Method of coating a substrate, evaporation source arrangement, and substrate for display manufacture

Abstract

A method of coating a substrate in a vacuum chamber. The substrate has a structure formed thereon including a first sidewall adjacent to a pixel region and a first overhang projecting from the first sidewall. The method includes arranging a first evaporation source in a first deposition position, the first evaporation source having a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction, and transporting the substrate being oriented essentially vertically past the first evaporation source in a transport direction while directing a first material toward the substrate from the first row of nozzles. In the first deposition position, the first main evaporation direction is tilted either upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle a to increase a deposition of the first material under the first overhang.

Description

METHOD OF COATING A SUBSTRATE, EVAPORATION SOURCE ARRANGEMENT, AND SUBSTRATE FOR DISPLAY MANUFACTURETECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to methods and apparatuses for coating substrates with a stack of layers, and a substrate for display manufacture comprising an organic light-emitting diode (OLED) pixel structure. More particularly, embodiments of the present disclosure relate to evaporation source arrangements and vacuum deposition systems for depositing materials of an OLED layer stack on a substrate, in particular without the use of a fine metal mask (FMM) with pixel holes. Metal layer(s) and / or organic layer(s) of an OLED layer stack can be deposited on a substrate, e.g., subsequently and / or synchronously by co-deposition. Embodiments of the present disclosure specifically relate to evaporation source arrangements and vacuum deposition systems, methods of OLED display manufacturing by thermal evaporation, and substrates obtained by utilizing such systems and methods.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 avacuum 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 using an evaporation source arrangement, and the evaporated materials are deposited onto a substrate through nozzles. Metallic materials are typically evaporated in an evaporation source at a temperature of 1 ,000°C or above, or of 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, onto large area substrates. For example, coevaporation of two or more metals or metal alloys can be provided. An OLED display, for example, may include a plurality of layers of organic material situated between two electrodes that are deposited onto 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 onto 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 organic 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 using 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 challenging.

[0007] For example, in some applications, a metal layer may be deposited on a layer of organic material to form a cathode of the OLED, e.g. within an OLED pixelstructure. Forming the cathode may include depositing the metal layer so that the metal layer contacts sidewalls of the pixel structure to form an electrical connection, i.e. a cathode contact. It is therefore desirable to quickly, reliably and efficiently form a cathode layer having the desired cathode contact.

[0008] 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, improved evaporation source arrangements, vacuum deposition systems, and device manufacturing methods adapted for OLED manufacturing would be beneficial.SUMMARY

[0009] According to one embodiment, a method of coating a substrate in a vacuum chamber is described. The substrate has a structure formed thereon including a first sidewall adjacent to a pixel region and a first overhang projecting from the first sidewall. The method includes arranging a first evaporation source in a first deposition position, the first evaporation source having a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction, and transporting the substrate being oriented essentially vertically past the first evaporation source in a transport direction while directing a first material toward the substrate from the first row of nozzles. In the first deposition position, the first main evaporation direction is tilted either upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle a to increase a deposition of the first material under the first overhang.

[0010] According to one embodiment, an evaporation source arrangement is described, including a first evaporation source for depositing a first layer on a substrate that is moved in an essentially vertical orientation past the first evaporation source in a substrate plane. The first evaporation source incudes a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate. The first main evaporation direction is tilted upwardly or downwardly relative to a surface normal of the substrate plane by a first tilt angle and is tilted laterally relative to the surface normal by a second tilt angle.

[0011] According to one embodiment, an evaporation source arrangement is described, including a first evaporation source for depositing two or more materials on a substrate. The first evaporation source includes two or more vapor distribution pipes including a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate. The two or more vapor distribution pipes define a front side of the first evaporation source directed toward a substrate plane. The nozzles of the first row of nozzles are tilted upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle a, and the first vapor distribution pipe is inclined relative to the direction of gravity in a plane parallel to the substrate plane by a vapor distribution pipe tilt angle y.

[0012] According to one embodiment, a substrate for display manufacture with an organic light-emitting diode, OLED, pixel structure is described. The OLED pixel structure includes sidewalls surrounding a pixel region, wherein two adjacent sidewalls of the sidewalls are provided at an angle and protrude from a surface of the substrate defining a corner region of the pixel region. Overhangs project inwardly towards the pixel region from the sidewalls, an organic layer is deposited in the pixel region essentially without contacting the two adjacent sidewalls in the corner region, and a metallic layer is deposited on the organic layer and contacts at least one of the two adjacent sidewalls, particularly both adjacent sidewalls.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] So that the manner in which the above recited features can be understood in detail, a more particular description, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments and are described in the following:FIG. 1 shows a schematic view of a vacuum deposition system with an evaporation source arrangement according to embodiments of the present disclosure;FIG. 2 shows a schematic view of an evaporation source arrangement according to embodiments of the present disclosure in a vertical sectional plane;FIG. 3 shows a schematic perspective view of an evaporation source arrangement describing aspects of an evaporation source according to embodiments of the present disclosure;FIG. 4A shows a schematic plan view of a structure for manufacturing an OLED layer stack according to embodiments on a substrate;FIG. 4B shows a schematic cutaway side view of a structure of an OLED layer stack manufactured according to methods of the present disclosure;FIG. 4C shows a schematic plan view of a structure of an OLED layer stack manufactured according to methods of the present disclosure;FIG. 5 shows a schematic side view of an evaporation source arrangement according to embodiments of the present disclosure having an evaporation direction tilted upwardly or downwardly relative to a surface normal of a substrate;FIG. 6 shows a schematic side view of an evaporation source arrangement according to embodiments of the present disclosure having an evaporation direction tilted laterally relative to a surface normal of a substrate;FIG. 7 shows a schematic plan view of an evaporation source arrangement according to embodiments of the present disclosure having a rotation of the vapor distribution pipe along a surface normal of the substrate; andFIG. 8 shows a schematic sectional view of a substrate with an OLED layer stack manufactured according to methods of the present disclosure.DETAILED DESCRIPTION OF EMBODIMENTS

[0014] 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.

[0015] 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.

[0016] 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 “mask” 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.

[0017] FIG. 8 is a schematic sectional view showing a part of an OLED layer stack 760 on a substrate 10 manufactured with OLED pixel patterning techniques. Adjacent pixel-defining 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 several sidewalls, such as two or more sidewalls, such as four sidewalls arranged in e.g. a quadratic or rectangular shape, and overhangs may be formed on the two or more sidewalls and project over the pixel region from different sides.

[0018] 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. The deposition of metals and organiclayers in predetermined regions, particularly under the overhangs, is challenging.

[0019] 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 12 may be made of a non-conductive inorganic material or alternatively of a conductive inorganic material. According to embodiments, the sidewall 11 may form a root of a cathode contact. Likewise, a corner region defined by two adjoining sidewalls 11 may form a root of a cathode contact.

[0020] 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 or more optically active organic materials), an optional electron injection layer EIL 712, the cathode layer 711 , and at least one encapsulation layer 710.

[0021] 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 that 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 small opening angle. For ensuring that 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 large 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 that leads to stray coating of regions of the deposition system and of the substrate that should not be coated.

[0022] 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. For example, methods described herein may ensure or improve an electrical contact of acathode 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 degrades the contact and increases 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. In the following, providing a cathode layer having adequate electrical contact with the conductive sidewall will be referred to as establishing and / or improving cathode contact.

[0023] FIG. 1 shows a vacuum deposition system 1000 with evaporation source arrangements 100 according to embodiments described herein in a schematic top view. The vacuum deposition system 1000 includes a first vacuum chamber 1001 that houses a first 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 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 10 or more evaporation sources for coating the substrate with a plurality of layers.

[0024] 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 10’5mbar and approximately 10’8mbar, particularly between 10’5mbar and 10’7mbar.

[0025] The vacuum deposition system 1000 may include a substrate transportationtrack 1013 configured to move a substrate 10 along a substrate transport path T past the first 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.

[0026] The vacuum deposition system 1000 may further include a shield transportation track 1012 extending between the substrate transportation track 1013 and the first 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 first 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 first evaporation source 101 , as is schematically depicted in FIG. 1.

[0027] 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 first 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. After coating, before the substrate 10 transitions from onechamber to a subsequent chamber, the evaporation source may be closed to stop evaporation. Then, the substrate can transition into the subsequent chamber, while the moveable shield 1030 returns to a position suitable for shielding a subsequent substrate.

[0028] 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.

[0029] 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. For instance, 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.

