WO2021052591A1

WO2021052591A1 - Evaporation source, evaporation system, and evaporation method

Info

Publication number: WO2021052591A1
Application number: PCT/EP2019/075243
Authority: WO
Inventors: Pejman KHAMEHGIR; Sebastian Franke
Original assignee: Applied Materials, Inc.
Priority date: 2019-09-19
Filing date: 2019-09-19
Publication date: 2021-03-25

Abstract

An evaporation source is provided. The evaporation source comprises a vapor distribution assembly (130) with a plurality of vapor nozzles (131) for directing an evaporated source material toward a substrate (10), and a shielding device (120) for at least partially blocking the evaporated source material (15) emitted from the plurality of vapor nozzles, the shielding device (120) being magnetically held at the vapor distribution assembly (130). Further, an evaporation system with an evaporation source and an evaporation method are provided.

Description

EVAPORATION SOURCE, EVAPORATION SYSTEM, AND EVAPORATION

METHOD

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 and an evaporation source for depositing an evaporated source material, e.g. an evaporated organic material, on a substrate. More specifically, embodiments described herein relate to an evaporation source with a plurality of vapor nozzles for directing an evaporated source material toward a substrate through a shielding device and through a mask.

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 and evaporated in a crucible of an evaporation source. The evaporated source material is guided through a vapor distribution assembly toward a plurality of vapor nozzles. The evaporated source material is directed by the plurality of 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. However, the blocked evaporated source material condenses 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 source that allows for a high up-time and a high deposition accuracy. More specifically, it would be beneficial to provide an evaporation source, an evaporation system, and an evaporation method 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, an evaporation source, an evaporation system, and an evaporation method are provided.

[0008] According to a first aspect of the present disclosure, an evaporation source is provided. The evaporation source includes a vapor distribution assembly with a plurality of vapor nozzles for directing an evaporated source material toward a substrate, and a shielding device for at least partially blocking the evaporated source material emitted from the plurality of vapor nozzles, the shielding device being magnetically held at the vapor distribution assembly.

[0009] According to a second aspect of the present disclosure, an evaporation system is provided. The evaporation system includes a vacuum chamber, an evaporation source arranged in the vacuum chamber, and a shield handling apparatus. The evaporation source includes a vapor distribution assembly with a plurality of vapor nozzles for directing an evaporated source material toward a substrate, and a shielding device for at least partially blocking the evaporated source material emitted from the plurality of vapor nozzles, the shielding device being magnetically held at the vapor distribution assembly. The shield handling apparatus is configured to detach the shielding device from the vapor distribution assembly, e.g. by pulling away the shielding device from the vapor distribution assembly.

[0010] Optionally, the shielding device may be cleaned in a cleaning region of the vacuum chamber and/or may be replaced with a second shielding device that is attached at the vapor distribution assembly by the shield handling apparatus.

[0011] According to a third aspect of the present disclosure, an evaporation method is provided. The evaporation method includes magnetically holding a shielding device at a vapor distribution assembly of an evaporation source in a vacuum chamber, the vapor distribution assembly including a plurality of vapor nozzles, and emitting an evaporated source material from the plurality of vapor nozzles, wherein at least a part of the evaporated source material is blocked by the shielding device.

[0012] According to a fourth aspect of the present disclosure, a shielding device configured to be detachably held at a vapor distribution assembly of an evaporation source is provided. The shielding device may be a shaping device or a shutter device as described herein. The shielding device may be at least partially made of a magnetic material, e.g. a metal, or may be provided with one or more magnet elements.

[0013] 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

[0014] 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:

[0015] FIG. 1 shows a schematic sectional view of an evaporation source according to embodiments described herein;

[0016] FIG. 2 shows a schematic sectional view of an evaporation source according to embodiments described herein; [0017] FIGS. 3A-3C show subsequent stages of an evaporation method according to embodiments described herein;

[0018] FIGS. 4A-4B show subsequent stages of an evaporation method according to embodiments described herein;

[0019] FIGS. 5A-5B show subsequent stages of an evaporation method according to embodiments described herein;

[0020] FIG. 6 shows a shielding device of an evaporation source according to embodiments described herein, the shielding device configured as a shaping device;

[0021] FIG. 7 shows a shielding device of an evaporation source according to embodiments described herein, the shielding device configured as a shaping device; [0022] FIG. 8 shows a shielding device of an evaporation source according to embodiments described herein, the shielding device configured as a shutter device; [0023] FIG. 9 shows a shielding device of an evaporation source according to embodiments described herein, the shielding device configured as a shutter device;

[0024] FIG. 10 shows an evaporation source with several vapor distribution assemblies and shielding devices according to embodiments described herein; [0025] FIG. 11 is a flow diagram illustrating an evaporation method according to embodiments described herein; and

[0026] FIG. 12 shows a schematic view of an evaporation system according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS [0027] 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.

