Evaporation source arrangement, vacuum deposition system, and method of coating a substrate

Abstract

An evaporation source arrangement for coating a substrate is described. The evaporation source arrangement includes an evaporation source (101) with a first vapor distribution pipe (110) with a first row of nozzles (111) for depositing a first material on the substrate; a rotation drive (113) for rotating the evaporation source around a rotation axis (R1); and a shield arrangement (200) that partially surrounds the evaporation source and includes an idle shield (202) and a shaper shield (201). The rotation drive is configured to rotate the evaporation source relative to the shield arrangement between an idle position, in which the first row of nozzles is directed toward the idle shield (202), and a first deposition position, in which the first row of nozzles is aligned with a first slit (211) provided in the shaper shield (201), the first slit (211) configured to limit a first opening angle (β1) of vapor plumes emitted by the first row of nozzles. Further described are a vacuum deposition system and methods of coating a substrate.

Description

EVAPORATION SOURCE ARRANGEMENT, VACUUM DEPOSITION SYSTEM, AND METHOD OF COATING A SUBSTRATETECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to methods and apparatuses for coating substrates with a stack of layers. More particularly, embodiments of the present disclosure relate to evaporation source arrangements and vacuum deposition systems for depositing layers of an OLED layer stack on a substrate, particularly on an essentially vertically oriented substrate. For example, inorganic layers, such as metal layer(s), and / or organic layer(s) of an OLED layer stack can be deposited on a substrate. Embodiments of the present disclosure specifically relate to evaporation source arrangements and vacuum deposition systems, as well as to methods of OLED display manufacturing by thermal evaporation.BACKGROUND

[0002] An organic light-emitting diode (OLED) is a light-emitting diode in which an electroluminescent layer is a film of organic compounds that emits light in response to an electric current. Since OLEDs emit light directly without involving backlight and color filters, the color gamut and viewing angles possible with OLED displays are greater as compared to traditional LCD displays. Further, OLEDs can be manufactured on flexible substrates, and accordingly, they can be utilized in a variety of applications. OLEDs are used in the manufacture of television screens, computer monitors, mobile phones, other hand-held devices, etc., for displaying information. OLEDs can also be used for general space illumination. An OLED display, for example, may include layers 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.

[0003] Organic materials and metallic materials are deposited on a substrate in a vacuum processing chamber for OLED manufacturing. Metallic materials are employed as, for example, electrode materials or electron injection layer (EIL) materials. The materials to be deposited are evaporated with evaporation sources, and the evaporated materials are directed on a substrate by nozzles. Metallic materials are typically evaporated in an evaporation source at a temperature of 1 ,000°C or above, or 1 ,500°C or above. Organic materials are typically evaporated in an evaporation source arrangement at temperatures between 250°C and 500°C.

[0004] Metallic and organic evaporators can be used for the production of organic light-emitting diodes (OLED). Also other applications utilize evaporators for depositing metal or organic layers, for example, on large area substrates. An OLED display, for example, may include a plurality of layers of organic material situated between two electrodes that are deposited on a substrate. One of the electrodes can include a transparent conductive layer such as ITO or other transparent conductive oxide materials (TOO). The second electrode can include a metal or a metal alloy.

[0005] OLED pixels can be deposited on a substrate through fine metal masks FMMs (also referred to as pixel masks) that have a plurality of small pixel holes that define individual pixel areas on the substrate. A precise alignment between the FMM and the substrate is necessary for the pixel deposition, which is challenging, since each of the small pixels includes a plurality of layers that are to be deposited on top of each other on a respective anode.

[0006] Another technique for forming OLED pixels on a substrate uses photo lithography to pattern pixels instead of fine metal masks (FMMs). Here, a structure that acts as a masking layer is formed directly on the substrate before the actual pixel deposition. Alignment issues can be reduced. However, quickly and reliably coating a substrate with an OLED layer stack without FMMs requires complex equipment and is also challenging.

[0007] In view of the above, it would be beneficial to provide methods of quickly and reliably coating a substrate with an OLED layer stack, particularly without a use of fine metal masks (FMMs). Further, improved evaporation source arrangements, vacuum deposition systems, and device manufacturing methods adapted for OLEDmanufacturing would be beneficial.SUMMARY

[0008] In light of the above, evaporation source arrangements, vacuum deposition systems, and methods of coating a substrate in a vacuum chamber are provided according to the independent claims. Further aspects, benefits, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings.

[0009] According to an aspect, an evaporation source arrangement for coating a substrate is provided. The evaporation source arrangement includes an evaporation source with a first vapor distribution pipe with a first row of nozzles for depositing a first material on the substrate; a rotation drive for rotating the evaporation source around a rotation axis; and a shield arrangement that partially surrounds the evaporation source and includes an idle shield and a shaper shield. The rotation drive is configured to rotate the evaporation source relative to the shield arrangement between an idle position, in which the first row of nozzles is directed toward the idle shield, and a first deposition position, in which the first row of nozzles is aligned with an essentially vertically oriented first slit provided in the shaper shield. The first slit is configured to limit the opening angle of the vapor plumes emitted by the first row of nozzles.

[0010] In some embodiments, the first vapor distribution pipe and optional further vapor distribution pipes of the evaporation source extend in an essentially vertical orientation and are configured to coat substrates having an essentially vertical orientation that are moved past the evaporation source on a substrate transport path. In particular, a large-area substrate having a surface area of 1 m2or more can be coated in an essentially vertical orientation.

[0011] According to another aspect, a vacuum deposition system is provided. The vacuum deposition system includes a first vacuum chamber and an evaporation source arrangement according to any of the embodiments described herein.

[0012] The vacuum deposition system may include a substrate transportation track configured to move a substrate along a substrate transport path past the evaporationsource arrangement; and optionally a shield transportation track between the substrate transportation track and the evaporation source arrangement and configured to move a movable shield in front of the substrate for shielding an edge region of the substrate and / or for shielding a substrate carrier. The substrate transportation track may be configured to move substrates having an essentially vertical orientation past the evaporation source arrangement.

[0013] According to another aspect, a method of coating a substrate in a vacuum chamber with an evaporation source arrangement is provided. The evaporation source arrangement includes an evaporation source having a first vapor distribution pipe with a first row of nozzles and a shield arrangement that partially surrounds the evaporation source and includes an idle shield and a shaper shield. The method includes: rotating the evaporation source around a rotation axis relative to the shield arrangement from an idle position to a first deposition position, wherein, in the idle position, the first row of nozzles is directed toward the idle shield and, in the first deposition position, the first row of nozzles is aligned with an essentially vertically oriented first slit provided in the shaper shield. The method further includes transporting the substrate past the evaporation source in the first deposition position, while directing a first material toward the substrate from the first row of nozzles, the first slit limiting a first opening angle of vapor plumes emitted by the first row of nozzles.

[0014] In particular, the first slit may be at least as long or longer as the first row of nozzles in an essentially vertical direction, so that the vapor plumes of (all) the nozzles of the first row of nozzles are shaped by the shaper shield having the first slit formed therein.

[0015] The shaper shield may be connected to the idle shield, particularly integrated with the idle shield, to form a continuous shielding wall that partially surrounds the evaporation source.

[0016] Optionally, the evaporation source includes at least a second vapor distribution pipe with a second row of nozzles. In the first deposition position, the second row of nozzles is aligned with the essentially vertically oriented first slit or with an essentially vertically oriented second slit, that is provided in the shaper shield. The first slit or the second slit limit a second opening angle of vapor plumes emitted by thesecond row of nozzles. In particular, the first slit and the second slit are at least as long or longer as the first row of nozzles and the second row of nozzles, so that (all) the vapor plumes emitted by the first and second rows of nozzles are shaped by the slit(s).

[0017] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. The 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 are also directed at methods for operating the described apparatus. The methods for operating the described apparatuses include method aspects for carrying out every function of the apparatus. Embodiments are also directed at methods of manufacturing processed substrates, particularly coated substrates, in a vacuum deposition system described herein and substrates manufactured in accordance with the methods and / or using the systems described herein, such as OLED substrates, particularly, OLED displays. Also other devices than OLED displays can be manufactured with the apparatuses and methods described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

[0019] FIG. 1 shows a schematic view of a vacuum deposition system with several evaporation source arrangements according to embodiments;

[0020] FIG. 2 shows a schematic view of an evaporation source arrangement according to embodiments;

[0021] FIG. 3 shows a schematic view of an evaporation source arrangement according to embodiments in a first deposition position in a horizontal sectional plane;

[0022] FIG. 4 shows the evaporation source arrangement of FIG. 3 in an idle position;

[0023] FIG. 5 is a schematic view of an evaporation source arrangement according to embodiments in a horizontal sectional plane;

[0024] FIG. 6 is a schematic perspective view of an evaporation source arrangement according to embodiments;

[0025] FIG. 7 is a flow chart for illustrating a coating method according to embodiments; and

[0026] FIG. 8 is a schematic sectional view of a substrate with an OLED layer stack manufactured according to methods of the present disclosure.DETAILED DESCRIPTION

[0027] Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on, or in conjunction with, any other embodiment to yield yet a further embodiment. It is intended that the present disclosure includes such modifications and variations.