[0030] FIG. 2 shows aspects of an evaporation source arrangement 100 according to embodiments described herein in further detail in a vertical sectional plane. 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 may have one or more crucibles 112 configured to evaporate a source material to be deposited and one or more vapor distribution pipes 110 configured for directing the evaporated material towards the substrate through a plurality of nozzles. For instance, a vapor distribution tube or vapordistribution 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 (typically an essentially vertical direction) of the vapor distribution pipe to provide an essentially vertical line source. Each vapor distribution pipe generally has one single row of nozzles, particularly one single vertical nozzle row suitable to coat substrates in a predefined orientation, such as an essentially vertical orientation. An “essentially vertical direction” as used herein may relate to a direction that corresponds to the direction of gravity or deviates from the direction of gravity by less than 10°.

[0031] For instance, the source material to be deposited may be an inorganic material, particularly a metallic material for use as an electrode material or an electron transport layer material in an OLED layer stack, or the source material may be an organic material for organic light emitting diode (OLED) production.

[0032] As is schematically depicted in FIG. 2, the evaporation source arrangement 100 includes a first evaporation source 101 with at least a first vapor distribution pipe 110. Further vapor distribution pipes of the first evaporation source are not shown in FIG. 2, but may be present. The first vapor distribution pipe 110 has a row of nozzles 111 that may be arranged along the longitudinal direction of the first vapor distribution pipe 110, e.g., above one another in an essentially vertical line array. The first evaporation source may, for example, be a line source for substrate coating in an essentially vertical orientation. The first 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, and the further evaporation sources may be configured to deposit one or more materials onto the substrate.

[0033] The first row of nozzles 111 includes a plurality of nozzles, particularly twenty or more nozzles. Each nozzle has a main evaporation direction M1. A “main evaporation 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 a longitudinal direction of the nozzle channel). Generally, a generally cone-shaped vapor plume emitted by a nozzle is centered around the main evaporation direction of the nozzles, e.g., with a maximum of vapor particles of the plume propagating along themain evaporation direction. Specifically, a vapor plume emitted by a nozzle is defined by a main evaporation direction and by an opening angle of the plume.

[0034] 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 to be symmetrical or to be asymmetrical relative to the main evaporation direction (= relative to the nozzle axis). For example, the vapor plume emitted by the first row of nozzles 111 may be shaped with a shaper shield to be asymmetrical relative to the first main evaporation direction (in horizontal sectional planes).

[0035] 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. Each vapor evaporation pipe generally has one single row of nozzles.

[0036] According to embodiments, the nozzles of the vertical nozzle row may be tilted with respect to the longitudinal direction of the distribution pipe, i.e. the nozzles may be provided at an angle other than the orthogonal angle shown in Fig. 2. Accordingly, the main evaporation direction may be tilted upwardly or downwardly relative to a surface normal of the substrate. Specifically, the main evaporation direction being tilted may mean that the main evaporation direction is not orthogonal to the longitudinal direction of the distribution pipe as shown in Fig. 2, such as is further explained herein with reference to, e.g., Fig. 5. The main evaporation direction may not be a horizontal direction, but may be tilted upwardly or downwardly relative to the horizontal direction, e.g., by a first tilt angle of 10° or more, or 15° or more. Additionally, further tilts and / or rotations may affect the main evaporation direction, as is explained in further detail with reference to Fig. 6 and Fig. 7.

[0037] Depending on the opening angles of the emitted vapor plumes, some of thevapor material propagates into regions below an overhang of a structure provided on a substrate to be deposited. However, depending on the overhang size, it may be difficult to provide a reliable contact between the evaporation material and the first sidewall under the overhang. Furthermore, vapor plumes with large opening angles may be difficult to handle due to a lack of directionality and a shadowing effect in various directions.

[0038] The evaporation source arrangement 100 may further include a rotation drive for rotating the first evaporation source 101 around a rotation axis, and a controller for controlling the rotational movement of the first evaporation source 101. The rotation drive may be configured for selecting and / or defining a source rotation angle f3, as described herein with reference to Fig. 6.

[0039] In the following, the evaporation source arrangement will be described with reference to directions and / or angles differing from those shown in Fig. 2. To clarify such angles, Fig. 3 to Fig. 7 include an x / y / z coordinate system. The coordinate system should be understood as being a global reference in a deposition system, and, unless specified otherwise, remains constant with respect to the deposition system. Unless specified otherwise, a linear progression, such as a motion, along any one of the x / y / z- directions will be referenced as a motion along the x / y / z direction. A rotation about any one of the x / y / z-directions will be referenced as a rotation about the x / y / z-axis, the x / y / z-axis defining the axis of rotation.

[0040] Fig. 3 schematically shows aspects of an evaporation source arrangement 100 according to embodiments. In particular, Fig. 3 may serve to visualize and / or define the directions and angles referenced in this disclosure. Fig. 3 shows an isometric view of a substrate 10 in a deposition process being transported so that a surface of the substrate 10 faces the evaporation source arrangement 100. A first row of nozzles 111 is provided along a first vapor distribution pipe 110 along the z-direction, the vapor distribution pipe 110 being aligned along the z-direction so that an axis 115 of the vapor distribution pipe 110 is essentially parallel to the z-direction. The z-direction may be parallel to an edge of the substrate 10, e.g. a rectangular substrate. The substrate 10 is transported along the transport path T in a transport direction past the evaporation source arrangement 100 so that the substrate is maintained along a substrate planeparallel to the y / z plane and moved along the y-axis. As shown in Fig. 3, the nozzles 111 essentially extend orthogonally from the vapor distribution pipe 110 in the x direction towards the surface of the substrate 10. Accordingly, a vapor plume being ejected from the nozzles has a main evaporation direction M1 essentially orthogonal to the surface of the substrate 10 and / or parallel to a surface normal of the substrate10. In the example shown in Fig. 3, the evaporation source arrangement 100 has no nozzle tilt, i.e. a nozzle tilt angle of 0°. Furthermore, the evaporation source arrangement 100 has no source rotation, i.e. a source rotation angle of 0°, and no vapor distribution pipe tilt, i.e. a vapor distribution pipe tilt angle of 0°.

[0041] Referring now to Fig. 4A, Fig. 4B and Fig. 4C, a structure 400 suitable for forming a pixel region 13, particularly of an OLED pixel, on a substrate 10 is schematically described. The structure 400 may correspond to and / or include aspects of the OLED layer stack 760 described with reference to Fig. 8. Fig. 4A shows a structure 400 before deposition. The structure 400 is essentially rectangular and / or quadratic, and includes sidewalls 11 , 1 T, 11 ”, 11 11 ”” (collectively 11 ) adjacent to a pixel region protruding along the -x-direction, and overhangs 12 projecting inwardly towards a PDL structure 715 along the y / z plane from the sidewalls 11 . The pixel region 13 may be essentially defined by, and / or include, the PDL structure 715. The overhangs 12 may partially shadow a material deposited onto the PDL structure 715. In particular, the overhang 12 may, particularly for a material deposited in a main evaporation direction M1 having no tilt angle, prevent a material from being deposited so that the material reaches below the overhang to contact one or more of the sidewalls11.

[0042] In the example shown in Fig. 4B and Fig. 4C, the structure 400 is shown after processing by an evaporation source arrangement according to embodiments. Two material layers 410, 420 have been deposited on the PDL structure 715. The bottom material layer 410 was deposited by an evaporation source, such as the evaporation source arrangement 100 shown in Fig. 3. In particular, for deposition of the material layer 410, the nozzles 111 were provided essentially parallel to the substrate and deposited a material in a main evaporation direction M1 essentially orthogonal to a surface of the substrate 10. Accordingly, the bottom material layer 410 is shadowed by the overhangs so that no or only limited material deposition occurs inan area adjacent the sidewalls 11 . For example, according to some embodiments, the bottom material layer may not be in contact with any of the sidewalls 11 , 11’, 11 ”, and / or not contact any of the corner regions 402, 402’.

[0043] It should be noted that, according to some embodiments, the deposition profile of the bottom material layer may differ from the profile shown in Fig. 4B and Fig. 4C. For example, in case a linear evaporation source having a row of nozzles is provided, the first layer 410 may extend further below the overhangs 12 in the z and / or -z direction, depending on the opening angle of the vapor plume and / or the relative position of the nozzle. Likewise, the first layer 410 may extend further below the overhangs 12 in the y and / or -y direction, depending on the opening angle of the vapor plume and / or the use of a shaper shield during deposition.

