AND A SHIELDING DEVICE FOR AN EVAPORATION SOURCE

TECHNICAL FIELD

[0001] The present disclosure generally relates to evaporation sources to deposit evaporated source materials and particularly to shielding devices for evaporation sources and methods of shielding evaporated source materials. More particularly, the present disclosure relates to evaporation sources for the evaporation of organic materials and to shielding devices used in deposition systems for manufacturing devices, particularly devices including organic materials therein.

BACKGROUND

[0002] Organic evaporators are a tool for the production of organic light-emitting diodes (OLED). OLEDs are a special type of light-emitting diode in which the emissive layer comprises a thin-film of certain organic compounds. Organic light emitting diodes (OLEDs) 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. Further, the fact that OLEDs can be manufactured onto flexible substrates results in further applications. An OLED display, for example, may include layers of organic material situated between two electrodes that are all 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.

[0003] There are many challenges encountered in the manufacture of such display devices. OLED displays or OLED lighting applications include a stack of several organic materials, which are for example evaporated in a vacuum. The organic materials are deposited in a subsequent manner through 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. Further, it has to be considered that there are several process conditions for the evaporation of the very sensitive organic materials.

[0004] For depositing the material on a substrate, the material is heated until the material evaporates. Distribution pipes guide the evaporated material to the substrates through outlets. In recent years, the precision of the deposition process has been increased, e.g. allowing for being able to provide small pixel sizes. In some processes, masks are used for defining the pixels when the evaporated material passes through the mask openings. Inaccuracy in depositing the material may result in an uneven filling of the pixel. This may negatively influence the properties of the manufactured product as well as the deposition process.

[0005] In view of the above, an improvement of the precision of the manufacturing process is beneficial.

SUMMARY

[0006] In light of the above, a shielding device for an evaporation source is provided. The evaporation source is configured to guide evaporated source material through one or more outlets. The shielding device includes one or more movable shielding device portions configured to block evaporated source material depending on an emission angle of a plume of evaporated source material from the one or more outlets and configured to be replaced by a movement.

[0007] According to an aspect of the present disclosure, a shielding device for an evaporation source is provided. The evaporation source is configured to guide evaporated source material through one or more outlets. The shielding device includes a movable shielding belt providing one or more movable shielding device portions configured to block evaporated source material depending on the emission angle of the plume of evaporated source material, an unwinding supply device for the belt, and a take-up device for the belt.

[0008] According to an aspect of the present disclosure, an evaporation source to deposit evaporated source material on a substrate is provided. The evaporation source includes a shielding device according to embodiments described herein.

[0009] According to an aspect of the present disclosure, a method of shielding evaporated source material released from an evaporation source is provided. The evaporation source includes one or more outlets. The method includes moving a first movable shielding device portion adjacent to the one or more outlets to block evaporated source material depending on an emission angle of a plume of evaporated source material during deposition, and replacing the first movable shielding device portion by a second movable shielding device portion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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:

[0011] FIG. 1 shows a schematic top view of a deposition apparatus including an evaporation source according to embodiments described herein;

[0012] FIG. 2 shows an schematic side view of a shielding device configuration according to embodiments described herein;

[0013] FIG. 3 A shows a schematic side view of a shielding device configuration according to embodiments described herein;

[0014] FIG. 3B shows a schematic perspective view of an evaporation source according to embodiments described herein;

[0015] FIG. 4A shows a schematic top view of an evaporation source according to embodiments described herein;

[0016] FIG. 4B shows a schematic side view of an evaporation source according to embodiments described herein;

[0017] FIG. 4C shows a schematic top view of an evaporation source according to embodiments described herein;

[0018] FIG. 5 A shows a schematic side view of a redirection device configuration according to embodiments described herein; [0019] FIG. 5B shows a schematic side view of a redirection device configuration according to embodiments described herein; and

[0020] FIG. 6 shows a flow diagram illustrating a method for shielding evaporated source material released from an evaporation source according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0021] 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, the same reference numbers refer to the 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.

[0022] Embodiments of the present disclosure allow for elongated lifetimes of a material release limiting apparatus. Material release limiting apparatuses border or delimit the angle of released deposition material. Such collimators or shapers are useful for improving a deposition process, particularly pixel accuracy of a masked deposition process. A problem of static collimators is the formation of debris particles at the sides of the collimator that face the deposition outlet releasing the material to be deposited onto a substrate. Thus, deposition is aggravated by the debris particles blocking the way of the material to be deposited onto the substrate.

[0023] In light of the above, material release limiting apparatuses limit the total deposition time due to the fact that maintenance has to occur after several deposition cycles to remove debris material from the collimator or shaper. Embodiments of the present disclosure allow for reducing or preventing the influence of material release limiting apparatuses on the total deposition time. Embodiments of the present disclosure provide a self-renewing effect, making maintenance of the collimator redundant. [0024] FIG. 1 shows a schematic top view of a deposition apparatus 100 including an evaporation source 20 according to embodiments described herein. The deposition apparatus 100 includes a vacuum chamber 110 in which the evaporation source 20 is provided. According to some embodiments, which can be combined with other embodiments described herein, the evaporation source 20 is configured for a translational movement along a surface of the substrate to be coated. Further, the evaporation source 20 may be configured for rotation around a rotation axis.

[0025] According to embodiments, the evaporation source 20 may have one or more evaporation crucibles and one or more distribution pipes 106. For instance, the evaporation source 20 shown in FIG. 1 includes two evaporation crucibles 104 and two distribution pipes 106. Typically, an evaporation source may include three evaporation crucibles 104 and three distribution pipes 106. As is shown in FIG. 1, a substrate 10 and a further substrate 11 are provided in the vacuum chamber 110 for receiving the evaporated source material.

[0026] Typically, the substrate may be made of any material suitable for material deposition. For instance, the substrate may be made of a material selected from the group consisting of glass (for instance soda-lime glass, borosilicate glass etc.), metal, polymer, ceramic, compound materials, carbon fiber materials or any other material or combination of materials which can be coated by a deposition process.

