Material deposition assembly and method of depositing materials on a substrate

Abstract

A material deposition assembly (100) for depositing materials on a substrate arranged in a substrate plane (15) in a vacuum deposition chamber is described. The material deposition assembly includes a first vapor distribution pipe (120-1) with a first nozzle row (130-1) for directing vapor plumes (140-1) of a first material onto the substrate plane and with a second nozzle row (130-2) for directing vapor plumes (140-2) of the first material onto the substrate plane; a second vapor distribution pipe (120-2) with a third nozzle row (130-3) for directing vapor plumes (140-3) of a second material onto the substrate plane and with a fourth nozzle row (130-4) for directing vapor plumes (140-4) of the second material onto the substrate plane. The first nozzle row (130-1) and the third nozzle row (130-3) are configured to deposit a first mixed sublayer comprising the first and second materials onto the substrate, and the second nozzle row (130-2) and the fourth nozzle row (130-4) are configured to deposit a second mixed sublayer comprising the first and second materials on top of the first mixed sublayer on the substrate being moved relative to the material deposition assembly in the substrate plane.

Description

MATERIAL DEPOSITION ASSEMBLY AND METHOD OF DEPOSITING MATERIALS ON A SUBSTRATETECHNICAL FIELD

[0001] The present disclosure relates to a material deposition assembly for depositing materials on a substrate and to methods for depositing materials on a substrate. In particular, embodiments relate to material deposition assemblies for depositing materials of an OLED layer stack on a substrate, such as metal materials to provide an electrode layer, particularly a cathode layer. Furthermore, the present disclosure relates to an organic light-emitting diode display device manufactured with methods of the present disclosure.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 than those of traditional LCD displays. Furthermore, 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 so as to form a matrix display panel having individually energizable pixels.

[0003] Organic materials and metallic materials are deposited on a substrate in a vacuum deposition chamber for OLED manufacturing. Metallic materials are employed as, for example, electrode materials or electron transport layer (ETL) materials. The materials to be deposited are evaporated in a material deposition arrangement, andthe evaporated materials are deposited on a substrate through nozzles.

[0004] Metallic evaporators can be used for the production of, for example, organic light-emitting diodes (OLED). However, other applications also utilize evaporators for depositing metal layers, for example, on large area substrates. For example, coevaporation of two or more metals or metal alloys can be provided. An OLED display, for example, may include 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 (TOO) materials. The second electrode can include a metal or a metal alloy.

[0005] OLED display devices typically include sub-pixels to provide improved performance. Sub-pixels may be delimited by overhang structures extending above the substrate. A sub-pixel circuit is manufactured on the substrate to obtain a sub-pixel that can be energized. Typically, a cathode is deposited over the organic material of the sub-pixels. The cathode material is at least partially deposited behind the overhang structures, e.g., for providing a cathode contact of the cathode layer with a contact structure.

[0006] In view of the above, providing improved material deposition assemblies and manufacturing methods adapted for OLED manufacturing would be beneficial. In particular, it would be beneficial to improve a material deposition assembly and a method of depositing materials on a substrate, for providing a metal cathode also behind overhang structures that may define the pixels of the OLED display device.SUMMARY

[0007] In light of the above, material deposition assemblies, methods of depositing materials on a substrate, and OLED devices 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.

[0008] According to an aspect, a material deposition assembly for depositing materials on a substrate arranged in a substrate plane is provided. The material deposition assembly includes a first vapor distribution pipe in fluid communication witha first evaporation crucible and including a first nozzle row for directing vapor plumes of the first nozzle row onto the substrate plane and a second nozzle row for directing vapor plumes of the second nozzle row onto the substrate plane, the vapor plumes of the first and second nozzle rows being vapor plumes of a first material. The material deposition assembly further includes a second vapor distribution pipe in fluid communication with a second evaporation crucible and including a third nozzle row for directing vapor plumes of the third nozzle row onto the substrate plane and a fourth nozzle row for directing vapor plumes of the fourth nozzle row onto the substrate plane, the vapor plumes of the third and fourth nozzle rows being vapor plumes of a second material. The first nozzle row and the third nozzle row are configured to deposit a first mixed sublayer comprising the first and second materials onto the substrate being moved relative to the material deposition assembly in the substrate plane; and the second nozzle row and the fourth nozzle row are configured to deposit a second mixed sublayer comprising the first and second materials on top of the first mixed sublayer on the substrate being moved relative to the material deposition assembly in the substrate plane.

[0009] In particular, the first nozzle row of the first vapor distribution pipe and the third nozzle row of the second vapor distribution pipe may be directed to deposit the first mixed sublayer on the substrate. The second nozzle row of the first vapor distribution pipe and the fourth nozzle row of the second vapor distribution pipe may be directed to deposit the second mixed sublayer on the substrate. Particularly, both the first and the second mixed sublayer can be deposited in one pass of the substrate relative to the material deposition assembly. For example, the substrate can be moved past the material deposition assembly, or the material assembly can be moved past the substrate during layer deposition.

[0010] In some embodiments, the first material and / or the second material may be a metal, particularly different metals, and the first and second mixed sublayers may be two sublayers of a cathode layer. The cathode layer may be a mixed layer that includes the first material and the second material in a predetermined mixing ratio.

[0011] According to some embodiments described herein, a cathode layer can be deposited behind two oppositely directed overhangs on the substrate, in one pass ofthe substrate past the material deposition assembly.

[0012] In some embodiments, the nozzles of the first and third nozzle rows are inclined relative to a normal direction of the substrate plane (= “substrate plane normal”) to deposit the first and second materials under a first overhang, and the nozzles of the second and fourth nozzle row may be oppositely inclined relative to the normal direction of the substrate plane to deposit the first and second materials under a second overhang. The second overhang may face in a different direction as compared to the first overhang. Specifically, the nozzles of the first and third nozzle rows and the nozzles of the second and fourth nozzle rows may be tilted in opposite directions to provide main evaporation directions that are inclined in opposite directions relative to a normal direction of the substrate.

[0013] According to an aspect, a material deposition assembly for depositing materials on a substrate arranged in a substrate plane is provided. The material deposition assembly includes a first vapor distribution pipe in fluid communication with a first evaporation crucible and comprising a first nozzle row for directing vapor plumes of a first material onto the substrate plane and a second nozzle row for directing vapor plumes of the first material onto the substrate plane; and one or two second vapor distribution pipes in fluid communication with at least one second evaporation crucible and comprising a third nozzle row for directing vapor plumes of a second material onto the substrate plane and a fourth nozzle row for directing vapor plumes of the second material onto the substrate plane. The first nozzle row and the third nozzle row are configured to deposit a first mixed sublayer comprising the first and second materials onto the substrate being moved relative to the material deposition assembly in the substrate plane; and the second nozzle row and the fourth nozzle row are configured to deposit a second mixed sublayer comprising the first and second materials on top of the first mixed sublayer on the substrate being moved relative to the material deposition assembly in the substrate plane.

[0014] According to another aspect, a method of depositing materials on a substrate is provided, particularly with a material deposition assembly according to any of the embodiments described herein. The material deposition assembly includes a first vapor distribution pipe with a first nozzle row and a second nozzle row, and asecond vapor distribution pipe adjacent to the first vapor distribution pipe (or optionally two second vapor distribution pipes adjacent to the first vapor distribution pipe on two opposite sides thereof) with a third nozzle row and a fourth nozzle row. The method includes: transporting the substrate relative to the material deposition assembly in a substrate plane while directing a first material toward the substrate from the first and second nozzle rows and a second material toward the substrate from the third and fourth nozzle rows; wherein the first nozzle row and the third nozzle row are directed such that a first mixed sublayer comprising the first and second materials is deposited onto the substrate, and the second nozzle row and the fourth nozzle row are directed such that a second mixed sublayer comprising the first and second materials is deposited onto the substrate on top of the first mixed sublayer.

