more detail in FIG. 9. The material collection cavity may be one essentially oval recess in an elongated bar element.

[00127] Alternatively, the shutter device may include a plurality of separate blocking elements, each blocking element configured to block a plume of evaporated source material emitted by an associated vapor outlet. For example, the shutter device may include a plurality of separate tube cylinders similar to the tube cylinders of FIG. 4 A, however, the tube cylinders being provided with a closed front wall for completely blocking the evaporated source material.

[00128] The shutter device 302 may be magnetically held at the vapor distribution assembly 130. For example, the shutter device 302 may include a magnetic material that can be held at a permanent magnetic plate that is fixed to the vapor distribution assembly 130. Alternatively, the shutter device 302 may be held with another fixing mechanism at the vapor distribution assembly, e.g. mechanically with a hook or clamp, or electrostatically.

[00129] As is schematically depicted in FIG. 5B, the shutter device 302 may be detached from the vapor distribution assembly 130 with a first shield holder 184 of a shield handling apparatus. For example, a first magnet device 189 of the first shield holder 184 may detach the shielding device 120 from the vapor distribution assembly. Thereafter, the detached shutter device may be cleaned.

[00130] FIG. 6 shows a shielding device of an evaporation system according to embodiments described herein, the shielding device being configured as a shaping device 301. The shaping device 301 may be used as a shielding device in any of the embodiments described herein. [00131] The shaping device 301 can be attached on the emission side of the vapor distribution assembly 130 for blocking a part of the evaporated source material emitted from the one or more vapor outlets having an emission angle greater than a predetermined maximum emission angle. In particular, the shaping device 301 may have a plurality of shaping apertures 310, each shaping aperture configured to shape the plume of evaporated source material of one associated vapor outlet. More specifically, the plurality of shaping apertures 310 may limit an expansion of the plumes of evaporated source material in a first direction V, particularly in an essentially vertical direction, and in a second direction L, particularly in a lateral direction essentially perpendicular to the first direction.

[00132] The shaping device 301 may be an elongated bar element having the plurality of shaping apertures provided therein as through holes, particularly as round or essentially circular through holes. For example, ten, thirty or more holes may be provided in the elongated bar element in a linear array. The linear array may extend in the first direction V, particularly in an essentially vertical direction. Accordingly, the plumes emitted by a row of vapor nozzles can be shaped with the array of shaping apertures of the shaping device 301.

[00133] The shaping device 301 may include a magnetic material, e.g. a metal such as Invar or Nickel. Accordingly, the shaping device 301 can be magnetically held at the vapor distribution assembly by a magnet element, particularly by a permanent magnetic plate. Alternatively or additionally, at least one permanent magnet may be integrated in the shaping device 301.

[00134] The shaping device 301 may include at least one alignment opening 321. An alignment pin of the vapor distribution assembly may be inserted into the at least one alignment opening 321 when the shaping device 301 is attached to the vapor distribution assembly (see also FIG. 3 A in this respect). Accordingly, a correct positioning of the shaping device 301 at the vapor distribution assembly can be ensured. In some embodiments, the at least one alignment opening 321 is a hole provided in the shaping device, e.g. an elongated hole or a hole with an upwardly tapering cross-section that allows an easy insertion of the alignment pin during the attachment and an alignment of the shaping device relative to the vapor distribution assembly in a vertical direction. Alternatively, or additionally, at least one alignment opening may have a hole dimension that gradually reduces with the hole depth, allowing an alignment of the shaping device relative to the vapor distribution assembly in the direction in which the hole dimension reduces (see FIG. 3A in this respect), e.g. in a lateral and/or vertical direction. [00135] In some embodiments, the alignment opening has a conical shape, and the alignment pin has a conical shape complementary to the conical shape of the alignment opening. An alignment in two directions can be achieved by inserting the alignment pin into the alignment opening.

[00136] The distance between two adjacent shaping apertures may be from 1 cm to 3 cm, e.g. about 2 cm. Thirty or more shaping apertures may be provided in a linear array. The diameter of one shaping aperture measured at the front end of the shaping aperture may be 3 mm or more and 25 mm or less. The shaping apertures may have a base wall with an opening through which a vapor nozzle can protrude into the shaping aperture (see FIG. 3A in this respect).

[00137] FIG. 7 shows another shielding device of an evaporation system according to embodiments described herein, the shielding device being configured as a shaping device 301. The shaping device 301 of FIG. 7 may be used as the shielding device in any of the embodiments described herein.

[00138] The shaping device 301 can be attached on the emission side of the vapor distribution assembly 130 for blocking a part of the evaporated source material emitted from the one or more vapor outlets having an emission angle greater than a predetermined maximum emission angle in at least one sectional plane. As is schematically depicted in FIG. 7, the shaping device 301 may be provided as a bar element having a first side wall extending in a first direction V and a second side wall extending parallel to the first side wall in the first direction V, such that an elongated shaping aperture 312 is formed between the first side wall and the second side wall. The shaping device 301 is to be attached to a vapor distribution assembly having a plurality of vapor outlets provided in a linear array, such that the first side wall extends on a first side of the plurality of vapor outlets and the second side wall extends on a second side of the plurality of vapor outlets opposite the first side.

