WO2017054890A1

WO2017054890A1 - Variable shaper shield for evaporators and method for depositing an evaporated source material on a substrate

Info

Publication number: WO2017054890A1
Application number: PCT/EP2015/072865
Authority: WO
Inventors: Jose Manuel Dieguez-Campo; Stefan Bangert; Heike Landgraf; Andreas Lopp
Original assignee: Applied Materials, Inc.
Priority date: 2015-10-02
Filing date: 2015-10-02
Publication date: 2017-04-06

Abstract

A shielding device (320) for an evaporation source configured to guide evaporated source material through a plurality of outlets distributed along a length direction of the evaporation source. The shielding device including three or more spaced-apart shaper shield segments (325) configured for blocking evaporated source material (312) depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source.

Description

VARIABLE SHAPER SHIELD FOR EVAPORATORS AND METHOD FOR DEPOSITING AN EVAPORATED SOURCE MATERIAL ON A SUBSTRATE

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to deposition of organic material, systems and methods for depositing materials, e.g. organic materials. Embodiments of the present disclosure particularly relate to shielding devices for evaporation sources, evaporation sources and apparatuses, and methods for evaporating materials and depositing evaporated materials on a substrate for manufacturing devices, particularly devices including organic materials therein.

BACKGROUND [0002] Organic evaporators are a tool for the production of organic light-emitting diodes (OLED). OLEDs are a special type of light-emitting diodes in which the emissive layer comprises a thin-film of certain organic compounds. Organic light emitting diodes (OLEDs) are used in the manufacture of television screens, computer monitors, mobile phones and other hand-held devices for displaying information. OLEDs can also be used for general space illumination. The range of colors, brightness, and viewing angles possible with OLED displays are greater than that of traditional LCD displays because OLED pixels directly emit light and do not need a back light. Therefore, the energy consumption of OLED displays is considerably less than that of traditional LCD displays. Further, the fact that OLEDs can be manufactured onto flexible substrates results in further applications. A typical OLED display, for example, may include layers of organic material situated between two electrodes that are all deposited on a substrate in a manner to form a matrix display panel having individually energizable pixels. The OLED is generally placed between two glass panels, and the edges of the glass panels are sealed to encapsulate the OLED therein.

[0003] There are many challenges encountered in the manufacture of such display devices. OLED displays or OLED lighting applications include a stack of several organic materials, which are for example evaporated in a vacuum. The organic materials are deposited in a subsequent manner through shadow masks. For the fabrication of OLED stacks with high efficiency, the co-deposition or co-evaporation of two or more materials, e.g. host and dopant, leading to mixed/doped layers is beneficial. Further, it has to be considered that there are several process conditions for the evaporation of the very sensitive organic materials.

[0004] For depositing the material on a substrate, the material is heated until the material evaporates. Pipes guide the evaporated material to the substrates through nozzles. In the past years, the precision of the deposition process has been increased, e.g. for being able to provide smaller and smaller pixel sizes. In some processes, masks are used for defining the pixels when the evaporated material passes through the mask openings. However, shadowing effects of a mask, the spread of the evaporated material and the like make it difficult to further increase the precision and the predictability of the evaporation process.

[0005] In view of the above, it is an object of embodiments described herein to increase the precision and predictability of evaporation processes for manufacturing devices having a high quality and precision.

SUMMARY

[0006] In light of the above, a shielding device, an evaporation source and a method for depositing an evaporated source material on a substrate according to the independent claims are provided.

[0007] According to an aspect of the present disclosure, a shielding device for an evaporation source is provided, the evaporation source being configured to guide evaporated source material through a plurality of outlets distributed along a length direction of the evaporation source. The shielding device includes three or more spaced-apart shaper shield segments configured for blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source.

[0008] According to a further aspect of the present disclosure, an evaporation source configured to evaporate a source material and deposit the evaporated source material on a surface of a substrate in a vacuum chamber is provided. The evaporation source includes: an evaporation crucible configured to evaporate the source material; a distribution pipe with a plurality of outlets provided along the length of the distribution pipe for providing a plume of evaporated source material from the plurality of outlets, wherein the distribution pipe is in fluid communication with the evaporation crucible; and a shielding device as described above.

[0009] According to a yet further embodiment of the present disclosure, a method for depositing an evaporated source material on a surface of a substrate in a vacuum chamber is provided. The method includes: evaporating the source material in an evaporation source having a plurality of outlets distributed along a length direction of the evaporation source; guiding the evaporated source material through the plurality of outlets of the evaporation source; and blocking the evaporated source material with three or more spaced-apart shaper shield segments depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source.

[0010] Further aspects, advantages and features of the present disclosure are apparent from the dependent claims, the description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS [0011] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be had by reference to typical embodiments. The accompanying drawings relate to embodiments of the present disclosure and are described in the following:

[0012] Fig. 1 shows a schematic top view of a deposition apparatus for depositing a source material in a vacuum chamber according to embodiments described herein;

[0013] Fig. 2A and Fig. 2B show schematic views of portions of an evaporation source according to embodiments described herein;

[0014] Fig. 2C shows a schematic view of another evaporation source according to embodiments described herein; [0015] Fig. 3 shows a schematic top view of an evaporation source according to embodiments herein;

[0016] Fig. 4 shows a schematic top view of an evaporation source according to yet further embodiments herein; [0017] Fig. 5 shows a schematic perspective view of an evaporation source according to embodiments herein;

[0018] Fig. 6 shows a schematic side view of a section of an evaporation source according to embodiments herein;

[0019] Fig. 7 shows a schematic front view of a section of a shielding device according to embodiments herein;

[0020] Fig. 8 shows a schematic side view of a section of a shielding device according to embodiments herein; and

[0021] Fig. 9 schematically shows a method for depositing an evaporated material on a substrate according to embodiments herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0022] Reference will now be made in detail to the various embodiments of the present disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to the same components. Generally, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation and is not meant as a limitation of the present disclosure. Features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations. [0023] As used herein, the term "source material" may be apprehended as a material that is evaporated and deposited on a surface of a substrate. For example, in embodiments described herein, an evaporated organic material that is deposited on a surface of a substrate may be a source material. Non-limiting examples of organic materials include one or more of the following: ITO, NPD, Alq₃, Quinacridone, Mg/AG, starburst materials, and the like.