[0044] The top material layer 420 was deposited by an evaporation source according to embodiments, in which the evaporation direction was tilted upwardly or downwardly, i.e. tilted and / or rotated around the y-axis, to increase a deposition of the second material under the overhang adjacent the sidewall 1 T. According to embodiments, the first layer 410 may be an organic layer, and the second layer 420 may be a metal layer forming a cathode of an OLED structure. Beneficially, by increasing the deposition of the second material under the overhang, a cathode contact may be improved. An upwardly or downwardly tilt may be achieved e.g. by utilizing tilted nozzles and / or a vapor distribution pipe 110 having nozzles provided thereon at a first tilt angle with respect to a surface normal of a surface of the substrate, e.g. as described herein with reference to Fig. 5.

[0045] According to embodiments, the material of the second layer 420 may be a metal and, in a first deposition position, a first main evaporation direction may be tilted upwardly or downwardly, e.g. by a first tilt angle, to increase a contact area between the metal and the first sidewall 1 T under the overhang 12. Optionally, the first main evaporation direction may additionally also be tilted laterally, i.e., in a horizontal direction relative to and away from the substrate normal, e.g. by a second tilt angle, to increase a contact area between the metal and the second sidewall 11 ” under the overhang 12, as is schematically depicted in Fig. 4C.

[0046] In the example shown in Figs. 4B and 4C, the evaporation direction was further tilted laterally relative to the surface normal of the substrate 10 by a second tilt angle to increase a deposition of the material layer 420 under the overhang adjacent to the sidewall 11 ”, and / or the corner region 402. Lateral tilting, as described herein, should be understood as a horizontal tilt along or against the direction of substrate movement along the transport path T, i.e. towards the y or -y direction. A lateral tilt may be achieved e.g. by a tilt of the first vapor distribution pipe in a horizontal direction, e.g. by rotating the vapor distribution pipe around the z-axis, e.g. as described herein with reference to Fig. 6.

[0047] Referring now to Fig. 5, an evaporation source arrangement 500 according to embodiments is shown. The evaporation source arrangement 500 may include several of the features of the evaporation source arrangement described with reference to Fig. 3. The evaporation source arrangement 500 is configured for depositing a layer on a substrate 10 that is moved past the evaporation source arrangement 500 along the transport direction T in a substrate plane. As shown in Fig. 5, the substrate plane may extend along the y / z-plane. The substrate 10 may be moved past the evaporation source arrangement 500 in the y direction. The evaporation source arrangement 500 includes an evaporation source with a vapor distribution pipe 110. The vapor distribution pipe 110 may extend in an essentially vertical direction, such as the z-direction. The evaporation source includes a row of nozzles 111 that have a main evaporation direction M2 for depositing a material on the substrate 10.

[0048] Fig. 5 shows the evaporation source arrangement in a deposition position. In the deposition position, the main evaporation direction is tilted upwardly relative to a surface normal of the substrate plane by a tilt angle a. Alternatively, in some embodiments, the main evaporation direction M2 may be tilted downwardly. As shown in Fig. 5, the tilt angle a may result from providing the nozzles 111 at a nozzle tilt angle, while the vapor distribution pipe 110 may remain essentially vertical, i.e. may have an axis 115 essentially parallel to the z-direction. In particular, the nozzle channels of the nozzles 111 of the first row may be tilted upwardly or downwardly relative to a horizontal direction, while the vapor distribution pipe may extend essentially vertically. In particular, the tilt angle a may be defined by a tilt of the nozzles 111 of the first row of nozzles relative to the vapor distribution pipe in a direction orthogonal to thetransport direction. Likewise, the tilt angle a may be defined by a tilt of the nozzles 111 of the first row of nozzles relative to a surface normal of the substrate plane.

[0049] As shown in Fig. 5, providing the main evaporation direction M2 at the tilt angle a allows the material plumes emitted by the nozzles of the first row to reach below the overhang 12. Accordingly, a deposition of the material is increased under the overhang 12 adjacent to the sidewall 11’ in the region 510 below the overhang.

[0050] According to some embodiments, the first tilt angle a may be defined by the sum of a nozzle tilt and a source tilt. For example, as shown in the example given in Fig. 5, the first tilt angle a may result from providing the nozzles 111 at a tilt angle a relative to the horizontal direction in an upward or downward direction. Alternatively, a tilt angle a may be achieved by providing the nozzles 111 at a first sub-angle a1 relative to the longitudinal direction of the vapor distribution pipe, and by providing the vapor distribution pipe 110 at a second sub-angle a2 relative to the direction of gravity, so that a1 + a2 = a. Providing the vapor distribution pipe 110 at the second sub-angle may include tilting and / or rotating the vapor distribution pipe 110 about the y-axis so that the axis 115 is angled relative to the z-axis. The axis 115 may define a longitudinal direction of the vapor distribution pipe. In other words, a longitudinal direction of the vapor distribution pipe 110 may not be vertical, but may have an angle relative to the direction of gravity, so that upper nozzles of the first row of nozzles and lower nozzles of the first row of nozzles have a different distance from the substrate. Pertaining to this aspect, according to some embodiments, the nozzles 111 of the evaporation source may be tilted relative to the axis 115 of the vapor distribution pipe by the first sub-angle a1 , and a front surface of the first vapor distribution pipe 110 that is provided with the first row of nozzles 111 may be tilted relative to the direction of gravity by the second sub-angle a2, wherein a sum of the first sub-angle a1 and the second subangle a2 defines a first tilt angle a of the first main evaporation direction relative to a surface normal of the substrate 10.

[0051] According to some embodiments, the second sub-angle a2 may be defined by a tilted length direction of the vapor distribution pipe relative to the direction of gravity. For example, if an upper part of the vapor distribution pipe is inclined toward the substrate, the first main evaporation direction of the first row of nozzles is inclineddownwardly. For example, if an upper part of the vapor distribution pipe is inclined away from the substrate, the first main evaporation direction of the first row of nozzles is inclined upwardly. In some embodiments, the second sub-angle a2 may be provided at an angle with respect to the z-axis of 10° or more, such as about 10°, about 15°, or even about 20°. In some embodiments, the first sub-angle a1 may be an angle of 15° or more, such as about 15°, about 20°, or even about 25°. For example, a sum of the sub-angles a1 and a2 may be about 35°, about 40°, or even about 45°.

[0052] Beneficially, embodiments utilizing two sub-angles to provide the first tilt angle a may be employed in embodiments suitable for depositing one or more materials, or two or more materials on a substrate. Accordingly, the evaporation source may include one vapor distribution pipe, or two or more vapor distribution pipes.

[0053] According to embodiments, the two or more vapor distribution pipes may include a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate. The two or more vapor distribution pipes may define a front side of the first evaporation source directed toward a substrate transport path. The first vapor distribution pipe may be arranged opposite to a rear side of the first evaporation source.

[0054] Beneficially, utilizing two sub-angles may allow the nozzles 111 to be provided at a lower tilt angle with respect to the vapor distribution pipe. This may beneficially reduce contamination of, e.g., an upper surface of the source with the first material.

[0055] Referring now to Fig. 6, an evaporation source arrangement 600 according to embodiments is shown. The evaporation source arrangement 600 includes several of the features of the evaporation source arrangement described with reference to Fig. 3 and / or Fig. 5. Aspects of the evaporation source arrangement 600 may be combined with aspects of the evaporation source arrangement 300 shown in Fig. 3 and / or the evaporation source arrangement 500 shown in Fig. 5.

[0056] In the deposition position shown in Fig. 6, the evaporation direction M2 is tilted laterally relative to the surface normal of the substrate by the second tilt angle f3, in addition to the upward or downward tilt by the first tilt angle. In the embodiment, thesecond tilt angle [3 can be achieved by rotating the vapor distribution pipe 110 about the axis 115 and / or the z-direction. The second tilt angle [3 may be a source rotation angle [3.

[0057] The second tilt angle [3 may increase a deposition of the first material in a first corner region defined between a first sidewall and a second sidewall on the substrate, such as the sidewall 11 ” and / or the corner region 402 shown in Fig. 4C.

[0058] In some embodiments, the tilt of the vapor distribution pipe 110 may be defined by a rotation of the evaporation source around an essentially vertically extending rotation axis, particularly about an axis parallel to the axis 115 or the z- direction. In some embodiments, a method of depositing a substrate may include rotating the evaporation source of the evaporation source arrangement 600 to define the second tilt angle [3. According to embodiments, the second tilt angle [3 is defined by a tilt or rotation of the first vapor distribution pipe and / or of the nozzles of the first row of nozzles relative to the substrate normal in a horizontal direction. Accordingly, the tilt angle [3 may define a lateral tilt of the evaporation direction M2.