[0028] 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 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.

[0029] 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.

[0030] 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 of vapor nozzles 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, shaping and/or blocking the evaporated source material emitted by the plurality of vapor outlets.

[0031] 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.

[0032] FIG. 1 shows a schematic view of an evaporation source 100 according to embodiments described herein. The evaporation source 100 may be arranged in a vacuum chamber (see FIG. 12). The evaporation source 100 includes a vapor distribution assembly 130 with a plurality of vapor nozzles 131 for directing an evaporated source material 15 toward a substrate 10 (e.g., ten, thirty or more vapor nozzles). The evaporated source material propagates through an inner volume of the vapor distribution assembly 130 towards the plurality of vapor nozzles 131, and each of the plurality of vapor nozzles 131 emits a plume of evaporated source material in the emission direction X.

[0033] FIG. 1 shows the evaporation source 100 in a deposition state in which the evaporated source material 15 is emitted from the plurality of vapor nozzles 131 toward the substrate 10. The plurality of vapor nozzles may be arranged one above the other in a linear array. Only two vapor nozzles of the plurality of vapor nozzles are shown in the sectional view of FIG. 1.

[0034] The evaporation source 100 further includes a shielding device 120 (also referred to herein as “first shielding device 120”) provided in front of the plurality of vapor nozzles 131 at the vapor distribution assembly 130. The shielding device 120 may be attached to the vapor distribution assembly 130 on an emission side of the vapor distribution assembly where the plurality of vapor nozzles 131 are provided. The emission side is also referred to herein as the “front side” of the vapor distribution assembly. The plurality of vapor nozzles 131 may optionally at least partially protrude into the shielding device 120.

[0035] The shielding device 120 may be arranged downstream of the plurality of vapor nozzles 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 plurality of vapor nozzles 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 plurality of vapor nozzles 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. The mask 12 may be a fine metal mask with a plurality of small openings, e.g. a million openings or more.

[0036] In some embodiments, the plurality of vapor nozzles 131 is provided in a linear array (e.g., ten or more vapor nozzles in a linear array), particularly one above the other in a vertical array of nozzles. The shielding device 120 may include a plurality of shielding portions in a linear array, particularly a plurality of shaping apertures 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 nozzle of the plurality of vapor nozzles. A shielding device having such a configuration is illustrated in a perspective view, e.g., in FIG. 6.

[0037] 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 plurality of vapor nozzles 131, particularly for blocking only evaporated source material 15 emitted by the plurality of vapor nozzles at an angle larger than a predetermined maximum emission angle. 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.

[0038] 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 vapor nozzles at a position where the plume diameters are small. Accordingly, vapor nozzles of the vapor distribution assembly can be arranged in close proximity next to each other, and the plumes of adjacent vapor nozzles can still be individually shaped by the shaping device. For example, the distance between two adjacent vapor nozzles depicted in FIG. 1 may be 5cm or less, particularly 3 cm or less.

[0039] 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 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.

[0040] In some embodiments (see, e.g., FIG. 5A), the shielding device is a shutter device configured to completely block the plumes of evaporated source material 15 emitted by the plurality of vapor nozzles 131. A shutter device may be placed in front of the plurality of vapor nozzles 131 in one or more of the following situations: (i) for blocking the material emission of the evaporation source 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 plurality of vapor nozzles

131. 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 plurality of vapor nozzles 131.

[0041] Attaching the shutter device to the vapor distribution assembly 130 is beneficial because the shutter device is then arranged close to the plurality of vapor nozzles at a position where the diameters of the emitted vapor plumes are small. A stray coating on a wall of the vacuum chamber and/or on components arranged in the vacuum chamber can be effectively reduced or entirely prevented, and the vapor nozzles can be reliably covered and protected.

[0042] In FIG. 1, the shielding device 120 is exemplarily depicted as a shaping device that blocks the evaporated source material 15 emitted by the plurality of vapor nozzles 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 plurality of vapor nozzles. Alternatively, the shielding device 120 may be a shutter device (as exemplarily illustrated in FIG. 5A) that completely blocks the evaporated source material.

