CN115074662A

CN115074662A - Evaporation source for depositing evaporated material and method for depositing evaporated material

Info

Publication number: CN115074662A
Application number: CN202210614575.7A
Authority: CN
Inventors: 乔斯·曼纽尔·迭格斯-坎波; 斯蒂芬·班格特; 哈拉尔德·沃斯特; 德烈亚斯·勒普; 戴特尔·哈斯
Original assignee: Applied Materials Inc
Current assignee: Applied Materials Inc
Priority date: 2016-05-10
Filing date: 2016-05-10
Publication date: 2022-09-20
Also published as: JP6941564B2; CN107592889A; WO2017194097A1; JP2018521216A; TWI638899B; KR20180116129A; KR102058612B1; TW201809322A

Abstract

Several embodiments described herein relate to an evaporation source (20) for depositing evaporated source material on a substrate. The evaporation source (20) includes: one or more distribution pipes (106) having a plurality of nozzles (22), wherein each nozzle of the plurality of nozzles (22) is configured for directing a plume of evaporated source material towards the substrate (10); and a shielding device (30) comprising a plurality of apertures (32), wherein at least one aperture of the plurality of apertures (32) is configured to shape a plume (318) of evaporated source material emitted from a single associated nozzle. According to other aspects, a masking device for an evaporation source and several methods of depositing evaporated source material on a substrate are described.

Description

Evaporation source for depositing evaporated material and method for depositing evaporated material

The present application is a divisional application of the patent application entitled "evaporation source for depositing evaporated material and method for depositing evaporated material" filed as 10/5/2016, application No. 201680027463.4.

Technical Field

Embodiments of the present disclosure relate to depositing materials on a substrate, and to apparatuses for depositing materials, such as organic materials, on a substrate. Embodiments of the present disclosure relate to evaporation sources for depositing evaporated source material, such as organic material, on a substrate. Other embodiments relate to masking devices for evaporation sources and to methods of depositing materials, such as organic materials, on a substrate.

Background

Organic vaporizers are tools used to manufacture Organic Light Emitting Diodes (OLEDs). OLEDs are a particular form of light emitting diode in which the light emitting 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 are also used for general space illumination. The feasible range of color, brightness and viewing angle of OLED displays is larger than that of conventional Liquid Crystal Displays (LCDs) because OLED pixels emit light directly and do not require backlighting. Therefore, the power consumption of the OLED display is much less than that of the conventional LCD. Furthermore, OLEDs can be fabricated on flexible substrates, which leads to further applications. A typical OLED display may, for example, comprise several layers of organic material, which are located between two electrodes, which are all deposited on a substrate in such a way that a matrix display panel is formed, which has independently (energizable) pixels. The OLED is typically placed between two glass panels, and the edges of the glass panels are sealed to encapsulate the OLED therein.

Manufacturing such display devices faces many challenges. OLED displays or OLED lighting applications include stacked structures of several organic materials, which are evaporated in vacuum, for example. These organic materials are deposited in a sequential manner through a shadow mask. For the fabrication of several stacked structures of OLEDs with high efficiency, co-deposition (co-position) or co-evaporation (co-evaporation) of two or more materials, such as host and dopant, forming a mixed/doped layer is advantageous. Furthermore, several process conditions for evaporating very sensitive organic materials have to be considered.

To deposit a material on a substrate, the material is heated until the material evaporates. The distribution pipe guides the evaporated material to the substrate through the nozzle. In recent years, the accuracy of the deposition process has increased, for example to be able to provide smaller and smaller pixel sizes. In some processes, a mask is used to define pixels when the evaporated material passes through the mask openings. However, shadowing effects (scattering effects) of the mask, diffusion of the evaporated material, and the like make it difficult to further improve the accuracy and predictability of the evaporation process.

In view of the above, it would be advantageous for an evaporation process for manufacturing devices with high quality and accuracy to increase accuracy and predictability.

Disclosure of Invention

In view of the above, several evaporation sources, several shielding devices for evaporation sources and several methods for depositing evaporated source material on a substrate are provided.

According to an aspect of the present disclosure, an evaporation source for depositing an evaporated source material on a substrate is provided. This evaporation source includes: one or more distribution pipes having a plurality of nozzles, wherein each nozzle of the plurality of nozzles is configured to direct a plume of evaporated source material toward the substrate; and a shielding device comprising a plurality of apertures, wherein at least one aperture of the plurality of apertures is configured to shape a plume of evaporated source material emitted from a single associated nozzle.

In some embodiments, each aperture of the plurality of apertures is configured to individually shape a plume of evaporated source material emitted from a single associated nozzle of the plurality of nozzles.

According to other aspects of the present disclosure, a shielding device for an evaporation source for depositing evaporated source material on a substrate is provided. The shielding device comprises a plurality of separate shielding units, wherein each shielding unit of the plurality of separate shielding units comprises one or more apertures configured as passages surrounded by a circumferential wall, respectively, wherein each aperture of the one or more apertures is configured to individually shape a plume of evaporated source material emitted from a single associated nozzle of the evaporation source.

According to other aspects of the present disclosure, a method for depositing evaporated source material on a substrate in a vacuum chamber is provided. The method comprises the following steps: directing an evaporated source material through a plurality of nozzles of an evaporation source, wherein each nozzle of the plurality of nozzles generates a plume of evaporated source material that is transported toward a substrate; and individually shaping the plumes of evaporated source material by a plurality of apertures of a masking device.