[0015] In some embodiments, the first and second mixed sublayers are deposited onto the substrate in one pass of the substrate relative to the material deposition assembly. In some embodiments, the first and third vapor plumes do not or not substantially overlap with or intersect the second and fourth vapor plumes, so that the first and second mixed sublayers are deposited on top of each other. Specifically, the first mixed sublayer may comprise particles directed from the first and third nozzle rows, but not from the second and fourth nozzle rows, and / or the second mixed sublayer may comprise particles directed from the second and fourth nozzle rows, but not the first and third nozzle rows.

[0016] According to another aspect, an organic light-emitting diode (OLED) display is provided. The OLED display includes a substrate with a plurality of pixels comprising a cathode layer. The cathode layer includes a first mixed sublayer of a first and a second material and a second mixed sublayer of the first and the second material over the first mixed sublayer. In some embodiments, the cathode layer can be manufactured according to any of the methods described herein and / or using any of the material deposition assemblies described herein.

[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 othermanner. 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 display devices. Also, devices other 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 schematically shows a vacuum deposition system with a material deposition assembly according to embodiments in a view from above;

[0020] FIG. 2 shows a schematic side view of a material deposition assembly according to embodiments;

[0021] FIG. 3 shows a cross section of a material deposition assembly according to embodiments;

[0022] FIG. 4 shows a cross section of a material deposition assembly according to embodiments in further detail;

[0023] FIG. 5 shows a cross section of a material deposition assembly according to further embodiments;

[0024] FIG. 6 shows a cross section of a material deposition assembly according to further embodiments;

[0025] FIG. 7 shows a cross section of a material deposition assembly according to further embodiments;

[0026] FIG. 8 illustrates a method of depositing materials on a substrate with a material deposition assembly according to embodiments; and

[0027] FIG. 9 shows a schematic view of a substrate with an OLED layer stack manufactured according to methods and / or using assemblies of the present disclosure.DETAILED DESCRIPTION

[0028] 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. 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 apply to a corresponding part or aspect in another embodiment as well.

[0029] A vacuum deposition chamber is a vacuum chamber configured for vacuum deposition of materials on a substrate, like for example the deposition of metallic materials for OLED display manufacturing, for example in order to form an electrode, particularly a cathode.

[0030] 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 10’5mbar and about 10’8mbar.

[0031] In the present disclosure, a "crucible" can be understood as a device having a reservoir for the material to be evaporated by heating the crucible. Accordingly, a"crucible" can be understood as a source material reservoir which can be heated to evaporate the source material into a material vapor, by evaporating the source material. The crucible can include a heater to evaporate the source material in the crucible into a gaseous material (i.e., a vapor material). For instance, initially the material to be evaporated can be in the form of a powder or a grain. The reservoir can have an inner volume for receiving the source material to be evaporated, e.g. a metallic material. In particular, the crucible may include a heating unit configured for heating the source material provided in the inner volume of the crucible up to a temperature at which the source material evaporates. For instance, the crucible may be a crucible for evaporating metal materials.

[0032] Embodiments described herein particularly relate to the deposition of materials, e.g. for display manufacturing to manufacture an OLED device, on a substrate.

[0033] FIG. 9 is a schematic sectional view showing two parts of an OLED layer stack 760 on a substrate 10 manufactured with OLED pixel patterning techniques in accordance with methods described herein. Adjacent pixel-defining layer (PDL) structures 715 are formed on an upper surface of the substrate 10 and define pixel regions 13, and overhang structures 720 are disposed on the PDL structures. 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. 9, a sidewall 11 adjacent to the pixel region 13 is schematically depicted, and an overhang 12 projects from the sidewall 11 partially over the pixel region 13. The pixel region 13 is surrounded by two or more sidewalls, and overhangs may be formed on said sidewalls and project partially over the pixel region 13 from different sides. In FIG. 9, a first overhang 190-R is provided on a first side of the pixel region 13 and a second overhang 190-L is provided on a second side of the pixel region 13, the first and second overhangs facing into different directions, particularly toward each other with a pixel region arranged therebetween.

[0034] By depositing various materials on the pixel regions to defined positions under the overhang 12, in combination with subsequent etching / patterning, individually switchable pixels can be formed on the substrate. The deposition of metals and organiclayers to predetermined regions, particularly under the overhangs, is challenging.

[0035] The lower portion 720B with the sidewall 11 can be made of a conductive material meant to be in contact with a cathode layer 710 of the OLED layer stack 760 and may allow a connection of the cathode layer 710 with a cathode potential. Alternatively or additionally, at least a part of the sidewall 11 may include an assistant cathode 716 meant to be in contact with the cathode layer 710 of the OLED layer stack. The upper portion 720A that forms the overhang 12 may be made of a non-conductive inorganic material or alternatively, of a conductive inorganic material.

[0036] The OLED layer stack 760 generally includes, in the following order, an anode layer 714, a hole injection layer 718, at least one organic layer 713 (made of one or more organic materials), an electron injection layer 712, and the cathode layer 710.

[0037] The at least one organic layer 713, the hole injection layer 718, and the electron injection layer 712 do not substantially contact the sidewall 11 , whereas the cathode layer 710 contacts the sidewall 11 under the overhang 12. For ensuring the underlying layers do not substantively contact the sidewall 11 under the overhang, the respective vapor plumes 732 may be shaped differently (e.g. have a different opening angle and / or a different tilting angle relative to a substrate normal) as compared to metal vapor plumes 731 that form the cathode layer 710. For example, the metal vapor plumes 731 may have a larger opening angle and / or a stronger tilting angle as compared to (e.g., organic) vapor plumes of underlying layers.

[0038] As is illustrated in FIG. 9, the cathode layer 710 according to some embodiments described herein includes a first mixed sublayer 701 (comprising a first metal and a second metal, e.g., Mg and Ag) and a second mixed sublayer 702 (comprising the first and second metal) deposited generally above the first mixed sublayer 701. Both the first and second mixed sublayers may include same materials, particularly a first and a second material co-deposited, as described herein. The first mixed sublayer 701 may provide a reliable cathode contact below the first overhang 190-R, and the second mixed sublayer 702 may provide a reliable cathode contact below the second overhang 190-L, or vice versa. The first and second mixed sublayerstogether may form a uniform cathode layer of the OLED layer stack, including the first and second materials in an essentially uniform mixing ratio.

[0039] In view of the above, according to embodiments described herein, methods and apparatuses are described that allow a reliable deposition of layers of an OLED layer stack on substrates, particularly on substrates with overhang structures formed thereon. Some of the methods described herein improve an electrical contact of a cathode layer with sidewalls under overhangs, particularly with sidewalls below a first overhang 190-R and a second overhang 190-L that face in opposite directions, e.g. provided on opposite sides of a pixel region. Embodiments described herein are, however, not limited to OLED layer manufacturing, and can be used for depositing other layers or layers stacks on various types of substrates.

[0040] FIG. 1 shows a vacuum deposition system 1000 with a material deposition assembly 100 in a first vacuum chamber 1001 according to embodiments described herein, in a schematic top view. The vacuum deposition system 1000 may optionally include one or more further vacuum chambers that may house one or more further evaporation sources, e.g., a second evaporation source 102. The vacuum deposition system 1000 may include five, ten, or more than ten evaporation sources, for coating the substrate with a plurality of layers. 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. Alternatively, one or more evaporation sources may be configured to coat non-vertically oriented substrates, such as horizontally oriented substrates. A plurality of materials, that may include one or more inorganic materials, particularly metals, and one or more organic materials, can be deposited in succession onto the substrate for providing a layer stack on the substrate, particularly 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.