[0027] According to some embodiments herein, a mask assembly for masking a substrate can be provided between the substrate and the evaporation source. The mask assembly may include a mask and a mask frame to hold the mask in a predetermined position. In embodiments herein, one or more additional tracks may be provided for supporting and displacing the mask assembly. For instance, the embodiment shown in FIG. 1 has a first mask 133 supported by a first mask frame 131 arranged between the evaporation source 20 and the substrate 10 and a second mask 134 supported by a second mask frame 132 arranged between the evaporation source 20 and the further substrate 11. The substrate 10 and the further substrate 11 may be supported on respective transportation tracks (not shown in FIG. 1) within the vacuum chamber 110.

[0028] FIG. 1 further shows a shielding device 200, which is provided to guide the evaporated source material from the distribution pipes 106 to the substrate 10 and/or to the further substrate 11, respectively, as will be explained below in more detail. The shielding device 200 may be provided downstream from the outlets, i.e. between the distribution pipes and the substrate. In some embodiments, the shielding device 200 may be detachably fixed to at least one distribution pipe, e.g. via screws. The shielding device delimits the plume of evaporated material.

[0029] According to embodiments described herein, the substrate may be coated with a source material in an essentially vertical position. Typically, the distribution pipe 106 is configured as a line source extending essentially vertically. In embodiments described herein, which can be combined with other embodiments described herein, the term“vertically” is understood, particularly when referring to the substrate orientation, to allow for a deviation from the vertical direction of 20° or below, e.g. of 10° or below. For example, this deviation can be provided because a substrate support with some deviation from the vertical orientation might result in a more stable substrate position. Yet, an essentially vertical substrate orientation during deposition of the source material is considered different from a horizontal substrate orientation. The surface of the substrate is coated by a line source extending in one direction corresponding to one substrate dimension and a translational movement along the other direction corresponding to the other substrate dimension.

[0030] In some embodiments, the evaporation source 20 may be provided in the vacuum chamber 110 of the deposition apparatus 100 on a track or linear guide 120. The nozzles may be guided on a looped track while the evaporation source moves with a combination of a translation and a rotation. The track or linear guide 120 is configured for the translational movement of the evaporation source 20. According to different embodiments, which can be combined with other embodiments described herein, a drive for the translational movement can be provided in the evaporation source 20, at the track or linear guide 120, within the vacuum chamber 110 or a combination thereof. Accordingly, the evaporation source can be moved along the surface of the substrate to be coated during deposition, particularly along a linear path. Uniformity of the deposited material on the substrate can be improved.

[0031] FIG. 1 further shows a valve 105, for example, a gate valve. The valve 105 allows for a vacuum seal to an adjacent vacuum chamber (not shown in FIG. 1). According to embodiments described herein, the valve 105 can be opened for the transport of a substrate or a mask into and/or out of the vacuum chamber 110. [0032] The deposition apparatus may be used for various applications, including applications for OLED device manufacturing including processing methods, wherein two or more source materials such as, for instance, two or more organic materials are evaporated simultaneously. In the example shown in FIG. 1, two or more distribution pipes 106 and corresponding evaporation crucibles are provided next to each other. For example, in some embodiments, three distribution pipes may be provided next to each other, each distribution pipe including a plurality of outlets with respective nozzles for introducing the evaporated source material from the interior of the respective distribution pipe into the deposition area of the vacuum chamber. The outlets or nozzles may be provided along the linear extension direction of the respective distribution pipe, e.g. at an equal spacing. Each distribution pipe may be configured for introducing a different evaporated source material into the deposition area of the vacuum chamber.

[0033] As used herein, the term“source material” may be understood as a material that is evaporated and deposited on a surface of a substrate. For example, in embodiments described herein, an evaporated organic material that is deposited on a surface of a substrate may be a source material. Non-limiting examples of organic materials include one or more of the following: ITO, NPD, Alq ₃ , Quinacridone, Mg/AG, starburst materials, and the like.

[0034] Although the embodiment shown in FIG. 1 provides a deposition apparatus 100 with an evaporation source 20 that is movable, the skilled person may understand that the above described embodiments may also be applied to deposition systems in which the substrate is moved during processing. For instance, the substrates to be coated may be guided and driven along stationary material deposition arrangements.

[0035] Embodiments described herein particularly relate to the deposition of organic materials, e.g. for OFED 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 substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m 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 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.

[0036] According to embodiments described herein, the evaporation source 20 can include a distribution pipe 106 and an evaporation crucible 104. For example, the distribution pipe can be an elongated cube with a first heating unit. The first heating unit may be configured to heat the distribution pipe to a temperature to prevent the evaporated source material from condensing at an inner wall of the distribution pipe. The evaporation crucible can be a reservoir for a source material, such as an organic material to be evaporated with a second heating unit. The second heating unit may be configured to heat the crucible to a temperature to allow the source material to evaporate. Additionally, heat shields may be provided around the tube of the distribution pipe 106 to reduce or prevent heat radiation to the surrounding chamber.

[0037] According to embodiments described herein, the distribution pipe may be heated by heating elements, which are mounted or attached to walls of the distribution pipe. For reducing the heat radiation toward the substrate, an outer shield which surrounds the heated inner wall of the distribution pipe may be cooled. An additional second outer shield may be provided to further reduce the heat load directed toward the deposition area or the substrate, respectively. According to some embodiments, which can be combined with other embodiments described herein, the shields can be provided as metal plates having conduits for cooling fluid, such as water, attached to the metal shields or provided within the metal shields. Additionally, or alternatively, thermoelectric cooling devices or other cooling devices can be provided to cool the shields. Accordingly, the interior of the distribution pipe can be kept at a high temperature, e.g. higher than the evaporation temperature of the source material, whereas the heat radiation toward the deposition area and toward the substrate can be reduced.