Other aspects, advantages and features of the present disclosure will become apparent from the description and the accompanying drawings.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure may be had by reference to several embodiments (a brief summary of which is provided above). The accompanying drawings relate to several embodiments of the disclosure and are described below:

fig. 1 shows a schematic top view of a deposition apparatus comprising an evaporation source according to embodiments described herein;

fig. 2A, 2B, and 2C show schematic diagrams of portions of an evaporation source according to embodiments described herein;

fig. 3 shows a schematic top view of an evaporation source according to embodiments described herein;

fig. 4 shows a schematic top view of an evaporation source with three distribution pipes according to embodiments described herein;

fig. 5 shows a schematic cross-sectional view of an evaporation source according to embodiments described herein;

FIG. 6 is a perspective view of a shade device according to embodiments described herein;

FIG. 7 is a perspective view of a shade device according to embodiments described herein;

fig. 8A and 8B are schematic diagrams of two subsequent stages during operation of a deposition apparatus having an evaporation source according to embodiments described herein; and is

Fig. 9 is a flow chart of a method to deposit evaporated source material on a substrate according to embodiments described herein.

Detailed Description

Reference will now be made in detail to various embodiments of the disclosure, one or more examples of which are illustrated in each figure. In the following description of the figures, like reference numerals refer to like parts. In general, only the differences with respect to the embodiments are described. Each example is provided by way of explanation, not meant as a limitation of the disclosure. Features illustrated or described as part of one embodiment may be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the present specification include such modifications and variations.

As used herein, the term "source material" may be understood as a material that is evaporated and deposited on the surface of a substrate. For example, in several embodiments described herein, the evaporated organic material deposited on the surface of the substrate may be a source material. Non-limiting examples of organic materials include one or more of the following: ITO, NPD, Alq ₃ Quinacridone (Quinacridone), Mg/AG, starburst (starburst) material, and the likeThe compound (I) is prepared.

As used herein, the term "evaporation source" can be understood as a configuration that provides an evaporated source material to be deposited on a substrate. In particular, the evaporation source may be configured to direct evaporated source material to be deposited on the substrate into a deposition region in a vacuum chamber, such as a vacuum deposition chamber of a deposition apparatus. The evaporated source material may be directed towards the substrate by a plurality of nozzles of the evaporation source. The nozzles may each have a nozzle outlet, which may be directed towards the deposition area, in particular towards the substrate to be coated.

The evaporation source may include: an evaporator or crucible that evaporates a source material to be deposited on a substrate; and a distribution tube fluidly connected to the crucible and configured to deliver the evaporated source material to the plurality of nozzles for injecting the evaporated source material into the deposition area.

In some embodiments, the evaporation source comprises two or more distribution pipes, wherein each distribution pipe has a single nozzle. In some embodiments, the evaporation source comprises two or more distribution pipes, wherein each distribution pipe comprises a plurality of nozzles. In some embodiments, one distribution pipe comprises two or more nozzles, in particular ten or more nozzles. In some embodiments, the evaporation source comprises two or more distribution pipes arranged adjacent to each other, wherein each of the two or more distribution pipes comprises ten or more nozzles.

As used herein, the term "crucible" can be understood to mean a device or reservoir that provides or contains the source material to be deposited. Generally, the crucible can be heated to evaporate the source material to be deposited on the substrate. According to several embodiments herein, the crucible can be in fluid communication with a distribution tube to which evaporated source material can be delivered.

As used herein, the term "distribution tube" can be understood as a tube used to guide and distribute evaporated source material. In particular, the distribution pipe may direct evaporated source material from the crucible to a plurality of nozzles in the distribution pipe. As used herein, the term "plurality of nozzles" generally includes at least two or more nozzles, each nozzle including a nozzle outlet to emit evaporated source material toward a substrate along a primary emission direction. According to several embodiments described herein, the distribution pipe may be a straight distribution pipe, in particular extending along a first (in particular longitudinal) direction, in particular extending along a vertical direction. In some embodiments, the distribution tube may comprise a tube having a cylindrical shape. The column may have a rounded bottom shape or any other suitable bottom shape. Several examples of distribution tubes will be described in more detail below. In some embodiments, the evaporation source may include two or three distribution pipes. In some embodiments, each distribution tube is in fluid communication with the crucible such that different materials can be deposited on the substrate.

Fig. 1 shows a schematic top view of a deposition apparatus 100 having an evaporation source 20 according to embodiments described herein. The deposition apparatus 100 includes a vacuum chamber 110, an evaporation source 20 being located in the vacuum chamber 110. According to some embodiments, which can be combined with other embodiments described herein, the evaporation source 20 is configured for translational movement along the surface of the substrate to be coated. Further, the evaporation source 20 may be configured for rotation about a rotation axis.

According to several embodiments, the evaporation source 20 can have one or more evaporation crucibles and one or more distribution pipes. For example, the evaporation source 20 as shown in fig. 1 comprises two evaporation crucibles 104 and two distribution pipes 106. As shown in fig. 1, a substrate 10 and other substrates 11 are provided in a vacuum chamber 110 for receiving evaporated source material.

According to some embodiments herein, a mask assembly to shield a substrate may be disposed between the substrate and an evaporation source. The mask assembly may include a mask and a mask frame to hold the mask in a predetermined position. In several embodiments herein, one or more additional rails may be provided to support and move the mask assembly. For example, the embodiment shown in fig. 1 has a first mask 133 and a second mask 134, the first mask 133 being supported by a first mask frame 131, the second mask 134 being supported by a second mask frame 132, the first mask frame 131 being arranged between the evaporation source 20 and the substrate 10, the second mask frame 132 being arranged between the evaporation source 20 and the other substrate 11. The substrate 10 and the other substrate 11 may be supported on respective transfer rails (not shown in fig. 1) in the vacuum chamber 110.