[0059] As shown in Fig. 6, providing the main evaporation direction M2 at the tilt angle [3 allows a material plume to reach below the overhang 12 in the region 610. In particular, a deposition of the material may be increased under the overhang 12 adjacent to the sidewall 11 ”.

[0060] According to embodiments, the evaporation source arrangement 600 may include a rotation drive for rotating the first evaporation source around a rotation axis, such as the axis 115. The evaporation source arrangement may further include, and / or be controlled by, a controller configured to cause a rotation of the first evaporation source to a first deposition position prior to a transport of the substrate past the first evaporation source. The first deposition position may be the position in which the main evaporation direction M2 has the second tilt angle f3 in a lateral direction and the first tilt angle a in a vertical direction relative to the surface normal of the substrate. In the first deposition position, the front side of the first evaporation source may be tilted laterally relative to the surface normal of the substrate by the second tilt angle [3. Further, in the first deposition position, the main evaporation direction may be tiltedupwardly or downwardly relative to the surface normal of the substrate, as described with reference to Fig. 5.

[0061] The structures shown in Fig. 4A, 4B, 4C, and the evaporation source assemblies shown in Fig. 5 and Fig. 6 may be particularly suitable for processing substrates 10 including OLED pixel structures having sidewalls extending essentially parallel and orthogonal to a transport direction of the substrate 10 during deposition. For example, in the structure shown in Fig. 4A, 4B, 4C, the sidewalls 11 protrude from the substrate in the x-direction, and extend along the y-direction and the z-direction around the pixel region, e.g., surrounding the pixel region in a rectangular or square arrangement. Specifically, the sidewalls 11 may extend parallel to edges of an essentially rectangular substrate.

[0062] In some embodiments, the structure 400 shown in Fig. 4A, Fig. 4B and Fig. 4C includes a third sidewall 11 ’” and a fourth sidewall 11 ’’’’adjacent to the pixel region on another side of the pixel region as the first sidewall and the second sidewall. The structure 400 has a third overhang projecting from the third sidewall and a fourth overhang projecting from the fourth sidewall partially over the pixel region. The third sidewall 1 T” and the fourth sidewall 11 ”” define a second corner region 402’.

[0063] As shown e.g. in Fig. 4C, when performing a deposition with an evaporation source having a vertical tilt angle a, optionally a lateral tilt angle f3, or a tilt angle combining vertical and lateral tilt angles a and f3, deposition may be increased adjacent a first sidewall and / or in a corner region of two adjoining sidewalls, and may be decreased adjacent to an oppositely arranged sidewall and / or corner region opposite the first sidewall and / or corner. For example, in Fig. 4C, deposition is increased in the first corner region 402, and decreased in the second corner region 402’.

[0064] In some embodiments, it may be beneficial to also deposit a material layer adjacent to the oppositely arranged sidewall and / or corner, particularly under respective overhangs. Accordingly, in some embodiments, a method of coating a substrate may include arranging a second evaporation source in a second deposition position, the second evaporation source having a second vapor distribution pipe with a second row of nozzles that have a second main evaporation direction. Afterprocessing the substrate 10 by the first evaporation source, the method includes transporting the substrate past the second evaporation source while directing a second material toward the substrate from the second row of nozzles. The second material may be the same material as the first material, and form a homogeneous layer with e.g. the top material layer 420 shown in Fig. 4B and Fig. 4C.

[0065] For example, according to embodiments, the first evaporation source may coat the substrate 10 with a first sublayer of a cathode layer, particularly including a metal or co-deposited metals, and the second evaporation source may coat the substrate with a second sublayer of the cathode layer, particularly including a metal or co-deposited metal, e.g. comprising the (same) co-deposited metals. In particular, the first evaporation source and the second evaporation source may deposit respective sub-layers of a cathode layer, wherein the first evaporation source may ensure a good cathode contact in a region below a first overhang or in a first corner region, and the second evaporation source may ensure a good cathode contact in a region below an oppositely arranged overhang or in an oppositely arranged corner region. A good cathode contact on different sides of a pixel region, particularly on oppositely arranged upper and lower sides of a pixel region, can be ensured.

[0066] In the second deposition position, the second main evaporation direction of the second row of nozzles may be tilted by a second tilt angle relative to the surface normal of the substrate, the first tilt angle and the second tilt angle having opposite signs relative to the surface normal. For example, in case the first evaporation source provides a first main evaporation direction at a first tilt angle a, optionally a second tilt angle fB, or a tilt angle combining a and fB, the second evaporation source may provide a second main evaporation direction at a third tilt angle -a, optionally a fourth tilt angle -P, or a tilt angle combining -a and -[3. Accordingly, the first tilt angle and the optional second tilt angle of the first row of nozzles increases the deposition of the first material under the first overhang and the second overhang, and the third tilt angle and the optional fourth tilt angle of the second row of nozzles increase a deposition of the first material under the third overhang and the fourth overhang.

[0067] Beneficially, in case the first material and the second material form a cathode layer in a pixel region surrounded by four sidewalls with respective overhangsprotruding partially over the pixel region, the cathode contact with respect to two, three, or four sidewalls can be improved. In particular, the first evaporation source with nozzles having a main evaporation direction tilted both upwardly and laterally may improve a cathode contact below a first and second overhang, and the second evaporation source with nozzles having a main evaporation direction tilted both downwardly and laterally in an opposite direction may improve a cathode contact below a third and fourth overhang. A cathode layer comprising two sublayers consisting of the same material can be deposited with the first and second evaporation source in the pixel region, the cathode layer being in good contact with the sidewalls surrounding a pixel region. In particular, a first sublayer of the cathode layer may be in good contact with a first sidewall and a second sidewall that adjoin each other in a first corner region, and a second sublayer of the cathode layer may be in good contact with a third sidewall and a fourth sidewall that adjoin each other in a second corner region opposite to the first corner region.

[0068] Some OLED pixel structures may include sidewalls extending in a direction that is rotated relative to the transport direction, relative to an edge of an essentially rectangular substrate, and / or about a surface normal of the substrate at an angle of 30° or more, such as at an angle of essentially 45°. For example, the structure may essentially correspond to the structure shown in Fig. 4A, 4B, 4C, but be rotated at an angle about the x-axis. For example, known structures that may be rotated relative to the transport direction at an angle of 30° or more include subpixel matrix schemes of the PenTile matrix family (also referred to herein as “PenTile pixels”). Such a pixel may have essentially the shape of a diamond or rhombus. The pixel may have a first corner region at a lower end of the pixel and a second corner region at an upper end of the pixel (exemplarily depicted in the lower part of Fig. 7).

[0069] Referring now to Fig. 7, an evaporation source arrangement 700 is shown in a deposition position for depositing a material layer onto the substrate 10. The evaporation source arrangement 700 includes several of the features of the evaporation source arrangement described with reference to Fig. 3, Fig. 5 and / or Fig.6. Aspects of the evaporation source arrangement 700 may be combined with aspects of the evaporation source arrangement 300 shown in Fig. 3, the evaporation source arrangement 500 shown in Fig. 5 and / or the evaporation source arrangement 600shown in Fig. 6.

[0070] The substrate 10 includes a structure having a pixel region 13, which is separately shown enlarged in Fig. 7. As shown in Fig. 7, the pixel region is rotated about the x-axis by an angle of about 45°. Accordingly, one or more sidewalls of the structure extend in a direction rotated relative to the transport direction by an angle of at least 30°, such as the angle of about 45° shown in Fig. 7.

[0071] As shown in Fig. 7, the vapor distribution pipe 110 of the evaporation source arrangement 700 is rotated along a surface normal of the substrate 10. Rotating the vapor distribution pipe as shown in Fig. 7 may beneficially allow applying the evaporation source arrangement 700 as explained with reference to Fig. 5 and 6 for substrates having a rotated pixel region 13, particularly diamond-shaped or “PenTile” pixels. In the shown example, the vapor distribution pipe 110 is rotated about the x- axis so that a tilt angle y of the vapor distribution pipe tilt angle is 20° or more, particularly 35° or more, more particularly about 45°.

[0072] The value of the tilt angle y of the vapor distribution pipe may be adjusted to the direction of extension of the sidewalls of the diamond-shaped pixels. For example, if the sidewalls of the pixels extend at about 45° relative to the vertical direction, the value of the tilt angle y may be about 45° relative to the vertical direction. However, it should be noted that the value of the tilt angle y does not necessarily need to exactly correspond to the direction of extension of the sidewalls of the pixels, and may e.g. be different by, e.g., 20° or less, or 10° or less.