[0028] Within the following description of the drawings, the same reference numbers refer to the same or to similar components. Generally, only the differences with respect to the individual embodiments are described. Unless specified otherwise, the description of a part or aspect in one embodiment can also apply to a corresponding part or aspect in another embodiment.

[0029] OLED pixels can be formed on a substrate using photo lithography and patterning, particularly without a fine metal mask (FMM). An FMM has a plurality of pixel holes and is positioned in front of the substrate and aligned relative to the substrate before the material deposition. OLED pixel patterning without FMMs is based on a structure that acts as a masking layer and is formed directly on the substrate before coating the substrate with a plurality of materials in a vacuum deposition system.The structure that is formed on the substrate may include sidewalls adjacent to pixel regions, particularly sidewalls surrounding the pixel regions, and overhang structures projecting from the sidewalls at least partially over the pixel regions, as is depicted exemplarily in FIG. 8.

[0030] FIG. 8 is a schematic sectional view of a part of an OLED layer stack 760 on a substrate 10 manufactured with OLED pixel patterning techniques. Adjacent pixeldefining layer (PDL) structures 715 are formed on an upper surface of the substrate 10 that define pixel regions, and overhang structures 720 are disposed on an upper surface of the PDL structures 715. The overhang structures 720 include a lower portion 720B with a sidewall and an upper portion 720A with an overhang protruding from the lower portion 720B partially over the pixel region 13. In FIG. 8, a first sidewall 11 adjacent to a pixel region 13 is schematically depicted, and a first overhang 12 projects from the first sidewall 11 partially over the pixel region 13. As will be appreciated, the pixel region 13 may be surrounded by two or more sidewalls, e.g. on opposite sides, and overhangs may be formed on the two or more sidewalls and project partially over the pixel region from different sides.

[0031] By depositing various materials on the pixel regions to defined positions under the overhangs, in combination with subsequent etching / patterning, individually switchable pixels can be formed on the substrate. However, the deposition of metals and organic layers to predetermined extents, particularly under overhangs, is challenging.

[0032] The lower portion 720B with the first sidewall 11 may be made of a conductive material that is intended to be in contact with a cathode layer 711 of the OLED layer stack 760 and allows a connection of the cathode layer 711 with a cathode potential. Alternatively or additionally, at least a part of the first sidewall 11 may include an assistant cathode 716 that is intended to be in contact with a cathode layer 711 of the OLED layer stack. The upper portion 720A with the overhang may be made of a non-conductive inorganic material or alternatively of a conductive inorganic material.

[0033] The OLED layer stack 760 generally includes an anode layer 714, an optional hole injection layer H IL 718, at least one organic layer 713 (made of one ormore optically active organic materials), an optional electron injection layer EIL 712, the cathode layer 711 , and at least one encapsulation layer 710.

[0034] As is shown in FIG. 8, the at least one organic layer 713 does not contact the first sidewall 11 , but the cathode layer 711 does contact the first sidewall 11 under the first overhang 12. For ensuring the at least one organic layer 713 does not substantively contact the first sidewall 11 under the first overhang, the at least one organic layer 713 may be deposited with an organic vapor plume 732 having a specific opening angle. For ensuring the cathode layer 711 reliably contacts the first sidewall 11 under the overhang, the cathode layer may be deposited with a metal vapor plume 731 having a specific opening angle. However, vapor plumes with large opening angles may not always be beneficial, for example, because a vapor plume with a large opening angle causes a substantial shadowing effect in different directions that may lead to stray coating of regions in the deposition system and of the substrate that should not be coated.

[0035] In view of the above, according to embodiments described herein, methods and apparatuses are described that allow a reliable deposition of OLED layer stacks on substrates, particularly on substrates with overhang structures formed thereon - without any limitation to such substrates. For example, methods described herein may ensure or improve an electrical contact of a cathode layer with a conductive sidewall under an overhang, and / or may reduce or prevent a contact of an organic layer with a conductive sidewall under an overhang. A contact between the organic layer and the conductive sidewall can degrade the contact and can increase the contact resistance between the cathode layer (that is deposited above the organic layer) and the conductive sidewall. A low contact resistance between the cathode layer and the conductive sidewall is beneficial, e.g., in order to reduce or prevent an influence on the l-V-curve of the manufactured OLED device.

[0036] As will be appreciated, the apparatuses and methods described herein can also be used for other applications, e.g., for forming pixels using fine metal masks or for manufacturing other layer stacks or for coating other types of substrates. Embodiments described herein generally relate to the coating of substrates having anessentially vertical orientation with one or more layers using an evaporation source with one or more essentially vertically oriented vapor distribution pipes.

[0037] FIG. 1 shows a vacuum deposition system 1000 with an evaporation source arrangement 100 according to embodiments described herein in a schematic top view. The vacuum deposition system 1000 includes a first vacuum chamber 1001 that houses an evaporation source 101 , and optionally one or more further vacuum chambers that may house one or more further evaporation sources, e.g., a second evaporation source 102 and / or a third evaporation source 103. The evaporation sources may be configured to coat vertically or essentially vertically oriented substrates that are transported past the evaporation sources on a substrate transportation track 1013. A plurality of materials, that may include one or more metals and / or one or more organic materials, can be deposited in succession onto the substrate in order to provide a layer stack on the substrate, e.g., an OLED layer stack. For example, the vacuum deposition system 1000 may include ten or more evaporation sources for coating the substrate with a plurality of layers.

[0038] In the present disclosure, a "vacuum deposition system" is to be understood as a system or arrangement configured for vacuum deposition of materials on a substrate. A "vacuum chamber" or “vacuum processing chamber” is to be understood as a chamber configured for vacuum deposition. The term "vacuum", as used herein, can be understood in the sense of a technical vacuum having a vacuum pressure of less than, for example, 10 mbar. Typically, the pressure in a vacuum chamber as described herein may be between 10-5 mbar and approximately 10-8 mbar, particularly between 10-5 mbar and 10-7 mbar.

[0039] The vacuum deposition system 1000 may include a substrate transportation track 1013 configured to move a substrate 10 along a substrate transport path T past the evaporation source 101 and past the optional further evaporation sources. The substrate transportation track 1013 may extend at least partially through the first vacuum chamber 1001 and through the optional further vacuum chambers and may include a substrate transportation system configured for substrate transport, e.g., a roller transportation system, one or more linear motors and / or a magnetic levitation system suitable for moving the substrate relative to and past the evaporation sources.The substrate may be carried by a substrate carrier 1020 during the transport and / or deposition.

[0040] The vacuum deposition system 1000 optionally further includes a shield transportation track 1012 extending between the substrate transportation track 1013 and the evaporation source 101 in the first vacuum chamber 1001. The shield transportation track 1012 is configured to move a movable shield 1030 in front of the substrate 10 for shielding one or more edge regions of the substrate 10 and / or for shielding at least parts of a substrate carrier 1020 that carries the substrate 10. The movable shield 1030 may be a movable edge exclusion shield with a shielding frame for covering one or more edge regions of the substrate. The shield transportation track 1012 may be located between the substrate transportation track 1013 and the evaporation source 101 in the first vacuum chamber 1001 and may include a shield transportation system, e.g., a roller transportation system, one or more linear motors and / or a magnetic levitation system suitable to move the movable shield 1030 in front of the substrate 10, such that one or more edge regions of the substrate are covered during coating with the evaporation source 101 , as is schematically depicted in FIG. 1 .

[0041] The movable shield 1030 may be movable back and forth on the shield transportation track 1012, as is schematically indicated by respective arrows in FIG. 1 , such that subsequent substrates moved along the substrate transport path T can be shielded by the movable shield 1030 during coating with the evaporation source 101. Each evaporation source may have an associated movable shield that is movable back and forth on a respective shield transportation track, for shielding an edge region of the substrate from being coated when the substrate is moved past the respective evaporation source.

[0042] Accordingly, an in-line system is provided that allows the deposition of a plurality of layers on a substrate in succession, while the substrate is moved past a plurality of evaporation sources through the vacuum deposition system 1000.

[0043] Embodiments described herein particularly relate to deposition of materials, e.g. for display manufacturing on large area substrates. According to some embodiments, large area substrates or substrate carriers supporting one or more substrates may have a size of 0.5 m2or larger, particularly of 1 m2or larger. Forinstance, the deposition system may be adapted for processing large area substrates, such as substrates of GEN 4.5, which corresponds to about 0.67 m2of substrate (0.73 m x 0.92 m), GEN 5, which corresponds to approximately 1 .4 m2(1 .1 m x 1 .3 m), GEN 6, which corresponds to approximately 2.7 m2(1.5 m x about 1.8 m), GEN 7.5, which corresponds to approximately 4.29 m2(1.95 m x 2.2 m), GEN 8.5, which corresponds to approximately 5.7 m2(2.2 m x 2.5 m), or even GEN 10, which corresponds to approximately 8.7 m2(2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can be implemented. According to yet further implementations, half sizes of the above-mentioned substrate generations can be processed. Alternatively or additionally, semiconductor wafers may be processed and coated in deposition systems according to the present disclosure.