Fig. 1 also depicts a shielding device 30, the shielding device 30 being provided to guide evaporated source material from the distribution pipe 106 to the substrate 10 and/or to the other substrate 11, respectively, as will be explained in more detail below. A shielding device 30 may be arranged downstream from the nozzle, i.e. the shielding device 30 is located between the dispensing tube and the substrate. In some embodiments, the shielding device 30 may be detachably fixed to the at least one distribution pipe, for example, via screws.

In several embodiments herein, if a mask is used to deposit a material on a substrate in, for example, an OLED manufacturing system, the mask may be a pixel mask having a pixel opening with a dimension of about 50 μm x 50 μm or even below that dimension, such as a pixel opening with a dimension of a cross-section (e.g., a minimum dimension of the cross-section) of about 30 μm or less, or about 20 μm. In one example, the pixel mask may have a thickness of about 40 μm. Considering the thickness of the mask and the size of the pixel opening, shadowing effects may occur where the walls of the pixel opening in the mask shadow the pixel opening. The masking device 30 described herein can limit the maximum impingement angle of evaporated source material on the mask and on the substrate and reduce the masking effect.

According to several embodiments described herein, the material of the shielding device 30 may be suitable for evaporated source materials having a temperature of about 100 ℃ to about 600 ℃. In some embodiments, the shielding means may comprise a material having a thermal conductivity greater than 21W/(m · K) and/or a material that is chemically inert to, for example, evaporated organic material. According to some embodiments, the shielding means may comprise at least one of Cu, Ta, Ti, Nb, Diamond Like Coating (DLC), and graphite, or may comprise a coating with at least one of the mentioned materials.

According to several embodiments described herein, the substrate may be coated with the source material in a substantially vertical position. Generally, the distribution pipe 106 is configured as a substantially vertically extending line source. In several embodiments described herein, which may be combined with other embodiments described herein, the term "perpendicular" is especially understood when referring to a substrate orientation as allowing a deviation of 20 ° or less than 20 °, such as a deviation of 10 ° or less than 10 °, from the perpendicular direction. For example, substrate supports with some deviation from a vertical orientation may allow for such deviation because it may result in a more stable substrate position. However, during deposition of the source material, a substantially vertical substrate orientation is considered to be 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 (dimension) and a translational motion in another direction corresponding to another substrate dimension.

In some embodiments, the evaporation source 20 may be disposed in the vacuum chamber 110 of the deposition apparatus 100 and located on a track or linear guide 120, such as a ring-shaped track (not shown in the figures). The rail or linear guide 120 is configured for translational movement of the evaporation source 20. According to different embodiments, which can be combined with other embodiments described herein, the drive for translational movement can be provided in the evaporation source 20, in the track or linear guide 120, in the vacuum chamber 110, or a combination of these configurations. Thus, the evaporation source may be moved along the surface of the substrate to be coated during deposition, in particular along a straight path. The uniformity of the deposited material on the substrate may be improved.

Fig. 1 also depicts a valve 105, such as a gate valve. The valve 105 allows vacuum sealing to an adjacent vacuum chamber (not shown in fig. 1). According to several embodiments described herein, the valve 105 can be opened for transferring a substrate or mask into the vacuum chamber 110 and/or out of the vacuum chamber 110.

According to some embodiments, which can be combined with other embodiments described herein, other vacuum chambers, such as service vacuum chamber 111, are disposed adjacent to vacuum chamber 110. The vacuum chamber 110 and the service vacuum chamber 111 may be connected by a valve 109. The valve 109 is configured to open and close a vacuum seal between the vacuum chamber 110 and the maintenance vacuum chamber 111. According to several embodiments described herein, the evaporation source 20 can be transferred to the maintenance vacuum chamber 111 when the valve 109 is in the open state. Thereafter, the valve may be closed to provide a vacuum seal between the vacuum chamber 110 and the service vacuum chamber 111. If valve 109 is closed, the maintenance vacuum chamber 111 can be vented and opened for maintenance of the evaporation source 20 without breaking the vacuum in the vacuum chamber 110.

The deposition apparatus may be used in a variety of applications, including applications for OLED device fabrication including several processing methods, in which two or more source materials, such as two or more organic materials, are evaporated simultaneously. In the example shown in fig. 1, two or more distribution pipes 106 and corresponding evaporation crucibles are arranged adjacent to each other. For example, in some embodiments, three distribution tubes may be disposed adjacent to each other. Each distribution tube includes a plurality of nozzles having respective nozzle outlets for directing evaporated source material from the interior of the respective distribution tube into the deposition area of the vacuum chamber. The nozzles may be arranged, for example, at equal intervals along the linear extension of the respective distribution pipe. Each distribution tube can be configured to direct a different evaporated source material into a deposition area of the vacuum chamber.

Although the embodiment shown in fig. 1 provides a deposition apparatus 100 having a movable evaporation source 20, it will be understood by those skilled in the art that the above-described embodiments may also be applied to a deposition system in which a substrate is moved in the deposition system during processing. For example, the substrate to be coated may be guided and driven along a stationary material deposition arrangement.

Several embodiments described herein relate in particular to the deposition of organic materials, for example for OLED display fabrication on large area substrates. According to some embodiments, the carrier or large area substrate supporting the one or more substrates may have a thickness of at least 0.174m ² The size of (c). For example, the deposition system may be adapted to process large area substrates, such as generation 5, generation 7.5, generation 8.5, or even generation 10 substrates, generation 5 substratesThe plate corresponds to about 1.4m ² Substrate (1.1m x 1.3.3 m), generation 7.5 corresponds to about 4.29m ² Substrate (1.95m x 2.2.2 m), generation 8.5 corresponds to about 5.7m ² Substrate (2.2m x 2.5.5 m), generation 10 corresponds to about 8.7m ² The substrate (2.85 m.times.3.05 m). Even higher generations, such as 11 th and 12 th generations, and corresponding substrate areas, may be implemented in a similar manner.