[0073] The first tilt angle a and / or the second tilt angle [3 according to embodiments may also be influenced by the vapor distribution pipe tilt angle y. For example, with respect to the substrate, a first tilt angle a may, when applying a non-0° vapor distribution pipe tilt angle y, influence the second tilt angle f3, and a second tilt angle [3 may, when applying a non-0° vapor distribution pipe tilt angle y, influence the first tilt angle a.

[0074] As shown in Fig. 7, when providing the vapor distribution pipe 110 at a vapor distribution pipe tilt angle y of 45°, a vapor distribution pipe 110 having an increased length may be provided, e.g. to provide coverage of the whole substrate. For example,the length may be dependent on the height of the substrate along the z direction multiplied by 1 1 cos (y), which may be the length multiplied by 2 in the example shown in Fig. 7.

[0075] Beneficially, when combining a first tilt angle a and / or a second tilt angle [3 with the vapor distribution pipe tilt angle y, a lower vapor distribution pipe tilt angle y may be employed to achieve the desired deposition of the first material under the first overhang and / or the second overhang. For example, the rotation of the vapor distribution pipe around a surface normal of the substrate, i.e. the vapor distribution pipe tilt angle y, may be below 45°. For example, the vapor distribution pipe tilt angle y may be in the range of 5° to 45 °. For example, the vapor distribution pipe tilt angle may be in the range of 10° to 40°, such as 15° to 35 °, such as about 20° or about 25°. In the given examples, the vapor distribution pipe tilt angle y in combination with the first tilt angle a in a range of 15° or more, or even 30° or more, such as about 20° or about 25° can beneficially result in the desired cathode contact. Additionally, or alternatively, a second tilt angle f3 in a range of 15° or more, or even 30° or more, such as about 20° or about 25° can be provided in combination with the vapor distribution pipe tilt angle y and / or the first tilt angle a.

[0076] According to embodiments, the systems and methods described herein may be particularly suitable for angled deposition of a metal over an organic material. For example, during the production of an OLED layer stack, the organic material deposition may be performed at a reduced angle or no angle, and followed by an angled metal deposition so that the metal is deposited under a first and / or second overhang. Angled deposition may beneficially provide a contact area between the deposited metal and the sidewall adjacent the overhang, i.e. a first and / or second sidewall. Angled deposition of a metal following the deposition of an organic layer being deposited at a different or no angle may beneficially prevent the organic layer from covering, interfering with, or reducing cathode contact.

[0077] According to embodiments, a method of coating a substrate in a vacuum chamber is described. The method may include the use of an evaporation source according to embodiments described herein. For example, the evaporation source may be the evaporation source of the evaporation source arrangement 500 described withreference to Fig. 5 and have a main evaporation direction that is tilted upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle a. Additionally, the evaporation source may be provided at a source rotation angle [3 as described with reference to Fig. 6, and / or provided at a vapor distribution pipe tilt angle y as described with reference to Fig. 7.

[0078] The method includes transporting a substrate 10 past the evaporation source in a transport direction while directing a first material toward the substrate from the first row of nozzles.

[0079] In some embodiments, the method may include shaping a vapor plume being generated by the row of nozzles. In particular, an evaporation source may be characterized by a shaper shield arranged in front of (at least) the first row of nozzles and configured to asymmetrically limit an opening angle of vapor plumes emitted by the first row of nozzles. The shaper shield is configured to shape the vapor plumes emitted by the first row of nozzles to be asymmetrical relative to the first main evaporation direction, so that the opening angle of the vapor plumes is different on opposite sides of the main evaporation direction. A material deposition on a side of the first main evaporation direction facing away from the first overhang can be more strongly limited than a material deposition on a side of the main evaporation direction facing toward the first overhang. In particular, a first half-angle of the vapor plumes on a first side of the main evaporation direction facing toward the region under the first overhang may be shaped to be larger than a second half-angle of the vapor plumes on a second side of the main evaporation direction facing away from the region under the first overhang. A ratio between a first thickness of the deposited first material under the first overhang and a second thickness of the deposited first material on uncovered regions of the substrate can be increased. The shaper shield can include a shield body with an essentially vertically extending slit that is aligned with the first row of nozzles to asymmetrically shape the vapor plumes emitted by the first row of nozzles.

[0080] 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 uses angled deposition under overhangs. “Angled deposition” as used herein refers to atilted main evaporation direction or tilted nozzle channels of the nozzles of one or more nozzle rows relative to the surface normal of the substrate for increasing (or decreasing) the deposition below the overhangs.

[0081] In particular, the following embodiments are described herein:

[0082] According to a first aspect, a method of coating a substrate in a vacuum chamber is described, wherein the substrate has a structure formed thereon comprising a first sidewall adjacent to a pixel region and a first overhang projecting from the first sidewall. A first evaporation source is provided in a first deposition position, the first evaporation source having a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction. A substrate is transported past the first evaporation source in a transport direction while directing a first material toward the substrate from the first row of nozzles, particularly a metal or other conductive material for forming a cathode layer of an OLED layer stack on the substrate.

[0083] In the first deposition position, the first main evaporation direction of the nozzles is tilted upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle (a) to increase a deposition of the first material under the first overhang. In particular, the nozzles (e.g., the nozzle channels of the nozzles) are tilted relative to the surface normal of the substrate such that the vapor is directed upwardly (or alternatively downwardly) into a region below the first overhang. The first material can thus be brought in good electrical contact with the first sidewall under the overhang, and / or an organic layer deposited on the substrate below the first material can be covered even in an edge region thereof below the first overhang.

[0084] In some embodiments, the structure formed on the substrate has a second sidewall adjacent to the pixel region and a second overhang projecting from the second sidewall, the first sidewall and the second sidewall defining a first corner region. The first sidewall may extend in an essentially horizontal direction, and the second sidewall may extend in an essentially vertical direction.

[0085] In the first deposition position, the first main evaporation direction may also be tilted laterally relative to the surface normal of the substrate by a second tilt angle (P) to increase a deposition of the first material under the second overhang and / or inthe first corner region. A “lateral” tilt of the first main evaporation direction may be provided by a nozzle channel of a nozzle that is inclined horizontally relative to the substrate normal. For example, the evaporation source can be rotated about an essentially vertical rotation axis to provide a lateral tilt of the first row of nozzles. The first material can thereby be deposited both under the first overhang adjacent to the first sidewall (e.g., a horizontally extending sidewall) and under the second overhang adjacent to the second sidewall (e.g., a vertically extending sidewall).

[0086] In some embodiments, the first tilt angle (a) is 15° or more, particularly 30° or more. In some embodiments, the second tilt angle ([3) is 15° or more, particularly 30° or more.

[0087] In some embodiments, the first material is a metal and, in the first deposition position, the first main evaporation direction is tilted (vertically and optionally horizontally relative to the substrate normal) to increase a contact area between the metal and the first sidewall under the first overhang and / or between the metal and the second sidewall under the first overhang and / or in the first corner region. In some implementations, a cathode layer may be deposited by the first evaporation source on top of an organic layer. Two or more edge regions of the organic layer can be covered by the cathode layer, e.g. so that a corner region formed by the edge regions is completely covered.

[0088] The first tilt angle (a) may be at least partially defined by an upward or downward tilt of the nozzles of the first row of nozzles relative to a longitudinal direction of the first vapor distribution pipe. In other words: The nozzle channels of the nozzles may not be perpendicular to the longitudinal direction of the first vapor distribution pipe, but may rather extend upwardly or downwardly relative to a horizontal direction, e.g., by an angle of 10° or more or 15° or more.

[0089] Alternatively or additionally, the first tilt angle (a) may be at least partially defined by a tilt of the longitudinal direction of the first vapor distribution pipe relative to the direction of gravity, e.g., by 10° or more or 15° or more, so that an upper part of the first vapor distribution pipe is closer to or further from the substrate than a lower part of the first vapor distribution pipe. The first tilt angle can be increased if the nozzlechannels of the nozzles are tilted relative to the length direction of the vapor distribution pipe by a first sub-angle, and the length direction of the vapor distribution pipe is tilted relative to the gravity direction by a second sub-angle.