[0043] 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, particularly 150°C or less. On the other hand, the vapor distribution assembly including the vapor nozzles may be held at a temperature above 250°C, e.g. 300°C or more. Since evaporated source material condenses at the shielding device 120 and accumulates thereon, there is a risk of clogging of the shielding device. It may therefore 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. Alternatively or additionally, a used shielding device may be exchanged by a clean shielding device at regular intervals. However, cleaning or exchanging of the shielding device 120 is time-consuming and may negatively affect the up-time of the evaporation source if the evaporation source cannot be used otherwise during the cleaning or exchange of the shielding device. The up-time of the evaporation source can be increased according to embodiments described herein.

[0044] According to embodiments described herein, the shielding device 120 is magnetically held at the vapor distribution assembly 130. Magnetically holding the shielding device 120 at the vapor distribution assembly 130 is beneficial because the shielding device 120 can be pulled away from the vapor distribution assembly, e.g. for cleaning or exchanging the shielding device. Accordingly, the shielding device can be easily and quickly detached from the vapor distribution assembly under vacuum, and there is no need for a complex detachment mechanism. Further, the generation of small particles in the vacuum chamber is reduced with a magnetic holding mechanism as compared to a mechanical holding mechanism.

[0045] In particular, the vapor distribution assembly 130 may include a first magnet element that is configured to magnetically hold the shielding device 120 at the vapor distribution assembly. The first magnet element may include a permanent magnet, an electromagnet and/or a ferromagnetic element configured to magnetically hold the shielding device. [0046] In some embodiments, the shielding device 120 includes a second magnet element or a magnetic material, such that the shielding device can be magnetically held at the vapor distribution assembly. For example, the shielding device may include a ferromagnetic material, e.g. a magnetic metal such as nickel, iron, or an iron-nickel alloy, particularly Invar, configured to be magnetically held at the first magnet element of the vapor distribution assembly. Alternatively or additionally, the second magnet element of the shielding device may be a permanent magnet configured to magnetically interact with the first magnet element of the vapor distribution assembly. The first magnet element may be a permanent magnet or a ferromagnetic element.

[0047] 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 nozzles 131 extend. The vapor distribution pipe

132 may extend in an essentially vertical direction, and the plurality of vapor nozzles 131 may be arranged in a linear array one above the other.

[0048] The vapor distribution assembly 130 may include a first magnet element 135, particularly a permanent magnet or a ferromagnetic element, provided in front of the front wall

133 of the vapor distribution pipe and configured to magnetically hold the shielding device. The first magnet element 135 may be configured to magnetically interact with a second magnet element of the shielding device. The first magnet element 135 may include a permanent magnet, particularly an AlNiCo magnet, a neodymium containing magnet, or a FeNb magnet. [0049] In some embodiments, the first magnet element 135 includes a magnetic plate, particularly a permanent magnetic plate, that may be held spaced apart from the front wall 133 of the vapor distribution pipe. The magnetic plate may be thermally decoupled from the vapor distribution pipe 132 and may be held spaced-apart therefrom. For example, the first magnet element 135 may be an AlNiCo plate, a neodymium containing plate or a FeNb plate. A vapor distribution assembly having a magnetic plate for holding the shielding device thereon is beneficial because the shielding device can be reliably held at the vapor distribution pipe at a correct position in the emission direction X over the whole longitudinal extension of the shielding device. The magnetic plate may have openings for the plurality of vapor nozzles 131 to extend therethrough, as is schematically depicted in FIG. 1.

[0050] In some embodiments, which can be combined with other embodiments described herein, the vapor distribution assembly 130 further includes an isolation plate 134 made of a thermally isolating material. The isolation plate 134 may include or be made of a ceramic isolator. The isolation plate 134 may be provided for thermally decoupling the vapor distribution pipe 132 from the shielding device 120. Accordingly, the vapor distribution pipe 132 and the shielding device 120 can reliably be held at different temperatures during the deposition process.

[0051 ] In some embodiments, the isolation plate 134 is arranged in front of the front wall 133 of the vapor distribution pipe 132, particularly between the front wall 133 and the shielding device 120. The isolation plate 134 may be held spaced-apart from the front wall 133, e.g. via pins, screws or bolts, and/or may be connected to the first magnet element 135. In particular, the first magnet element 135 may be a magnetic plate provided on a front surface of the isolation plate 134, as is schematically depicted in FIG. 1. The isolation plate 134 may have openings for the plurality of vapor nozzles 131 to extend therethrough.