[0024] As used herein, the term "fluid communication" may be understood in that two elements being in fluid communication can exchange fluid via a connection, allowing fluid to flow between the two elements. In one example, the elements being in fluid communication may include a hollow structure, through which the fluid may flow. According to some embodiments, at least one of the elements being in fluid communication may be a pipe-like element.

[0025] As used herein, the term "evaporation source" may be understood as an arrangement providing a source material to be deposited on a substrate. In particular, the evaporation source may be configured for providing a source material to be deposited on a substrate in a vacuum chamber, such as a vacuum deposition chamber of a deposition apparatus. According to some embodiments described herein, the evaporation source may be configured to evaporate the source material to be deposited on the substrate. For instance, the evaporation source may include an evaporator or a crucible, which evaporates the source material to be deposited on the substrate, and a distribution pipe, which, in particular, releases the evaporated source material in a direction towards the substrate, e.g. through an outlet.

[0026] As used herein, the term "crucible" may be understood as a device or a reservoir providing or containing the source material to be deposited. Typically, the crucible may be heated for evaporating the source material to be deposited on the substrate. According to embodiments herein, the crucible may be in fluid communication with the distribution pipe to which the source material being evaporated by the crucible may be delivered.

[0027] As used herein, the term "distribution pipe" may be understood as a pipe for guiding and distributing evaporated source material. In particular, the distribution pipe may guide evaporated source material from a crucible to a plurality of outlets (such as an openings) in the distribution pipe. As used herein, the term "a plurality of outlets" typically includes at least two or more outlets. According to embodiments herein, the distribution pipe may be a linear distribution pipe extending in a first, especially longitudinal, direction. In embodiments described herein, the longitudinal direction may typically refer to the length direction of the distribution pipe. In some embodiments, the distribution pipe may include a pipe having the shape of a cylinder. The cylinder may have a circular bottom shape or any other suitable bottom shape. Examples of distribution pipes will be described in more detail below.

[0028] Fig. 1 shows a top view of an evaporation source 100 positioned in a vacuum chamber 110 of a deposition apparatus 150. According to some embodiments, which can be combined with other embodiments described herein, the evaporation source is configured for a translational movement and a rotation around an axis. According to typical embodiments herein, the evaporation source may have one or more evaporation crucibles and one or more distribution pipes. For instance, the evaporation source shown in Fig. 1 includes two evaporation crucibles 104 and two distribution pipes 106. As is shown in Fig. 1, a first substrate 121 and a second substrate 122 are provided in the vacuum chamber 110 for receiving evaporated source material.

[0029] According to embodiments herein, a mask assembly for masking a substrate can be provided between the substrate and the evaporation source. The mask assembly may include a mask and a mask frame to hold the mask in a predetermined position. In embodiments herein, one or more additional tracks may be provided for supporting and displacing the mask assembly. For instance, the embodiment shown in Fig. 1 has a first mask 133 supported by a first mask frame 131 arranged between the evaporation source 100 and the first substrate 121 and a second mask 134 supported by a second mask frame 132 arranged between the evaporation source 100 and the second substrate 122. The first substrate 121 and the second substrate 122 may be supported on respective transportation tracks (not shown in the figures) within the vacuum chamber 110.

[0030] Fig. 1 further shows a shielding device 320 according to embodiments herein, which is provided to guide the evaporated source material from the one or more distribution pipes 106 to the first substrate 121 and/or to the second substrate 122 respectively. In embodiments herein, if masks are used for depositing material on a substrate, such as in an OLED production system, the mask may be a pixel mask with pixel openings having the size of about 50 μιη x 50 μιη, or even below, such as a pixel opening with a dimension of the cross section (e.g. the minimum dimension of a cross section) of about 30 μιη or less, or about 20 μιη. In one example, the pixel mask may have a thickness of about 40 μιη. Considering the thickness of the mask and the size of the pixel openings, a shadowing effect may appear, where the walls of the pixel openings in the mask shadow the pixel opening. The shielding device described herein may delimit the evaporated source material and reduce the shadowing effect.

[0031] According to embodiments described herein, the material of the shielding device may be adapted for evaporated source material having a temperature of about 100° C to about 600°C. In some embodiments, the shielding device may include a material having a thermal conductivity larger than 21 W / (m-K) and/or a material being chemically inert to, for instance, evaporated organic material. According to some embodiments, the shielding device may include at least one of Cu, Ta, Ti, Nb, DLC, and graphite or may include a coating with at least one of the named materials.

[0032] According to embodiments described herein, the substrates may be coated with a source material in an essentially vertical position. Typically, the distribution pipe provides a line source extending essentially vertically. In embodiments described herein, which can be combined with other embodiments described herein, the term "essentially vertically" is understood, particularly when referring to the substrate orientation, to allow for a deviation from the vertical direction of 20° or below, e.g. of 10° or below. For example, this deviation can be provided because a substrate support with some deviation from the vertical orientation might result in a more stable substrate position. Yet, an essentially vertical substrate orientation during deposition of the source material is considered different from a horizontal substrate orientation. The surface of the substrate is coated by a line source extending in one direction corresponding to one substrate dimension and a translational movement along the other direction corresponding to the other substrate dimension.