[0041] The vacuum deposition system 1000 may include the substrate transportation track 1013 configured to move the substrate 10 along a substrate transport path T past the material deposition assembly 100 and past the optional further evaporation sources. The substrate transportation track 1013 may extend atleast 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.

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

[0043] Embodiments described herein particularly relate to the deposition of materials, e.g. for display manufacturing on large area substrates. According to some embodiments, large area substrates or carriers supporting one or more substrates may have a size of 1 m2or larger. For instance, the deposition system may be adapted for processing large area substrates, such as substrates of GEN 5, which corresponds to approximately 1.4 m2substrates (1.1 m x 1.3 m), GEN 6, which corresponds to approximately 2.7 m2(1.5 m x 1.8 m), GEN 7.5, which corresponds to approximately 4.29 m2substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to approximately 5.7 m2substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to approximately 8.7 m2substrates (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can be similarly implemented. Alternatively or additionally, semiconductor wafers may be processed and coated in deposition systems according to the present disclosure.

[0044] FIG. 2 schematically shows a material deposition assembly 100 according to embodiments described herein in a view from the side. The material deposition assembly 100 may have crucibles 121 configured to evaporate different source materials (e.g., a host material and a dopant material, or two different metals) to be codeposited onto the substrate and vapor distribution pipes configured to direct the evaporated source materials towards the substrate through a plurality of nozzles. For instance, a vapor distribution tube or vapor distribution pipe may provide a line source with a plurality of nozzles arranged in a row (or “line array”) one above the other alonga length direction of the vapor distribution pipe. The row of nozzles may be provided along a longitudinal direction V (typically an essentially vertical direction, or alternatively a non-vertical direction, such as a horizontal direction) of the vapor distribution pipe to provide an essentially vertical line source, or alternatively an essentially horizontal line source. Each vapor distribution pipe may have at least one row of nozzles, particularly two rows of nozzles, suitable to coat substrates having an essentially vertical orientation. Alternatively, the one or more vapor distribution pipes of the material deposition assembly may be configured to coat non-vertically oriented substrates, such as horizontally or essentially horizontally oriented substrates.

[0045] 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 less than 10°. An “essentially horizontal direction” relates to a direction that is horizontal + / - 10°.

[0046] In some embodiments, a crucible may be located at the bottom of the respective vapor distribution pipe for feeding the material vapor into the vapor distribution pipe from below (“bottom -feed”). In some embodiments, as it is shown in FIG. 2, a crucible may be located between the bottom and top of the respective vapor distribution pipe, e.g., at a middle or center position, for feeding the material vapor into the vapor distribution pipe at a center position (“center-feed”).

[0047] A vapor distribution pipe may have an enclosure, hollow space, or tube, in which the evaporated material can be provided or guided, for example from the crucible to the nozzles. According to embodiments which can be combined with any other embodiments described herein, the length of the distribution pipe may correspond at least to the height of the substrate to be deposited. In particular, the length of the distribution pipe may be longer than the height of the substrate to be deposited, at least by 10% or even 20%. For instance, the source material to be deposited may be a metallic material for use as electrode material or electron transport layer materials in organic light emitting diode (OLED) production.

[0048] As is schematically depicted in FIG. 2, the material deposition assembly 100 includes a first vapor distribution pipe 120 extending in the longitudinal direction V and including rows of nozzles 130 for depositing a first material onto the substrate 10, and(at least) a second vapor distribution pipe (not shown in FIG. 2, but shown in FIG. 3) extending in the longitudinal direction V, adjacent to the vapor distribution pipe 120, the second vapor distribution pipe having rows of nozzles for depositing a second material onto the substrate. The material deposition assembly may optionally have further vapor distribution pipes. The nozzles of each row of nozzles may be arranged one above the other in an essentially vertical nozzle array, as is schematically depicted in FIG. 2, e.g., 20 or more nozzles per nozzle row. The material deposition assembly 100 may be configured to deposit at least two different materials onto the substrate with two or more vapor distribution pipes arranged adjacent to each other, e.g. two different metals. The vapor distribution pipes may be arranged on a source body 113 that may optionally be rotatable around a rotation axis.

[0049] FIG. 3 shows a material deposition assembly 100 according to embodiments in a sectional view, particularly in a horizontal sectional plane. The material deposition assembly 100 is configured to deposit first and second materials on the substrate 10 that is arranged in the substrate plane 15, in front of the material deposition assembly 100. Typically, the substrate 10 is moved past the material deposition assembly 100 along a substrate transport path T.

[0050] The material deposition assembly 100 includes a first vapor distribution pipe 120-1 for directing a first material toward the substrate plane 15, i.e., onto the substrate 10, and a second vapor distribution pipe 120-2 for directing a second material toward the substrate plane 15, i.e., onto the substrate 10. The first vapor distribution pipe 120- 1 may be in fluid communication with a first material crucible for evaporating the first material, and the second vapor distribution pipe 120-2 may be in fluid communication with a second material crucible for evaporating the second material.

[0051] The first vapor distribution pipe 120-1 includes a first nozzle row 130-1 and a second nozzle row 130-2, both nozzle rows configured to direct the first material toward the substrate 10. The second vapor distribution pipe 120-2 includes a third nozzle row 130-3 and a fourth nozzle row 130-4, both nozzle rows configured to direct the second material toward the substrate 10.

[0052] The first nozzle row 130-1 and the third nozzle row 130-3 are configured to deposit a first mixed sublayer including the first and second materials onto thesubstrate 10 being moved past to the material deposition assembly 100. The second nozzle row 130-2 and the fourth nozzle row 130-4 are configured to deposit a second mixed sublayer comprising the first and second materials onto the substrate 10 being moved past to the material deposition assembly 100. The second mixed sublayer is generally deposited over the first mixed sublayer (apart from edge regions under overhangs, where only one of the first and second mixed sublayers may be present, as is illustrated in FIG. 9). In particular, both the first and second mixed sublayers may be deposited on the substrate in a single pass of the substrate 10 past the material deposition assembly 100, as is schematically illustrated in FIG. 3.

[0053] As is schematically depicted in FIG. 3, the first nozzle row 130-1 may be configured to direct the first material from the first vapor distribution pipe 120-1 onto a first region 110-R in the substrate plane 15, and the third nozzle row 130-3 may be configured to direct the second material onto a third region in the substrate plane substantially overlapping with the first region 110-R for depositing the first mixed sublayer. In particular, the first region and the third region may be essentially congruent with a first-sublayer deposition area consisting of the first region and the third region. An overlap area of the first region and the first-sublayer deposition area may be 90% or more of the first-sublayer deposition area, and an overlap area of the third region and the first-sublayer deposition area may be 90% or more of the first-sublayer deposition area.

[0054] The second nozzle row 130-2 may be configured to direct the first material onto a second region 110-L in the substrate plane 15, and the fourth nozzle row 130- 4 may be configured to direct the second material onto a fourth region in the substrate plane substantially overlapping with the second region 110-L for depositing the second mixed sublayer over the first mixed sublayer. In particular, the second region and the fourth region may be essentially congruent with a second-sublayer deposition area consisting of the second region and the fourth region. An overlap area of the second region and the second-sublayer deposition area may be 90% or more of the second- sublayer deposition area, and an overlap area of the fourth region and the second- sublayer deposition area may be 90% or more of the second-sublayer deposition area. Providing a good overlap between the first region and the third region in the substrate plane ensures a uniform mixing of the first and second materials throughout the firstmixed material sublayer, and providing a good overlap between the second region and the fourth region in the substrate plane ensures a uniform mixing of the first and second materials throughout the second mixed material sublayer. Overall, a good mixing of the first and second materials within both the first and second mixed sublayers that may constitute the cathode layer can be provided.