[0052] In some embodiments, which can be combined with other embodiments described herein, the plurality of vapor nozzles 131 protrude at least partially into the shielding device 120, particularly into shaping apertures or vapor collection cavities of the shielding device 120. A reliable shielding can be ensured and an unwanted stray coating of the vapor distribution assembly can be reduced or avoided. Further, adjacent nozzles can be arranged in close vicinity to each other, while it is still possible to individually shape each plume of evaporated source material with a respective shaping wall of the shaping device. For example, the plurality of vapor nozzles may protrude through the isolation plate 134 and through the first magnet element 135 configured as a magnetic plate partially into the shielding device 120, as is schematically depicted in FIG. 1.

[0053] The shielding device 120 of FIG. 1 includes a magnetic material, particularly a ferromagnetic material, more particularly a metal such as nickel or Invar, such that the shielding device 120 can be magnetically held at the first magnet element 135. The first magnet element 135 may be a permanent magnetic plate.

[0054] The shielding device 120 of FIG. 1 is a shaping device configured to block a part of the evaporated source material emitted from the plurality of vapor nozzles having an emission angle greater than a predetermined maximum emission angle. In particular, the shielding device 120 may include a plurality of shaping apertures respectively configured to individually shape a plume of evaporated source material emitted from one associated vapor nozzle of the plurality of vapor nozzles. Alternatively, the shielding device may be a shutter device that completely blocks the emitted source material, as is schematically depicted in FIG. 5 A.

[0055] In some embodiments, which can be combined with other embodiments described herein, one of the vapor distribution assembly and the shielding device includes an alignment opening 321, and the other one of the vapor distribution assembly and the shielding device comprises an alignment pin 322 protruding into the alignment opening.

[0056] The alignment pin 322 may be inserted into the alignment opening 321 when the shielding device 120 is attached to the vapor distribution assembly 130. Accordingly, a correct positioning of the shielding device 120 at the vapor distribution assembly 130 can be ensured, e.g. in at least one of the vertical direction and a lateral direction, the lateral direction being perpendicular to the vertical direction and to the emission direction X. In some embodiments, the alignment opening 321 is a hole provided in the shielding 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 shielding device relative to the vapor distribution assembly in the direction in which the hole dimension reduces (see FIG. 1 in this respect), e.g. in the lateral direction and/or in vertical direction. [0057] In some embodiments, the alignment opening 321 has a conical shape, and the alignment pin 322 has a conical shape complementary to the conical shape of the alignment opening 321. An alignment in two directions can be achieved by inserting the alignment pin into the alignment opening.

[0058] FIG. 2 is a schematic sectional view of an evaporation source 100 according to embodiments described herein. The evaporation source 100 of FIG. 2 essentially corresponds to the evaporation source of FIG. 1, such that reference can be made to the above explanations, which are not repeated here.

[0059] The shielding device 120 of the evaporation source 100 of FIG. 2 includes at least one second magnet element 125, e.g. a permanent magnet. The vapor distribution assembly 130 of FIG. 2 includes a first magnet element 135, e.g. a plate made of a ferromagnetic or permanent magnetic material. The shielding device 120 can be held at the vapor distribution assembly 130 by the attractive magnetic force between the first magnet element 135 and the at least one second magnet element 125.

[0060] The shielding device 120 can be detached from the vapor distribution assembly 130 in a simple and quick manner by pulling the shielding device 120 away from the vapor distribution assembly, e.g. with a shield handling apparatus including a shield holder with a magnet device. Similarly, the shielding device 120 can be attached at the vapor distribution assembly 130 in a simple and quick manner by moving the shielding device 120 toward the first magnet element 135 until the attractive magnetic force between the first magnet element 135 and the shielding device 120 is sufficient for holding the shielding device at the vapor distribution assembly 130.

[0061] FIGS. 3A-3C show subsequent stages of an evaporation method according to embodiments described herein. The evaporation source 100 of FIGS. 3A-3C corresponds to the evaporation source 100 of FIG. 1, such that reference can be made to the above explanations, which are not repeated here.