[00139] The shaping device 301 of FIG. 7 is configured to limit an expansion of the plumes of evaporated source material emitted by the plurality of vapor outlets in a second direction L perpendicular to the first direction V, particularly in a lateral direction. One single elongated shaping aperture of the shaping device 301 may limit the expansion of the plumes of evaporated source material emitted by several vapor outlets in one direction, particularly in the lateral direction. In this case, the vapor nozzles themselves may have a nozzle section configured to limit the expansion of the plumes of evaporated source material in a direction different from the lateral direction, particularly in the vertical direction. Nozzles with a shaping section are also referred to herein as “shaping nozzles” and are schematically depicted in FIG. 10.

[00140] FIG. 10 shows a front view of an evaporation source of an evaporation system according to some embodiments described herein. The evaporation source includes a plurality of vapor distribution assemblies arranged next to each other, each vapor distribution assembly including a plurality of vapor outlets 131 in a linear array. For example, one vapor distribution assembly may be configured to evaporate a host material on a substrate and an adjacent vapor distribution assembly may be configured to co-evaporate a dopant material on the substrate. Each vapor distribution assembly may include an essentially vertically extending vapor distribution pipe with a plurality of vapor nozzles having a respective vapor outlet. The distance between the nozzle rows of adjacent vapor distribution assemblies may be 10 cm or less, particularly 5 cm or less, allowing for a co-operation of host and dopant on the same spot.

[00141] A shielding device may be attached to each of the vapor distribution assemblies. In the exemplary embodiment of FIG. 10, each of the vapor distribution assemblies is provided with the shaping device 301 of FIG. 7 attached thereto.

[00142] The nozzles may be shaping nozzles that have a nozzle section configured to limit a plume expansion in a first direction V, particularly in the vertical direction. The plume expansion in a second direction L, particularly in the lateral direction, may be limited by the shielding devices. Each vapor distribution assembly may have a respective shielding device attached thereto. The shielding devices can be detached and cleaned in accordance with any of the methods described herein. Further, the shielding devices can be replaced with other shielding devices. For example, one or more of the shielding devices of FIG. 10 may be replaced with a shutter device for conducting a quality check. For example, all shielding devices of FIG. 10 may be replaced with a shutter device for conducting a cleaning procedure of the vacuum chamber. For example, one or more shielding devices of FIG. 10 may be replaced with a clean shaping device for continuing with the deposition process.

[00143] FIG. 8 shows another shielding device of an evaporation system according to embodiments described herein, the shielding device being configured as a shutter device 302. The shutter device 302 may be used as a shielding device in any of the embodiments described herein. The shutter device completely blocks the plumes of evaporated source material emitted by the one or more vapor outlets of the vapor distribution assembly. [00144] The shutter device 302 of FIG. 8 includes a plurality of vapor collection cavities 313 having a circumferential side wall and a front wall closing the circumferential side wall. Each vapor collection cavity may be configured to block the plume of evaporated source material emitted by one associated vapor nozzle. The shutter device 302 may be an elongated bar element having a plurality of blind holes provided therein. The blind holes may be cylindrical or may have another cross-sectional shape. For example, the shutter device 302 may have ten, thirty or more vapor collection cavities in a linear array for blocking the evaporated source material emitted by an array of vapor nozzles. The vapor nozzles may protrude into the vapor collection cavities. An undesired stray coating of other components of the evaporation system can be reduced or avoided.

[00145] FIG. 9 shows another shielding device of an evaporation system according to embodiments described herein, the shielding device being configured as a shutter device 302. The shutter device 302 may be used as a shielding device in any of the embodiments described herein. The shutter device completely blocks the plumes of evaporated source material emitted by the one or more vapor outlets of the vapor distribution assembly.

[00146] The shutter device 302 of FIG. 9 includes a vapor collection cavity having a circumferential side wall and a front wall closing the circumferential side wall. The vapor collection cavity may have an elongated shape and may be configured to block the plumes of evaporated source material emitted by a linear array of vapor nozzles. For example, the vapor collection cavity may be an elongated recess, particularly a recess with an essentially oval side wall, in an elongated bar element. A dimension of the vapor collection cavity in the first direction V may be more than ten times a dimension of the vapor collection cavity in the second direction F.

[00147] FIG. 11 is a flow diagram illustrating a method of operating an evaporation source according to embodiments described herein.

[00148] In box 610, evaporated source material is emitted from a plurality of vapor outlets of a vapor distribution assembly, particularly from a plurality of vapor nozzles. A part of the evaporated source material is blocked by the shielding device that is provided downstream of the plurality of vapor outlets. The shielding device has a temperature below the evaporation temperature of the evaporated source material, such that the evaporated source material that is blocked by the first shielding device condenses on the shielding device. Attached source material may accumulate on a wall surface of the shielding device.

[00149] In box 620, the shielding device is detached from the vapor distribution assembly, particularly with a shield handling apparatus as described herein.