[0033] The evaporation source 100 shown in Fig. 1 may be provided in the vacuum chamber 110 of the deposition apparatus 150 on a track, e.g. a looped track (not shown in the figures) or linear guide 120. The track or linear guide 120 is configured for the translational movement of the evaporation source 100. According to different embodiments, which can be combined with other embodiments described herein, a drive for the translational movement can be provided in the evaporation source 100, at the track or linear guide 120, within the vacuum chamber 110 or a combination thereof.

[0034] Fig. 1 further shows a valve 105, for example, a gate valve. The valve 105 allows for a vacuum seal to an adjacent vacuum chamber (not shown in the figures). According to embodiments herein, the valve 105 can be opened for the transport of a substrate or a mask into and/or out of the vacuum chamber 110.

[0035] According to some embodiments, which can be combined with other embodiments described herein, a further vacuum chamber, such as maintenance vacuum chamber 111 is provided adjacent to the vacuum chamber 110. The vacuum chamber 110 and the maintenance vacuum chamber 111 are connected by a valve 109. The valve 109 is configured for opening and closing a vacuum seal between the vacuum chamber 110 and the maintenance vacuum chamber 111. According to embodiments herein, the evaporation source 100 can be transferred to the maintenance vacuum chamber 111 while the valve 109 is in an open state. Thereafter, the valve can be closed to provide a vacuum seal between the vacuum chamber 110 and the maintenance vacuum chamber 111. If the valve 109 is closed, the maintenance vacuum chamber 111 can be vented and opened for maintenance of the evaporation source 100 without breaking the vacuum in the vacuum chamber 110.

[0036] The described material deposition arrangement may be used for various applications, including applications for OLED device manufacturing including processing methods, wherein two or more source materials such as, for instance, two or more organic materials are evaporated simultaneously. In the example shown in Fig. 1, two or more distribution pipes and corresponding evaporation crucibles are provided next to each other.

[0037] Although the embodiment shown in Fig. 1 provides a deposition apparatus with a movable evaporation source, the skilled person may understand that the above described embodiments may also be applied to deposition systems in which the substrate is moved during processing. For instance, the substrates to be coated may be guided and driven along stationary material deposition arrangements.

[0038] Embodiments described herein particularly relate to deposition of organic materials, e.g. for OLED display manufacturing on large area substrates. According to some embodiments, large area substrates or carriers supporting one or more substrates may have a size of at least 0.174 m². For instance, the deposition system may be adapted for processing large area substrates, such as substrates of GEN 5, which corresponds to about 1.4 m substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7 m² substrates (2.2 m x 2.5 m), or even

GEN 10, which corresponds to about 8.7 m substrates (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can similarly be implemented.

[0039] According to embodiments herein, which can be combined with other embodiments described herein, the substrate thickness can be from 0.1 to 1.8 mm and the holding arrangement for the substrate can be adapted for such substrate thicknesses. However, particularly the substrate thickness can be about 0.9 mm or below, such as 0.5 mm or 0.3 mm, and the holding arrangements are adapted for such substrate thicknesses. Typically, the substrate may be made from any material suitable for material deposition. For instance, the substrate may be made from a material selected from the group consisting of glass (for instance soda-lime glass, borosilicate glass etc.), metal, polymer, ceramic, compound materials, carbon fiber materials or any other material or combination of materials which can be coated by a deposition process.

[0040] Fig. 2A to Fig. 2C show portions of an evaporation source according to embodiments described herein. As shown in Fig. 2A, the evaporation source can include a distribution pipe 106 and an evaporation crucible 104. For example, the distribution pipe can be an elongated cube with heating unit 215. The evaporation crucible can be a reservoir for a source material, such as an organic material to be evaporated with a heating unit 225.

[0041] According to embodiments, which can be combined with other embodiments described herein, a plurality of openings and/or outlets, such as nozzles, may be arranged along a length direction of the evaporation source. In particular, the plurality of openings and/or outlets may be arranged along a length direction of the distribution pipe. According to an alternative embodiment, one elongated opening extending along the length direction of the evaporation source and/or the length of the distribution pipe can be provided. For example, the elongated opening can be a slit. [0042] According to some embodiments, which can be combined with other embodiments described herein, the distribution pipe extends essentially vertically in a length direction. For example, the length of the distribution pipe 106 corresponds at least to the height of the substrate to be deposited in the deposition apparatus. In many cases, the length of the distribution pipe 106 will be longer than the height of the substrate to be deposited, at least by 10% or even 20%, which allows a uniform deposition at the upper end of the substrate and/or the lower end of the substrate. [0043] According to some embodiments, which can be combined with other embodiments described herein, the length of the distribution pipe can be 1.3 m or above, for example 2.5 m or above. According to one configuration, as shown in Fig. 2A, the evaporation crucible 104 is provided at the lower end of the distribution pipe 106. Typically, the source material is evaporated in the evaporation crucible 104. The evaporated source material enters at the bottom of the distribution pipe 106 and is guided essentially sideways through the plurality of openings in the distribution pipe, e.g. towards an essentially vertical oriented substrate.

[0044] According to some embodiments, which can be combined with other embodiments described herein, the plurality of outlets are arranged to have a main emission direction to be horizontal +/- 20°. According to some specific embodiments, the main emission direction can be oriented slightly upward, e.g. to be in a range from horizontal to 15° upward, such as 3° to 7° upward. Similarly, the substrate can be slightly inclined to be substantially perpendicular to the evaporation direction, which may reduce the generation of undesired particles. For illustrative purposes, the evaporation crucible 104 and the distribution pipe 106 are shown without heat shields in Fig. 2A. The heating unit 215 and the heating unit 225 can be seen in the schematic perspective view shown in Fig. 2B.