[0062] In FIG. 3 A, the shielding device 120 is magnetically held at the vapor distribution assembly 130 of the evaporation source 100 in a vacuum chamber. Evaporated source material is emitted from the plurality of vapor nozzles 131, and at least a part of the evaporated source material emitted from the plurality of vapor nozzles is blocked by the shielding device 120. [0063] The vapor distribution assembly 130 includes a vapor distribution pipe 132 and a plurality of vapor nozzles 131 in a linear array. 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 nozzle of the plurality of vapor nozzles 131. In particular, the shielding device 120 may include a plurality of shaping apertures respectively configured to individually shape a plume of evaporated source material emitted from one associated vapor nozzle.

[0064] The plurality of vapor nozzles 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 nozzles. The shielding apertures may be holes or apertures which are provided in an elongated body of the shielding 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.

[0065] For detaching the shielding device 120 from the vapor distribution assembly 130, a shield holder 184 of a shield handling apparatus 180 (also referred to herein as a “first shield holder 184”) can be moved toward the vapor distribution assembly 130, and the shielding device 120 can be detached from the vapor distribution assembly 130 with the shield holder 184. 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 to a holding state for activating a magnetic field attracting the shielding device 120 to the shield holder 184. The first magnet device 189 may include an electropermanent magnet (EPM) 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.

[0066] An electropermanent magnet (EPM) may be understood as a switchable magnet device including an arrangement of permanent magnets, wherein a direction of magnetization of at least one of the permanent magnets can be changed by applying an electric pulse to a coil of the electropermanent magnet. Accordingly, the electropermanent magnet can be switched between a holding state in which a magnetic material is attracted toward the electropermanent magnet and a release state in which a magnetic material is attracted to a lesser extent or repelled from the electropermanent magnet. Since the actual magnetic holding force is generated by the permanent magnets, an electropermanent magnet does not need a continuous power or current supply.

[0067] FIG. 3B shows the shielding device 120 that is held at the shield holder 184 of the shield handling apparatus 180. The shield holder 184 can move toward the vapor distribution assembly 130 and away from the vapor distribution assembly 130, e.g. for transporting the detached shielding device into a cleaning region inside the vacuum chamber.

[0068] As is schematically depicted in FIG. 3B, the shielding device 120 can be magnetically detached from the vapor distribution assembly 130, particularly by switching a first magnet device 189 of the shield holder 184 that is brought into contact with the shielding device 120 to a holding state. The shielding device 120 can then be pulled away from the vapor distribution assembly 130 while being magnetically held at the shield holder 184.

[0069] 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 vacuum chamber. The shielding device 120 may be at least partially heated up at the cleaning position, particularly with 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 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 a material collection wall 160. In some embodiments, the at least one heating device 185 may include at least one of an infrared heater, resistive heater, inductive 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, such that heat radiation can be directed toward the shielding device 120 that is held at the shield holder 184.

[0070] Optionally, at least one cooling device 188 may be provided for cooling down the shielding device 120 after the cleaning. In this case, the cleaned shielding device can more quickly be re-used at the vapor distribution assembly.

[0071] 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 devices, can be increased.

[0072] In some embodiments, a material collection wall 160, particularly a material collection box having a bottom wall and side walls, may be provided in a 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 can accumulate 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 maybe 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. Moving the detached shield holder to the material collection wall 160 may include a translational movement and/or a rotational movement of the shield holder 184.

[0073] 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. The second shielding device can be magnetically held at the vapor distribution assembly 130, particularly at the first magnet element 135 of the vapor distribution assembly.

[0074] FIGS. 4A-4B show subsequent stages of an evaporation method according to embodiments described herein. The method essentially corresponds to the method of FIGS. 3A- 3C, such that reference can be made to the above explanations, which are not repeated here.

[0075] 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 include ten or more tube cylinders which are respectively magnetically held at a permanent magnetic plate that is provided at the vapor distribution assembly.

[0076] As is schematically depicted in FIG. 4A and FIG. 4B, the vapor distribution assembly may include a plurality of grooves or steps 323 for ensuring a correct positioning of the plurality of separate tube cylinders at the vapor distribution assembly. For example, 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 nozzles 131 and may be centered with respect to said vapor nozzle. [0077] The plurality of separate tube cylinders may include a magnetic material. Accordingly, the plurality of separate tube cylinders can be magnetically held at the first magnet element 135 of the vapor distribution assembly 130 which may be a permanent magnetic plate. Further, the plurality of separate tube cylinders can be detached from the vapor distribution assembly 130 by a shield holder 184 that includes a first magnet device 189 for magnetically pulling the tube cylinders to the first shield holder 184, as is schematically depicted in FIG. 4B.