[0044] FIG. 2 shows an evaporation source arrangement 100 according to embodiments described herein in further detail. In the present disclosure, an "evaporation source arrangement" is to be understood as an arrangement configured for material deposition by evaporation on a substrate. The evaporation source arrangement 100 includes an evaporation source with one or more crucibles 112 configured to evaporate one or more source materials and with one or more vapor distribution pipes 110 configured for directing the evaporated material(s) towards the substrate through a plurality of nozzles. Each vapor distribution pipe is in fluid connection with a respective crucible so that an evaporation source with several vapor distribution pipes can direct (same or different) source materials evaporated in several crucibles onto the substrate.

[0045] For instance, a vapor distribution tube or vapor distribution pipe may provide a line source with a plurality of nozzles that are arranged in a row (or “line array”), one above the other along a longitudinal direction of the vapor distribution pipe. The row of nozzles may be provided along a longitudinal direction (an essentially vertical direction) of the vapor distribution pipe to provide an essentially vertical line source. Each vapor distribution pipe typically has one single row of nozzles, particularly one single vertical nozzle row suitable to coat substrates in an essentially vertical orientation.

[0046] An “essentially vertical direction” as used herein relates to a direction that corresponds to the direction of gravity or deviates from the direction of gravity by lessthan 10°. In particular, the substrate 10 and the vapor distribution pipe(s) may be slightly inclined relative to an (exactly) vertical direction during the coating, e.g., both the substrate and the vapor distribution pipe(s) by an angle of 2° or more and 8° or less, e.g., about 3°. Therein, the longitudinal direction of the vapor distribution pipe(s) may be parallel to the substrate surface. Specifically, a slight “inclination downward” of the substrate surface during the material deposition can improve the layer quality.

[0047] In some embodiments, the evaporation source is configured to coat the substrate with one or more inorganic materials, particularly metals, of an OLED layer stack. In other embodiments, the evaporation source is configured to coat the substrate with one or more organic materials of an OLED layer stack. In some embodiments, a first evaporation source arrangement as described herein coats the substrate with one or more organic materials and a second evaporation source arrangement as described herein subsequently coats the substrate with one or more inorganic materials, particularly metals. The source material to be deposited may be an inorganic, particularly a metallic material for use as an electrode material or an electron injection layer material in an OLED layer stack, or the source material may be an organic material for organic light emitting diode (OLED) production.

[0048] As is schematically depicted in FIG. 2, the evaporation source arrangement 100 includes an evaporation source 101 with a first vapor distribution pipe 110. Further vapor distribution pipes of the evaporation source are not shown in FIG. 2, but may optionally be present (see, e.g., FIG. 3, showing an evaporation source with three vapor distribution pipes arranged next to each other at a front side of the evaporation source). The first vapor distribution pipe 110 has a first row of nozzles 111 provided along the longitudinal direction of the first vapor distribution pipe 110. The nozzles of the row may be arranged above one another in an essentially vertical line array. The evaporation source may be a line source for coating substrates in an essentially vertical orientation. The evaporation source 101 may be configured to deposit one or more materials onto the substrate with one or more vapor distribution pipes arranged adjacent to each other, each vapor distribution pipe connected to a crucible.

[0049] The first row of nozzles 111 includes a plurality of nozzles, particularly twenty or more nozzles. Each nozzle has a main evaporation direction. A “mainevaporation direction” of a nozzle can be understood as a direction that is defined by the nozzle channel and the nozzle opening of the nozzle (typically corresponding to the direction of the nozzle channel, i.e., to the nozzle axis). Generally, a cone-shaped vapor plume emitted by a nozzle is centered around the main evaporation direction of the nozzle, e.g., with a maximum of vapor particles of the plume propagating along the main evaporation direction. Specifically, a vapor plume emitted by a nozzle or impinging on a substrate is defined by a main evaporation direction and by an opening angle of the plume.

[0050] A vapor plume can be rotationally symmetrical with respect to the main evaporation direction, and / or a vapor plume can be shaped with one or more shaper shields 201 to be symmetrical, or to be asymmetrical relative to the main evaporation direction and relative to the nozzle axis.

[0051] If the nozzle channels of the nozzles of the first row are essentially parallel to each other, the nozzles of the first row have a corresponding first main evaporation direction relative to the substrate surface. Parallel vapor plumes propagating in the first main evaporation direction M1 are schematically depicted in FIG. 2. Accordingly, the first row of nozzles is characterized by a (common) main evaporation direction of the nozzles. For example, the first row of nozzles 111 of FIG. 2 has the first main evaporation direction M1. Other rows of nozzles described herein are defined by a respective main evaporation direction that is common among the nozzles of the respective row (see reference numerals M1 and M2 in FIG. 3). Each vapor evaporation pipe typically has one single row of nozzles.

[0052] The evaporation source arrangement 100 includes a rotation drive 113 for rotating the evaporation source 101 around a rotation axis R1 , particularly around an essentially vertical rotation axis. A controller 114 may be provided for controlling and / or triggering rotational movements of the evaporation source 101 with the rotation drive 113 to different rotational positions. The evaporation source can be rotated with the rotation drive 113 at least between a deposition position for coating the substrate and an “idle position”, in which the first row of nozzles is directed toward a shutter wall, herein referred to as an “idle shield 202” that is provided inside the vacuum chamber and partially surrounds the evaporation source. The evaporation source can be rotatedto the idle position in idle times of the deposition system, for example, when no substrate to be coated is arranged in front of the evaporation source.

[0053] The evaporation source arrangement 100 includes a shield arrangement 200 that partially surrounds the evaporation source and includes the idle shield 202. In the idle position of the evaporation source, the first row of nozzles 111 is directed toward the idle shield 202 so that the first material emitted by the first row of nozzles is directed onto an inner shielding surface of the idle shield, that acts as a shutter wall and accumulates thereon (see FIG. 4). An undesired material deposition on other surfaces inside the vacuum chamber, such as chamber walls, during idle times of the deposition system can be reduced or prevented.

[0054] However, if a conventional shutter is used for shielding, there may still be a risk of a material accumulation on various surfaces in the vacuum chamber or on chamber walls during a rotation of the evaporation source between different rotational positions. Further, in conventional systems, shields used to shape or limit the opening angles of the vapor plumes are typically mounted at the evaporation source, which reduces the flexibility in adjusting the opening angles of the vapor plumes and increases the cleaning requirements, and - in addition - the substrate-to-nozzle distance may be larger, resulting in a larger process chamber size.

[0055] In view of the above, the embodiments of the present disclosure reduce an undesired stray coating on surfaces in the vacuum chamber during a source rotation and provide a simple and effective way of adapting the opening angles of vapor plumes emitted by nozzles of one or more nozzle rows.

[0056] The shield arrangement 200 of the embodiments described herein includes the idle shield 202 and additionally a shaper shield 201 that is connected to the idle shield 202, particularly integrated with the idle shield 202 to form a continuous shielding surface that partially surrounds the evaporation source. The rotation drive 113 is configured to rotate the evaporation source relative to both the idle shield 202 and the shaper shield 201. In other words, the shaper shield 201 is not mounted at the evaporation source to be rotatable with the evaporation source, but is connected to the idle shield 202 to form the shield arrangement 200 that is stationary with respect to the rotation of the evaporation source. The shaper shield 201 includes (at least) anessentially vertically oriented first slit 211. In the first deposition position that is shown in FIG. 2 and in FIG. 3, the first row of nozzles 111 is aligned with the first slit 211 provided in the shaper shield 201 , so that the first slit 211 limits the first opening angle of the vapor plumes emitted by the first row of nozzles.

[0057] In other words, the nozzles of the first row of nozzles are arranged in alignment with the first slit in the first deposition position. “Aligned with the first slit” refers to a position of the first row of nozzles that allows at least a part of the vapor plumes emitted by the nozzles of the first row of nozzles to propagate through the first slit toward the substrate, while another part of the vapor plumes is blocked by the shaper shield. In particular, vapor particles of the vapor plumes close to the main evaporation direction can propagate through the first slit while vapor particles of the vapor plumes horizontally distant from the main evaporation direction may be blocked by the shaper shield.

[0058] By providing a continuous shield arrangement or shielding wall that includes the idle shield 202 connected with the shaper shield 201 and that partially surrounds the evaporation source 101 , the first material emitted by the first row of nozzles 111 can be blocked by the shield arrangement 200 not only in the idle position, but also during a source rotation between the idle position and the first deposition position, substantially until the evaporation source is arranged in the first deposition position. In particular, even during a source rotation, the first material can escape from the shield arrangement 200 (only) through the first slit or through further slits in the shaper shield for propagating toward the substrate. An undesired coating on chamber walls can be reduced or prevented. In particular, the first material emitted by the first row of nozzles is either directed onto the inner shielding surface of the shield arrangement 200 to accumulate thereon or is directed through one or more slits in the shaper shield onto the substrate or onto the movable shield 1030 that can move together with the substrate past the evaporation source and can act as an edge exclusion shield (see FIG. 1 ), even during a rotation of the evaporation source.