[0045] Fig. 2B shows an enlarged schematic view of a portion of the evaporation source, in particular, of the distribution pipe 106 connected to the evaporation crucible 104. A flange unit 203 is provided, which is configured to provide a connection between the evaporation crucible 104 and the distribution pipe 106. For example, the evaporation crucible and the distribution pipe are provided as separate units, which can be separated and connected or assembled at the flange unit, e.g. for operation of the evaporation source.

[0046] The distribution pipe 106 has an inner hollow space 210. A heating unit 215 is provided to heat the distribution pipe. The distribution pipe 106 can be heated to a temperature such that the evaporated source material provided by the evaporation crucible 104 does not condense at an inner portion of the wall of the distribution pipe 106. Two or more heat shields 217 are provided around the tube of the distribution pipe 106. The heat shields are configured to reflect heat energy provided by the heating unit 215 back towards the inner hollow space 210. The energy to heat the distribution pipe 106, i.e. the energy provided to the heating unit 215, can be reduced because the heat shields 217 reduce heat losses. Heat transfer to other distribution pipes and/or to the mask or substrate can be reduced. According to some embodiments, which can be combined with other embodiments described herein, the heat shields 217 can include two or more heat shield layers, e.g. five or more heat shield layers, such as ten heat shield layers.

[0047] Typically, as shown in Fig. 2B, the heat shields 217 include openings at positions of the outlets 212 in the distribution pipe 106. The enlarged view of the evaporation source shown in Fig. 2B shows four outlets. The outlets 212 can be provided along a length direction of the distribution pipe 106. As described herein, the distribution pipe 106 can be provided as a linear distribution pipe, for example, having a plurality of openings disposed therein. For instance, the distribution pipe may have more than 30 outlets, such as 40, 50 or 54 outlets arranged along a length direction of the distribution pipe. According to embodiments herein, the outlets may be spaced apart from each other. For instance, the outlets may be spaced apart by a distance of 1 cm or more, for example, by a distance from 1 cm to 3 cm, like for example, by a distance of 2 cm.

[0048] A distribution pipe as understood herein has an enclosure, hollow space, or pipe, in which the material can be provided or guided, for example from the evaporation crucible. The distribution pipe can have a plurality of openings (or an elongated slit) such that the pressure within the distribution pipe is higher than outside of the distribution pipe. For example, the pressure within the showerhead can be at least one order of magnitude higher than that outside of the distribution pipe.

[0049] During operation, the distribution pipe 106 is connected to the evaporation crucible 104 at the flange unit 203. The evaporation crucible 104 is configured to receive the source material to be evaporated and to evaporate the source material. Fig. 2B shows a cross- section through the housing of the evaporation crucible 104. A refill opening is provided, for example, at an upper portion of the evaporation crucible, which can be closed using a plug 222, a lid, a cover or the like for closing the enclosure of evaporation crucible 104. [0050] An outer heating element 225 is provided within the enclosure of the evaporation crucible 104. The outer heating element 225 can extend at least along a portion of the wall of the evaporation crucible 104. According to some embodiments, which can be combined with other embodiments described herein, additionally or alternatively one or more central heating elements can be provided. Fig. 2B shows two central heating elements 226, 228. The first central heating element 226 and the second central heating element 228 can respectively include a first conductor 229 and a second conductor 230 for providing electrical power to the central heating elements 226, 228.

[0051] To improve the heating efficiency of the source material within the evaporation crucible, the evaporation crucible 104 can further include a shield 227 configured to reflect heat energy provided by the outer heating unit 225 and, if present, by the central heating elements 226, 228, back into the enclosure of the evaporation crucible 104.

[0052] According to some embodiments, which have been described herein, heat shields such as shields 217 and shield 227 can be provided for the evaporation source. The heat shields can reduce energy loss from the evaporation source, which also reduces the overall energy consumed by the evaporation source to evaporate a source material. However, as a further aspect, particularly for deposition of organic materials, heat radiation originating from the evaporation source, especially heat radiation towards the mask and the substrate during deposition can be reduced. Particularly for the deposition of organic materials on masked substrates, and even more for display manufacturing, the temperature of the substrate and the mask needs to be precisely controlled. Heat radiation originating from the evaporation source can be reduced or avoided by heat shields such as, for instance, shields 217 and shield 227.

[0053] These shields can include several shielding layers to reduce the heat radiation to the outside of the evaporation source. As a further option, the heat shields may include shielding layers, which are actively cooled by a fluid, such as air, nitrogen, water or other appropriate cooling fluids. According to yet further embodiments described herein, the one or more heat shields can include sheet metals surrounding respective portions of the evaporation source, for instance, surrounding the distribution pipe 106 and/or the evaporation crucible 104. According to embodiments herein, the sheet metals can have thicknesses of 0.1 mm to 3 mm, can be selected from at least one material selected from the group consisting of ferrous metals (SS) and non-ferrous metals (Cu, Ti, Al), and/or can be spaced with respect to each other, for example, by a gap of 0.1 mm or more.

[0054] According to some embodiments described herein and as exemplarily shown with respect to Fig. 2A and Fig. 2B, the evaporation crucible 104 is provided at a lower side of the distribution pipe 106. According to yet further embodiments, which can be combined with other embodiments described herein, a vapor conduit 242 may be provided at the central portion of the distribution pipe 106 or at another position between the lower end of the distribution pipe and the upper end of the distribution pipe.