[0038] According to some embodiments, which can be combined with other embodiments described herein, the distribution pipe 106 extends essentially vertically in a length direction. For example, the length of the distribution pipe 106 corresponds at least to the height of the substrate to be deposited in the deposition apparatus. Accordingly, uniformity of the deposition of the evaporated source material may be improved. The length of the distribution pipe 106 may be longer than the height of the substrate to be deposited, at least by 10% or even 20%, which allows for a uniform deposition at the upper end of the substrate and/or the lower end of the substrate. Alternatively, the distribution pipe 106 may be shorter in length than the height of the substrate. Uniformity of the distribution of the evaporated source material may be provided, for example, by a greater diameter of the nozzles provided at the outermost position at the distribution pipe.

[0039] According to embodiments described herein, the evaporation source includes one or more outlets 22. Particularly, the one or more outlets 22 may be arranged at the distribution pipe 106. The one or more outlets 22 may be configured as one or more nozzles. The one or more nozzles may be configured to deposit evaporated source material onto a substrate. Particularly, the nozzles may be configured to form a plume of evaporated source material for depositing the evaporated source material onto the substrate.

[0040] According to embodiments that can be combined with any other embodiment described herein, the shielding device 200 may be arranged at the one or more outlets 22 or nozzles. The shielding device 200 may delimit the plume of evaporated source material. The shielding device 200 may delimit the evaporated source material released by one nozzle.

[0041] For example, the shielding device may surround one nozzle. The shielding device may delimit the plume of evaporated source material released by the nozzle in two or more directions viewed from the nozzle as a center point. Particularly, delimiting the plume may occur in a vertical and/or a horizontal direction viewed from the nozzle and directed towards the substrate.

[0042] According to embodiments, the distribution pipe 106 includes one or more outlets 22. The outlets 22 may be arranged vertically along the distribution pipe. The outlets may be configured as nozzles to deposit the evaporated source material on the substrate. For instance, the distribution pipe may have more than 30 nozzles, such as 40, 50 or 54 nozzles arranged along a length direction of the distribution pipe. According to embodiments herein, the nozzles may be spaced apart from each other. For instance, the nozzles may be spaced apart by a distance of 1 cm or more, for example, by a distance from 1 cm to 3 cm, for example, by a distance of 2 cm.

[0043] According to some embodiments, which can be combined with other embodiments described herein, the outlets are arranged such that the outlets or nozzles define a main emission direction X that is essentially horizontal (+/- 10°). According to some specific embodiments, the main emission direction X can be oriented slightly upward, e.g. to be in a range from horizontal to 10° upward, such as 3° to 7° upward. Similarly, the substrate can be slightly inclined to be substantially perpendicular to the evaporation direction, which may reduce the generation of particles.

[0044] FIG. 2 shows a shielding device 200 according to embodiments described herein. The shielding device 200 includes one or more movable shielding device portions 205. The shielding device 200 may include one or more shielding belts 210. The one or more shielding belts 210 may include the movable shielding device portions 205. The shielding device 200 may include an unwinding supply device 212 for the belt and a take-up device 214 for the belt. For example, the unwinding supply device 212 and the take-up device 214 may be arranged vertically to one another. Additionally or alternatively, the unwinding supply device 212 and the take-up device 214 for the belt may be arranged horizontally to one another.

[0045] FIG. 2 shows an unwinding supply device 212 at an upper portion of a shielding device 200 and a take-up device 214 at a lower portion of the shielding device. For example, the outlets 22 can be between the unwinding supply device 212 and the take-up device 214. According to yet further embodiments, which can be combined with other embodiments described herein, the unwinding supply device 212 and the take-up device 214 can be at the same side, e.g. an upper portion or a lower portion of the shielding device 200. The redirection devices 220 can then be utilized accordingly to redirect the belt back to the same side of the shielding device 220.

[0046] According to embodiments described herein, the shielding device 200 may be arranged at a distribution pipe. The shielding device 200 may be arranged around one or more outlets 22 or nozzles. The outlets or nozzles may release evaporated source material. The outlets or nozzles may release the evaporated source material in a plume. The plume may be delimited by the shielding device. Delimiting the plume may lead to a deposition of evaporated source material at the shielding device. For example, the evaporated source material is blocked by the shielding device. Delimiting or blocking of the evaporated source material may lead to the deposition of the blocked material at the shielding device. For example, the blocked evaporated source material may be deposited on a surface of the shielding device. [0047] According to embodiments described herein, the one or more movable shielding device portions can be replaced to reduce a film thickness of the material deposited on the surface of the shielding device. Shielding device portions may be provided adjacent to the outlets or nozzles. The blocked evaporated source material may be deposited onto the movable shielding device portions 205. When the blocked evaporated source material has been deposited onto a movable shielding device portion, the movable shielding device portion may be replaced by another movable shielding device portion. Particularly, the other movable shielding device portion may be free from deposited material at the time of replacement. The person skilled in the art may understand that the replacement may be repeated in a continuous manner or may be provided in a step-wise manner.

[0048] According to embodiments described herein, the one or more movable shielding device portions may be provided by an unwinding supply device for the belt. The unwinding supply device may be moved to provide the one or more movable shielding device portions. For example, the unwinding supply device may be rotated to provide the movable shielding device portions. The one or more movable shielding device portions may be taken up by a take-up device for the belt. The take-up device may be moved for taking up the one or more movable shielding device portions. For example, the take-up device may be rotated to take up the movable shielding device portions. For example, the unwinding supply device may provide one or more movable shielding device portions that are free from deposited evaporated source material and the take-up device may take up one or more movable shielding device portions carrying deposited evaporated source material.

[0049] According to embodiments described herein, a shielding device for an evaporation source may be provided. The evaporation source may be configured to guide evaporated source material through one or more outlets. The shielding device may include one or more movable shielding device portions configured to block evaporated source material depending on an emission angle of a plume of evaporated source material from the one or more outlets and configured to be replaced by a movement.