[0059] The shaper shield 201 of the shield arrangement 200 is configured to shape the vapor plumes emitted by the first row of nozzles 111 , the first slit 211 (i.e. , opposing wall edges of the shaper shield that form the first slit) limiting the vapor plumes emittedby the first row of nozzles when the first row of nozzles is aligned with the first slit. A “shaping” of a vapor plume refers to a blocking of a part of the vapor plume, i.e. , a limitation of the opening angle of the vapor plumes on (at least) one side of the vapor plumes. In particular, since the first slit is essentially vertically oriented, the opening angle of the vapor plumes of the nozzles of a row can be restricted on one horizontal side or on two opposite horizontal sides of the respective main evaporation direction. In particular, the slit width and the slit shape may be adapted to shape the vapor plumes of all the nozzles of the first row of nozzles in an essentially corresponding way.

[0060] Accordingly, with the evaporation source arrangement described herein, cleaning efforts can be reduced and the vapor plumes emitted by the first row of nozzles can be shaped and limited with the shaper shield as appropriate, e.g., for avoiding shadowing effects in various directions and / or for increasing or decreasing a deposition under overhangs relative to a deposition on uncovered substrate regions, as is explained in further detail below.

[0061] FIG. 3 is a schematic view of an evaporation source arrangement 100 with an evaporation source 101 according to embodiments described herein in a horizontal sectional plane. The evaporation source 101 includes the first vapor distribution pipe 110 with the first row of nozzles 111 that have a first main evaporation direction M1 for depositing a first material onto the substrate, an optional second vapor distribution pipe 120 with a second row of nozzles 121 for depositing a second material onto the substrate, and an optional third vapor distribution pipe 130 with a third row of nozzles 131 for depositing a third material onto the substrate. The vapor distribution pipes are mounted adjacent to each other on a rotatable source body 301 that can be rotated around the rotation axis R1 with the rotation drive (not shown in FIG. 3).

[0062] The evaporation source arrangement 100 further includes the shield arrangement 200 that partially surrounds the evaporation source 101 , wherein the shield arrangement 200 includes the shaper shield 201 and the idle shield 202. In the first deposition position shown in FIG. 3, the first row of nozzles 111 is aligned with the first slit 211 that is provided in the shaper shield 201 , so that the first slit 211 limits the first opening angle ([31 ) of the vapor plumes emitted by the nozzles of the first row ofnozzles.

[0063] FIG. 4 shows the evaporation source 101 of FIG. 3 after rotation to the idle position around the rotation axis R1 , e.g., by an angle of 30° or more and 180° or less, particularly 60° or more and 120° or less. In the idle position, the first row of nozzles 111 of the first vapor distribution pipe 110 (and the optional further rows of nozzles of the optional further vapor distribution pipes) is directed to the idle shield 202 that acts as a shutter. In particular, the vapor propagation paths of (all) the nozzles of the first row of nozzles 111 and of optional further nozzle rows are blocked / covered by the idle shield 202, so that the vapor material emitted by the row(s) of nozzles impinges on and accumulates on an inner wall surface of the idle shield.

[0064] The evaporation source arrangement of FIGS. 3 and 4 may include some of the features or all the features of the evaporation source arrangement of FIG. 2, so that reference can be made to the above explanations, which are not repeated here.

[0065] A controller may be provided for triggering a rotation of the evaporation source to the first deposition position prior to a transport of the substrate 10 past the evaporation source 101 for coating the substrate and / or to trigger a rotation of the evaporation source to the idle position subsequent to the transport of the substrate past the evaporation source. The evaporation source may be maintained in the first deposition position that is shown in FIG. 3 during the movement of the substrate 10 past the evaporation source. In the first deposition position, the first row of nozzles is aligned with the first slit of the shaper shield, and optional further rows of nozzles are aligned with the first slit or with one or more further slits of the shaper shield.

[0066] As is shown in FIG. 3 and FIG. 4, the idle shield 202 may partially surround the evaporation source 101 , particularly by an angle of 90° or more, 180° or more, or even 270° or more. In particular, the idle shield 202 may have a shielding wall with a curved, round and / or circular contour in horizontal sectional planes that surrounds the rotation axis R1 and the evaporation source 101 by an angle of at least 90°, particularly 120° or more. A reliable shielding of the vapor material emitted by the evaporation source in the idle position can be ensured, even if the evaporation source includes two, three or more rows of nozzles arranged next to each other at the front side 60 of the evaporation source. For example, the idle shield 202 may partially surround theevaporation source in an enclosure-like, essentially tube-like or essentially cylinderlike manner, as is shown in FIGS. 2-4.

[0067] In some embodiments described herein, the idle shield 202 and the shaper shield 201 are connected to each other to form a continuous shielding interface therebetween. In other words, there is generally no gap or opening between the idle shield and the shaper shield through which vapor material could propagate during a rotation of the evaporation source between the first deposition position and the idle position. Rather, an interface between the idle shield and the shaper shield may be provided as a continuous shielding wall. In particular, the shaper shield and the idle shield may be formed as a continuous shielding wall that partially surrounds the evaporation source and includes one or more essentially vertical slits configured to be aligned with the one or more nozzle rows in a deposition position. A material accumulation on other surfaces in the vacuum chamber can be reduced or avoided and cleaning efforts can be reduced.

[0068] The first slit 211 of the shaper shield (and optional further slits) may have a slit width of 3 cm or more and 30 cm or less in a direction perpendicular to the longitudinal direction of the slit. The slit width may depend on a distance between the shaper shield and the respective nozzle row in the first deposition position. For example, a distance between the first row of nozzles 111 and the shaper shield 201 may be from 10 cm to 30 cm, and the slit width of the first slit 211 may be from 5 cm to 30 cm.

[0069] In some embodiments, which can be combined with other embodiments described herein, the evaporation source 101 further includes a second vapor distribution pipe 120 with a second row of nozzles 121 for depositing a second material on the substrate. In the first deposition position, the second row of nozzles 121 may be aligned with a second slit 212 in the shaper shield 201 , wherein the second slit is configured to limit a second opening angle ([32) of vapor plumes emitted by the second row of nozzles 121. The first slit 211 and the second slit 212 may have an essentially vertical orientation, respectively. In particular, an orientation of the slit may be adapted to the orientation of the respective nozzle row, so that the vapor plumes of all the nozzles of a nozzle row can be shaped in an essentially corresponding way whenpropagating through the respective vertically oriented slit that is aligned with the respective nozzle row.

[0070] In some embodiments, which can be combined with other embodiments described herein, the evaporation source 101 further includes a third vapor distribution pipe 130 with a third row of nozzles 131 for depositing a third material on the substrate. In the first deposition position, the third row of nozzles 131 may be aligned with a third slit in the shaper shield 201 , wherein the third slit is configured to limit a third opening angle of vapor plumes emitted by the third row of nozzles 131. The third slit of the shaper shield may have an essentially vertical orientation, respectively. In other embodiments, the vapor plumes emitted by two (or more) rows of nozzles may be shaped by one common essentially vertically oriented slit of the shaper shield (see, e.g., FIG. 5).

[0071] Accordingly, the vapor plumes emitted by the nozzles of two or more nozzles rows can be shaped by one or more slits of the shaper shield. In some embodiments, each nozzle row may have an associated slit configured to shape the vapor plumes emitted by the nozzles row. In some embodiments, two or more nozzles rows may be associated to a common slit of the shaper shield in the first deposition position (see FIG. 5). A better directionality of the vapor plumes can be ensured, shadowing effects can be decreased, and deposition on other surfaces inside the vacuum chamber can be reduced.

[0072] In some embodiments, which can be combined with other embodiments described herein, the first row of nozzles and the second row of nozzles are tilted toward each other to enable a co-deposition of a mixed material layer onto the substrate by co-deposition of the first material from the first row of nozzles and of the second material from the second row of nozzles. The shaper shield 201 may be configured to limit opening angles of the vapor plumes emitted by the first and second rows of nozzles. In particular, the shaper shield 201 may be configured to ensure a large overlap area of the first and second materials on the substrate, e.g., by limiting the vapor plumes emitted by the first row of nozzles and / or by limiting the vapor plumes emitted by the second row of nozzles. A first impact area of the first material on the substrate may substantially overlap with a second impact area of the second materialon the substrate, particularly with an overlap ratio of 80% or more, particularly 90% or more. An overlap ratio may be defined as a ratio between the first impact area and the overlap area or a ratio between the second impact area and the overlap area. A high- quality mixed material layer can be deposited onto the substrate.

[0073] In some embodiments, which can be combined with other embodiments described herein, the first vapor distribution pipe 110 is configured as an essentially vertical line source on a rotatable source body 301. Two, three or more vapor distribution pipes configured as essentially vertical line sources may be mounted on the rotatable source body 301.

[0074] A height of the shield arrangement 200 (in particular, a height of the shaper shield and of the idle shield) may be 150 cm or more, particularly 200 cm or more. Alternatively or additionally, an inner shielding surface of the shield arrangement 200 facing toward the evaporation source may have a surface area of 1 m2or more, particularly 2 m2or more, or even 3 m2or more. A large inner shielding surface of the shield arrangement ensures an effective and reliable shielding in different rotational positions of the evaporation source, also if the evaporation source is long and adapted to coat large-area substrates (for example, the vapor distribution pipe(s) may have a height of 1 m or more, in some embodiments 1.5 m or more). A curvature and / or a radius of the idle shield may be adapted to a curvature and / or a radius of a rotational trajectory of the rows of nozzles during the rotation movement. For example, during a rotation of the evaporation source between the first deposition position and the idle position, a distance between the first row of nozzles and the inner shielding surface of the idle shield may remain in a range from 5 cm to 30 cm, particularly in a range below 10 cm.