[0078] 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. The detached tube cylinders may be replaced with another shielding device. [0079] FIGS. 5A-5B show subsequent stages of an evaporation method according to embodiments described herein. The method essentially corresponds to the method of FIGS. 3A- 3C, such that reference can be made to the above explanations, which are not repeated here.

[0080] 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 to completely block the plumes of evaporated source material 15 emitted by the plurality of vapor nozzles. 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. [0081] As is schematically depicted in FIG. 5 A, each 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. The shutter device is magnetically held at the vapor distribution assembly 130.

[0082] 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 or rectangular recess in an elongated bar element.

[0083] 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 nozzle. 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.

[0084] The shutter device 302 is 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.

[0085] As is schematically depicted in FIG. 5B, the shutter device 302 may be detached from the vapor distribution assembly 130 with a shield holder 184 of a shield handling apparatus. For example, a first magnet device 189 of the shield holder 184 may detach the shielding device 120 from the vapor distribution assembly. Thereafter, the detached shutter device may be cleaned, e.g. in the vacuum chamber or outside the vacuum chamber after unloading from the vacuum chamber.

[0086] FIG. 6 shows a shielding device of an evaporation source 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. [0087] 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 plurality of vapor nozzles 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.

[0088] 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.

[0089] 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 the first magnet element 135, particularly by a permanent magnetic plate. Alternatively or additionally, at least one second magnet element, e.g. a permanent magnet or a ferromagnetic element, may be integrated in the shaping device 301.

[0090] The shaping device 301 may include an alignment opening 321. An alignment pin of the vapor distribution assembly may be inserted into the alignment opening 321 when the shaping device 301 is attached to the vapor distribution assembly (see also FIG. 3 A in this respect). Alternatively or additionally, the shaping device 301 may be provided with one or more alignment pins protruding from a side surface of the shaping device 301. The one or more alignment pins can be inserted into alignment openings provided at the vapor distribution assembly.

[0091] 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, i.e. at the shaping edge, may be 3 mm or more and 25 mm or less. The shaping apertures may have an annular base wall with an opening through which a vapor nozzle protrudes into the shaping aperture (see FIG. 3A in this respect).

[0092] FIG. 7 shows another shielding device of an evaporation source 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.

[0093] 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. A dimension of the elongated shaping aperture in the first direction V may be more than ten times a dimension of the elongated shaping aperture in the second direction L. In some implementations, the longitudinal dimension of the shaping device 301 may essentially correspond to the length of the distribution pipe in the first direction V.

[0094] The shaping device 301 can be attached to a vapor distribution assembly 130 having a plurality of vapor nozzles provided in a linear array, the linear array extending in the first direction V, such that the first side wall extends on a first side of the plurality of vapor nozzles and the second side wall extends on a second side of the plurality of vapor nozzles opposite the first side.

[0095] 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 nozzles in a second direction L perpendicular to the first direction V, particularly in the 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 or all vapor nozzles of the plurality of vapor nozzles in the second direction (L), particularly in the lateral direction. In this case, the vapor nozzles themselves may optionally 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 in combination with the shaping device 301 of FIG. 7.

[0096] According to some embodiments, which can be combined with other embodiments described herein, the plurality of vapor nozzles are shaping nozzles including a nozzle section configured to limit the vertical expansion of the emitted plumes of evaporated source material. Downstream of the shaping nozzles, the lateral expansion of the emitted plumes of evaporated source material may be limited by the shielding device. Accordingly, the plume expansion is limited in two dimensions, which reliably reduces the shadowing effect of the pixel mask during deposition. [0097] FIG. 10 shows a front view of an evaporation source 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 nozzles 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. 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. [0098] A shielding device as described herein 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 that is detachably held thereon, particularly magnetically held thereon.

[0099] 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. [00100] The shielding devices can be replaced with other shielding devices, e.g. in regular intervals for cleaning. 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.

[00101] FIG. 8 shows another shielding device of an evaporation source 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 plurality of vapor nozzles of a vapor distribution assembly.

[00102] 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. For example, 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.

[00103] The shutter device 302 may include a second magnet element or may be made of a magnetic material, such that the shutter device 302 can be magnetically held at the vapor distribution assembly. [00104] FIG. 9 shows another shielding device of an evaporation source 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. [00105] 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 L.

[00106] FIG. 11 is a flow diagram for illustrating an evaporation method according to embodiments described herein.