According to several embodiments, which can be combined with other embodiments described herein, the substrate thickness may be from 0.1 to 1.8mm, and the holding arrangement for the substrate may be adapted to such a substrate thickness. The substrate thickness may be about 0.9mm or less than 0.9mm, for example 0.5mm or 0.3mm, and the holding configuration is suitable for such substrate thickness. In general, the substrate may be made of any material suitable for material deposition. For example, the substrate may be made of a material selected from the group consisting of glass (e.g., soda-lime glass, borosilicate glass, etc.), metal, polymer, ceramic, composite, carbon fiber material, or any other material or combination of materials that can be coated by a deposition process.

According to some embodiments, which can be combined with other embodiments described herein, the deposition apparatus 100 can further comprise a material collection unit 40, and the material collection unit 40 can be configured as a shielding wall. The material collection unit 40 may be arranged to collect evaporated source material emitted from the evaporation source and/or from the shielding device 30 when the evaporation source is in the rotational position, in particular during rotation of the evaporation source 20 around the rotation axis.

In some embodiments, a heating device 50 may be provided for cleaning a masking device in a maintenance position of the deposition apparatus 100. The maintenance position may be a position of the deposition apparatus in which the evaporation source is in a rotated position compared to a deposition position of the deposition apparatus in which the nozzles of the evaporation source are directed towards the substrate to be coated.

Fig. 2A-2C illustrate portions of an evaporation source 20 according to embodiments described herein. As shown in fig. 2A, the evaporation source 20 can include a distribution pipe 106 and an evaporation crucible 104. For example, the distribution pipe may be an elongated cube with a heating unit 225. The evaporation crucible may be a reservoir for a source material to be evaporated, for example, an organic material, using the heating unit 225.

According to several embodiments, which can be combined with other embodiments described herein, a plurality of nozzles 22 can be arranged along the length direction of the evaporation source 20. In particular, the plurality of nozzles may be arranged along the length of the distribution pipe.

According to some embodiments, which can be combined with other embodiments described herein, the distribution pipe 106 extends substantially vertically in the length direction. For example, the length of the distribution pipe 106 corresponds to at least the height of the substrate to be deposited in the deposition apparatus. In many cases, the length of the distribution pipe 106 will be at least 10% or even 20% longer than the height of the substrate to be deposited, giving a uniform deposition at the upper end of the substrate and/or the lower end of the substrate.

According to some embodiments, which can be combined with other embodiments described herein, the length of the distribution pipe may be 1.3m or more than 1.3m, such as 2.5m or more than 2.5 m. According to one configuration, as shown in FIG. 2A, the evaporation crucible 104 is disposed at the lower end of the distribution tube 106. Generally, 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 substantially laterally directed through the plurality of outlets in the distribution pipe, e.g., toward a substantially vertically oriented substrate.

According to some embodiments, which can be combined with other embodiments described herein, the plurality of nozzles is arranged such that the nozzle outlets define a main emission direction X which is substantially horizontal (+/-20 °). According to some particular embodiments, the main emission direction X may be oriented slightly upwards, for example in the range from horizontal to 15 ° upwards, for example 3 ° to 7 ° upwards. Similarly, the substrate may be slightly tilted to be substantially perpendicular to the evaporation direction, and particle generation may be reduced. For illustrative purposes, the evaporation crucible 104 and the distribution tube 106 are depicted in FIG. 2A without a thermal shield. The heating unit 215 and the heating unit 225 may be seen in the schematic perspective view in fig. 2B.

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

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 may be heated to a temperature such that the evaporated source material provided by the evaporation crucible 104 does not condense inside the wall of the distribution pipe 106. Two or more thermal shields 217 are disposed around the tubes of the distribution pipe 106. The thermal shield is configured to reflect thermal energy provided by the heating unit 215 back towards the interior hollow space 210. The energy used to heat the distribution pipe 106, i.e. the energy provided to the heating unit 215, can be reduced, since the heat shield 217 reduces heat losses. Heat transfer to other distribution pipes and/or to the mask or substrate may be reduced. According to some embodiments, which can be combined with other embodiments described herein, the thermal shield 217 can include two or more thermal shield layers, for example five or more thermal shield layers, for example ten thermal shield layers.

Generally, as shown in fig. 2B, the thermal shield 217 includes openings at the locations of the nozzles in the distribution pipe 106. The enlarged view of the evaporation source shown in fig. 2B depicts four nozzles (schematically depicted as outlets). These nozzles may be arranged along the length of the distribution pipe 106. As described herein, the distribution pipe 106 may be provided as a linear distribution pipe, e.g., having a plurality of nozzles. For example, the distribution pipe may have more than 30 nozzles, such as 40, 50 or 54 nozzles, arranged along the length of the distribution pipe. According to several embodiments described herein, the nozzles may be spaced apart from each other. For example, the nozzles may be spaced apart by a distance of 1cm or more, for example from 1cm to 3cm, for example 2 cm.

During operation, the distribution tube 106 is connected to the evaporation crucible 104 at the flange unit 203. The evaporation crucible 104 is configured to receive a source material to be evaporated and to evaporate the source material. Fig. 2B shows a cross-sectional view through the shell of the evaporation crucible 104. For example, a filling opening is provided in the upper part of the evaporation crucible, and the filling opening can be closed with a plug (plug)222, a lid (lid), a cover (cover), or the like for closing the housing of the evaporation crucible 104.