[0055] Fig. 2C illustrates an example of the evaporation source having a distribution pipe 106 and a vapor conduit 242 provided at a central portion of the distribution pipe. Evaporated source material generated in the evaporation crucible 104 is guided through the vapor conduit 242 to the central portion of the distribution pipes 106. The evaporated source material exits the distribution pipe 106 through a plurality of outlets 212. The distribution pipe 106 is supported by a support 102 as described with respect to other embodiments described herein. According to yet further embodiments herein, two or more vapor conduits 242 may be provided at different positions along the length of the distribution pipe 106. The vapor conduits 242 can either be connected to one evaporation crucible or to several evaporation crucibles. For example, each vapor conduit 242 can have a corresponding evaporation crucible 104. Alternatively, the evaporation crucible 104 can be in fluid communication with two or more vapor conduits 242, which are connected to the distribution pipe 106.

[0056] As described herein, the distribution pipe can be a hollow cylinder. The term cylinder can be understood as commonly accepted as having a circular bottom shape and a circular upper shape and a curved surface area or shell connecting the upper circle and the lower circle. According to further additional or alternative embodiments, which can be combined with other embodiments described herein, the term cylinder can further be understood in the mathematical sense as having an arbitrary bottom shape and an identical upper shape and a curved surface area or shell connecting the upper shape and the lower shape. The cylinder does not necessarily need to have a circular cross-section.

[0057] Fig. 3 shows a schematic top view of an evaporation source according to embodiments herein. The evaporation source shown in Fig. 3 includes one distribution pipe 106. According to embodiments herein, the distribution pipe may extend in a length direction and a plurality of outlets may be arranged along the length direction of the distribution pipe. The walls of the distribution pipe may be heated by heating elements 380, which are mounted or attached to the walls. For reducing the heat radiation towards the substrate, the mask or another portion of a deposition apparatus from the heated portion of the distribution pipe 106, a first outer shield 302, which surrounds the distribution pipe may be cooled. An additional second outer shield 304 may be provided to reduce the heat load directed towards the deposition area or a substrate, respectively. The second outer shield 304 may have a front wall 305, facing the substrate 330 and/or facing the mask 340. The second outer shield 304 may include one or more side walls. For instance, the outer shield 304 includes a first side wall 306 and a second side wall 307. According to embodiments herein, the front wall 305, first side wall 306 and second side wall 307 may be provided as a U- shaped outer shield 304 to reduce the heat radiation towards the deposition area, i.e. a substrate and/or a mask.

[0058] According to some embodiments, which can be combined with other embodiments described herein, the shields can be provided as metal plates having conduits for cooling fluid, such as water, attached to the metal shields or provided within the metal shields. Additionally, or alternatively, thermoelectric cooling device or other cooling device can be provided to cool the shields. Typically, the outer shields, i.e. the outermost shields surrounding the inner hollow space of a distribution pipe, can be cooled.

[0059] As further shown in Fig. 3, a shielding device 320 is provided, for example, attached to the outer shield 304 or as part of the outer shield 304. According to some embodiments, the shielding device 320 can also be cooled to further reduce the heat load emitted towards the deposition area. Arrow 312 illustrates the evaporated source material exiting the distribution pipe 106. According to embodiments herein, the evaporation source typically includes a plurality of outlets distributed along a length direction of the evaporation source. For instance, the evaporation source may include 30 or more outlets, such as, for instance, at least 54 outlets, which may be spaced apart from each other by a distance of, for example, 2 cm. According to embodiments herein, the shielding device delimits the distribution cone or plume 318 of evaporated source material distributed towards the substrate 330. Typically, the shielding device is configured to block at least a portion of the evaporated source materials.

[0060] According to embodiments herein, the shielding device includes at least one side surface. The at least one side surface may be configured for blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a planar direction perpendicular to the length direction of the evaporation source. In Fig. 3, the shielding device 320 includes a first side wall 321 and a second side wall 322. Each of the first and second side walls provide a side surface configured for blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane perpendicular to the length direction of the evaporation source. According to embodiments herein, the at least one side wall may extend at least along the length of the evaporation source. In embodiments described herein, the at least one side wall may protrude from the evaporation source in a direction towards the substrate and/or the mask. For instance, the at least one side wall may protrude from the evaporation source in a direction towards the substrate and/or the mask by a distance of 6 cm or more. For instance, by a distance from 6 cm to 15 cm, like, for example, by a distance of 12 cm.

[0061] According to embodiments herein, the at least one side surface may be configured for blocking evaporated source material of the plume 318 of evaporated source material having a predetermined emission angle (Θ) greater than 30°, in particular greater than 40° from a main emission direction 350 of the evaporated source material from the plurality of outlets in a plane perpendicular to the length direction of the evaporation source. In embodiments described herein, the shielding device may be configured to block the evaporated source material of the plume of evaporated source material having a predetermined emission angle (Θ) from a main emission direction of the evaporated source material from each of the plurality of outlets.

[0062] According to embodiments herein, the shielding device may include one or more shaper shield segments. In particular, the shielding device 320 may include three or more shaper shield segments 325 configured for blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source. In embodiments described herein, the shaper shield segments may be spaced-apart from each other.

[0063] In the embodiment shown in Fig. 3, the three or more shaper shield segments 325 are configured for blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source. In some embodiments described herein, a substrate may be treated with evaporated source material that is deposited on the substrate through a mask, for example, a shadow mask. For a deposition at high resolution of, for example, more than 800 pixels per inch, each pixel of evaporated source material formed at the surface of the substrate is typically formed by the evaporated source material emitted from more than one of the outlets of the evaporation source. For example, the evaporated source material from ten of the plurality of outlets of the evaporation source may partake in the formation of each of the pixels formed at the surface of the substrate.