[0050] According to embodiments described herein, the shielding device 200 may be arranged at an evaporation source 20. Evaporated source material may be transported via distribution pipe 106 and through outlets 22. The shielding device 200 may include one or more movable shielding device portions 205. The movable shielding device portions may be arranged adjacent to one or more outlets 22 at the distribution pipe 106. The shielding device 200 and/or the movable shielding device portions 205 may be configured to block evaporated source material released through outlets 22. For example, the evaporated source material may be released in a plume. The plume of evaporated source material may be delimited by the shielding device 200. For example, evaporated source material that is released apart from a maximum emission angle may be collected by the shielding device 200. The shielding device 200 may block the evaporated source material that is released apart from a maximum emission angle.

[0051] According to embodiments described herein, the shielding device 200 may include one or more shielding belts 210. The one or more shielding belts may be arranged inbetween the unwinding supply device 212 and the take-up device 214 for the belt. The unwinding supply device 212 may be configured to provide the one or more shielding belts. For example, the shielding belts 210 may be attached to the unwinding supply device and may be unwound by rotating the unwinding supply device. The take-up device 214 may be configured for receiving the one or more shielding belts.

[0052] According to embodiments described herein, the unwinding supply device for the belt and the take-up device for the belt may be configured as rolls that may be moved around an axis. The axis may be arranged in a substantially horizontal plane with respect to the unwinding supply device and/or the take-up device. The one or more shielding belts 210 may be detachably fixed to the unwinding supply device, i.e. to a roll.

[0053] According to embodiments described herein, the unwinding supply device and the take-up device for the belt may be configured as a cylindrical hollow body that may rotate around a rotation axis. The cylindrical hollow body may e.g. be a sheath or sleeve. The cylindrical hollow body may be removably arranged at a bearing. The one or more shielding belts may be attached to the cylindrical hollow body e.g. to the unwinding supply device.

[0054] According to embodiments which can be combined with other embodiments described herein, detachment of the one or more shielding belts may occur by a movement of the unwinding supply device 212, i.e. the unwinding belt supply roll. For example, the movement is a movement of the movable shielding device portion from the unwinding supply device in the direction of the take-up device for the belt. The unwinding supply device may rotate in an anticlockwise direction, indicated by rotation arrow 6 in FIG. 2. Alternatively, the unwinding supply device may rotate in a clockwise direction for unwinding the one or more shielding belts.

[0055] According to embodiments described herein, the one or more shielding belts may be taken up by a take-up device 214. The belt-take up device may take up the one or more shielding belts by a movement. For example, the take-up device may rotate in a clockwise direction, indicated by rotation arrow 5 in FIG. 2. For example, when the unwinding supply device rotates in an anticlockwise direction, the take-up device may rotate in a clockwise direction and vice versa.

[0056] The movement of the unwinding supply device and/or of the take-up device for the belt may be controlled by an actuator 216. The unwinding supply device and/or the take-up device may be driven by an actuator. The actuator may provide the movement to replace one or more movable shielding device portions. The actuator 216 may be provided at the unwinding supply device 212 and/or to the take-up device 214 for the belt. For example, the actuator may be attached to the unwinding supply device 212 and/or to the take-up device 214.

[0057] The one or more shielding belts and/or the one or more movable shielding device portions may be moved with a velocity in the range of mm per min. For example, the one or more shielding belts and/or the one or more movable shielding device portions may be moved with a velocity in the range of 0.1 to 10 mm/min. Additionally or alternatively, the velocity of the movement may be chosen such that flaking of the collected evaporated source material from the one or more movable shielding device portions or the one or more shielding belts is avoided or prevented.

[0058] According to embodiments described herein, the movement of the one or more shielding belts and/or the one or more movable shielding device portions may be provided discontinuously. For example, the one or more shielding belts and/or the one or more movable shielding device portions may be moved during an idle time i.e. when the evaporation source switches from one substrate to another substrate. During idle time, the velocity of the movement may for example be 25 mm/s or below.

[0059] According to embodiments described herein, the shielding device 200 may be arranged at an evaporation source. The shielding device may be provided at a distribution pipe of the evaporation source. The shielding device may be provided adjacent to the outlets 22 of the distribution pipe. According to embodiments, the one or more shielding belts may be provided adjacent to the outlets 22, particularly the one or more movable shielding device portions 205 may be provided adjacent to the outlets 22.

[0060] For example, a first and a second movable shielding device portion 205 are arranged at an outlet 22. The first movable shielding device portion may be provided adjacent to the outlet 22. The second movable shielding device portion may be provided next to the first movable shielding device portion, e.g. remote from the outlet in a first position. The second movable shielding device portion may be provided such that the second movable shielding device portion may replace the first movable shielding device portion upon movement of the first and second movable shielding device portions, i.e. movement of the belt. The movement of the first and second movable shielding device portions may be directed away from the unwinding supply device for the belt and towards the take-up device for the belt. The second movable shielding belt portion may replace the first movable shielding device portion upon movement.

[0061] According to embodiments described herein, the one or more shielding belts and/or the one or more movable shielding device portions may be guided in a substantially vertical direction (indicated by direction arrow 7 in FIG. 2) and/or a substantially horizontal direction (indicated by direction arrow 8 in FIG. 2). The shielding device may include one or more redirection devices 220. Redirection device 220 may be configured to change the direction of the one or more shielding belts and/or the one or more movable shielding device portions. For example, the one or more shielding belts are guided around redirection device 220. According to embodiments described herein, two redirection devices 220 may be arranged in a horizontal plane. For example, two redirection devices may be arranged above an outlet of the distribution pipe in a first horizontal plane and another two redirection devices may be arranged below the outlet of the distribution pipe in a second horizontal plane that is aligned with the direction of the first horizontal plane.