An external heating unit 225 is disposed in the housing of the evaporation crucible 104. The outer heating unit 225 may extend along at least a portion of the wall of the evaporation crucible 104. According to some embodiments, which can be combined with other embodiments described herein, one or more central heating elements can additionally or alternatively be provided. Fig. 2B illustrates two

central heating elements

226, 228. The first central heating element 226 and the second central heating element 228 may include a first conductor 229 and a second conductor 230, respectively, for providing electrical power to the

central heating elements

226, 228.

To improve the heating efficiency of the source material in the evaporation crucible, the evaporation crucible 104 may further include a thermal shield 227. The thermal shield 227 is configured to reflect thermal energy provided by the outer heating unit 225 back into the housing of the evaporation crucible 104, and if present, the thermal shield 227 is configured to reflect thermal energy provided by the

central heating elements

226, 228 back into the housing of the evaporation crucible 104.

According to some embodiments, a thermal shield, such as thermal shield 217 and thermal shield 227, may be provided for the evaporation source. The thermal shield reduces energy loss from the evaporation source and also reduces the overall energy lost to evaporating source material. As a further aspect, especially for depositing organic materials, the thermal radiation originating from the evaporation source (especially the thermal radiation towards the mask and the substrate during deposition) may be reduced. Particularly for depositing organic materials on a substrate masked by a mask, and even more particularly for display manufacturing, the temperature of the substrate and the mask needs to be accurately controlled. Heat radiation from the evaporation source can be reduced or avoided by heat shields, such as heat shield 217 and heat shield 227.

These shields may comprise several shield layers to reduce heat radiation to the outside of the evaporation source 20. Alternatively, the thermal shield may comprise several shield layers that are actively cooled by a fluid, such as air, nitrogen, water, or other suitable cooling fluid. According to still other embodiments described herein, the one or more thermal shields may comprise a metal sheet surrounding various portions of the evaporation source, such as surrounding the distribution pipe 106 and/or the evaporation crucible 104. According to several embodiments described herein, the metal sheet may have a thickness of 0.1mm to 3mm, may be selected from at least one material of the group consisting of ferrous metals (SS) and non-ferrous metals (Cu, Ti, Al), and/or may be spaced with respect to each other by a gap of, for example, 0.1mm or more.

According to some embodiments described herein and as exemplarily illustrated with respect to fig. 2A and 2B, the evaporation crucible 104 is disposed at the lower side of the distribution pipe 106. According to still other embodiments, which may be combined with other embodiments described herein, the steam conduit 242 may be disposed at a central portion of the distribution pipe 106 or at another location between the lower end of the distribution pipe and the upper end of the distribution pipe.

Fig. 2C shows an example of the evaporation source 20 having the distribution pipe 106 and the vapor conduit 242, the vapor conduit 242 being disposed at a central portion of the distribution pipe. The evaporated source material generated in the evaporation crucible 104 is guided to the central portion of the distribution pipe 106 through the vapor conduit 242. The evaporated source material exits the distribution pipe 106 through the plurality of nozzles 22. The distribution pipe 106 may be supported by the support 102. According to still other embodiments herein, two or more steam conduits 242 may be disposed at different locations along the length of the distribution pipe 106. The vapor conduit 242 may be connected to one evaporation crucible or to several evaporation crucibles. For example, each vapor conduit 242 may have a corresponding evaporation crucible. Alternatively, the evaporation crucible 104 can be in fluid communication with two or more vapor conduits 242, the two or more vapor conduits 242 being connected to the distribution pipe 106.

As described herein, the distribution tube may be a hollow cylinder. The term cylinder is understood to mean the generally accepted bottom shape with a circular shape and the upper shape with a circular shape and the curved surface area or shell connecting the upper and lower circles. According to other additional or alternative embodiments, which can be combined with other embodiments described herein, the term cylinder can be understood in the mathematical sense (chemical sense) as having any bottom shape and a uniform upper shape and a curved surface area and shell connecting the upper and lower shapes. The cylinder need not have a circular cross-section.

Fig. 3 shows a schematic cross-sectional view of an evaporation source 20 according to embodiments described herein. The evaporation source 20 shown in fig. 3 comprises a distribution pipe 106. According to several embodiments described herein, the distribution pipe 106 may extend in a length direction, in particular in a substantially perpendicular direction, which may be perpendicular to the drawing plane of fig. 3. A plurality of nozzles 22 may be arranged along the length of the distribution pipe 106. One nozzle 23 of the plurality of nozzles 22 is schematically shown in fig. 3 as the outlet of the dispensing tube 106. The cross-section of fig. 3 intersects the outlet of the nozzle 23. As shown in fig. 3, the evaporated source material may flow from the interior of the distribution pipe 106 toward the substrate 10 through the outlet of the nozzle 23. The nozzle 23 is configured for directing a plume 318 of evaporated source material towards the substrate 10. Furthermore, the remaining nozzles (not shown in fig. 3) of the plurality of nozzles 22 are also configured to direct respective plumes of evaporated source material toward the substrate 10.

The evaporation source 20 further comprises a shielding device 30, which shielding device 30 may be arranged downstream of the nozzles 22. The shielding device 30 may be configured for guiding the evaporated source material toward the substrate 10 and for individually shaping the plumes of the evaporated source material. Accordingly, the shielding device 30 may also be referred to herein as a "shaped shield". The shielding device may be detachably fixed to the distribution pipe 106, e.g. by fixing elements, such as screws (not shown in fig. 3).

The shielding device 30 comprises a plurality of apertures 32, wherein at least one aperture of the plurality of apertures 32 is configured to individually shape the plume of evaporated source material emitted from a single associated nozzle. For example, in fig. 3, the apertures 33 are configured to individually shape the plumes 318 emitted from the nozzles 23, wherein no other plumes emitted from a second nozzle pass through the apertures 33 and no other plumes are shaped by the apertures 33. That is, nozzle 23 is the single associated nozzle of orifice 33.