[0075] In some embodiments, the first slit 211 of the shaper shield may be configured to limit the first opening angle ([31 ) to 40° or more and 100° or less, particularly 50° or more and 90° or less. The “opening angle” of vapor plumes as used herein refers to the plume opening angle in horizontal sectional planes (see FIG. 3). The first slit 211 may limit the first opening angle of the vapor plumes of the first row of nozzles on only one side or alternatively, on two opposite sides of the first main evaporation direction M1. In particular, a part of the vapor plumes on (only) one sideof the first main evaporation direction M1 may be blocked by the shaper shield, or parts of the vapor plumes on two opposite sides of the first main evaporation direction M1 may be blocked by the shaper shield. In other words, the first slit 211 can limit the first opening angle on one side or on both sides of the main evaporation direction M1. A predetermined “coating window” on the substrate by the first row of nozzles can be ensured. Analogously, a predetermined “coating window” on the substrate by optional second and / or third rows of nozzles can be ensured by respective slits in the shaper shield. For example, a good overlap between two coating windows provided by the first and second rows of nozzles can be ensured by a respective shaping of the vapor plumes with the shaper shield 201 as described herein. Alternatively or additionally, an overlap between two coating windows provided by the first and the third rows of nozzles can be reduced or avoided by a respective shaping of the vapor plumes emitted by the first and third rows of nozzles with the shaper shield 201 as described herein.

[0076] According to some embodiments, the first main evaporation direction M1 and the second main evaporation direction M2 are tilted toward each other to enable a co-deposition of a mixed material layer onto the substrate, and the third row of nozzles 131 may be configured to deposit a further layer that includes the third material above or below the mixed material layer onto the substrate. In particular, the first main evaporation direction M1 and the third main evaporation direction M3 may be tilted away from each other to enable a deposition of the further layer above or below the mixed material layer.

[0077] The shaper shield 201 may be configured to increase an overlap ratio between the vapor plumes emitted from the first and second rows of nozzles, and / or the shaper shield 201 may be configured to reduce or prevent an overlap between the vapor plumes emitted from the first row of nozzles and the third row of nozzles. Accordingly, a further layer deposited with the third vapor distribution pipe can be deposited above or below a mixed-material layer, co-deposited with the first and second vapor distribution pipes. A reliable shaping (increasing or decreasing a respective vapor plume overlap) can be ensured by one, two or three slits provided in the shaper shield.

[0078] In some embodiments, which can be combined with other embodiments described herein, a substrate 10 having a structure formed thereon is coated with the evaporation source arrangement. The structure includes a first sidewall 11 adjacent to a pixel region 13 and a first overhang 12 projecting from the first sidewall at least partially over the pixel region 13. An OLED layer stack, as exemplarily illustrated in FIG. 8, can be deposited on the substrate having such an overhang structure formed thereon. In particular, according to some embodiments described herein, the evaporation source coats the substrate having the structure formed thereon with one or more organic materials or with one or more metals of an OLED layer stack.

[0079] In FIG. 3, the evaporation source 101 is arranged in the first deposition position by rotating the evaporation source 101 around the rotation axis R1 to the first deposition position using the rotation drive. In some embodiments, a controller (the controller 114 is depicted in FIG. 2) is provided that is configured to trigger a rotation of the evaporation source to the first deposition position, prior to the substrate being transported past the evaporation source 101 for coating the substrate. The controller may be further configured to trigger a rotation of the evaporation source back to the idle position subsequent to the transport of the substrate past the evaporation source. When a subsequent substrate is transported past the evaporation source, the controller 114 may again trigger a rotation of the evaporation source to the first deposition position.

[0080] Optionally, in the first deposition position, the first main evaporation direction M1 of the nozzles of the first row of nozzles 111 may be tilted relative to a surface normal SN of the substrate by a first tilt angle a1 . A tilted deposition can, for example, either increase or decrease a deposition of the first material under the first overhang 12. In particular, in some embodiments, the nozzle channels of the first row of nozzles are not perpendicular to the substrate surface, but rather inclined. In some embodiments, the first tilt angle a1 is 15° or more, particularly 25° or more, or even 35° or more, relative to the surface normal of the substrate in the first deposition position.

[0081] The first slit 211 of the shaper shield 201 is aligned with the first row of nozzles 111 in the first deposition position, such that vapor plumes are directed onto the substrate that are tilted relative to the substrate normal and that have a restrictedopening angle. Shaped and tilted vapor plumes emitted by rows of nozzles are particularly suitable to either increase (or ensure) or to reduce (or avoid) a material deposition below an overhang. In particular, both an inclination and a shaping of the vapor plumes can be provided according to embodiments described herein.

[0082] In some embodiments, the first main evaporation direction M1 is tilted “toward” the region under the first overhang 12 to increase a deposition of the first material in the region under the first overhang 12 as compared to a main evaporation direction that is perpendicular to the substrate surface. Specifically, the first material may be a metal, particularly silver, and, in the first deposition position, the first main evaporation direction M1 is inclined to increase a contact area between the metal and the first sidewall under the first overhang. Using the first vapor distribution pipe 110, a cathode layer can be deposited that has an improved electrical contact with the first sidewall 11.

[0083] In the first deposition position, the shaper shield 201 is arranged in front of the first row of nozzles 111 for limiting the first opening angle of the vapor plumes emitted by the first row of nozzles. In some embodiments, the shaper shield 201 is configured to shape the vapor plumes to be asymmetrical relative to the first main evaporation direction M1. In other words, a first sub-angle of the opening angle on a first side of the main evaporation direction M1 may be larger than a second sub-angle of the opening angle on a second side of the main evaporation direction M1 , as is schematically depicted in FIG. 3. By asymmetrically shaping the vapor plumes, the deposition under the first overhang can be increased relative to the deposition in an oppositely facing direction. More specifically, a ratio between a first deposition amount in a region under the first overhang and a second deposition amount on uncovered regions of the substrate can be increased by asymmetrically cutting the vapor plumes on two opposite sides thereof. Or expressed differently: A thickness of the deposited material under the first overhang relative to a thickness of the deposited material on an uncovered substrate region can be increased. Further, vapor plumes having a better focus and / or a better directionality can be provided.

[0084] In particular, the shaper shield 201 as described herein can ensure that the opening angle of the vapor plumes emitted by the first row of nozzles is adapted toensure a suitable ratio between the thicknesses of the deposited layer in a region below the first overhang and in uncovered regions of the substrate. Also, the extent to which respective layers reach under the overhang can be appropriately set by one or both of (i) limiting the opening angle of the vapor plumes, particularly to be asymmetrical relative to the main evaporation direction, and (ii) ensuring that the main evaporation direction of the vapor plumes is tilted relative to the surface normal of the substrate. The position and / or the width of the slit(s) in the shaper shield can be adapted as appropriate.

[0085] An angled deposition of one or more materials on the substrate, when the evaporation source is arranged in the first deposition position, can ensure an increased or decreased material deposition in a region below an overhang, as may be beneficial for the deposition of an OLED layer stack. Particularly, a cathode layer can be deposited by angled deposition under the overhang, ensuring a good electrical contact between the cathode material and the first sidewall 11 . In addition, an organic layer can be deposited via angled deposition so as to reduce or prevent a contact between the organic layer and the first sidewall 11 under the overhang.

[0086] As is illustrated in FIG. 3, the two or more vapor distribution pipes of the evaporation source define a front side 60 of the evaporation source. The front side 60 of the evaporation source refers to the side of the evaporation source that includes the row(s) of nozzles and is arranged opposite to a rear side 61 of the evaporation source. During the material deposition on the substrate, the front side 60 faces toward the substrate. The front side 60 of the evaporation source can, for example, be defined as a line that intersects the first row of nozzles 111 (or the center row of nozzles in case of several nozzles rows) and extends along a tangent to a rotational trajectory of the first row of nozzles 111. Alternatively, the front side 60 of the evaporation source can be defined as extending along a connection line that connects geometric centers of two or more vapor distribution pipes of the evaporation source in a horizontal sectional plane.

[0087] According to some embodiments, in the first deposition position, the front side 60 of the evaporation source is tilted relative to the substrate transportation path T by a first sub-angle x1 , and a front surface of the first vapor distribution pipe 110 thatis provided with the first row of nozzles 111 is tilted relative to the front side 60 of the evaporation source by a second sub-angle x2, wherein a sum of the first sub-angle x1 and the second sub-angle x2 defines a first tilt angle a1 of the first main evaporation direction M1 relative to a surface normal SN of the substrate.

[0088] In particular, the first sub-angle x1 may be 10° or more, particularly 15° or more, and the second sub-angle x2 may be 15° or more, particularly 25° or more. Hence, the first tilt angle a1 of the first main evaporation direction M1 relative to the surface normal may be 25° or more, particularly 40° or more.