[0055] In some embodiments, which can be combined with other embodiments described herein, the first region 110-R and the second region 110-L in the substrate plane do not substantially overlap, particularly do not overlap at all, i.e., are distinct from each other. In particular, the first region 110-R (= the “first-sublayer deposition area” as defined above) and the second region 110-L (= the “second-sublayer deposition area” as defined above) are substantially distinct from each other. An overlap area of the first region 110-R and the second region 110-L may be less than 10% of the first region and less than 10% of the second region. By providing the first- sublayer deposition area and the second-sublayer deposition area in the substrate plane that are distinct from each other, two defined sublayers can be deposited on top of each other, particularly with an essentially constant mixing ratio of the first and second materials in both sublayers and particularly in the whole two-layer system which may constitute a cathode layer.

[0056] In some embodiments, the nozzles of the first nozzle row 130-1 and of the third nozzle row 130-3 are oriented toward a first lateral side relative to the substrate plane normal 112, and the nozzles of the second nozzle row 130-2 and the fourth nozzle row 130-4 are oriented toward a second lateral side relative to the substrate plane normal 112, away from the first lateral side. In particular, as is shown in FIG. 3, the nozzle channels of the nozzles of the first and third nozzle rows may be inclined relative to the substrate plane normal 112 toward a first side, particularly for increasing a deposition below a first overhang 190-R, and the nozzle channels of the nozzles of the second and fourth nozzle rows may be inclined relative to the substrate plane normal 112 toward a second side away from the first side, particularly for increasing a deposition below a second overhang 190-L, wherein the first and second overhangs may face in different directions, e.g., toward each other over a pixel region.

[0057] In some embodiments, the nozzles of the first nozzle row 130-1 have a first main evaporation direction (which may typically essentially correspond to the length direction of the respective nozzle channels) inclined relative to the substrate plane normal 112 at a first angle (a1 ) in a range between 10° and 80°, particularly between 30° and 70°, more particularly about 55°, and / or the nozzles of the third nozzle row 130-3 may have a third main evaporation direction inclined relative to the substrate plane normal 112 at a third angle in a range between 10° and 80°, particularly between 20° and 60°, more particularly about 45°. In particular, the first and third angles that define an inclination of the nozzles of first and third nozzle rows relative to the substrate plane normal 112 may be directed to provide a good overlap of the vapor plumes 140-1 emitted by the first nozzle row 130-1 and the vapor plumes 140-3 emitted by the third nozzle row 130-3 in the substrate plane, while ensuring a tilted evaporation to an area below a first overhang 190-R. In some embodiments, the (absolute value of the) first angle is larger than the (absolute value of the) third angle, in order to improve the overlap.

[0058] In some embodiments, the nozzles of the second nozzle row 130-2 have a second main evaporation direction (which may typically essentially correspond to the length direction of the respective nozzle channels) inclined relative to the substrate plane normal 112 at a second angle (a2) in a range between -10° and -80°, particularly between -30° and -70°, more particularly about -55°, and / or the nozzles of the fourth nozzle row 130-4 may have a fourth main evaporation direction inclined relative to the substrate plane normal 112 at a fourth angle in a range between -10° and -80°, particularly between -20° and -60°, more particularly about -45°. In particular, the second and fourth angles that define an inclination of the nozzles of second and fourth nozzle rows relative to the substrate plane normal 112 may be directed to provide a good overlap of the vapor plumes 140-2 emitted by the second nozzle row 130-2 and the vapor plumes 140-4 emitted by the fourth nozzle row 130-4 in the substrate plane, while ensuring a tilted evaporation to an area below a second overhang 190-L. In some embodiments, the (absolute value of the) second angle is larger than the (absolute value of the) fourth angle, in order to improve the overlap.

[0059] In some embodiments, the first angle and the second angle may have essentially same absolute values, but opposite signs relative to the substrate planenormal 112, and / or the third angle and the fourth angle may have essentially same absolute values, but opposite signs relative to the substrate plane normal 112.

[0060] In some embodiments, the material deposition assembly 100 may be overall configured substantially symmetrical with respect to a symmetry plane 112 (particularly a vertically extending symmetry plane) perpendicular to the substrate plane 15. In particular, the first vapor distribution pipe 120-1 with the first and second nozzle rows may be essentially symmetrical with respect to the symmetry plane, and the second vapor distribution pipe 120-2 (which may be optionally replaced by two second vapor distribution pipes 120-2, as shown in FIG. 6) with the third and fourth nozzle rows may be essentially symmetrical with respect to the symmetry plane. The layer uniformity and the layer configuration of the layers deposited by the material deposition assembly can be improved by providing a symmetrical deposition assembly.

[0061] In some implementations, the nozzles of the first nozzle row and / or the nozzles of the second nozzle row emit vapor plumes with plume opening angles (P) (in a lateral direction) in a range from 10° to 80°, particularly from 20° to 50°, such as about 30°. Alternatively or additionally, the nozzles of the third nozzle row and / or the nozzles of the fourth nozzle row emit vapor plumes with plume opening angles (in a lateral direction) in a range from 20° to 90°, particularly from 30° to 60°, such as about 45°. In some embodiments, the (lateral) plume opening angles (P) may be defined by respective shaper shields arranged between the nozzle row and the substrate plane that may be configured to define a lateral width of the vapor plumes. In some embodiments, the plume opening angles of the nozzles of the first and second nozzle row are smaller as compared to the plume opening angles of the nozzles of the third and fourth nozzle row, in order to improve an overlap provided by the first and third nozzle rows and / or to improve an overlap provided by the second and fourth nozzle rows.

[0062] A large plume opening angle (in a lateral direction L) can ensure that at least an edge of the vapor plumes will enter in an area below an overhang. However, an opening angle that is too large can lead to a reduced layer uniformity and to undesired stray coating in the vacuum chamber. The above-mentioned ranges of plume opening angles and nozzle tilting angles in combination can ensure a good layer uniformitywhile ensuring deposition under overhang areas, e.g., to ensure a reliable cathode contact.

[0063] It is noted that, in some embodiments, the plume opening angles are defined by shields (i.e., by a “shaper arrangement”) that may be positioned between the vapor distribution pipes and the substrate plane (see figures 4 to 7). The shields may block lateral edges of the vapor plumes, e.g., for improving plume overlaps between the vapor plumes of the first and third nozzle rows and between the vapor plumes of the second and fourth nozzle rows and / or for avoiding plume overlaps between the vapor plumes of the first and second nozzle rows. In some embodiments, the shields are configured to ensure that the vapor plumes emitted by nozzle rows impinge on a predetermined area in the substrate plane, respectively.

[0064] In particular, the material deposition assembly may include a shaper arrangement disposed between the first and second vapor distribution pipes and the substrate plane, wherein the shaper arrangement may include two or more essentially vertically extending slit openings, e.g., one vertical slit opening per nozzle row, to define lateral plume opening angles and / or to limit lateral edges of the vapor plumes emitted by the first, second, third and fourth nozzle rows. The shaper arrangement 160 is shown in figures 4 to 7.