[0062] According to embodiments described herein, the one or more redirection devices 220 may be stationary or may be rotated around a rotation axis. For example, the belt may slide over a stationary redirection device upon movement of the belt. The redirection device may be rotated together with the belt upon movement of the belt. The one or more redirection devices may be provided as rolls. The redirection devices may be rotated by the movement of the one or more shielding belts and/or the movement of the one or more movable shielding device portions.

[0063] According to embodiments, one or more shielding belts may be arranged between the unwinding supply device and the take-up device for the belt. The shielding belts may overlie each other. Advantageously, the shielding belts may trap collected evaporated source material when overlying each other. Thus, evaporated source material may be prevented from reentering the system once collected by the shielding device. Further advantageously, overlying of the shielding belts may provide for a space-saving way to provide a shielding device for many outlets at the same time. Take-up of the shielding belts may be facilitated.

[0064] The shielding belts may be provided at the same unwinding supply device and the same take-up device for the belt. The shielding belts may be moved simultaneously by the unwinding supply device and/or the take-up device. Although four shielding belts 210A, 210B, 210C, 210D and three outlets 22 are shown in FIG. 2, the person skilled in the art may understand that the shielding device may include more than four shielding belts and/or that the evaporation source may include more than three outlets. According to embodiments, the number of shielding belts may depend on the number of outlets provided at the distribution pipe. For example, if n outlets are provided by the distribution pipe, n+l shielding belts may be provided. The outlets may be separated by a shielding belt.

[0065] According to embodiments described herein, at least parts of the shielding belts and/or the movable shielding belt portions may be guided over the redirection devices 220. The shielding belts and/or movable shielding belt portions may be arranged in a horizontal plane between the outlets. Particularly, one shielding belt may be arranged between two outlets. Additionally or alternatively, two shielding belts may be arranged between two outlets.

[0066] According to embodiments described herein, the shielding belts may be transported simultaneously. The shielding belts may be transported jointly. The joint shielding belts may be divided at a redirection device 220. For example, first two redirection devices are arranged in a horizontal plane above an outlet and second two redirection devices are arranged in a horizontal plane below the outlet. A first shielding belt of the joint shielding belts may be guided via the first two redirection devices and a second shielding belt of the joint shielding belts may be guided via the second two redirection devices. The first and second shielding belts may be joined together after passing the first and second redirection devices.

[0067] According to embodiments described herein, the shielding belts may include a thickness in the range of 0.010 mm to 0.500 mm, particularly in the range of 0.020 mm to 0.100 mm. The one or more shielding belts may be made of metal, particularly of stainless steel and/or may be coated with titanium. Additionally or alternatively, the one or more shielding belts may be made from aluminium, for example, when temperatures of T <550 °C are applied.

[0068] FIG. 3A shows a shielding device configuration according to embodiments described herein. A plurality of shielding devices 200 may be arranged at an evaporation source, i.e. at a distribution pipe 106 of an evaporation source. The distribution pipe may include outlets 22. The plurality of shielding devices may be arranged in horizontal planes adjacent to the distribution pipe 106. The planes may be arranged such that each outlet of the distribution pipe is surrounded by at least two of the shielding device 200. For example, the plurality of shielding devices may be arranged between the distribution pipe and the substrates to be coated with evaporated source material. According to embodiments, above and below a plurality of outlets a shielding device may be provided.

[0069] According to embodiments described herein, a second shielding device 24 may be arranged at the evaporation source. The second shielding device may be referred to herein as “shaper shield”. The second shielding device 24 may be arranged vertically at the evaporation source. Particularly, the second shielding device 24 may be arranged vertically at a distribution pipe 106. The second shielding device may be arranged downstream from the one or more outlets 22 i.e. between the evaporation source and the substrate. The second shielding device may be configured to block evaporated source material laterally of the outlets. For example, the shaper shield may block evaporated source material at two sides of the distribution pipe. The second shielding device may provide limitation of the plume of evaporated material in vertical planes additionally to the limitation in horizontal planes by the plurality of shielding devices 200. The shielding device 200 and the shaper shield may surround the outlets 22 to block evaporated source material that is released apart from a maximum emission angle. [0070] For example, the one or more shielding device portions include a first shielding device portion to be provided adjacent to an outlet of the one or more outlets, and a second shielding device portion to be provided at a distance from the outlet of the one or more outlets and being movable to be adjacent to the outlet of the one or more outlets while the first portion moves distant to the outlet of the one or more outlets.

[0071] The plurality of shielding devices may be arranged such that the unwinding supply devices 212 and/or the take-up devices 214 for the belt are arranged above each other. The person skilled in the art will understand that the unwinding supply devices 212 and/or the take-up devices may be arranged in opposed directions i.e. an unwinding supply device being arranged above or below a take-up device or vice versa. The unwinding supply devices may rotate in the direction of the take-up devices or vice versa. The unwinding supply devices may rotate in an anticlockwise direction indicated by rotation arrow 5. The take-up devices 214 may rotate in a clockwise direction indicated by rotation arrow 6.

[0072] According to embodiments described herein, the shielding device 200 may be configured to block evaporated source material depending on an emission angle of a plume of evaporated source material from the one or more outlets and configured to be replaced by a movement. “Blocking” of evaporated source material may be understood as selectively holding back particles being released from the evaporation source. For example, particles of the plume that are not directed in the main emission direction X and/or particles that are released with an emission angle that is different from the emission angle Q may be collected by the shielding device.

[0073] According to embodiments described herein, the shielding device may be configured to collect evaporated source material particles by adsorption and/or condensation at one or more surfaces of the shielding device. The one or more shielding belts and/or the movable shielding belt portions of the shielding device may be configured to adsorb and/or condense particles on one or more surfaces. Accordingly, the shielding belts, the movable shielding belt portions and/or the surface may have a first temperature and the evaporated source material may have a second temperature, the first temperature being lower than the second temperature. For example, the temperature of the shielding device may be lower than the temperature of the evaporated source material. [0074] FIG. 3B shows a schematic perspective view of an evaporation source according to embodiments described herein. A plurality of shielding devices may be arranged at the distribution pipe of the evaporation source. The shielding devices may be mounted to the distribution pipe via fixing devices, e.g. screws. Particularly, the unwinding supply device and the take-up device for the belt may be mounted to the distribution pipe. A second shielding device 24 may be arranged at the distribution pipe 106. The second shielding device 24 may be arranged such that the shielding device 200 and the second shielding device 24 surround outlets at the distribution pipe.