[00107] In box 620, the evaporation method includes: magnetically holding a shielding device at a vapor distribution assembly of an evaporation source in a vacuum chamber. Evaporated source material is emitted from a plurality of vapor nozzles of the vapor distribution assembly, wherein at least a part of the evaporated source material is blocked by the shielding device.

[00108] In optional box 610, the shielding device is attached at the vapor distribution assembly. Attaching may include moving the shielding device held at a shield handling apparatus toward the vapor distribution assembly until the shielding device is attracted by a first magnet element of the vapor distribution assembly. The shielding device may then be released by the shield handling apparatus, e.g. by switching an electropermanent magnet to a release state.

[00109] Attaching may include inserting an alignment pin of one of the vapor distribution assembly and the shielding device into an alignment recess of the other one of the vapor distribution assembly and the shielding device.

[00110] In optional box 630, the shielding device may be detached from the vapor distribution assembly, e.g. after a predetermined operation time of the evaporation source for cleaning or exchange of the used shielding device. Detaching may include moving a shield holder of a shield handling apparatus to the shielding device and switching a first magnet device of the first shield holder to a holding state. The shielding device can then be pulled away from the vapor distribution assembly. [00111] The detached shielding device may be cleaned in the vacuum chamber. Alternatively, the detached shielding device may be unloaded from the vacuum chamber, e.g. for cleaning.

[00112] The detached shielding device may be replaced by a second shielding device. The second shielding device may be attached to the vapor distribution assembly and may then be magnetically held at the vapor distribution assembly. The second shielding device may be attached to the vapor distribution assembly by a second shield holder of the shield handling apparatus.

[00113] FIG. 12 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 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. The evaporation source further includes a shielding device 120 for at least partially blocking the evaporated source material emitted from the plurality of vapor nozzles, the shielding device being magnetically held at the vapor distribution assembly.

[00114] The shield handling apparatus 180 is configured for detaching the shielding device 120 from the vapor distribution assembly. The shield handling apparatus may further be configured for attaching a second shielding device 121 at the vapor distribution assembly and/or for transporting the detached shielding device into a cleaning region for cleaning.

[00115] The evaporation source 100 may include two, three or more crucibles and vapor distribution pipes that are supported on a common source support. The common support may be movable past a substrate 10 in the vacuum chamber. A shielding device 120 may be magnetically held at each of the vapor distribution pipes and be configured to partially block the plumes of evaporated source material emitted by the plurality of vapor nozzles of the respective vapor distribution pipe. An evaporation source with three vapor distribution pipes arranged adjacent to each other and three shielding devices is schematically depicted in FIG. 10 in a front view. [00116] As is schematically depicted in FIG. 12, 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 plurality of vapor nozzles 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.

[00117] In some embodiments, a shielding wall 150 may be provided in the vacuum chamber 11 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 may optionally be supported on the same movable support as the vapor distribution pipes and may move together with the evaporation source past the substrate.

[00118] The shield handling apparatus 180 may be configured for exchanging shielding devices of the evaporation source and may include 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.

[00119] 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 and of the other shield holders is not restricted to a magnetic holder and another type of holder may be provided. [00120] A shield holder configured for magnetically holding the first shielding 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 that is switchable between a holding state for holding a shielding device and a release state for releasing a shielding device. The second shield holder and further shield holders of the shield holding device 182 may be configured in a corresponding way.

[00121] 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 184 is directed toward the vapor distribution assembly to a second rotation position in which the first shield holder 184 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 into the cleaning region of the vacuum chamber is possible.

[00122] 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 m². 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 m² substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m² substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7 m² substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m² substrates (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can similarly be implemented. Alternatively or additionally, semiconductor wafers may be processed and coated in the evaporation system.

[00123] 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.

Claims

1. An evaporation source (100), comprising: a vapor distribution assembly (130) with a plurality of vapor nozzles (131) for directing an evaporated source material (15) toward a substrate (10); and a shielding device (120) for at least partially blocking the evaporated source material (15) emitted from the plurality of vapor nozzles, the shielding device being magnetically held at the vapor distribution assembly.

2. The evaporation source of claim 1, wherein the vapor distribution assembly (120) comprises a vapor distribution pipe (132) with a front wall (133) through which the plurality of vapor nozzles extend, particularly wherein the vapor distribution pipe extends in an essentially vertical direction and the plurality of vapor nozzles are arranged in a linear array one above the other.

3. The evaporation source of claim 2, further comprising a first magnet element (135) provided in front of the front wall (133) and configured to magnetically hold the shielding device (120) at the vapor distribution assembly (120).