[0089] In other words, the first tilt angle a1 of the first main evaporation direction M1 relative to the surface normal may be based on two contributing factors: (1 ) An inclination of the first row of nozzles 111 relative to the front side 60 (i.e. , the nozzle channels are not perpendicular to the front side 60), and (2) an inclination of the front side 60 of the whole evaporation source with respect to a frontal deposition position, in which the front side 60 is parallel to the substrate transport path T. The second contributing factor can, e.g., be obtained and adapted by rotating the evaporation source around the rotation axis to a tilted position, and the first contributing factor can, e.g., be obtained and adapted by a specific geometric shape and / or arrangement of the front surface of the first vapor distribution pipe and / or the first row of nozzles, such that the nozzle channels of the first nozzle row are tilted (i.e., not perpendicular) relative to the front side 60.

[0090] The above two contributing factors to the first tilt angle a1 can increase the overall inclination of the first main evaporation direction M1 relative to the surface normal SN to further increase or decrease the deposition under the overhang, as may be appropriate depending on the material or layer to be deposited. Furthermore, the main evaporation directions of several nozzle rows can be tilted in unison (e.g., via the source rotation) as well as relative to each other (e.g., by tilting the nozzles of a row relative to the front side 60 of the evaporation source), which increases the flexibility and allows a deposition of specific layers onto a substrate using one evaporation source. The deposition speed and the deposition flexibility can be improved.

[0091] In some embodiments, which can be combined with other embodiments described herein, the second main evaporation direction M2 of the second row ofnozzles 121 and the first main evaporation direction M1 of the first row of nozzles 111 are tilted toward each other for enabling a co-deposition of a mixed material layer on the substrate in the first deposition position. In particular, the first row of nozzles 111 and the second row of nozzles 121 may be mounted such that the first and second main evaporation directions approach each other. Specifically, first vapor plumes emitted by the first row of nozzles and second vapor plumes emitted by the second row of nozzles may overlap during propagation to enable a co-deposition of two materials for forming a mixed material layer on the substrate.

[0092] In some implementations, a mixed material layer, particularly a mixed metal layer, is co-deposited onto the substrate with the first and second vapor distribution pipes during the transport of the substrate 10 past the evaporation source 101. Alternatively, a mixed organic layer that includes at least two different organic materials is co-deposited onto the substrate with the first row of nozzles and the second row of nozzles being tilted toward each other.

[0093] The mixed metal layer may be a cathode layer of an OLED layer stack, particularly a cathode layer comprising co-deposited silver and magnesium. The mixed organic layer may be an organic layer of an OLED layer stack. In some embodiments, the evaporation source is configured to coat the substrate with a mixed organic layer that is co-deposited using the first vapor distribution pipe and the second vapor distribution pipe. In other embodiments, the evaporation source is configured to coat the substrate with a mixed metal layer, particularly a cathode layer, that is co-deposited using the first vapor distribution pipe and the second vapor distribution pipe.

[0094] In some embodiments, which can be combined with other embodiments described herein, the evaporation source 101 has a third vapor distribution pipe 130 with a third row of nozzles that have a third main evaporation direction. The third vapor distribution pipe may be configured to coat the substrate with a further material layer above or below a layer deposited by the first (and / or second) vapor distribution pipe. Optionally, the third main evaporation direction and the first main evaporation direction are tilted away from each other in order to enable a sequential deposition of two layers on top of each other on the substrate in the first deposition position. In other words, the first and third rows of nozzles may be configured such that first vapor plumes emittedby the first row of nozzles and third vapor plumes emitted by the third row of nozzles do not overlap during propagation toward the substrate, such that separate layers can be deposited on top of each other with the first and the third vapor distribution pipes.

[0095] In particular, during the transport of the substrate past the evaporation source, an electron injection layer EIL can be deposited onto the substrate with the third vapor distribution pipe 130 and a cathode layer can be (co-)deposited on the electron injection layer with at least the first vapor distribution pipe 110, particularly with the first and second vapor distribution pipes in synchrony by co-deposition. In particular, a co-deposited cathode layer can be deposited on top of the electron injection layer, wherein the co-deposited cathode layer is deposited with the first and second vapor distribution pipes, and the electron injection layer is deposited with the third vapor distribution pipe. Accordingly, a single movement of the substrate past the evaporation source leads to a coating of the substrate with (at least) two layers on top of each other, at least one of said two layers being a mixed-material layer deposited by co-deposition.

[0096] In another embodiment, the third main evaporation direction of the third row of nozzles may be tilted toward the first and the second main evaporation directions to enable a co-deposition of a mixed material layer that includes at least three (same or different) materials deposited from at least three rows of nozzles (as illustrated in FIG. 5).

[0097] In some embodiments, the first, second, and third materials are different materials, e.g., three different metals and / or three different organic materials. The first, second, and third materials can optionally include same components. For example, the first, second, and / or third materials can include the same main components, but different sub-components, e.g., different dopants. In other embodiments, the first and second material are the same material, but the third material is a different material. In yet further embodiments, at least two of the first, second, and third materials are the same material.

[0098] FIG. 5 is a schematic view of an evaporation source arrangement according to embodiments in a horizontal sectional view. The evaporation source arrangement includes an evaporation source 101 with a first vapor distribution pipe 110 with a firstrow of nozzles, a second vapor distribution pipe 120 with a second row of nozzles, and an optional third vapor distribution pipe 130 with a third row of nozzles. A rotation drive is provided for rotating the evaporation source around the rotation axis.

[0099] A shield arrangement 200 according to any of the embodiments described herein partially surrounds the evaporation source 101 and includes an idle shield 202 and a shaper shield 201 . The rotation drive is configured to rotate the evaporation source relative to the shield arrangement between an idle position, in which the first row of nozzles is directed toward the idle shield 202, and a first deposition position, in which the first row of nozzles and the second row of nozzles are aligned with an essentially vertically oriented first slit 211 provided in the shaper shield 201 . Optionally, also the third row of nozzles may be aligned with the first slit 211 in the first deposition position.

[0100] The first slit 211 is configured to limit a first opening angle [31 of vapor plumes emitted by the first row of nozzles, particularly on one (horizontal) side of the main evaporation direction of the first row of nozzles, and the first slit 211 is configured to also limit a second opening angle [32 of vapor plumes emitted by the second row of nozzles, particularly on one (horizontal) side of the main evaporation direction of the second row of nozzles. In other words, one slit may limit the opening angles of the vapor plumes emitted by two or more rows of nozzles. A good overlap between the vapor plumes emitted by two or more nozzle rows arranged next to each other on a rotatable source body can be ensured. The quality of mixed-material layers deposited by co-deposition from two or more vapor distribution pipes can be improved.

[0101] Alternatively, as is schematically depicted in FIG. 3, the shaper shield 201 may have two or more essentially vertically oriented slits that are respectively associated to one single row of nozzles, so that the vapor plumes emitted by several rows of nozzles can be shaped individually on one side or on two opposite sides of the respective main evaporation direction with a respective slit of the shaper shield.

[0102] FIG. 6 is a schematic perspective view of an evaporation source arrangement 100 according to embodiments described herein. The evaporation source arrangement may include some features or all the features of the embodiments shownin figures 1 to 5, so that reference can be made to the above explanations, which are not repeated here.

[0103] The shield arrangement 200 of the evaporation source arrangement 100 includes an idle shield 202 and a shaper shield 201. The evaporation source 101 is rotatable around a rotation axis relative to the shield arrangement 200 that partially surrounds the evaporation source, e.g., by an angle of 90° or more. The shaper shield 201 includes the essentially vertically oriented first slit 211 and optionally an essentially vertically oriented second slit 212. The length of the slit(s) may be at least as long as the respective row of nozzles.

[0104] In the first deposition position, the first slit 211 may be located in alignment with the first row of nozzles of the first vapor distribution pipe 110, and / or the second slit 212 may be located in alignment with the second row of nozzles of the second vapor distribution pipe 120. The first slit 211 may be configured to shape the vapor plumes emitted by the first row of nozzles by horizontally limiting the opening angle of the vapor plumes on one side or on two opposite sides of the first main evaporation direction of the first row or nozzles. In particular, horizontally outer portions of the vapor plumes may be blocked by the shaper shield. The optional second slit 212 may be configured to shape the vapor plumes emitted by the second row of nozzles by horizontally limiting the opening angle of the vapor plumes on one side or on two opposite sides of the second main evaporation direction of the second row of nozzles. In particular, horizontally outer portions of the vapor plumes may be blocked by oppositely arranged edges of the shaper shield that form the second slit therebetween. Further slits and / or further vapor distribution pipes are possible.

[0105] The shaper shield 201 and the idle shield 202 are connected to each other to provide a continuous shielding interface therebetween. Accordingly, a continuous shield arrangement that acts as both an idle shield and as a shaper shield partially surrounds the evaporation source. One or more vertical slits in the shaper shield are provided to limit the opening angles of the vapor plumes emitted by one or more respective nozzle rows.

[0106] As is schematically depicted in FIG. 6, the shaper shield 201 may include shielding plates 230 arranged adjacent to each other. The first slit 211 , the optionalsecond slit 212, and optional further slits are respectively located between two adjacent shielding plates. For example, two essentially vertically oriented shielding plates of the shaper shield may be arranged with a gap therebetween that constitutes the essentially vertically extending first slit 211 . More than two shielding plates 230 may be provided, with an essentially vertically extending slit formed between two adjacent shielding plates, respectively.