[0064] According to embodiments herein, in addition to blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane perpendicular to the length direction of the evaporation source, the shielding device may also be configured to block evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source. According to yet further embodiments herein, the shielding device is configured to block evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in any plane between the plane perpendicular to the length direction of the evaporation source and the plane parallel to the length direction of the evaporation source. For instance, the shielding device is configured to block evaporated source material of the plume 318 of evaporated source material having a predetermined emission angle (Θ) greater than 30°, in particular greater than 40° from a main emission direction 350 of the evaporated source material from the plurality of outlets in any plane between the plane perpendicular to the length direction of the evaporation source and the plane parallel to the length direction of the evaporation source.

[0065] In embodiments described herein, the term "angle of the plume of evaporated source material from the plurality of outlets" should be understood by the skilled person as including the angle of the plume of evaporated material from each of any number of outlets of the evaporation source.

[0066] According to yet further embodiments, which can be combined with other embodiments described herein, each of the shaper shield segments may be moveable with respect to the shielding device. For example, each of the shaper shield segments may be movable in a direction towards and away from the evaporation source. Each of the shaper shield segments may be movable by a distance of 3 cm or more, such as, for example, by a distance of 5 cm in a direction towards and away from the evaporation source.

[0067] In embodiments described herein, each of the shaper shield segments may, for example, have a length of at least 3 cm. According to embodiments herein, the length of the shaper shield segments may be anywhere from 3 cm to 8 cm such as, for instance, 6 cm. According to embodiments herein, each of the shaper shield segments 325 may have a width that is dimensioned to span from the first side wall 321 to the second side wall 322 of the shielding device 320. According to embodiments herein, the shaper shield segments may connect the first side wall 321 with the second side wall 322 of the shielding device 320. [0068] According to yet further embodiments, which can be combined with other embodiments described herein, the shaper shield segments are typically arranged to extend in a plane perpendicular to the length direction of the evaporation source. In embodiments herein, the shaper shield segments may also be tiltable in a direction towards and away from the evaporation source (see Fig. 6 and description below). Tilting one or more of the shaper shield segments may, for instance, help to reduce unwanted source material particles deposited on the shielding device flaking off and contaminating the substrate.

[0069] According to embodiments herein, individually adjusting each of the shaper shield segments 325 inside the plume 318 of evaporated source material allows the manipulation of the deposition profile over the complete length of the evaporation source in small segments without having to exchange the outlet configuration of the evaporation source. According to embodiments herein, the plurality of outlets of the evaporation source may have a simpler construction and any time consuming adjustment of each outlet before or during an evaporation process to optimize the deposition profile may be avoided.

[0070] Fig. 4 shows a schematic top view of an evaporation source according to yet further embodiments herein. In order to avoid unnecessary repetitions, only the differences with respect to the embodiment shown in Fig. 3 are described. Fig. 4 shows an embodiment having three distribution pipes, which are provided over an evaporator control housing 402 adjacent to the distribution pipes and connected thereto via a thermal insulator 479. The evaporator control housing is configured to maintain an atmospheric pressure within the evaporator control housing and is configured to house at least one element selected from the group consisting of: a switch, a valve, a controller, a cooling unit, a cooling control unit, a heating control unit, a power supply, and a measurement device. In embodiments herein, a component for operating the evaporation source for the evaporation source array can be provided under atmospheric pressure close to the evaporation crucible and the distribution pipe and can be moved through the deposition apparatus together with the evaporation source. [0071] In embodiments herein, a plurality of outlets are distributed along the length of each of the distribution pipes 106, 107, 108. Each distribution pipe is in fluid communication with an evaporation crucible (not shown in Fig. 4). Each of the plurality of openings of each distribution pipe 106, 107,108 has a main emission direction 450, 451, 452 for the evaporated source material. Due to the essentially triangular shape of the distribution pipes, the evaporation cones or plumes originating from the three distribution pipes are in close proximity to each other, such that mixing of the source materials from the different distribution pipes and outlets can be improved.

[0072] According to embodiments herein, the shielding device 320 delimits the distribution cone or plume of evaporated source material distributed towards the substrate 330 and/or mask 340 from each of the distribution pipes 106, 107, 108 in a similar manner as described with respect to Fig. 3 above. In the embodiment shown in Fig. 4, the three or more shaper shield segments 325 have been displaced closer towards the evaporation source (see arrow 460). According to embodiments herein, the dimensions of the shielding device including the dimensions of the shaper shield segments may be adjusted to the number of distribution pipes.

[0073] Fig. 5 shows a schematic view of the shielding device and evaporation source according to embodiments herein. Arrow 560 shows a general movement direction of the shielding device 320 towards and away from the evaporation source 100. In embodiments described herein, the shielding device 320 may be removably attached to the evaporation source. A removably attached shielding device may allow for retrofitting existing evaporation sources and/or allows for an easy exchange of the shielding device. According to embodiments herein, the shielding device may include a temperature system with which energy may be provided or taken away from the evaporated source material. The temperature system may be coupled to the evaporator control unit shown in Fig. 4. The embodiment shown in Fig. 5 further shows an exemplary plane 570 parallel to the length direction of the evaporation source 100.

[0074] Fig. 6 shows a schematic side view of a section of an evaporation source according to embodiments herein. The section shown in Fig. 6 includes three outlets 612, 613, 614 that emit evaporated source material along three respective main emission directions 650, 651, 652. The schematic side view shown in Fig. 6 includes a schematic section of a shielding device including three shaper shield segments. In embodiments herein, the shaper shield segments 325, 326, 327 are spaced apart from each other. For instance, each shaper shield segment 325, 326, 327 may be arranged between each of the main emission directions 650, 651, 652 of each of the three outlets 612, 613, 614.