[0065] In some embodiments, which can be combined with other embodiments described herein, the first nozzle row 130-1 and the second nozzle row 130-2 of the first vapor distribution pipe 120-1 are arranged generally between the third nozzle row 130-3 and the fourth nozzle row 130-4 of the second vapor distribution pipe 120-2, as is schematically depicted in FIG. 3, or vice versa. In particular, the four nozzle rows may be located in the same plane or substantially in the same plane (that may extend parallel to the substrate plane 15), with the first and second nozzle rows arranged between the third and fourth nozzle rows. Accordingly, the substrate can be moved past the third, first, second, and fourth nozzle rows in succession, while depositing the first and second mixed sublayers on the substrate. A compact and space-saving material deposition assembly can be provided.

[0066] In some implementations, the second vapor distribution pipe 120-2 is arranged at least in part along a perimeter of the first vapor distribution pipe 120-1 , inparticular to at least partially surround the first vapor distribution pipe 120-1 , particularly by an angle of 90° or more, more particularly 120° or more, or even about 180°. Specifically, the second vapor distribution pipe 120-2 may surround the first vapor distribution pipe 120-1 on two or three sides thereof, e.g., by an angle of 120° or more, or by about 180°. When the second vapor distribution pipe 120-2 partially surrounds the first vapor distribution pipe 120-1 , the first and second nozzle rows of the first vapor distribution pipe 120-1 can be arranged between the third and fourth nozzle rows of the second vapor distribution pipe 120-2, and a compact and space-saving material deposition assembly can be provided that includes two vapor distribution pipes configured to deposit two mixed material layers.

[0067] In addition, when two or more walls of the first vapor distribution pipe extend adjacent to, and particularly parallel to, two or more walls of the second vapor distribution pipe, heat can be reliably transferred between the second and first vapor distribution pipes, so that the overall heating efforts can be reduced. For example, heat from the second vapor distribution pipe that partially surrounds the first vapor distribution pipe can be transferred to the first vapor distribution pipe being arranged adjacent thereto on several sides thereof, so that a reduced number of heaters for heating the first vapor distribution pipe may be sufficient. In some embodiments, the first vapor distribution pipe can be passively (or indirectly) heated by the second vapor distribution pipe, so that, for example, no inner heater of the first vapor distribution pipe may be required.

[0068] In some embodiments, which can be combined with other embodiments described herein, the first material may have a first vaporization temperature and the second material may have a second vaporization temperature higher than the first vaporization temperature. The first vapor distribution pipe can be passively or indirectly heated by the second vapor distribution pipe. For example, the first vaporization temperature may be below 1000°C and the first material may be magnesium, and / or the second vaporization temperature may be above 1000°C and the second material may be silver. In some embodiments, an inner volume of the first vapor distribution pipe is maintained in a temperature range from 400°C to 800°C, and an inner volume of the second vapor distribution pipe is maintained in a temperature range from 1000°C to 1400°C.

[0069] In particular, in some embodiments, the second vapor distribution pipe 120- 2, but not the first vapor distribution pipe 120-1 , may include an inner heater, the inner heater configured to directly heat the second vapor distribution pipe 120-2 and to indirectly heat the first vapor distribution pipe 120-1 .

[0070] In some implementations, the first vapor distribution pipe 120-1 is at least partially arranged in a spatial region between the second vapor distribution pipe 120-2 and the substrate plane 15. In particular, the second vapor distribution pipe 120-2 may surround the first vapor distribution pipe 120-1 on a rear side (viewed from the substrate plane) and at least partially on two lateral side thereof, i.e. , in the substrate transport direction before and after the first vapor distribution pipe. A compact material deposition assembly can be provided, and one second material crucible is sufficient for providing the second material to the two nozzle rows of the second vapor evaporation pipe arranged on two sides of the first vapor distribution pipe in a substrate transport direction. Further, thermal energy can be saved.

[0071] In some embodiments, a distance of the first nozzle row and the second nozzle row from the substrate plane 15 may be in a range between 100mm and 300mm; and a distance of the third nozzle row and the fourth nozzle row from the substrate plane 15 may be in a range between 100mm and 300mm. In particular distances of the first, second, third and fourth nozzle rows from the substrate plane 15 may be substantially equal, particularly in a range between 100 mm and 300 mm.

[0072] According to embodiments described herein, cathode contacts can be provided under a first overhang and under a second overhang on opposite sides of a pixel area, as is schematically depicted in FIG. 9, wherein the first mixed material layer of the cathode layer provides a good cathode contact under a first overhang and the second mixed material layer of the cathode layer provides a good cathode contact under a second overhang, the first and second overhangs being provided on opposite sides of a pixel region.

[0073] In addition, the material mixing within the cathode layer, including areas behind overhangs, can be improved and a high material utilization can be ensured. Further, a compact material deposition assembly can be provided.

[0074] In some embodiments, the material deposition assembly may include more than two vapor distribution pipes, e.g. one or more further vapor distribution pipes for depositing further materials on the substrate, such as Ytterbium, to provide, e.g., an electron injection layer below the cathode layer.

[0075] FIG. 4 shows a cross section of a material deposition assembly 100 according to some embodiments of the present disclosure. The material deposition assembly 100 is generally similar to the material deposition assembly of FIG. 3, so that reference can be made to the above explanations, which are not repeated here. The material deposition assembly 100 includes a first vapor distribution pipe 120-1 with a first nozzle row 130-1 and a second nozzle row 130-2.

[0076] The plurality of nozzles of the first nozzle row 130-1 extends perpendicularly to the cross section shown in FIG. 4. Each nozzle of the first nozzle row 130-1 may have an orthogonal projection onto the cross section shown in FIG. 4 in correspondence of the point M. The plurality of nozzles of the second nozzle row 130-2 extends perpendicularly to the cross section shown in FIG. 4. Each nozzle of the second nozzle row 130-2 may have an orthogonal projection onto the cross section shown in FIG. 4 in correspondence of the point N.

[0077] The material deposition assembly 100 further includes a second vapor distribution pipe 120-2 with a third nozzle row 130-3 and a fourth nozzle row 130-4. The plurality of nozzles of the third nozzle row 130-3 extends perpendicularly to the cross section shown in FIG. 4. Each nozzle of the third nozzle row 130-3 may have an orthogonal projection onto the cross section shown in FIG. 4 in correspondence of the point P. The plurality of nozzles of the fourth nozzle row 130-4 extends perpendicularly to the cross section shown in FIG. 4. Each nozzle of the fourth nozzle row 130-4 may have an orthogonal projection onto the cross section shown in FIG. 4 in correspondence of the point Q.

[0078] The material deposition assembly 100 is configured to deposit the first and second material onto a substrate arranged in the substrate plane 15 that also extends perpendicularly to the plane of FIG. 4. The first nozzle row 130-1 , the second nozzle row 130-2, the third nozzle row 130-3, and the fourth nozzle row 130-4 extend substantially parallel to the substrate plane 15.

[0079] The vapor of the first material is guided within the first vapor distribution pipe 120-1 and reaches the nozzles of the first nozzle row 130-1 and the nozzles of the second nozzle row 130-2. The first material can be directed onto the substrate by the first nozzle row 130-1 and by the second nozzle row 130-2.

[0080] The nozzles of the first nozzle row 130-1 are configured to direct the vapor plumes 140-1 of the first nozzle row onto the substrate plane 15. The vapor plumes 140-1 of the first nozzle row are therefore vapor plumes of the first material. The nozzles of the second nozzle row 130-2 are configured to direct the vapor plumes 140- 2 of the second nozzle row onto the substrate plane 15. The vapor plumes 140-2 of the second nozzle row are therefore vapor plumes of the first material.

[0081] The vapor plumes 140-1 of the first nozzle row 130-1 are the vapor plumes emitted by the nozzles of the first nozzle row. The vapor plumes 140-1 of the first nozzle row 130-1 may have a projection onto the cross section shown in FIG. 4 formed by the region delimited by the triangle AMC. A main evaporation direction provided by the first nozzle row 130-1 is a direction parallel to the line MB.