[0107] The shielding plates 230 can be one-body components or can respectively include two or more plate components connected to each other to form one shielding plate. The transport and the mounting of the shaper shield can be facilitated if the shielding plates comprise sub-components connectable to each other. The shielding plates can have a height of 150 cm or more, particularly 200 cm or more, respectively. Alternatively or additionally, the idle shield 202 can include one, two or more wall components that are connected to each other to form a continuous shielding wall that partially surrounds the evaporation source, particularly in a curved or round contour.

[0108] The shielding plates 230 can be essentially flat shielding plates, e.g., essentially flat metal plates, particularly metal sheets. In particular, the idle shield 202 may include a curved shielding wall that partially surrounds the evaporation source in a circumferential direction. The shaper shield 201 may include two or more essentially flat shielding plates that are arranged next to each other between the evaporation source and the substrate transport path.

[0109] In some embodiments, the idle shield 202 includes a door that can be opened to allow access to the evaporation source through the door. For example, the evaporation source can be accessed for service or maintenance in the idle position of the evaporation source through the door that is provided in the idle shield.

[0110] The idle shield can be cooled, e.g., actively cooled with a cooling device, e.g., with a water cooling device, to ensure that the vapor material impinging on an inner wall surface of the idle shield condenses and adheres thereon. The idle shield can be cleaned, e.g., in regular cleaning intervals. Cleaning of the idle shield may include a partial or complete removal of the material accumulated on the idle shield by the evaporation source during idle times of the evaporation source. Also the shapershield can be cleaned, e.g., at regular intervals, for removing material accumulated on the shielding plates.

[0111] In some embodiments, which can be combined with other embodiments described herein, positions of the shielding plates 230 relative to the evaporation source 101 , a slit width of the first slit 211 and / or slit widths of optional further slits are adjustable. Alternatively or additionally, one or more the shielding plates of the shaper shield can be exchanged with shielding plates having other widths. For example, a width of the first slit can be increased for increasing the first opening angle of the vapor plumes propagating through the first slit toward the substrate from the first row of nozzles. For example, a width of the first slit can be reduced for more strongly limiting the first opening angle of the vapor plumes emitted by the first row of nozzles. For example, a position of one or more shielding plates can be modified, e.g., by displacing one or more shielding plates in an essentially circumferential direction of the evaporation source, for modifying the shape of the vapor plumes propagating through the shaper shield. In some embodiments, the position and / or the width of the first slit can be adapted to a predetermined first tilt angle of the first main evaporation direction and / or to a predetermined opening angle or shape of the vapor plumes to be provided. For example, an asymmetry of the vapor plumes relative to the first main evaporation direction can be modified by differently reducing or increasing a slit width on two opposite horizontal sides of the first main evaporation direction.

[0112] In some embodiments, the shield arrangement 200 has a holding frame 240, wherein upper and lower sections of the shielding plates 230 may be removably mounted at the holding frame 240 to be displaceable relative to the holding frame and fixable at the holding frame at various positions. For example, upper and / or lower sections of the shielding plates 230 may be fixed at the holding frame with fixing elements, e.g., with screws or clamps, that can be removed or loosened for displacing the shielding plates 230 along a longitudinal direction of the holding frame 240. Each shielding plate may be fixable at various positions along the longitudinal direction of the holding frame for adapting a slit width and / or a slit position. Alternatively or additionally, one or more shielding plates can be removed from the holding frame and replaced by other shielding plates that have a different width. Accordingly, the shaper shield can be adjusted to the number of nozzle rows of the evaporation source as wellas to various predetermined tilt angles and predetermined plume widths or shapes of one or more nozzles rows.

[0113] In some embodiments, the shaper shield 201 includes at least three shielding plates, wherein the first slit 211 and a second slit 212 are located between respective adjacent shielding plates. In the first deposition position, the first row of nozzles 111 is aligned with the first slit 211 and a second row of nozzles 121 of a second vapor distribution pipe 120 is aligned with the second slit 212.

[0114] In some embodiments, which can be combined with other embodiments described herein, the shield arrangement may further include a top shield 250 connected to an upper part of the idle shield 202 and / or to an upper part of the shaper shield 201 , wherein the top shield is oriented essentially horizontally. Alternatively or additionally, the shield arrangement may include a bottom shield 260 connected to a lower part of the idle shield 202 and / or the shaper shield 201 , wherein the bottom shield is oriented essentially horizontally. Specifically, the idle shield and the shaper shield may be oriented essentially vertically, in correspondence with an orientation of the vapor distribution pipe(s) of the evaporation source, while the top shield and / or the bottom shield may be oriented essentially horizontally.

[0115] The top shield 250 may be arranged above the propagation paths of the vapor plumes emitted by the first row of nozzles in at least one of the idle position and the first deposition position of the evaporation source. The top shield may be configured to reduce or prevent vapor from leaving an area between the shield arrangement and the evaporation source in an upward direction. The bottom shield 260 may be arranged below the propagation paths of the vapor plumes emitted by the first row of nozzles in at least one of the idle position and the first deposition position. The bottom shield may be configured to reduce or prevent vapor from leaving an area between the shield arrangement and the evaporation source in downward direction. In particular, the top shield may be formed as a top cover that at least partially covers the area between the idle and / or shaper shield and the evaporation source. The bottom shield may be formed as a lower cover that at least partially closes the area between the idle and / or shaper shield and the evaporation source towards the bottom. A coatingof other surfaces inside the vacuum chamber and / or of the chamber walls can be reduced or prevented and cleaning requirements can be reduced.

[0116] In some embodiments, the shaper shield that includes the first slit 211 and optional further slit(s) is not oriented exactly vertically, but rather slightly inclined relative to the direction of gravity in correspondence with an inclination of the substrate and of the vapor distribution pipe(s), e.g., by an angle of 1 ° or more and 10° or less, particularly 2° or more and 6° or less. An inclination of the shaper shield relative to the vertical direction may be advantageous in consideration of a slight inclination of the vapor distribution pipe(s) and / or of the substrate during deposition relative to the vertical orientation, e.g., by an angle of 1 ° or more and 10° or less. By slightly inclining the shaper shield in correspondence with an inclination of the respective row of nozzles, the vapor plumes of upper nozzles of the nozzle row can be shaped to better correspond in shape and opening angle to the vapor plumes of lower nozzles of the nozzle row.

[0117] In some embodiments, the first slit has a shape and a slit width adapted to ensure the same opening angle of all the vapor plumes emitted by the first row of nozzles along the longitudinal direction of the vapor distribution pipe. In other words: all the vapor plumes emitted by the first row of nozzles may be limited by the shaper shield to impinge on the substrate with a corresponding opening angle and / or a corresponding tilt angle. The same may hold for the vapor plumes emitted by optional further rows of nozzles that are shaped by optional further slits of the shaper shield.

[0118] For example, if the shaper shield is parallel to the first row or nozzles in the first deposition position, the slit width of the first slit may be constant over the full length of the first slit and the first slit may have an essentially rectangular shape. On the other hand, if the shaper shield is not exactly parallel to the first row of nozzles in the first deposition position (for example, if the shaper shield is inclined relative to the vertical direction, the distance between the first vapor distribution pipe and the shaper shield may vary from top to bottom of the first row of nozzles, depending on the respective rotational position of the evaporation source and / or on the circumferential position of a respective vapor distribution pipe at the evaporation source), the geometric shape of the first slit may be adapted along its longitudinal direction to ensure a correspondingshaping of all the vapor plumes of the first row of nozzles. Specifically, the shape of the first slit may be (slightly) trapezoidal and / or the slit width may have a (slight) variation along the longitudinal direction of the slit, particularly with an increasing slit width toward the bottom of the slit.

[0119] Accordingly, in some embodiments, the first slit (and the optional further slit(s)) of the shaper shield may have a constant slit width and may be rectangular. Alternatively or additionally, at least one slit may have a varying slit width and / or a trapezoidal geometric shape for ensuring a corresponding shaping of all the vapor plumes emitted by the associated row of nozzles so that the vapor plumes of the row impinge with corresponding opening angles on the substrate surface.

[0120] FIG. 7 is a flow diagram that schematically illustrates a coating method described herein. The coating method can be carried out in a vapor deposition system and / or with an evaporation source arrangement according to any of the embodiments described herein.

[0121] In block 791 , the method includes rotating the evaporation source around a rotation axis relative to the shield arrangement 200 from an idle position to a first deposition position. In the idle position, the first row of nozzles is directed toward the idle shield. In the first deposition position, the first row of nozzles is aligned with an essentially vertically oriented first slit 211 provided in the shaper shield.

[0122] In block 792, the substrate is transported past the evaporation source that is maintained in the first deposition position while directing a first material toward the substrate from the first row of nozzles. During the substrate transport past the evaporation source, the first slit 211 limits the first opening angle ([31 ) of the vapor plumes emitted by the first row of nozzles.

[0123] In block 793, after the transport of the substrate past the evaporation source, the evaporation source is rotated around the rotation axis relative to the shield arrangement back to the idle position, in which the first row of nozzles is directed toward the idle shield.

[0124] Prior to the transport of a subsequent substrate past the evaporation source, the evaporation source may be rotated again to the first deposition position or to another deposition position for coating the subsequent substrate.