[0075] According to embodiments herein, each of the shaper shield segments 325, 326, 327 may have a length 681 parallel to a corresponding main emission direction 650, 651, 652 from 3 cm to 8 cm such as, for instance, 6 cm. In embodiments herein, the shaper shield segments 325, 326, 327 may be spaced away from a front edge 601 of the shielding device 320. According to embodiments herein, the distance 680 between the front edge of the shielding device and the shaper shield segments may, for instance, be from 1 cm to 5 cm such as, for example, 2 cm. According to embodiments herein, the plurality of shaper shield segments may each be spaced away from the front edge of the shielding device at a different and/or the same distance. Offsetting the three or more shaper shield segments backwards from the front edge of the shielding device may improve the uniformity of the deposited layer of source material by helping to homogenize the evaporated material emitted by the plurality of outlets arranged along the length direction of the evaporation source before the evaporated material exits the shielding device towards the substrate and/or the mask.

[0076] Fig. 6 further shows a guiding element 660, which may be provided for each of the shaper shield segments 325, 326, and 327 respectively. According to embodiments herein, which can be combined with other embodiments described herein, the guiding element is configured for allowing each of the shaper shield segments to be movable with respect to the shielding device 320 in a direction towards and away from the evaporation source 100. For instance, the guiding element may include a railing system arranged at a side surface of the shielding device. The railing system may include a plurality of rails, which may be arranged essentially perpendicular to the length direction of the evaporation source. The plurality of rails may be adapted to guide the movement of each of the shaper shield segments closer to and further away from the evaporation source. For instance, the shaper shield segments may be movable (see arrow 640) by a distance of at least 1 cm towards and/or away from the evaporation source. According to embodiments herein, which may be combined with other embodiments herein, the shaper shield segments may be moveable by, for instance, 5 cm towards and/or away from the evaporation source. [0077] According to embodiments herein, which can be combined with other embodiments described herein, the guiding element 660 of each of the three or more shaper shield segments 325, 326, and 327 may be spaced away from the evaporation source 100. For instance, each of the three or more spaced-apart shaper shield segments may have a distance 683 from the plurality of outlets of at least 1 cm. In embodiments herein, the guiding element may be arranged to allow each of the shaper shield segments to move towards and away from the plurality of outlets. [0078] According to embodiments herein, which can be combined with other embodiments described herein, each of the three or more shaper shield segments 325, 326, 327 may be configured to be tiltable 630 towards and/or away from the evaporation source 100. Each of the shaper shield segments may be tiltable independently from any of the other shaper shield segments. According to embodiments herein, adjusting the position of each of the shaper shield segments allows for an easy and accurate way of manipulating the deposition profile.

[0079] Fig. 7 shows a schematic front view of a section of a shielding device according to embodiments herein. The shielding device includes three or more shaper shield segments 325, 326, 327 arranged between the plurality of outlets of the evaporation source. According to the embodiment shown in Fig. 7, the evaporation source includes a plurality of outlets arranged along the length direction of the evaporation source in a plane 770 parallel to the length direction of the evaporation source. Each of the plurality of shaper shield segments 325, 326, 327 may be arranged between a set of three outlets of the evaporation source, which are arranged in a direction essentially perpendicular to the length direction of the evaporation source. In embodiments described herein, which may be combined with other embodiments described herein, the distance 782 between the outlets of each row of outlets arranged along a plane 772 perpendicular to the length direction of the evaporation source may be 1 cm or more. For instance, the distance between each outlet in the length direction of the evaporation source may be at least 2 cm.

[0080] According to embodiments herein, which may be combined with other embodiments herein, the three or more shaper shield segments 325, 326, 327 may be arranged between the first side wall 321 and the second side wall 322 of the shielding device 320. For instance, in embodiments herein, the shaper shield segments may have a width 783 from 4 cm to 20 cm. In embodiments herein, the width of the shaper shield segments may be adapted according to the specific dimensions of the shielding device and evaporation source. In typical embodiments herein, the shielding device is configured to surround the plurality of outlets. [0081] Fig. 8 shows a schematic side view of a shielding device according to embodiments herein, which can be combined with any of the other embodiments described herein. The shielding device includes a plurality of shaper shield segments 825 arranged between the main emission directions of the plurality of outlets 812 of the evaporation source 100. The embodiment shown in Fig. 8 includes a shaper shield segment arranged between every second main emission direction of the plurality of outlets 812. According to embodiments herein, the length 881 of the shaper shield segments 825 in a direction parallel to the main emission direction of the plurality of outlets 812 may be adapted to block evaporated source material having a predetermined emission angle (Θ) greater than 30°, in particular greater than 40° from a main emission direction of the evaporated source material from any of the plurality of outlets in a plane perpendicular to the length direction of the evaporation source. For instance, the length 881 may be anywhere from 30 mm to 90 mm.

[0082] According to embodiments herein, providing a shielding device with a shaper shield segment arranged between every second main emission direction of the plurality of outlets reduces the number of parts of the shielding device and may help to reduce the cost of ownership of the shielding device.

[0083] Fig. 9 schematically shows a method for depositing an evaporated material on a substrate according to embodiments herein. In embodiments described herein, the evaporation source including the shielding device as shown in Fig. 1 through Fig. 8 may be used in this method. Typically according to embodiments herein, the method 900 may be used to deposit an evaporated source material on a surface of a substrate in a vacuum chamber and includes evaporating 910 the source material in an evaporation source having a plurality of outlets distributed along a length direction of the evaporation source. According to embodiments herein, the evaporation source including a shielding device as described with respect to Fig. 1 through Fig. 8 may be used in the method for depositing an evaporated source material on a substrate. The method further includes guiding 920 the evaporated source material through the plurality of outlets of the evaporation source and blocking 930 the evaporated source material with three or more spaced-apart shaper shield segments depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source.