[0082] The vapor plumes 140-2 of the second nozzle row 130-2 are the vapor plumes emitted by the nozzles of the second nozzle row. The vapor plumes 140-2 of the second nozzle row 130-2 may have a projection onto the cross section shown in FIG. 4 formed by the region delimited by the triangle DNF. A main evaporation direction provided by the second nozzle row 130-2 is a direction parallel to the line NE.

[0083] The second vapor distribution pipe 120-2 is in fluid communication with a second evaporation crucible configured to evaporate a second material different from the first material. The vapor of the second material is guided through the second vapor distribution pipe 120-2 and reaches the nozzles of the third nozzle row 130-3 and the nozzles of the fourth nozzle row 130-4.

[0084] The nozzles of the third nozzle row 130-3 are configured to direct the vapor plumes 140-3 of the third nozzle row onto the substrate plane 15. The vapor plumes 140-3 of the third nozzle row are therefore vapor plumes of the second material. The nozzles of the fourth nozzle row 130-4 are configured to direct the vapor plumes 140-4 of the fourth nozzle row onto the substrate plane 15. The vapor plumes 140-4 of the fourth nozzle row are therefore vapor plumes of the second material.

[0085] The vapor plumes 140-3 of the third nozzle row 130-3 are the vapor plumes emitted by the nozzles of the third nozzle row. The vapor plumes 140-3 of the third nozzle row 130-3 may have a projection onto the cross section shown in FIG. 4 formed by the region delimited by the triangle APC. A main evaporation direction provided by the third nozzle row 130-3 is a direction parallel to the line PB.

[0086] The vapor plumes 140-4 of the fourth nozzle row 130-4 are the vapor plumes emitted by the nozzles of the fourth nozzle row. The vapor plumes 140-4 of the fourth nozzle row 130-4 may have a projection onto the cross section shown in FIG. 4 formed by the region delimited by the triangle DQF. A main evaporation direction provided by the fourth nozzle row 130-4 is a direction parallel to the line QE.

[0087] In some embodiments, one or more heat shields 150-1 may be provided between the first and the second vapor distribution pipes, and / or one or more heat shields 150-2 may be provided on outer sides of the second vapor distribution pipe facing away from the first vapor distribution pipe.

[0088] The second vapor distribution pipe 120-2 may be provided with an inner heater 180 to control a temperature within the second vapor distribution pipe. In some embodiments, the first vapor distribution pipe 120-1 is passively heated by the heat of the second vapor distribution pipe 120-2.

[0089] A shaper arrangement 160 may be disposed between the first and the second vapor distribution pipes and the substrate plane 15 to properly shape the vapor plumes.

[0090] The first nozzle row 130-1 and the third nozzle row 130-3 are configured to deposit the first mixed sublayer comprising the first and the second materials onto the substrate, and the second nozzle row 130-2 and the fourth nozzle row 130-4 are configured to deposit the second mixed sublayer onto the substrate, when the substrate is moved relative to the material deposition assembly in the substrate plane 15, particularly in a single pass. In the embodiment shown in FIG. 4, the substrate maybe moved in the substrate plane 15. The substrate passes along the points C, B, A, D, E, F, i.e. moves in the substrate plane 15 from right to left with respect to the cross section of FIG. 4.

[0091] The first mixed sublayer of the first and the second materials is deposited onto the substrate in the first region 110-R in the substrate plane 15. The second mixed sublayer of the first and the second materials is deposited on top of the first mixed sublayer onto the substrate in the second region 110-L in the substrate plane 15 (however, in edge regions under overhangs, only one of the first and second mixed sublayers may optionally be present, as is illustrated in FIG. 9).

[0092] According to some embodiments, when the substrate is moved in the substrate plane 15 past the material deposition assembly, the first mixed sublayer is deposited by the first and third nozzle rows, followed (immediately) by the deposition of the second mixed sublayer by the second and fourth nozzle rows on top of the first mixed sublayer.

[0093] The main evaporation direction provided by the first nozzle row 130-1 and the main evaporation direction provided by the third nozzle row 130-3, i.e. the direction along MB and PB respectively, and the lateral plume opening angles of the nozzles of the first and third nozzle rows may be chosen such that both the vapor plumes 140-1 of the first nozzle row and the vapor plumes 140-3 of the third nozzle row intersect the substrate plane 15 substantially in the same first region 110-R of the substrate plane 15. The lateral plume openings can be appropriately adjusted by the shaper arrangement 160 that may cut lateral edges of the vapor plumes.

[0094] The main evaporation direction provided by the second nozzle row 130-2 and the main evaporation direction provided by the fourth nozzle row 130-4, i.e. the direction along NE and QE respectively, and the lateral plume opening angles of the nozzles of the second and fourth nozzle row may be chosen such that both the vapor plumes 140-2 of the second nozzle row and the vapor plumes 140-4 of the fourth nozzle row intersect the substrate plane 15 substantially in the same second region 110-L of the substrate plane 15. The lateral plume openings can be appropriately adjusted by the shaper arrangement 160 that may cut lateral edges of the vapor plumes.

[0095] The main evaporation direction of the first nozzle row 130-1 and the main evaporation direction of the third nozzle row 130-3 can be configured such that the first material and the second material are directed at least in part behind the first overhang 190-R of the OLED device arranged on a first side of a pixel region.

[0096] The main evaporation direction of the second nozzle row 130-2 and the main evaporation direction of the fourth nozzle row 130-4 can be configured such that the first material and the second material are directed at least in part behind a second overhang 190-L of the OLED device, wherein the second overhang and the first overhang may be provided on opposite sides of the pixel region and face toward each other.

[0097] When the substrate is moved in the substrate plane, the overhang structures move together with the substrate. Accordingly, by moving the substrate past the material deposition assembly, a mixed sublayer of both the first and the second materials is deposited behind the first overhang 190-R and behind the second overhang 190-L, and also behind a plurality of other first overhangs facing into a first direction and a plurality of other second overhangs facing into a second direction provided on the substrate and delimiting a plurality of pixel regions.

[0098] In particular, the vapor plumes 140-1 of the first nozzle row 130-1 in combination with the vapor plumes 140-3 of the third nozzle row 130-3 deposit a first mixed sublayer below the first overhang 190-R; and the vapor plumes 140-2 of the second nozzle row 130-2 in combination with the vapor plumes 140-4 of the fourth nozzle row 130-4 deposit a second mixed sublayer below the second overhang 190- L.

[0099] The first and second materials can hence be deposited under overhang structures of the OLED device provided on opposite sides of a pixel region and facing toward each other, when the substrate is moved in the substrate plane, particularly in one pass of the substrate past the material deposition assembly. As a consequence, no additional metal evaporation sources may be required for coating the substrate with a cathode layer that reaches under oppositely arranged overhead structures.

[0100] FIG. 5 shows a cross section of a material deposition assembly 200 according to further embodiments. The material deposition assembly 200 shown in FIG. 5 is similar to the material deposition assembly 100 shown in FIG. 4, with the difference that an inner heater 280 is provided also in the first vapor distribution pipe 120-1.

[0101] FIG. 6 shows a cross section of a material deposition assembly 300 according to some further embodiments. The embodiment shown in FIG. 6 is generally similar to the embodiments of FIG. 3 and FIG. 4, with the difference that the (single) second vapor distribution pipe is replaced by two separate second vapor distribution pipes that may be provided on different sides of the first vapor distribution pipe.