[0090] In some embodiments, the first vapor distribution pipe is inclined relative to the direction of gravity in a plane parallel to the substrate by a vapor distribution pipe tilt angle (y). In other words, the vapor distribution pipe may be also rotated around a horizontal rotation axis (the rotation axis being essentially parallel to the substrate normal) to be inclined relative to a vertical direction. In some embodiments, the vapor distribution pipe tilt angle (y) is higher than 5° and lower than 45 °. A vapor distribution pipe tilt angle (y) is beneficial, if the sidewalls of the structure on the substrate do not extend in vertical and horizontal directions, but in inclined directions. For example, a vapor distribution pipe tilt angle (y) is beneficial if a pixel of the PenTile type is to be deposited on the substrate.

[0091] In some embodiments, the first sidewall extends in a direction essentially parallel to the transport direction, i.e., in an essentially vertical direction. In some embodiments, the second sidewall extends in an essentially vertical direction. For example, the first, second, third, and fourth sidewalls may surround the pixel region in an essentially rectangular setup.

[0092] In some embodiments, the first sidewall extends in a direction rotated relative to the transport direction at an angle of at least 30° and below 60°, particularly about 45°. For example, the first sidewall and three further sidewalls may surround the pixel region in a rhombus-shape or diamond-shape.

[0093] In some embodiments, the method may further include: arranging a second evaporation source in a second deposition position, the second evaporation source having a second vapor distribution pipe with a second row of nozzles that have a second main evaporation direction; and transporting the substrate being oriented essentially vertically past the second evaporation source while directing the first material or a second material toward the substrate from the second row of nozzles. In the second deposition position, the second main evaporation direction of the second row of nozzles may be tilted downwardly or upwardly relative to the surface normal ofthe substrate by a third tilt angle, the first tilt angle and the third tilt angle having opposite signs relative to the surface normal. In other words: if the first tilt angle is tilted upwardly, the third tilt angle is tilted downwardly (and vice versa), particularly by the same angle relative to the substrate normal. Accordingly, the region under upper and lower overhangs surrounding a pixel region can be deposited with the material and a good cathode contact with respect to two or more sidewalls surrounding the pixel region can be ensured.

[0094] In some embodiments, the structure formed on the substrate further comprises a third sidewall adjacent to the pixel region on an opposite side as the first sidewall and a third overhang projecting from the third sidewall. The first tilt angle of the first row of nozzles increases the deposition of the first material under the first overhang, and the third tilt angle of the second row of nozzles increase a deposition of the second material under the third overhang. The first and second materials may be the same material, particularly a metal for providing a cathode layer.

[0095] In some embodiments, the structure formed on the substrate further comprises a fourth sidewall adjacent to the pixel region on an opposite side as a second sidewall, the third sidewall and the fourth sidewall defining a second corner region, and a fourth overhang projecting from the fourth sidewall. In the second deposition position, the second main evaporation direction may optionally be tilted laterally relative to the surface normal of the substrate by a fourth tilt angle to increase a deposition of the first or second material under the fourth overhang and in the second corner region. The third sidewall may extend in an essentially horizontal direction, and the fourth sidewall may extend in an essentially vertical direction. The first, second, third, and fourth sidewall may surround an essentially rectangular pixel region.

[0096] In particular, the second tilt angle and the fourth tilt angle may be lateral tilt angles having opposite signs relative to the surface normal of the substrate. The region under the second overhang can be reliably coated with the first row of nozzles having the second tilt angle (= lateral tilt angle), and the region under the fourth overhang can be reliably coated with the second row of nozzles having the fourth tilt angle.

[0097] In some embodiments, the first evaporation source coats the substrate witha first sublayer of a cathode layer, particularly comprising co-deposited metals, and the second evaporation source coats the substrate with a second sublayer of the cathode layer, particularly comprising the co-deposited metals. The cathode layer can be deposited on top of an organic layer, and form an essentially homogeneous cathode layer that is deposited by at least two evaporation sources at different tilt angles covering the organic layer.

[0098] Embodiments described herein include a deposition of a metal over an organic material, wherein the metal is deposited via angled deposition under the first overhang, the second overhang, the third overhang and / or the fourth overhang to provide a contact area between the metal and the first sidewall, particularly a large contact area under two or more overhangs.

[0099] In some embodiments, the first evaporation source includes the first vapor distribution pipe and at least one further vapor distribution pipe, each vapor distribution pipe comprising one single row of nozzles having twenty or more nozzles.

[0100] According to another aspect, an evaporation source arrangement is described, comprising: a first evaporation source for depositing a first layer on a substrate that is moved in an essentially vertical orientation past the first evaporation source in a substrate plane, the first evaporation source comprising a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate. The first main evaporation direction is tilted upwardly or downwardly relative to a surface normal of the substrate plane by a first tilt angle, particularly 15° or more, or 25° or more. The first main evaporation direction is optionally also tilted laterally relative to the surface normal by a second tilt angle, particularly 15° or more, or 25° or more.

[0101] The evaporation source arrangement may further include second evaporation source arranged downstream of the first evaporation source along a transport path for depositing a second layer on the substrate that is moved past the second evaporation source. The second evaporation source includes a second vapor distribution pipe with a second row of nozzles that have a second main evaporation direction for depositing a material, such as the first material or a second material (i.e.the same material as the first material, or a material different from the first material) on the substrate. In some embodiments, both the first evaporation source and the second evaporation coat the substrate with the first material in direct succession, so that two sub-layers of a cathode layer can be deposited with the first and second deposition source.

[0102] The second main evaporation direction is tilted downwardly or upwardly relative to the surface normal of the substrate plane by a third tilt angle and is optionally tilted laterally relative to the surface normal by a fourth tilt angle. The first tilt angle and the third tilt angle have opposite signs. In other words, if the first tilt angle is upwardly relative to the surface normal of the substrate, the third tilt angle is downwardly, and vice versa. The second tilt angle and the fourth tilt angle having opposite signs relative to the surface normal. In other words, if the second tilt angle is tilted in a first horizontal direction relative to the surface normal, the fourth tilt angle is tilted in an opposite horizontal direction. A reliable deposition under four overhangs that surround a pixel region can be ensured.

[0103] According to another aspect, a first evaporation source for depositing two or more materials on a substrate is provided. The first evaporation source includes two or more vapor distribution pipes, including a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate, wherein the two or more vapor distribution pipes define a front side of the first evaporation source directed toward a substrate plane. The nozzles of the first row of nozzles are tilted upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle (a), and the first vapor distribution pipe is inclined relative to the direction of gravity in a plane parallel to the substrate plane by a vapor distribution pipe tilt angle (y).

[0104] The first tilt angle, the second tilt angle, the third tilt angle and / or the fourth tilt angle may be 15° or more, particularly 25° or more. Optionally, the vapor distribution pipe tilt angle (y) may be 15° or more, particularly 25° or more, or even up to 45°, but preferably less than 45°.

[0105] According to embodiments, a substrate is described. The substrate may bea substrate such as the substrate 10 described with reference to the Figures, particularly Fig. 5, Fig. 6, Fig. 7 and / or Fig. 8. The substrate may be obtained by carrying out a method according to any of the embodiments described herein. The substrate may be obtained by processing a substrate having an overhang structure according to embodiments described herein and / or in a vacuum deposition system having an evaporation source arrangement according to embodiments described herein.

[0106] For example, as shown in Fig. 4 and Fig. 8, the substrate 10 may include sidewalls 11 surrounding a pixel region 13. Two adjacent sidewalls 11’, 11” are provided at an angle, protrude from a surface of the substrate and define a corner region 402 of the pixel region 13. Overhangs 12 project inwardly towards the pixel region from the sidewalls 11. An organic layer 410 is deposited in the pixel region 13. In some embodiments, the organic layer may not or at least not substantially contact the two adjacent sidewalls 11 ’, 11” in the corner region 402. A cathode layer, particularly a metallic layer 420, is deposited over the organic layer 410 and may contact at least one of the two adjacent sidewalls 1 T, 11 ”, particularly both of the two adjacent sidewalls, providing a reliable cathode contact. The cathode layer may be directly or indirectly deposited over the organic layer, e.g. with zero, one or more further layers in between.

[0107] In some embodiments, the organic layer 410 may contact adjacent sidewalls in two or less corner regions. In some embodiments, the metallic layer may contact adjacent sidewalls in two or more corner regions. For example, the organic layer may contact none, one or two corner regions, i.e. sidewalls below overhangs in corner regions. For example, the metallic layer may contact two, three or all of four corner regions, i.e., sidewalls below overhangs in corner regions.

[0108] According to some embodiments, e.g. as shown in Fig. 7, the substrate 10 has an essentially rectangular shape comprising substrate edges, and the sidewalls 11 surround the pixel region in a rhombus- or diamond shape to provide pixel edges rotated relative to the substrate edges.