[00150] In box 630, the detached shielding device is cleaned, particularly in a cleaning region of the vacuum chamber. Optionally, a second shielding device may be attached to the vapor distribution assembly, such that the deposition procedure can continue during the cleaning of the shielding device.

[00151] At least one of the shielding devices may be a shutter device. At least one of a quality check, a cleaning process and a servicing process may be performed in the vacuum chamber while the shutter device is attached to the vapor distribution assembly. The shutter device may cover and shield the plurality of vapor outlets, such that the vapor outlets are protected when the shutter device is attached to the vapor distribution assembly. This may allow a cleaning procedure to be conducted in the vacuum chamber.

[00152] In some embodiments, which may be combined with other embodiments described herein, the shielding device is cleaned in the vacuum chamber. Cleaning may include at least locally heating the shielding device for releasing attached source material from the shielding device. Heating may include directing electromagnetic radiation onto the source material accumulated on the shielding device for releasing the source material from the shielding device. For example, at least one of microwave radiation, thermal radiation, laser radiation, IR radiation, and UV radiation may be directed to the shielding device, particularly onto sections of the shielding device which are covered by source material. The evaporation system may include a heating device for heating the shielding device, particularly a source of electromagnetic radiation. The source of electromagnetic radiation may include one or more light sources such as a lamp, e.g. a halogen heat lamp, a UV lamp, an IR light source, a laser, a flash lamp, or an LED. In some embodiments, the source of electromagnetic radiation may be or comprise a microwave generator or a heat radiator. In some embodiments, one or more halogen heat lamps, e.g. tungsten-halogen heat lamps may be provided for heating the shielding device. The heat lamp may be a broadband emission lamp with an emission range reaching from UV radiation to NIR radiation. In some embodiments, a plurality of lamps may be provided, which may be directed to different sections of the shielding device, e.g. to the edges of different shaping apertures. In some embodiments, one or more laser sources may be used for at least locally heating the shielding device at the cleaning position. In particular, the condensed source material may be laser evaporated. For example, one or more VCSELs (vertical-cavity surface-emitting lasers) may be provided.

[00153] In some embodiments, one or more microwave sources may be used for re evaporating the source material from the shielding device. Microwave sources may be cheap as compared to some of the light sources mentioned above. Microwave sources may further provide a good radiation uniformity. In some embodiments, the shielding device may be heated via one or more UV lamps. Organic materials may absorb UV light, particularly in the wavelength range between 350 nm and 400 nm, wherein the absorption of UV light may lead to heating and re-evaporation of the organic materials. The heating load on the shielding device may be smaller as compared to other heating devices. UV light may lead to a decomposition of some organic molecules.

[00154] The heating device may be arranged such that electromagnetic radiation can be directed to surface sections of the shielding device when the shielding device is at the cleaning position. For example, the heating device may be attached to or placed in the material collection wall 160 or provided at the shield handling apparatus 180. Heating with a source of electromagnetic radiation provides the advantage that the accumulated source material is directly heated such that the source material may easily re-evaporate, and the temperature of the shielding device may be kept comparatively low (“top -down-heating”). Accordingly, the shielding device can be cooled down more quickly after the cleaning.

[00155] Alternatively, the heating device may be a resistive or an inductive heater configured to heat the shielding device to a temperature above the evaporation temperature.

[00156] Embodiments described herein allow for the cleaning of shielding devices of evaporation sources in a cleaning region of a vacuum chamber. Detaching the shielding device from a vapor distribution assembly before the cleaning provides the following advantages: (1) The detached shielding device can be cleaned at a cleaning position remote from the vapor distribution assembly. A stray coating of the vapor distribution assembly and of other components in the deposition area during cleaning can be reduced or avoided. Cleaning the shielding device while the shielding device is attached to the vapor distribution assembly may not be beneficial because there is a risk of a stray coating of the vapor distribution assembly (“backside deposition”). Further, the deposition process can continue with a second shielding device, such that the up-time of the evaporation system can be increased. (2) A shutter device can be replaced by a shaping device, or vice versa. Attaching a shutter device to the vapor distribution assembly such that the plurality of vapor outlets are covered protects the vapor outlets and allows for cleaning and/or maintenance procedures in the vacuum chamber. (3) A shaping nozzle for shaping the plumes in one dimension in combination with a detachable shaping device for shaping the plumes in a second dimension perpendicular to the first dimension allows for a high material utilization and an arrangement of two or more nozzle rows in close vicinity. The detachable shaping device can be detached from the vapor distribution assembly for cleaning and/or regeneration.

[00157] Embodiments described herein particularly relate to deposition of organic materials, e.g. for OLED display manufacturing on large area substrates. According to some embodiments, large area substrates or carriers supporting one or more substrates may have a size of at least 0.174 m ² . For instance, the deposition system may be adapted for processing large area substrates, such as substrates of GEN 5, which corresponds to about 1.4 m ² substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m ² substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7 m ² substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m ² 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. Alternatively or additionally, semiconductor wafers may be processed in the evaporation system.

[00158] This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any devices or systems and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, mutually non exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.