In some embodiments, each of these apertures 32 of the shielding device can be configured to individually shape a single plume of evaporated source material emitted from a single associated nozzle. That is, a separate orifice may be disposed in front of each of the plurality of nozzles. Thus, each plume of evaporated source material emitted from the plurality of nozzles 22 can be individually shaped by the associated one of the plurality of apertures.

It may be advantageous to shape the plumes of evaporated source material separately compared to a masking device having several apertures configured to shape more than one plume simultaneously. In particular, individually shaping the plumes of evaporated source material may result in improved deposition accuracy and may reduce the shadowing effect provided by the mask. For example, individually shaping the plume of evaporated source material may result in a smaller plume angle (plume angle), with a more well-defined plume flank (plume flash). Large impingement angles of the plumes on the mask and/or the substrate may be avoided. Furthermore, the individual plumes may be appropriately directed.

In some embodiments, the number of nozzles of the evaporation source may correspond to the number of apertures of the shielding device. For example, a shielding device having ten or more holes may be arranged in front of a distribution pipe having ten or more nozzles. For example, a screening device with thirty or more apertures may be arranged in front of three distribution pipes, wherein each distribution pipe comprises ten or more nozzles. However, in the following description, with reference to orifice 33 and nozzle 23 as in fig. 3, i.e., the single associated nozzle of orifice 33, the remaining orifices of the plurality of orifices 32 may be shaped and arranged correspondingly with respect to the respective associated nozzles in some embodiments.

In some embodiments, the holes may be arranged in front of the associated nozzle, as shown in fig. 3. For example, the main emission direction X of the nozzle 23 may correspond to a line between the center of the outlet of the nozzle 23 and the center of the hole 33. The aperture 33 can be configured as a passage 43 for the plume 318, the passage 43 being surrounded by the peripheral wall 34, wherein the peripheral wall 34 can be configured to block at least a portion of the plume 318 of evaporated source material emitted from the nozzle 23. In some embodiments, the perimeter wall 34 can be configured to block an outer corner portion of the plume 318 of evaporated source material.

As used herein, "aperture" may mean an opening or channel at least partially surrounded by a wall, the aperture being configured to shape a plume of a single evaporated source material directed through the aperture, in particular to limit the maximum opening angle of the plume and to block an outer angular portion of the plume. In some embodiments, the passage may be entirely surrounded by a peripheral wall so as to shape the plume in each section plane, each section plane including the main emission direction X of the associated nozzle.

As schematically shown in fig. 3, the aperture 33 may be configured as a passage for the plume 318, which is surrounded by the peripheral wall 34. The circumferential wall 34 may extend around the main emission direction X of the plume 318, thereby circumferentially (circularly) shaping the plume. In some embodiments, the peripheral wall 34 may extend from a bottom wall 41 of the shielding device 30 parallel to the main emission direction X, wherein the bottom wall 41 may extend substantially perpendicular to the main emission direction X. The bottom wall 41 may have an opening 42 for the plume 318 or an outlet of the nozzle 23 for entering the bore 33.

In some embodiments, which may be combined with other embodiments described herein, the shielding means may be arranged at a close distance from the distribution pipe 106, e.g. at a distance of 5cm or less or 1cm or less in the main emission direction X. Arranging the holes at a close distance downstream of the nozzles may be advantageous, since it is possible to shape the plume individually, even if adjacent nozzles of the plurality of nozzles are arranged at a close distance with respect to each other.

In some embodiments, the nozzle 23 may protrude at least partially into the shielding device 30. That is, there may be a cross-section intersecting both the nozzle and the shielding means and perpendicular to the main emission direction X. For example, as shown in fig. 3, the outlet of the nozzle 23 protrudes into the hole 33. The nozzle outlet may protrude into an opening 42 in the bottom wall 41 or into a channel 43 surrounded by the peripheral wall 34. This allows shaping of the plume 318 emitted from the nozzle 23 directly from the downstream nozzle exit so that adjacent nozzles can be positioned close to the nozzle 23 (see fig. 4).

In some embodiments, which may be combined with other embodiments described herein, the nozzles 23 do not directly mechanically contact the sheltering device 30. For example, the nozzle may protrude into the hole at a distance from the wall of the hole, as shown in fig. 3. Avoiding direct contact between the nozzle and the shielding means may have the effect of thermal decoupling between the nozzle and the shielding means. Direct heat conduction between the normally hot nozzle and the shielding means can be avoided, so that heat radiation from the shielding means towards the substrate can be reduced.

In some embodiments, the minimum distance between the nozzle 23 and the shielding device 30 may be less than 3mm or less than 1mm and/or greater than 0.1 mm. Since the evaporation source can be arranged at a sub-atmospheric pressure, the heat flow between the nozzle and the shielding means can be substantially reduced.

In some embodiments, the shade device 30 may be actively or passively cooled. Heat flow between the cooled shielding device 30 and the nozzles may be reduced by thermally decoupling the plurality of holes from the plurality of nozzles.

In some embodiments, which can be combined with other embodiments described herein, the peripheral wall 34 can be configured to block a plume 318 of evaporated source material having an emission angle that is greater than the first maximum emission angle θ relative to the main emission direction X in the first cross-section.