[0109] In particular, the following implementations according to embodiments aredescribed:Implementation 1.: A method of coating a substrate in a vacuum chamber, the substrate having a structure formed thereon comprising a first sidewall adjacent to a pixel region and a first overhang projecting from the first sidewall, the method comprising: arranging a first evaporation source in a first deposition position, the first evaporation source having a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction; and transporting the substrate being oriented essentially vertically past the first evaporation source in a transport direction while directing a first material toward the substrate from the first row of nozzles, wherein, in the first deposition position, the first main evaporation direction is tilted either upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle (a) to increase a deposition of the first material under the first overhang.Implementation 2.: The method of implementation 1 , wherein the structure formed on the substrate has a second sidewall adjacent to the pixel region and a second overhang projecting from the second sidewall, the first sidewall and the second sidewall defining a first corner region, wherein, in the first deposition position, the first main evaporation direction is also tilted laterally relative to the surface normal of the substrate by a second tilt angle (P) to increase a deposition of the first material under the second overhang and / or in the first corner region.Implementation 3.: The method of implementation 1 or 2, wherein the first tilt angle (a) is 15° or more, particularly 30° or more. Alternatively or additionally, the second tilt angle (P) may be 15° or more, particularly 30° or more.Implementation 4.: The method of any one of the preceding implementations, wherein the first material is a metal and, in the first deposition position, the first main evaporation direction is tilted to increase a contact area between the metal and the first sidewall under the first overhang.Implementation 5.: The method of any of implementations 1 to 4, wherein the first tilt angle (a) is at least partially defined by an upward or downward tilt of the nozzles of the first row of nozzles relative to a longitudinal direction of the first vapor distribution Pipe-Implementation 6.: The method of any of implementations 1 to 5, wherein the first tilt angle (a) is at least partially defined by a tilt of a longitudinal direction of the first vapor distribution pipe relative to the direction of gravity by 10° or more, so that an upper part of the first vapor distribution pipe is closer to or further from the substrate than a lower part of the first vapor distribution pipe.Implementation 7.: The method of any of implementations 1 to 6, wherein the first vapor distribution pipe is inclined relative to the direction of gravity in a plane essentially parallel to the substrate by a vapor distribution pipe tilt angle (y).Implementation 8.: The method of implementation 7, wherein the vapor distribution pipe tilt angle (y) is higher than 5° and lower than 45 °.Implementation 9.: The method of any of implementations 2 to 8, wherein the first sidewall extends in a direction essentially parallel to the transport direction, and the second sidewall extends in an essentially vertical direction. In particular, the first sidewall may extend in an essentially horizontal direction and the second sidewall may extend in an essentially vertical direction during material deposition.Implementation 10.: The method of any one of implementations 1 to 8, wherein the first sidewall extends in a direction rotated relative to the transport direction at an angle of at least 30°, particularly about 45°, more particularly wherein the first sidewall and three further sidewalls surround the pixel region in a rhombus-shape or diamond-shape. In particular, the four sidewalls surrounding the pixel region may be inclined relative to the substrate edges to have a diamond-shape or rhombus-shape.Implementation 11.: The method of any of implementations 1 to 10, further comprising: arranging a second evaporation source in a second deposition position, the second evaporation source having a second vapor distribution pipe with a second row of nozzles that have a second main evaporation direction; and transporting the substrate being oriented essentially vertically past the second evaporation source while directing the first material or a second material toward the substrate from the second row of nozzles, wherein, in the second deposition position, the second main evaporation direction of the second row of nozzles is tilted either downwardly or upwardly relative to the surface normal of the substrate by a third tilt angle, the first tilt angle and thethird tilt angle having opposite signs relative to the surface normal of the substrate. In other words, the first main evaporation direction is tilted upwardly and the second main evaporation direction is tilted downwardly, or vice versa.Implementation 12.: The method of implementation 11 , wherein the structure formed on the substrate further comprises: a third sidewall adjacent to the pixel region on an opposite side as the first sidewall and a third overhang projecting from the third sidewall, wherein the first tilt angle of the first row of nozzles increases the deposition of the first material under the first overhang and the third tilt angle of the second row of nozzles increase a deposition of the second material under the third overhang.Implementation 13.: The method of implementation 12, wherein the structure formed on the substrate further comprises a fourth sidewall adjacent to the pixel region on an opposite side as a second sidewall, the third sidewall and the fourth sidewall defining a second corner region, and a fourth overhang projecting from the fourth sidewall, wherein in the second deposition position, the second main evaporation direction is also tilted laterally relative to the surface normal of the substrate by a fourth tilt angle to increase a deposition of the first or second material under the fourth overhang and / or in the second corner region.Implementation 14.: The method of any of implementations 11 to 13, wherein the first evaporation source coats the substrate with a first sublayer of a cathode layer, particularly comprising co-deposited metals, and the second evaporation source coats the substrate with a second sublayer of the cathode layer, particularly comprising the co-deposited metals.Implementation 15.: The method of any of implementations 1 to 14, comprising a deposition of a metal over an organic material, wherein the metal is deposited via angled deposition under the first overhang to provide a contact area between the metal and the first sidewall.Implementation 16.: The method of any of implementations 1 to 15, wherein the first evaporation source includes the first vapor distribution pipe and at least one further vapor distribution pipe, each vapor distribution pipe comprising one single row of nozzles having twenty or more nozzles.Implementation 17.: An evaporation source arrangement, comprising: a first evaporation source for depositing a first layer on a substrate that is moved in an essentially vertical orientation past the first evaporation source in a substrate plane, the first evaporation source comprising a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate, wherein the first main evaporation direction is tilted upwardly or downwardly relative to a surface normal of the substrate plane by a first tilt angle and is tilted laterally relative to the surface normal by a second tilt angle.Implementation 18.: The evaporation source arrangement of implementation 17, further comprising: a second evaporation source arranged downstream of the first evaporation source along a transport path for depositing a second layer on the substrate that is moved past the second evaporation source, the second evaporation source comprising a second vapor distribution pipe with a second row of nozzles that have a second main evaporation direction for depositing the first material or a second material on the substrate; wherein the second main evaporation direction is tilted downwardly or upwardly relative to the surface normal of the substrate plane by a third tilt angle and is tilted laterally relative to the surface normal by a fourth tilt angle, the first tilt angle and the third tilt angle having opposite signs and the second tilt angle and the fourth tilt angle having opposite signs relative to the surface normal.Implementation 19.: An evaporation source arrangement, comprising: a first evaporation source for depositing two or more materials on a substrate, comprising: two or more vapor distribution pipes including a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate, wherein the two or more vapor distribution pipes define a front side of the first evaporation source directed toward a substrate plane; wherein the nozzles of the first row of nozzles are tilted upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle (a), and the first vapor distribution pipe is inclined relative to the direction of gravity in a plane essentially parallel to the substrate plane by a vapor distribution pipe tilt angle (y).Implementation 20.: The evaporation source arrangement of any of implementations 17 to 19, wherein the first tilt angle, the second tilt angle, the third tilt angle and / or the fourth tilt angle is 25° or more.Implementation 21. A substrate for display manufacture comprising an organic lightemitting diode, OLED, pixel structure, the OLED pixel structure comprising: sidewalls surrounding a pixel region, comprising two adjacent sidewalls provided at an angle, the two adjacent sidewalls protruding from a surface of the substrate and defining a corner region of the pixel region; overhangs projecting inwardly towards the pixel region from the sidewalls; an organic layer deposited in the pixel region essentially without contacting the two adjacent sidewalls in the corner region; and a metallic layer deposited on the organic layer and contacting at least one of the two adjacent sidewalls. The metallic layer may be a cathode layer.Implementation 22. The substrate according to implementation 21 , wherein the metallic layer contacts both the two adjacent sidewalls in the corner region.Implementation 23. The substrate according to implementation 21 or 22, wherein the sidewalls comprise four sidewalls surrounding the pixel region and defining four corner regions of the pixel region; the organic layer contacting adjacent sidewalls of the four sidewalls in two or less corner regions; and the metallic layer contacting adjacent sidewalls of the four sidewalls in two or more corner regions, particularly in three or four corner regions.Implementation 24.: The substrate according to implementation 23, wherein the four sidewalls surround the pixel region in a rectangle- or rhombus shape, and the metallic layer contacts adjacent sidewalls of the four sidewalls in each of the four corner regions.Implementation 25.: The substrate according to any of implementations 21 to 24, wherein the substrate has an essentially rectangular shape comprising substrate edges, and the sidewalls surround the pixel region in a rhombus- or diamond shape to provide pixel edges rotated relative to the substrate edges. In particular, the sidewalls may respectively extend in a direction rotated relative to the substrate edges by an angle of 20° or more and 70° or less, particularly 30° or more and 60° or less, more particularly about 45°.Implementation 26.: A substrate for display manufacture comprising an organic lightemitting diode, OLED, pixel structure, manufactured by the method of coating a substrate according to any of implementations 1 to 16.