[0075] The distance between two shielding devices may be similar to the distance between two outlets. The shielding devices may be spaced apart by a distance of 1 cm or more, for example, by a distance from 1 cm to 3 cm, for example, by a distance of 2 cm. The person skilled in the art may understand that the shielding devices may be arranged in the gaps between two neighboring outlets that are arranged in a vertical orientation.

[0076] According to embodiments, the evaporated source material may be collected at two sides of the shielding belt and/or the movable shielding belt portions. The shielding belts and/or the movable shielding belt portions may include an upper surface 211 and a lower surface 213 for adsorbing or condensing evaporated source material. For example, the upper surface 211 of a shielding device that is arranged between two vertically oriented neighboring outlets of the distribution pipe may collect the evaporated source material of the upper outlet, and the lower surface 213 of the shielding device may collect the evaporated source material of the lower outlet. The evaporated source material may be collected at surfaces of the second shielding device 24. For example, the evaporated source material may be collected at the surfaces facing the outlets 22.

[0077] Advantageously, the collected material that is adsorbed or condensed at the shielding belts and/or the movable shielding belt portions is transported towards the take-up device for the belt. By rotation of the take-up device, the shielding belts and/or movable shielding belt portions are wound onto the take-up device. Thus, the collected material is trapped between the single turns of the shielding belts and/or the movable shielding belt portions on the belt- take-up device. That way, the material collected at the belts may not enter the system. Impurities in the system are reduced or prevented from entering the system and deposition accuracy is improved. [0078] Further advantageously, the shielding belts and/or movable shielding device portions collect the material of two outlets which results in a very thin material deposition on the belts. Flaking of the material from the shielding device is thus prevented, particularly during movement of the shielding belts and/or the movable shielding belt portions.

[0079] Advantageously, and particularly with respect to the embodiments described with regard to FIG. 3A, the shielding belts may be joined after having passed the outlets depositing the evaporated source material. Thus, the collected material may be trapped between the shielding belts and/or the movable shielding belt portions. The collected material is prevented from entering the system before reaching the take-up device for the belt. Thus, impurities during belt movement may be prevented from entering the system. Further, the collected material may be transported to the take-up device for the belt.

[0080] Further advantageously, if two shielding belts are arranged between two outlets, each of the shielding belts or the respective movable shielding belt portions may collect material at one surface. Thus, in total, less material may be present at the shielding belt surface, particularly preventing flaking of the material. In contrast, if one shielding belt is arranged between two outlets, the material may be collected at two surfaces of the shielding device resulting in a higher amount of simultaneously collected material, making the process of collecting material more efficient by saving belt supply material.

[0081] FIG. 4A shows a schematic top view of an evaporation source 20 according to embodiments described herein. FIG. 4B shows a schematic side view of an evaporation source 20 according to embodiments described herein. The evaporation source 20 shown in FIGS. 4A and 4B includes a distribution pipe 106. According to embodiments described herein, the distribution pipe 106 may extend in a length direction which may be perpendicular to the drawing plane of FIG. 4A, particularly in an essentially vertical direction. One or more outlets 22 may be arranged along the length direction of the distribution pipe 106. The outlets may be configured as nozzles. One outlet 22 of the one or more outlets 22 is schematically illustrated in FIG. 4A as an outlet of the distribution pipe 106. As is indicated in FIGS. 4A and 4B, evaporated source material may stream from the interior of the distribution pipe 106 through the outlet toward the substrate 10, 11. The outlet is configured for directing a plume 342 of evaporated source material toward the substrate 10, 11. A mask 340 may be arranged between the substrate 10 and the distribution pipe 106 as displayed in FIGS 4A and 4B. [0082] The evaporation source 20 further includes a shielding device 200 which may be arranged downstream from the one or more outlets 22. The shielding device 200 may be configured for guiding the evaporated source material toward the substrate 10, 11 and for individually shaping the plumes of evaporated source material.

[0083] The shielding device 200 may be arranged such that apertures 32 are formed. The apertures may frame individual outlets. The apertures 32 are configured to individually shape the plume of evaporated source material emitted from a single associated outlet. For framing the outlet and/or forming the aperture, the shielding device includes shielding belts that may be transported adjacent to the outlets. The shielding belts may be joined together. For example, a first shielding belt may pass in a horizontal plane above the outlet whereas a second shielding belt may pass in a horizontal plane below the outlet as described with respect to FIG. 2.

[0084] According to embodiments, one movable shielding device portion of the first shielding belt may be moved in a horizontal direction above an outlet, indicated by direction arrow 8 in FIG. 2. A second movable shielding device portion of the first shielding belt may be positioned in a vertical direction indicated by direction arrow 7 in FIG. 2. The second movable shielding device portion may be positioned above the horizontally directed first movable shielding device portion. Simultaneously, one shielding device portion of the second shielding belt may be positioned in a horizontal direction below the outlet. A second movable shielding device portion of the second shielding belt may be positioned in a vertical direction. The second movable shielding device portion of the second shielding belt may be positioned laterally of the outlet.

[0085] The person skilled in the art may understand that the horizontal and vertical directions may be interchanged when the shielding device is oriented horizontally. Then, the vertical direction becomes a horizontal direction and the horizontal direction becomes a vertical direction. The lateral position may then become a position above or below the outlet.