The drawing of fig. 3 illustrates a first cross section. The first profile may comprise a main emission direction X. In some embodiments, the first cross-section is a horizontal plane and/or a plane extending perpendicular to the length direction of the distribution pipe 106. As shown in fig. 3, the peripheral wall 34 of the aperture 33 is configured to block an outer corner portion of the plume 318 of evaporated source material along the first cross section so that an opening angle of the emission cone (emission cone) is limited to an angle of 2 θ. That is, the peripheral wall 34 blocks the portion of the evaporated source material emitted by the nozzle 23 at an emission angle larger than the first maximum emission angle θ.

In some embodiments, the first maximum emission angle θ is an angle from 10 ° to 45 °, particularly an angle from 20 ° to 30 °, more particularly about 25 °. Thus, the opening angle 2 θ of the emission cone in the first section plane may be 20 ° or more and 90 ° or less, in particular about 50 °. As shown in fig. 3, the shadowing effect due to the mask 340 may be reduced by reducing the first maximum emission angle θ.

In some embodiments, which can be combined with other embodiments described herein, the circumferential wall 34 can be configured to block a plume 318 of evaporated source material having an emission angle that is greater than a second maximum emission angle relative to the main emission direction X in a second cross section perpendicular to the first cross section.

The second cross-section may be a plane perpendicular to the plane of the drawing of fig. 3. The second cross section may comprise the main emission direction X. In some embodiments, the second cross-section is a vertical plane and/or a plane extending parallel to the length direction of the distribution pipe 106. The peripheral wall 34 of the aperture 33 may be configured to block an outer corner portion of the plume 318 of evaporated source material along the second cross section such that the aperture angle of the emission cone is limited to an angle of 2 β. That is, the peripheral wall 34 blocks the portion of the evaporated source material emitted by the nozzle 23 at an emission angle larger than the second maximum emission angle along the second cross section.

In some embodiments, the second maximum emission angle is an angle from 10 ° to 60 °, particularly an angle from 30 ° to 40 °, more particularly about 45 °. Thus, the opening angle of the emission cone in the second cross section may be 20 ° or more and 120 ° or less, in particular about 90 °. The shadowing effect in a plane perpendicular to the plane of the drawing of fig. 3 due to the mask 340 may be reduced by reducing the second maximum emission angle θ.

In some embodiments, the second maximum emission angle is an angle different from, in particular greater than, the first maximum emission angle. This is because a larger maximum emission angle may be feasible in the length direction of the distribution pipe 106. In particular, adjacent nozzles are generally configured to emit the same vaporized material in the length direction of the distribution pipe, and the spacing of adjacent nozzles along the distribution pipe can be more easily adjusted. On the other hand, nozzles adjacent to each other in a direction perpendicular to the length direction of the distribution pipe may be configured to emit different materials, so that it may be advantageous to accurately set the overlapping of plumes of the adjacent nozzles.

The first cross-section may be a horizontal plane, the first maximum emission angle may be from 20 ° to 30 °, the second cross-section may be a vertical plane, and the second maximum emission angle may be from 40 ° to 50 °.

In some embodiments, the distance between two adjacent nozzles in the length direction of the distribution pipe 106 may be from 1cm to 5cm, in particular from 2cm to 4 cm. Thus, the distance between two adjacent holes of the plurality of holes, i.e. the distance between the centers of the respective holes, may be from 1cm to 5cm, in particular from 2cm to 4 cm. For example, the distance between two adjacent holes may correspond to the distance between the two adjacent associated nozzles, respectively.

In some embodiments, which may be combined with other embodiments described herein, aperture 33 is configured as a circular arc (round) passage 43 for plume 318 surrounded by perimeter wall 34. A "circular arc shaped channel" can be understood as a channel having a rounded profile, for example a curved profile, a circular profile, or an elliptical profile, in a cross section perpendicular to the main emission direction X. For example, the peripheral wall 34 may have a circular or elliptical shape in a cross section perpendicular to the main emission direction X.

The circular channel may shape plume 318 so as to be rotationally symmetric with respect to the primary emission direction. The elliptical channel may shape plume 318 to have a large opening angle corresponding to the major axis of the elliptical channel in a first cross-section and a small opening angle corresponding to the minor axis of the elliptical channel in a second cross-section. The major axis of the elliptical channel may be arranged in a vertical direction and the minor axis of the elliptical channel may be arranged in a horizontal direction.

The peripheral wall 34 may form a circle in a cross section perpendicular to the main emission direction X. The diameter of this circle, i.e. the inner diameter of the channel, may be 3mm or more and may be 25mm or less, in particular 5mm or more and 15mm or less. The diameter of the channel may be measured at the downstream end of the channel, which defines the maximum opening angle of plume 318.

In some embodiments, the length of the peripheral wall 34 in the main emission direction X may be constant. In other embodiments, which may be combined with other embodiments described herein, the aperture 33 may be configured as a passage 43 for the plume 318 surrounded by the circumferential wall 34, wherein the length of the circumferential wall in the main emission direction X varies along the circumferential direction. More particularly, the leading end 35 of the peripheral wall 34 directed towards the substrate may be at a distance from the nozzle outlet which varies along the circumferential direction. By providing a circumferential wall of varying length along the circumferential direction, the opening angle of plumes 318 may be configured to be different in various cross-sections.

As shown in fig. 3, the peripheral wall 34 may have a first length T1 in a first cross section including the main emission direction X, and a second length T2 in a second cross section including the main emission direction X and extending perpendicular to the first cross section, which is smaller than the first length T1. The first cross-section may be perpendicular to the length direction of the distribution pipe, e.g. a horizontal plane. The second cross-section may be parallel to the length of the distribution pipe, e.g. a vertical plane.

The length of the peripheral wall may vary continuously from a first length T1 in the first cross section to a second length T2 in the second cross section. That is, the leading end 35 of the peripheral wall 34 may not include a step (step) in the circumferential direction and may not be interrupted. Thus, the opening angle of plumes 318 may gradually change in the circumferential direction. The deposition accuracy can be improved.