[0110] 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.

[0111] In particular, this written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any devices or systems and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if 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 claimed is:1 . A method of coating a substrate in a vacuum chamber, the substrate having a structure formed thereon comprising a first sidewall adjacent to a pixel region and a first overhang projecting from the first sidewall, the method comprising: arranging a first evaporation source in a first deposition position, the first evaporation source having a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction; and transporting the substrate being oriented essentially vertically past the first evaporation source in a transport direction while directing a first material toward the substrate from the first row of nozzles, wherein, in the first deposition position, the first main evaporation direction is tilted either upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle (a) to increase a deposition of the first material under the first overhang.

2. The method of claim 1 , wherein the structure formed on the substrate has a second sidewall adjacent to the pixel region and a second overhang projecting from the second sidewall, the first sidewall and the second sidewall defining a first corner region, wherein, in the first deposition position, the first main evaporation direction is also tilted laterally relative to the surface normal of the substrate by a second tilt angle ([3) to increase a deposition of the first material under the second overhang and in the first corner region.

3. The method of claim 1 or 2, wherein the first tilt angle (a) is 30° or more.

4. The method of claim 1 or 2, wherein the first material is a metal and, in the first deposition position, the first main evaporation direction is tilted to increase a contact area between the metal and the first sidewall under the first overhang.

5. The method of claim 1 or 2, wherein the first tilt angle (a) is at least partially defined by an upward or downward tilt of the nozzles of the first row of nozzles relative to a longitudinal direction of the first vapor distribution pipe.

6. The method of claim 1 or 2, wherein the first tilt angle (a) is at least partially defined by a tilt of a longitudinal direction of the first vapor distribution pipe relative to the direction of gravity by 10° or more, so that an upper part of the first vapor distribution pipe is closer to or further from the substrate than a lower part of the first vapor distribution pipe.

7. The method of claim 1 or 2, wherein the first vapor distribution pipe is inclined relative to the direction of gravity in a plane parallel to the substrate by a vapor distribution pipe tilt angle (y).

8. The method of claim 7, wherein the vapor distribution pipe tilt angle (y) is higher than 5° and lower than 45 °.

9. The method of claim 2, wherein the first sidewall extends in a direction essentially parallel to the transport direction and the second sidewall extends in an essentially vertical direction.

10. The method of claim 1 or 2, wherein the first sidewall extends in a direction rotated relative to the transport direction at an angle of at least 30°.11 . The method of claim 1 or 2, further comprising: arranging a second evaporation source in a second deposition position, the second evaporation source having a second vapor distribution pipe with a second row of nozzles that have a second main evaporation direction; and transporting the substrate being oriented essentially vertically past the second evaporation source while directing the first material or a second material toward the substrate from the second row of nozzles, wherein, in the second deposition position, the second main evaporation direction of the second row of nozzles is tilted either downwardly or upwardly relative to the surface normal of the substrate by a third tilt angle, the first tilt angle and the third tilt angle having opposite signs relative to the surface normal.

12. The method of claim 11 , wherein the structure formed on the substrate further comprises: a third sidewall adjacent to the pixel region on an opposite side as the first sidewall and a third overhang projecting from the third sidewall, wherein the first tilt angle of the first row of nozzles increases the deposition of the first material under the first overhang and the third tilt angle of the second row of nozzles increase a deposition of the second material under the third overhang.

13. The method of claim 12, wherein the structure formed on the substrate further comprises a fourth sidewall adjacent to the pixel region on an opposite side as a second sidewall, the third sidewall and the fourth sidewall defining a second corner region, and a fourth overhang projecting from the fourth sidewall, wherein in the second deposition position, the second main evaporation direction is also tilted laterally relative to the surface normal of the substrate by a fourth tilt angle to increase a deposition of the first or second material under the fourth overhang and in the second corner region.

14. The method of claim 11 , wherein the first evaporation source coats the substrate with a first sublayer of a cathode layer, particularly comprising co-deposited metals, and the second evaporation source coats the substrate with a second sublayer of the cathode layer, particularly comprising the co-deposited metals.

15. The method of claim 1 or 2, comprising a deposition of a metal over an organic material, wherein the metal is deposited via angled deposition under the first overhang to provide a contact area between the metal and the first sidewall.

16. The method of claim 1 or 2, wherein the first evaporation source includes the first vapor distribution pipe and at least one further vapor distribution pipe, each vapor distribution pipe comprising one single row of nozzles having twenty or more nozzles.

17. An evaporation source arrangement, comprising: a first evaporation source for depositing a first layer on a substrate that is moved in an essentially vertical orientation past the first evaporation source in a substrate plane, the first evaporation source comprising a first vapor distribution pipe with a first row ofnozzles that have a first main evaporation direction for depositing a first material on the substrate, wherein the first main evaporation direction is tilted upwardly or downwardly relative to a surface normal of the substrate plane by a first tilt angle and is tilted laterally relative to the surface normal by a second tilt angle.

18. The evaporation source arrangement of claim 17, further comprising: a second evaporation source arranged downstream of the first evaporation source along a transport path for depositing a second layer on the substrate that is moved past the second evaporation source, the second evaporation source comprising a second vapor distribution pipe with a second row of nozzles that have a second main evaporation direction for depositing the first material or a second material on the substrate; wherein the second main evaporation direction is tilted downwardly or upwardly relative to the surface normal of the substrate plane by a third tilt angle and is tilted laterally relative to the surface normal by a fourth tilt angle, the first tilt angle and the third tilt angle having opposite signs and the second tilt angle and the fourth tilt angle having opposite signs relative to the surface normal.

19. An evaporation source arrangement, comprising: a first evaporation source for depositing two or more materials on a substrate, comprising: two or more vapor distribution pipes including a first vapor distribution pipe with a first row of nozzles that have a first main evaporation direction for depositing a first material on the substrate, wherein the two or more vapor distribution pipes define a front side of the first evaporation source directed toward a substrate plane; wherein the nozzles of the first row of nozzles are tilted upwardly or downwardly relative to a surface normal of the substrate by a first tilt angle (a), and the first vapor distribution pipe is inclined relative to the direction of gravity in a plane parallel to the substrate plane by a vapor distribution pipe tilt angle (y).

20. The evaporation source arrangement of any of claims 17 to 19, wherein the first tilt angle, the second tilt angle, the third tilt angle and / or the fourth tilt angle is 25° or more.21 . A substrate for display manufacture comprising an organic light-emitting diode, OLED, pixel structure, the OLED pixel structure comprising: sidewalls surrounding a pixel region, comprising two adjacent sidewalls provided at an angle, the two adjacent sidewalls protruding from a surface of the substrate and defining a corner region of the pixel region; overhangs projecting inwardly towards the pixel region from the sidewalls; an organic layer deposited in the pixel region essentially without contacting the two adjacent sidewalls in the corner region; and a metallic layer deposited on the organic layer and contacting at least one of the two adjacent sidewalls.

22. The substrate according to claim 21 , wherein the metallic layer contacts both the two adjacent sidewalls in the corner region.

23. The substrate according to claim 21 or 22, wherein the sidewalls comprise four sidewalls surrounding the pixel region and defining four corner regions of the pixel region; the organic layer contacting adjacent sidewalls of the four sidewalls in two or less corner regions; and the metallic layer contacting adjacent sidewalls of the four sidewalls in two or more corner regions.

24. The substrate according to claim 23, wherein the four sidewalls surround the pixel region in a rectangle- or rhombus shape, and the metallic layer contacts adjacent sidewalls of the four sidewalls in each of the four corner regions.

25. The substrate according to claim 21 or 22, whereinthe substrate has an essentially rectangular shape comprising substrate edges, and the sidewalls surround the pixel region in a rhombus- or diamond shape to provide pixel edges rotated relative to the substrate edges.

26. A substrate for display manufacture comprising an organic light-emitting diode, OLED, pixel structure, manufactured by the method of coating a substrate according to claim 1 or 2.

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