4. The evaporation source of claim 3, wherein the first magnet element (135) comprises a permanent magnetic plate, particularly an AlNiCo plate or a FeNb plate, held spaced-apart from the front wall (133) of the vapor distribution pipe.

5. The evaporation source of any of claims 2 to 4, further comprising an isolation plate (134) made of a thermally isolating material arranged in front of the front wall (133), particularly between the front wall (133) and the shielding device (120).

6. The evaporation source of any of claims 1 to 5, wherein the plurality of vapor nozzles (131) protrude at least partially into the shielding device (120).

7. The evaporation source of any of claims 1 to 6, wherein a second magnet element (125) is integrated in the shielding device (120) or wherein the shielding device (120) comprises a magnetic material, particularly a ferromagnetic material, more particularly nickel or Invar.

8. The evaporation source of any of claims 1 to 7, wherein the shielding device is a shutter device (302) configured to completely block the evaporated source material emitted from the plurality of vapor nozzles.

9. The evaporation source of any of claims 1 to 7, wherein the shielding device is a shaping device configured to block a part of the evaporated source material emitted from the plurality of vapor nozzles having an emission angle greater than a predetermined maximum emission angle.

10. The evaporation source of claim 9, wherein the shielding device comprises a plurality of shaping apertures (310) respectively configured to individually shape a plume of evaporated source material emitted from one associated vapor nozzle of the plurality of vapor nozzles.

11. The evaporation source of claim 9 or 10, wherein the plurality of vapor nozzles (131) is provided in a linear array, particularly one above the other in a vertical array of nozzles, and the shielding device comprises a plurality of shaping apertures in a linear array.

12. The evaporation source of claim 9 or 10, wherein the plurality of vapor nozzles is provided in a linear array extending in a first direction (V), and the shielding device comprises a first side wall extending in the first direction (V) and a second side wall extending parallel to the first side wall in the first direction (V), wherein an elongated shaping aperture (312) is formed between the first side wall and the second side wall for limiting an expansion of the plumes of evaporated source material emitted by several or all vapor nozzles of the plurality of vapor nozzles in a second direction different from the first direction.

13. The evaporation source of any of claims 1 to 11, wherein the shielding device is provided as an elongated bar element with a plurality of cylindrical shaping apertures or blind holes provided therein.

14. The evaporation source of claim 9, wherein the shielding device comprises a plurality of separate shielding units, particularly tube cylinders, each shielding unit magnetically held at a permanent magnetic plate fixed at the vapor distribution assembly.

15. The evaporation source of any of claims 1 to 14, wherein one of the vapor distribution assembly and the shielding device comprises an alignment opening (321) and the other one of the vapor distribution assembly and the shielding device comprises an alignment pin (322) protruding into the alignment opening.

16. An evaporation system (200), comprising: a vacuum chamber (11); an evaporation source (100) arranged in the vacuum chamber, comprising: a vapor distribution assembly (130) with a plurality of vapor nozzles (131) for directing an evaporated source material toward a substrate (10); and a shielding device (120) for at least partially blocking the evaporated source material emitted from the plurality of vapor nozzles, the shielding device (120) being magnetically held at the vapor distribution assembly (130); and a shield handling apparatus (180) for detaching the shielding device (120) from the vapor distribution assembly (130).

17. The evaporation system of claim 16, wherein the shield handling apparatus (180) includes a shield holder (182) with a first magnet device (189) for magnetically holding the shielding device at the shield holder, particularly wherein the first magnet device includes an electropermanent magnet.

18. An evaporation method, comprising: magnetically holding a shielding device (120) at a vapor distribution assembly (130) of an evaporation source in a vacuum chamber, the vapor distribution assembly comprising a plurality of vapor nozzles; and emitting an evaporated source material (15) from the plurality of vapor nozzles, wherein at least a part of the evaporated source material is blocked by the shielding device.

19. The evaporation method of claim 18, further comprising attaching the shielding device at the vapor distribution assembly, the attaching comprising: moving the shielding device (120) held by a shield handling apparatus (180) toward the vapor distribution assembly (130) until the shielding device is attracted by a first magnet element (135) of the vapor distribution assembly (130); and releasing the shielding device (120) from the shield handling apparatus (180).

20. The evaporation method of claim 18 or 19, further comprising: detaching the shielding device (120) from the vapor distribution assembly (130); and cleaning the shielding device.