[0084] According to embodiments herein, blocking the evaporated source material may include blocking evaporated source material of the plume of evaporated source material having an emission angle greater than 30°, in particular greater than 40° from a main emission direction of the evaporated source material from the plurality of outlets in the plane parallel to the length direction of the evaporation source. In embodiments herein, the method of blocking the evaporated source material may include blocking evaporated source material of the plume of evaporated source material having an emission angle greater than 30°, in particular greater than 40° from a main emission direction of the evaporated source material from the plurality of outlets in the a plane perpendicular to the length direction of the evaporation source.

[0085] In embodiments described herein, the shielding device may be configured to block evaporated source material having an emission angle greater than 30°, in particular greater than 40° from a main emission direction of the evaporated source material from the plurality of outlets in any plane between the plane perpendicular to the length direction of the evaporation source and the plane parallel to the length direction of the evaporation source.

[0086] According to embodiments herein, the method 900 for depositing an evaporated material on a substrate may include adjusting 940 the position of at least one of the three or more spaced-apart shaper shield segments to adjust the emission angle of the plume of evaporated source material in a plane parallel to the length direction of the evaporation source. In embodiments described herein, which may be combined with other embodiments described herein, adjusting the position of at least one of the three or more spaced-apart shaper shield segments includes moving at least one of the three or more spaced-apart shaper shield segments in a direction towards and/or away from the evaporation source.

[0087] In embodiments described herein, adjusting the position of at least one of the three or more spaced-apart shaper shield segments allows to tune the uniformity of the deposited films on the substrate. Typically, by adjusting the position of at least one of the three or more spaced-apart shaper shield segments inside the plume of evaporated source material by some millimeters (e.g. from 10 mm to 50 mm) it is possible to manipulate the deposition profile over the complete length of the evaporation source in small segments without having to exchange and/or modify the outlet configuration.

[0088] This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any devices or systems and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. A shielding device for an evaporation source, the evaporation source being configured to guide evaporated source material through a plurality of outlets distributed along a length direction of the evaporation source, the shielding device comprising:

three or more spaced-apart shaper shield segments configured for blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source.

2. The shielding device according to claim 1, wherein the three or more spaced-apart shaper shield segments are configured for blocking evaporated source material of the plume of evaporated source material having an emission angle greater than 40° from a main emission direction of the evaporated source material from the plurality of outlets in the plane parallel to the length direction of the evaporation source.

3. The shielding device according to claim 1 or 2, wherein each of the three or more spaced-apart shaper shield segments have a distance from the plurality of outlets of at least 1 cm.

4. The shielding device according to claim 1 or 3, wherein each of the three or more spaced-apart shaper shield segments have a length of at least 3 cm.

5. The shielding device according to any of claims 1 to 4, wherein the shielding device further comprises at least one side surface configured for blocking evaporated source material depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane perpendicular to the length direction of the evaporation source.

6. The shielding device according to claim 5, wherein the at least one side surface is configured for blocking evaporated source material of the plume of evaporated source material having an emission angle greater than 40° from a main emission direction of the evaporated source material from the plurality of outlets in the plane perpendicular to the length direction of the evaporation source.

7. The shielding device according to any of claims 1 to 6, wherein the three or more spaced-apart shaper shield segments are moveable with respect to the shielding device in a direction towards and away from the evaporation source.

8. The shielding device according to claim 7, wherein each of the three or more spaced- apart shaper shield segments is moveable independently from the other shaper shield segments.

9. An evaporation source configured to evaporate a source material and deposit the evaporated source material on a surface of a substrate in a vacuum chamber, the evaporation source comprising:

an evaporation crucible configured to evaporate the source material;

a distribution pipe with a plurality of outlets provided along the length of the distribution pipe for providing a plume of evaporated source material from the plurality of outlets, wherein the distribution pipe is in fluid communication with the evaporation crucible; and

a shielding device according to any of claims 1 to 8.

10. The evaporation source according to claim 9, wherein the shielding device is removably connected to the evaporation source and/or wherein the three spaced-apart shaper shield segments of the shielding device are assigned to at least three outlets along the length direction of the distribution pipe.

11. The evaporation source according to claim 8 to 10, further comprising at least three evaporation crucibles and at least three distribution pipes with a plurality of outlets provided along the length of each distribution pipe, wherein each distribution pipe is in fluid communication with a respective one of the evaporation crucibles.

12. A method for depositing an evaporated source material on a surface of a substrate in a vacuum chamber, the method comprising:

evaporating the source material in an evaporation source having a plurality of outlets distributed along a length direction of the evaporation source; guiding the evaporated source material through the plurality of outlets of the evaporation source; and

blocking the evaporated source material with three or more spaced-apart shaper shield segments depending on the emission angle of the plume of evaporated source material from the plurality of outlets in a plane parallel to the length direction of the evaporation source.

13. The method according to claim 12, wherein blocking the evaporated source material includes blocking evaporated source material of the plume of evaporated source material having an emission angle greater than 40° from a main emission direction of the evaporated source material from the plurality of outlets in the plane parallel to the length direction of the evaporation source and/or a plane perpendicular to the length direction of the evaporation source.

14. The method according to claim 12 or 13, further including adjusting the position of at least one of the three or more spaced-apart shaper shield segments to adjust the emission angle of the plume of evaporated source material in a plane parallel to the length direction of the evaporation source.

15. The method according to claim 14, wherein adjusting the position of at least one of the three or more spaced-apart shaper shield segments includes moving at least one of the three or more spaced-apart shaper shield segments in a direction towards and/or away from the evaporation source.