[0086] In some embodiments, the number of outlets of the evaporation source may correspond to the number of apertures of the shielding device. For example, a shielding device forming ten or more apertures may be arranged in front of a distribution pipe with ten or more outlets. [0087] In some embodiments, the aperture may be arranged in front of the associated outlet, as is shown in FIGS. 4A and 4B. For example, the main emission direction X of the outlet 22 may correspond to a connection line between the center of the outlet of the outlet 22 and the center of the aperture 32. The aperture 32 may be configured as a passage for the plume 342 that is surrounded by a shielding belt, wherein the shielding belt may be configured to block at least a portion of the plume 342 of evaporated source material emitted from the outlet 22. In some embodiments, the shielding belt may be configured to block an outer angular portion of the plume 342 of evaporated source material.

[0088] An“aperture” as used herein may refer to an opening or a passage at least partially surrounded by a shielding belt which is configured to shape a single plume of evaporated source material which is guided therethrough, particularly for limiting the maximum opening angle of the plume and for blocking outer angular portions of the plume. In some embodiments, the passage may be surrounded, for example, entirely surrounded, by one or more shielding belts such as to shape the plume in two or more sectional planes which include the main emission direction X of the associated outlet. The one or more shielding belts may extend around the main emission direction X of the plume 342 such as to circumferentially shape said plume. In some embodiments, the width of the one or more shielding belts may extend parallel to the main emission direction X.

[0089] In some embodiments, which may be combined with other embodiments herein, the shielding device may be arranged at a close distance to the distribution pipe 106, e.g. at a distance of 5 cm or less or 1 cm or less in the main emission direction X. Arranging the apertures at a close distance downstream from the nozzles may be beneficial, because an individual shaping of the plumes may be possible even if adjacent outlets of the one or more outlets are arranged at a close distance with respect to each other. The minimum distance between the outlet 22 and the shielding device 200 may be less than 3 mm or less than 1 mm and/or more than 0.1 mm in some embodiments.

[0090] In some embodiments, the shielding device 200 may be actively or passively cooled. According to embodiments, the shielding device may be cooled with a heat sink. The heat sink may be arranged such that the shielding device i.e. the shielding belts may be moved past the heat sink. The heat sink may have a temperature that is lower than the temperature of the shielding device. Thus, heat may be dissipated from the shielding device to the heat sink resulting in cooling of the shielding device. [0091] According to embodiments, the shielding device may be cooled by a cooling device. The cooling device may include pre-cooling and/or in-situ cooling. For example, the shielding device may be cooled prior to be arranged at the evaporation source by a pre cooling device. Additionally or alternatively, the pre-cooling device may include a cooling device arranged at the unwinding supply device for the belt. For example, a cooling coil may be arranged at the unwinding supply device.

[0092] According to embodiments described herein, the cooling device may be an in-situ cooling device. The in-situ cooling device may be a heat sink. The heat sink may be arranged near the shielding device. For example, the heat sink may be arranged at the distribution pipe where the shielding device is arranged as well.

[0093] In some embodiments, which may be combined with other embodiments described herein, the one or more shielding belts may be configured to block the evaporated source material of the plume 342 of evaporated source material having an emission angle greater than a first maximum emission angle Q with respect to the main emission direction X in a first sectional plane.

[0094] The drawing plane of FIG. 4A illustrates the first sectional plane. The first sectional plane may include the main emission direction X. In some embodiments, the first sectional plane is a horizontal plane and/or a plane that extends perpendicularly to the length direction of the distribution pipe 106. The shielding device 200 of the aperture 32 is configured to block an outer angular portion of the plume 342 of evaporated source material in the first sectional plane, such that the opening angle of the emission cone is limited to an angle of 2Q. In other words, the shielding device 200 blocks the portion of the evaporated source material emitted by the outlet 22 at an emission angle greater than the first maximum emission angle Q.

[0095] In some embodiments, the first maximum emission angle Q is an angle from 10° to 45°, particularly from 20° to 30°, more particularly about 25°. Accordingly, the opening angle 2Q of the emission cone in the first sectional plane may be 20° or more and 90° or less, particularly about 50°.

[0096] As is illustrated in FIG. 4A, the shielding device 200 may have a width T. Particularly, the width is the width of the one or more shielding belts. In some embodiments, the width T may have a length between 10 mm and 35 mm, particularly about 20 to 25 mm. The“width” of the shielding device 200 may correspond to the length of a projection of a vector connecting the outlet and the front end of the shielding belt in a respective sectional plane on the main emission direction X.

[0097] FIG. 4C shows an evaporation source 20 according to embodiments described herein including one or more distribution pipes e.g. a distribution pipe 106A, a second distribution pipe 106B, and a third distribution pipe 106C which extend next to each other in a length direction, respectively, wherein the length direction is perpendicular to the drawing plane of FIG. 4C. The evaporation source 20 includes a plurality of outlets 22, wherein one outlet of each of the distribution pipes is schematically depicted as an outlet of the respective distribution pipe in FIG. 4C. Further, the evaporation source 20 includes a shielding device 200 including a plurality of apertures 32, wherein each aperture of the plurality of apertures 32 is arranged in front of a single associated outlet and is configured to shape the plume of evaporated source material emitted from the respective single associated outlet. According to embodiments, each of the one or more distribution pipes may be provided with a shielding device.

[0098] The main emission direction of the outlets of the distribution pipe 106A may be inclined with respect to the main emission direction of the nozzles of the second distribution pipe 106B and/or of the third distribution pipe 106C. For example, the main emission directions may be inclined such that the plumes of evaporated source material emitted from the distribution pipe 106 A may overlap with the plumes of evaporated source material emitted from the second distribution pipe 106B and/or from the third distribution pipe 106C. In some embodiments, the distribution pipes are arranged such that main emission directions of the distribution pipes may intersect essentially on the surface of the substrate. The plumes emitted from different distribution pipes in a sectional plane may be directed to essentially the same area on the substrate.