[0102] The material deposition assembly 300 shown in FIG. 6 includes, instead of one second vapor distribution pipe partially surrounding the first vapor distribution pipe, two second vapor distribution pipes 120-2L and 120-2R arranged adjacent to the first vapor distribution pipe 120-1 , particularly on two opposite sides thereof in the substrate transport direction. Each of the two second vapor distribution pipes has one of the third and fourth nozzle rows. For example, a right second vapor distribution pipe 120-2R may have the third nozzle row 130-3 and a left second vapor distribution pipe 120-2L may have the fourth nozzle row 130-4.

[0103] One common second material crucible may be provided for evaporating the second material that is guided through the two second vapor distribution pipes to the third and fourth nozzle rows. Alternatively, each of the two second vapor distribution pipes may have a respective own second material crucible for evaporating the second materials.

[0104] Just like the previously described embodiments that have one second vapor distribution pipe that is arranged partially behind the first vapor distribution pipe, the material deposition assembly 300 of FIG. 6 is configured to deposit a first mixed sublayer including the first and second materials on the substrate with the first nozzle row 130-1 and the third nozzle row 130-3, and is configured to deposit a second mixed sublayer including the first and second materials on the substrate with the second nozzle row 130-2 and the fourth nozzle row 130-4. Reference is made to the above explanations, which are not repeated here. In particular, the first region 110-R in thesubstrate plane (= the first-sublayer deposition area) does not overlap with the second region 110-L in the substrate plane 15 (= the second-sublayer deposition area) in some embodiments.

[0105] FIG. 7 shows a cross section of a material deposition assembly 400 according to some further embodiments of the present disclosure.

[0106] The material deposition assembly 400 of FIG. 7 is generally similar to the material deposition assembly 300 shown in FIG. 6, so that reference can be made to the above explanations, which are not repeated here. The first region 110-R and the second region 110-L in the substrate plane 15 are adjacent to each other in the embodiment shown in FIG. 7, and the first nozzle row and the third nozzle row are tilted toward each other, and the second nozzle row and the fourth nozzle row are tilted toward each other. In particular, the main evaporation directions of the first and third nozzle rows may have different signs relative to the substrate plane normal 112, and / or the main evaporation directions of the second and fourth nozzle rows may have different signs relative to the substrate plane normal. In the embodiment of FIG. 7, the deposition behind the overhangs may be reduced and possibly less uniform as compared to the previous embodiments.

[0107] Material deposition assemblies according to the present disclosure may be substantially symmetrical with respect to a symmetry plane perpendicular to the substrate plane.

[0108] FIG. 5 illustrates a method 500 of depositing materials on a substrate with a material deposition assembly according to any of the embodiments of the present disclosure.

[0109] The method 500 may be carried out with a material deposition assembly according to any of the embodiments described herein.

[0110] The method 500 includes transporting 502 the substrate past the material deposition assembly in a substrate plane 15 while directing the first material toward the substrate from the first and second nozzle rows and while directing the second material toward the substrate from the third and fourth nozzle rows.

[0111] The first nozzle row and the third nozzle row are directed such that a first mixed sublayer comprising the first and second materials is deposited onto the substrate, and the second nozzle row and the fourth nozzle row are directed such that a second mixed sublayer comprising the first and second materials is deposited onto the substrate on top of the first mixed sublayer.

[0112] In some embodiments, the vapor plumes 140-1 emitted by the first nozzle row 130-1 have a first main evaporation direction inclined relative to the substrate plane normal 112 at an angle in a range between 30° and 70°, in particular about 55°. Alternatively or additionally, the vapor plumes 140-3 emitted by the third nozzle row 130-3 may have a third main evaporation direction inclined relative to the substrate normal at an angle in a range between 20° and 60°, in particular about 45°. Alternatively or additionally, the vapor plumes 140-2 emitted by the second nozzle row 130-2 may have a second main evaporation direction inclined relative to the substrate normal at an angle in a range between -30° and -70°, in particular about -55°. Alternatively or additionally, the vapor plumes 140-4 emitted by the fourth nozzle row 130-4 may have a fourth main evaporation direction inclined relative to the substrate normal at an angle in a range between -20° and -60°, in particular about -45°.

[0113] In some implementations, the first material is a first metal, particularly Magnesium (Mg), and / or the second material is a second metal, particularly silver (Ag). The first material crucible may be a magnesium crucible and the second material crucible(s) may be a silver crucible.

[0114] The first mixed sublayer may constitute a lower part of a cathode layer of an OLED layer stack, and the second mixed sublayer may constitute an upper part of a cathode layer of an OLED layer stack.

[0115] In some embodiments, the substrate includes first and second overhangs facing toward each other on opposite sides of a pixel region, and the first material and the second material are directed at least in part behind the overhangs. In particular, the first mixed sublayer may reach further under the first overhang than the second mixed sublayer, and the second mixed sublayer may reach further under the second overhang than the first mixed sublayer, or vice versa. A good cathode contact can be provided under the first overhang and under the second overhang.

[0116] In some embodiments, the first vapor distribution pipe 120-1 is passively heated by heat from the one or two second vapor distribution pipes. For example, the second vapor distribution pipe may include an inner heater that passively heats also the first vapor distribution pipe, and the first vapor distribution pipe may not include an inner heater.

[0117] In some embodiments, the first material is magnesium and the second material is silver, particularly wherein the first and second mixed sublayers respectively have a mixing ratio of silver relative to magnesium, in the range from one part of silver over one part of magnesium (1 :1 ) to ten parts of silver over one part of magnesium (10:1 ), particularly a mixing ratio Ag:Mg between 8:1 and 10:1 , such as 9:1.

[0118] In some embodiments, a first temperature within the first vapor distribution pipe is between 400°C and 800°C, particularly about 500°C, and / or a second temperature within the second vapor distribution pipe is between 1000°C and 1400°C, particularly about 1200°C.

[0119] According to another aspect described herein, an OLED display device is provided, as is exemplarily shown in FIG. 9. The OLED display device includes a substrate with a plurality of OLED pixels respectively including a cathode layer. The cathode layer is manufactured according to any of the methods and / or using any of the material deposition assemblies described herein.

[0120] The cathode layer includes a first mixed sublayer comprising the first material and the second material and a second mixed sublayer comprising the first material and the second material on top of the first mixed sublayer.

[0121] The first mixed sublayer may reach further below a first overhang structure than the second mixed sublayer. The second mixed sublayer may reach further below a second overhang structure than the first mixed sublayer. In particular, in edge regions of the mixed sublayers under the overhangs, only one of the first and second mixed sublayers may be deposited, as is illustrated in FIG. 9.

[0122] 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, but rather angled deposition of a plurality of layers of an OLED layer stack at least partially under overhangs.

[0123] 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.

[0124] 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. A material deposition assembly (100) for depositing materials on a substrate arranged in a substrate plane (15) in a vacuum deposition chamber, the material deposition assembly comprising: a first vapor distribution pipe (120-1 ) in fluid communication with a first evaporation crucible and comprising a first nozzle row (130-1 ) for directing vapor plumes (140-1 ) of the first nozzle row onto the substrate plane and a second nozzle row (130-2) for directing vapor plumes (140-2) of the second nozzle row onto the substrate plane, the vapor plumes of the first and second nozzle rows being vapor plumes of a first material; and a second vapor distribution pipe (120-2) in fluid communication with a second evaporation crucible and comprising a third nozzle row (130-3) for directing vapor plumes (140-3) of the third nozzle row onto the substrate plane and a fourth nozzle row (130-4) for directing vapor plumes (140-4) of the fourth nozzle row onto the substrate plane, the vapor plumes of the third and fourth nozzle rows being vapor plumes of a second material, wherein the first nozzle row (130-1 ) and the third nozzle row (130-3) are configured to deposit a first mixed sublayer comprising the first and second materials onto the substrate being moved relative to the material deposition assembly in the substrate plane (15), and the second nozzle row (130-2) and the fourth nozzle row (130-4) are configured to deposit a second mixed sublayer comprising the first and second materials on top of the first mixed sublayer on the substrate being moved relative to the material deposition assembly in the substrate plane (15).