[0125] The rotational movement of the evaporation source can be triggered by a respective controller.

[0126] In the first deposition position, a first main evaporation direction M1 of the first row of nozzles may be tilted relative to a surface normal of the substrate by a first tilt angle (a1 ). The first tilt angle may be 15° or more, particularly 35° or more.

[0127] A substrate having a structure formed thereon that acts as a “masking layer” can be coated, particularly with one or more layers of an OLED layer stack. The structure may include a first sidewall 11 adjacent to a pixel region 13 and a first overhang 12 projecting from the first sidewall. The evaporation source may coat the substrate with one or more organic materials or with one or more metals of an OLED layer stack.

[0128] In some embodiments, the evaporation source 101 further comprises a second vapor distribution pipe 120 with a second row of nozzles 121 for depositing a second material on the substrate and optionally a third vapor distribution pipe 130 with a third row of nozzles 131 for depositing a third material on the substrate. In the idle position, the first, second and (optionally) third rows of nozzles may be directed toward an inner shielding surface of the idle shield that blocks the vapor emitted by the nozzle rows. In the first deposition position, the first row of nozzles, the second row of nozzles and optionally the third row of nozzles may be aligned with at least one of the first slit and one or more further slits provided in the shaper shield 201 to limit opening angles of vapor plumes emitted by at least one of the first, second, and optionally third rows of nozzles, particularly to limit the opening angles of the vapor plumes emitted by the first, second, and third rows of nozzles.

[0129] Thus, in view of the embodiments described herein, improved evaporation source arrangements and improved coating methods are provided, particularly for “maskless” OLED pixel deposition that does not use fine metal masks. Cleaning efforts can be reduced, and the directionality of vapor plumes emitted by rows of nozzles canbe improved by a shaper shield that is integrated with the idle shield to provide a continuous shielding surface partially surrounding the evaporation source.

[0130] While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[0131] In particular, the 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 the claims have structural elements that do not differ from the literal language of the claims, or if the claims include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

WHAT IS CLAIMED1. An evaporation source arrangement (100) for coating a substrate (10), comprising: an evaporation source (101 ) with a first vapor distribution pipe (110) with a first row of nozzles (111 ) for depositing a first material on the substrate; a rotation drive (113) for rotating the evaporation source around a rotation axis (R1 ); and a shield arrangement (200) that partially surrounds the evaporation source and comprises an idle shield (202) and a shaper shield (201 ), the rotation drive configured to rotate the evaporation source relative to the shield arrangement between an idle position, in which the first row of nozzles is directed toward the idle shield (202), and a first deposition position, in which the first row of nozzles is aligned with an essentially vertically oriented first slit (211 ) provided in the shaper shield (201 ), the first slit (211 ) configured to limit a first opening angle ([31 ) of vapor plumes emitted by the first row of nozzles.

2. The evaporation source arrangement of claim 1 , wherein the first vapor distribution pipe (110) is configured as an essentially vertical line source on a rotatable source body, a height of the shield arrangement (200) is 150 cm or more, and an inner shielding surface of the shield arrangement (200) facing toward the evaporation source is 1 m2or more.

3. The evaporation source arrangement of claim 1 or 2, wherein the first slit (211 ) of the shaper shield (201 ) is configured to limit the first opening angle ([31 ) to 40° or more and 100° or less.

4. The evaporation source arrangement of any of claims 1 to 3, wherein the idle shield (202) partially surrounds the evaporation source (101 ) by an angle between 90° and 270° in an essentially enclosure-like, tube-like or cylinder-like manner.

5. The evaporation source arrangement of any of claims 1 to 4, wherein the evaporation source (101 ) further comprises a second vapor distribution pipe (120) witha second row of nozzles (121 ) for depositing a second material on the substrate, and, in the first deposition position, the second row of nozzles (121 ) is aligned with an essentially vertically oriented second slit (212) in the shaper shield (201 ), the second slit configured to limit a second opening angle ([32) of vapor plumes emitted by the second row of nozzles (121 ).

6. The evaporation source arrangement of any of claims 1 to 5, wherein the evaporation source is configured to coat the substrate with a mixed organic layer codeposited with two or more vapor distribution pipes of the evaporation source.

7. The evaporation source arrangement of any of claims 1 to 6, wherein the idle shield (202) and the shaper shield (201 ) are connected to each other to provide a continuous shielding interface therebetween.

8. The evaporation source arrangement of any of claims 1 to 7, wherein the shaper shield (201 ) comprises shielding plates (230) with the first slit (211 ) and optional further slits located therebetween.

9. The evaporation source arrangement of claim 8, wherein positions of the shielding plates (230) relative to the evaporation source (101 ) or a slit width of the first slit (211 ) are adjustable.

10. The evaporation source arrangement of claim 8 or 9, the shield arrangement (200) comprising a holding frame (240), wherein upper and lower sections of the shielding plates (230) are removably mounted at the holding frame (240) to be displaceable relative to the holding frame and fixable at the holding frame at various positions.

11. The evaporation source arrangement of any of claims 8 to 10, wherein the shaper shield (201 ) comprises at least three shielding plates with the first slit (211 ) and a second slit (212) located between respective adjacent shielding plates, and, in the first deposition position, the first row of nozzles (111 ) is aligned with the first slit (211 ) and a second row of nozzles (121 ) of a second vapor distribution pipe (120) is aligned with the second slit (212).

12. The evaporation source arrangement of any of claims 1 to 11 , wherein the shield arrangement (200) further comprises at least one of a top shield (250) connected to an upper part of at least one of the idle shield (202) and the shaper shield (201 ) and oriented essentially horizontally, and a bottom shield (260) connected to a lower part of at least one of the idle shield (202) and the shaper shield (201 ) and oriented essentially horizontally.

13. The evaporation source arrangement of any of claims 1 to 12, further comprising a controller (114) configured to trigger a rotation of the evaporation source to the first deposition position prior to a transport of the substrate past the evaporation source (101 ) for coating the substrate and to trigger a rotation of the evaporation source to the idle position subsequent to the transport of the substrate past the evaporation source.

14. The evaporation source arrangement of claim 13, wherein, in the first deposition position, a first main evaporation direction (M1 ) of the first row of nozzles (111 ) is tilted relative to a surface normal (SN) of the substrate by a first tilt angle (a1 ) of 25° or more, and the first row of nozzles (111 ) is aligned with the first slit (211 ).

15. The evaporation source arrangement of claim 14, wherein, in the first deposition position, a front side (60) of the evaporation source is tilted relative to a substrate transport path (T) by a first sub-angle (x1 ), and a front surface of the first vapor distribution pipe (110) that is provided with the first row of nozzles (111 ) is tilted relative to the front side (60) of the evaporation source by a second sub-angle (x2).

16. A vacuum deposition system, comprising: a first vacuum chamber (1001 ); the evaporation source arrangement (100) according to any of claims 1 to 15 in the first vacuum chamber; a substrate transportation track (1013) configured to move a substrate (10) along a substrate transport path (T) past the evaporation source arrangement; anda shield transportation track (1012) between the substrate transportation track and the evaporation source arrangement (100) and configured to move a movable shield (1030) in front of the substrate (10) for shielding an edge region of the substrate.

17. A method of coating a substrate in a vacuum chamber with an evaporation source arrangement (100), the evaporation source arrangement comprising an evaporation source (101 ) having a first vapor distribution pipe (110) with a first row of nozzles (111 ) and a shield arrangement (200) that partially surrounds the evaporation source and comprises an idle shield (202) and a shaper shield (201 ), the method comprising: rotating the evaporation source around a rotation axis (R1 ) relative to the shield arrangement (200) from an idle position to a first deposition position, wherein, in the idle position, the first row of nozzles is directed toward the idle shield and, in the first deposition position, the first row of nozzles is aligned with an essentially vertically oriented first slit (211 ) provided in the shaper shield; and transporting the substrate past the evaporation source in the first deposition position while directing a first material toward the substrate from the first row of nozzles, the first slit (211 ) limiting a first opening angle ([31 ) of vapor plumes emitted by the first row of nozzles.

18. The method of claim 17, wherein, in the first deposition position, a first main evaporation direction (M1 ) of the first row of nozzles is tilted relative to a surface normal of the substrate by a first tilt angle (a1 ) of 15° or more.

19. The method of claim 17 or 18, wherein the substrate has a structure formed thereon comprising a first sidewall (11 ) adjacent to a pixel region (13) and a first overhang (12) projecting from the first sidewall (11 ), and the evaporation source coats the substrate with one or more organic materials or with one or more inorganic materials, particularly metals, of an OLED layer stack.

20. The method of any of claims 17 to 19, wherein the evaporation source (101 ) further comprises a second vapor distribution pipe (120) with a second row of nozzles (121 ) for depositing a second material on the substrate and a third vapor distributionpipe (130) with a third row of nozzles (131 ) for depositing a third material on the substrate, and in the idle position, the first, second, and third rows of nozzles are directed toward an inner shielding surface of the idle shield, and in the first deposition position, the first row of nozzles, the second row of nozzles and the third row of nozzles are aligned with at least one of the first slit and one or more further slits provided in the shaper shield (201 ) to limit opening angles of vapor plumes emitted by at least one of the first, second, and third rows of nozzles.

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