[0099] According to embodiments described herein, each of the distribution pipes 106 A, B and C may include a shielding device. Alternatively, one or more shielding devices may be arranged horizontally, i.e. the unwinding supply device and the take-up device for the belt may be arranged in a horizontal plane instead of a vertical plane as depicted in FIG. 2. When being arranged in a horizontal plane, several shielding devices may be arranged below each other in the respective planes of the outlets of the distribution pipes. The redirection devices may be arranged laterally in respective vertical planes that correspond to the vertical planes of the distribution pipes.

[00100] In some embodiments, one of the distribution pipes, e.g. distribution pipe 106A, may be configured to deposit a main material, and at least one further distribution pipe, e.g. the second distribution pipe 106B, may be configured to deposit a secondary material, e.g. a dopant.

[00101] According to embodiments described herein, the velocity of the shielding devices may differ in comparison to each other. For example, if a main and a secondary material are deposited, the velocity of the shielding device i.e. the shielding belts may depend on the chemical composition of the material to be deposited. For example, the velocity of the shielding device arranged at the distribution pipe delivering the dopant may be transported at a different velocity than the shielding device arranged at the distribution pipe delivering the main material. This difference may occur due to the different particles of the main and the secondary material. As a rule of thumb, the bigger the particles, the faster the shielding device velocity.

[00102] FIGs. 5 A and 5B shows schematic side views of a redirection device configuration according to embodiments described herein. The redirection device 220 may include one or more guiding devices 218 and/or one or more support devices 219. The shielding belt may be arranged around the redirection device 220, such that the guiding device 218 and/or the support device 219 are prevented from getting into contact with evaporated source material.

[00103] According to embodiments and with respect to FIG. 5A, a guiding device 218 may be arranged with two support devices 219. The support devices may be arranged laterally and/or below the guiding device. The guiding device 218 and the support devices 219 may be rotated. Rotation may occur upon movement of the shielding belt. For example, the support devices may rotate in an anticlockwise direction and the guiding device may rotate in a clockwise direction or vice versa.

[00104] According to embodiments, the redirection device, i.e. the guiding device and/or the support device may be configured as a cylindrical body e.g. a roll. The redirection device may have a diameter of 1 to 30 mm, particularly 3 to 20 mm and more particularly 5-15 mm. Typically, the guiding device may include a greater size than the support device. [00105] According to embodiments and with respect to FIG. 5B, the redirection device 220 may include four support devices 219. The shielding belt may be arranged around the support devices 219 such that the support devices are prevented from coming into contact with the evaporated source material. The support devices may be rotated in a clockwise and/or an anticlockwise direction. The support devices may be arranged side by side and/or on top of each other.

[00106] Advantageously, the shielding device including the movable shielding device portions leads to a prolonged deposition process time without interruptions, since removal of debris material attached to the shielding device is redundant. Furthermore, the lifetime of the shielding device is improved and can be adjusted depending on the process that is run by the system. For example, the length of the shielding belts may be adjusted depending on the respective process setup influencing the time of usage of the respective shielding belt.

[00107] FIG. 6 shows a flow diagram illustrating a method 600 for shielding evaporated source material released from an evaporation source according to embodiments described herein. The evaporation source includes one or more outlets. The method includes moving a first movable shielding device portion adjacent to the one or more outlets to block evaporated source material depending on an emission angle of a plume of evaporated source material during deposition as shown in box 650. As indicated by box 660, the method further includes replacing the first movable shielding device portion by a second movable shielding device portion. The first and second shielding device portions may be part of a shielding belt. The method may include moving the shielding belt. The method further may include moving more than one shielding belts simultaneously.

[00108] According to embodiments described herein, blocking the evaporated source material may include that the first and second movable shielding device portions collect particles by adsorption or condensation. The particles collected are derived from the plume of deposition material released from the evaporation source.

[00109] According to embodiments described herein, moving a first movable shielding device portion and replacing the first movable shielding device portion by a second movable shielding device portion may be a continuous process. The first and second movable shielding device portions may be in continuous movement. Advantageously, continuously moving the first and second movable shielding device portions may lead to an improved prevention of flaking of the material that is collected by the first and second movable shielding device portions since fewer particles are deposited at the same area of the first and second movable shielding device portions.

[00110] According to embodiments described herein, moving a first movable shielding device portion and replacing the first movable shielding device portion by a second movable shielding device portion may be stopped. Accordingly, the first and the second movable shielding device portion may maintain the position. While maintaining the position, the evaporated source material may be deposited on a substrate. The first and second movable shielding device portions may collect the material that is derived from the evaporation plume and released at a different angle than the opening angle 2Q. After deposition, e.g. when the evaporation source is turned at an idle position to deposit material to the further substrate, moving a first movable shielding device portion and replacing the first movable shielding device portion by a second movable shielding device portion may be restarted. For example, the first and second movable shielding device portions may be also be stopped during maintenance of the system. For example, stopping and restarting of the movement of the movable shielding device portions may occur after 10 deposition cycles. One cycle may be regarded as deposition of evaporated source material onto two substrates.

[00111] According to embodiments described herein, replacing the first movable shielding device portion may include moving the first movable shielding device portion distant to the one or more outlets as indicated by box 670. The second movable shielding device portion may be moved in the position of the first movable shielding device portion. Material collected by the first movable shielding device portion may thus be transported away from the outlet.

[00112] According to embodiments described herein, the method may further include trapping evaporated source material by taking up the first and second movable shielding device portions on a take-up device for the belt as indicated by box 680. Trapping may include rotating the take-up device. Rotation of the take-up device may lead to winding of the first shielding device portion onto the take-up device. Thus, the collected material is trapped between the single turns of the wound first movable shielding device portion.

[00113] Additionally or alternatively and according to embodiments described herein, trapping evaporated source material may include joining more than one first shielding device portions of more than one shielding belts. Thus, the material collected by the more than one first shielding device portions may be trapped inbetween the more than one shielding belts. Additionally or alternatively, the joined more than one first shielding device portions may be wound onto the take-up device together.

[00114] 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.