2. The material deposition assembly according to claim 1 , wherein the first nozzle row (130-1 ) and the second nozzle row (130-2) are arranged generally between the third nozzle row (130-3) and the fourth nozzle row (130-4) in a direction parallel to the substrate plane (15).

3. The material deposition assembly according to claim 1 or 2, wherein the second vapor distribution pipe (120-2) is arranged at least in part along a perimeter of the first vapor distribution pipe (120-1 ) to at least in part surround the first vapor distribution pipe (120-1 ), particularly by an angle of 90° or more, more particularly 120° or more.

4. The material deposition assembly of any of claims 1 to 3, wherein the first vapor distribution pipe (120-1 ) is at least partially arranged in a spatial region between the second vapor distribution pipe (120-2) and the substrate plane (15).

5. The material deposition assembly of any of claims 1 to 4, wherein the first nozzle row (130-1 ) is configured to direct the first material onto a first region (110-R) in the substrate plane (15), and the third nozzle row (130-3) configured to direct the second material onto a third region in the substrate plane substantially overlapping with the first region (110-R) for depositing the first mixed sublayer, and / or the second nozzle row (130-2) is configured to direct the first material onto a second region (110-L) in the substrate plane (15), and the fourth nozzle row (130-4) is configured to direct the second material onto a fourth region in the substrate plane substantially overlapping with the second region (110-L) for depositing the second mixed sublayer on the first mixed sublayer.

6. The material deposition assembly of any of claims 1 to 5, wherein the nozzles of the first and third nozzle rows are oriented toward a first lateral side relative to a substrate plane normal; and the nozzles of the second and fourth nozzle rows are oriented toward a second lateral side relative to the substrate plane normal opposite to the first lateral side.

7. The material deposition assembly of any of claims 1 to 6, wherein nozzles of the first nozzle row (130-1 ) provide a first main evaporation direction inclined relative to a substrate plane normal at an angle in a range between 30° and 70°, in particular about 55°; andnozzles of the third nozzle row (130-3) provide a third main evaporation direction inclined relative to the substrate plane normal at an angle in a range between 20° and 60°, in particular about 45°.

8. The material deposition assembly of any of claims 1 to 7, wherein a distance of the first nozzle row and the second nozzle row from the substrate plane (15) is in a range between 100mm and 300mm; and a distance of the third nozzle row and the fourth nozzle row from the substrate plane (15) is in a range between 100mm and 300mm, in particular wherein distances of the first, second, third and fourth nozzle rows from the substrate plane (15) are substantially equal.

9. The material deposition assembly of any of claims 1 to 8, wherein nozzles of the first and the second nozzle rows are configured to provide vapor plumes with plume opening angles in a range from 20° to 50°, and / or wherein nozzles of the third and the fourth nozzle rows are configured to emit vapor plumes with plume opening angles in a range from 30° to 60°.

10. The material deposition assembly of any of claims 1 to 9, further comprising a shaper arrangement (160) disposed between the first and second vapor distribution pipes and the substrate plane (15), the shaper arrangement comprising two or more essentially vertically extending slit openings to define plume opening angles and / or to limit lateral edges of the vapor plumes (140-1 , 140-2, 140-3, 140-4) emitted by the first, second, third and fourth (130-1 , 130-2, 130-3, 130-4) nozzle rows.

11. The material deposition assembly of any of claims 1 to 10, wherein the second vapor distribution pipe (120-2), but not the first vapor distribution pipe (120-1 ) comprises an inner heater (180), the inner heater configured to directly heat the second vapor distribution pipe (120-2) and to indirectly heat the first vapor distribution pipe (120-1 ).

12. The material deposition assembly of any of claims 1 to 11 , wherein the material deposition assembly is substantially symmetric with respect to a symmetry plane (112) extending perpendicular to the substrate plane (15).

13. A material deposition assembly (100, 200, 300, 400) for depositing materials on a substrate arranged in a substrate plane, comprising: a first vapor distribution pipe (120-1 ) in fluid communication with a first evaporation crucible and comprising a first nozzle row (130-1 ) for directing vapor plumes (140-1 ) of a first material onto the substrate plane (15) and comprising a second nozzle row (130-2) for directing vapor plumes (140-2) of the first material onto the substrate plane (15); and one or two second vapor distribution pipes (120-2, 120-2L, 120-2R) in fluid communication with at least one second evaporation crucible and comprising a third nozzle row for directing vapor plumes of a second material onto the substrate plane and a fourth nozzle row for directing vapor plumes of the second material onto the substrate plane, wherein the first nozzle row (130-1 ) and the third nozzle row are configured to deposit a first mixed sublayer comprising the first and second materials onto the substrate, and the second nozzle row (130-2) and the fourth nozzle row are configured to deposit a second mixed sublayer comprising the first and second materials on top of the first mixed sublayer on the substrate being moved relative to the material deposition assembly in the substrate plane (15).

14. A method of depositing materials on a substrate with a material deposition assembly comprising a first vapor distribution pipe (120-1 ) with a first nozzle row (130-1 ) and a second nozzle row (130-2), and comprising one or two second vapor distribution pipes (120-2) adjacent to the first vapor distribution pipe (120-1 ) with a third nozzle row (130-3) and a fourth nozzle row (130-4), the method comprising: transporting the substrate past the material deposition assembly in a substrate plane (15) while directing a first material toward the substrate from the first and the second nozzle rows and a second material toward the substrate from the third and the fourth nozzle rows;wherein the first nozzle row and the third nozzle row are directed such that a first mixed sublayer comprising the first and second materials is deposited onto the substrate, and the second nozzle row and the fourth nozzle row are directed such that a second mixed sublayer comprising the first and second materials is deposited onto the substrate on top of the first mixed sublayer.

15. The method of claim 14, wherein vapor plumes (140-1 ) emitted by the first nozzle row (130-1 ) have a first main evaporation direction inclined relative to a substrate normal at a first angle; and vapor plumes (140-3) emitted by the third nozzle row (130-3) have a third main evaporation direction inclined relative to the substrate normal at a third angle, wherein an absolute value of the first angle is larger than of the third angle.

16. The method of claim 14 or 15, wherein the first material is a first metal, particularly Mg, and the second material is a second metal, particularly Ag.

17. The method of any of claims 14 to 16, wherein the first mixed sublayer constitutes a lower part of a cathode layer of an OLED layer stack, and the second mixed sublayer constitutes an upper part of a cathode layer of an OLED layer stack.

18. The method of any of claims 14 to 17, wherein the substrate includes overhangs (190-L, 190-R) facing into different directions, and the first material and the second material are directed at least in part behind the overhangs.

19. The method of any of claims 14 to 18, wherein the first vapor distribution pipe (120-1 ) is passively heated by heat of the one or two second vapor distribution pipes, in particular wherein the first material is magnesium and the second material is silver, more particularly wherein the first and second mixed sublayers comprise a mixing ratio of silver relative to magnesium in the range from one part of silver over one part of magnesium to ten parts of silver over one part of magnesium.

20. An OLED display device comprising: a substrate with a plurality of pixels respectively comprising a cathode layer,wherein the cathode layer comprises a first mixed sublayer comprising a first material and a second material and a second mixed sublayer comprising the first material and the second material on top of the first mixed sublayer, the cathode layer manufactured according to the method of any of claims 14 to 19.

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