In some embodiments, the first length T1 may be a length between 8mm and 20mm, in particular about 12mm, and/or the second length T2 may be a length between 3mm and 15mm, in particular about 6.5 mm. The "length" of the circumferential wall may correspond to the length of the projection of the vector connecting the front end of the circumferential wall and the nozzle outlet in the respective section plane in the main emission direction X.

When the leading end 35 of the peripheral wall has a wavy or undulating shape in the circumferential direction, pixels having sharp edges may be deposited on the substrate. The wave crest may lie in a first cross section (i.e. the plane of the drawing of fig. 3) and the wave base may be arranged in a second cross section (i.e. a plane perpendicular to the first cross section). The front end 35 of the perimeter wall 34 may include two peaks and two valleys, as shown in FIG. 3.

In some embodiments, the at least one aperture may have a diameter of 3mm or more and 25mm or less, in particular a diameter of 5mm or more and 15mm or less. Wherein the diameter of the hole may be measured at the front end 35 of the hole, the front end 35 of the hole defining the maximum emission angle of the plume 318 propagating towards the substrate 10.

The wall of the distribution pipe may be heated by a heating element, which is mounted or fitted to the wall of the distribution pipe. To reduce the heat radiation towards the substrate, an outer shield surrounding the heated inner wall of the distribution pipe may be cooled. An additional second outer shield may be provided to further reduce the heat load towards the deposition area or the substrate, respectively. According to some embodiments, which can be combined with other embodiments described herein, these shields can be provided as metal plates with conduits for cooling fluid, such as water, fitted or provided in the metal shields. A thermoelectric cooling device or other cooling device may additionally or alternatively be provided to cool the shroud. Thus, the interior of the distribution tube may be kept at a high temperature, e.g. higher than the evaporation temperature of the source material, while the heat radiation towards the deposition area and towards the substrate may be reduced.

Fig. 4 shows the evaporation source 20 comprising a distribution pipe 106, a second distribution pipe 107, and a third distribution pipe 108, the distribution pipe 106, the second distribution pipe 107, and the third distribution pipe 108 respectively extending adjacent to each other in a length direction, wherein the length direction is perpendicular to the drawing of fig. 4, according to embodiments described herein. The evaporation source 20 comprises a plurality of nozzles 22, wherein one nozzle of each distribution tube is depicted in fig. 4 as an outlet of the respective distribution tube. Furthermore, the evaporation source 20 comprises a shielding device 30, the shielding device 30 comprising a plurality of apertures 32, wherein each aperture of the plurality of apertures 32 is arranged in front of a single associated nozzle and is configured to shape a plume of evaporated source material emitted from the respective single associated nozzle.

The holes may be constructed and arranged similarly to the holes 33 shown in fig. 3, so that reference may be made to the above description, which is not repeated here.

In particular, in some embodiments, the nozzles may protrude into the holes, respectively, without contacting the holes. Thus, the shielding device 30 may be thermally decoupled from the plurality of nozzles 22 and/or from the distribution pipes. The heat radiation towards the substrate may be reduced.

In some embodiments, which may be combined with other embodiments described herein, the shielding device may comprise a plurality of separate shielding units 60, the shielding units 60 being arranged adjacent to each other, wherein each shielding unit of the plurality of separate shielding units 60 comprises one or more apertures of the plurality of apertures 32.

As used herein, a "separate" masking unit may mean two or more masking units that are not in direct contact with each other and that are provided as separate components without direct mechanical connection. As shown in fig. 4, the shielding units of the plurality of separated shielding units 60 are not in direct contact with each other. For example, the separate shielding units may be separately fixed to the respective distribution pipes using one or more respective fixing elements.

In some embodiments, each of the plurality of discrete masking units 60 may comprise a single aperture of the plurality of apertures 32. Each aperture may be configured as a channel surrounded by a shielding wall configured to shape a plume of a single evaporated source material.

In other embodiments, at least one of the plurality of separate masking units 60 comprises two, three, four, five or more holes, such as the plurality of holes 32 arranged in a line, which may be connected to each other by a support structure. The distance between two adjacent holes of the at least one shielding unit may be 1cm or more and 5cm or less, respectively.

In some embodiments, each of the plurality of shielding units may include two or more holes of the plurality of holes. The mounting of the shielding device 30 to the distribution pipe may be helpful when the number of shielding units of the shielding device is reduced. Therefore, it may be advantageous to increase the number of holes per shielding unit.

In some embodiments, the number of apertures per masking element is 10 or less, in particular 5 or less. When the shielding unit does not extend over a longer length, the shielding unit may more easily follow the local thermal expansion and contraction of one of the distribution pipes. In particular, when one of the distribution pipes expands or contracts, adjacent shielding units may move relative to each other.

In fig. 4 it is shown that the shielding units connected to the distribution pipe 106 are mechanically decoupled from the remaining shielding units so as to be movable relative to the remaining shielding units. For example, the temperature of the distribution pipe 106 may be varied differently from the temperature of the second distribution pipe 107 and from the temperature of the third distribution pipe 108, such that the distribution pipes may move slightly relative to each other during deposition. These shielding units may follow the movement of the respective dispensing tube, since they are mechanically decoupled from the remaining shielding units, respectively. Thus, even when the distribution pipes are moved relative to each other, or when one of the distribution pipes is thermally expanded or contracted, the plume of evaporated source material can be shaped in a stable manner. One or more apertures of the masking unit may follow the movement of the one or more associated nozzles, respectively.

In some embodiments, each of the plurality of separate masking units 60 may be mechanically decoupled from the remaining masking units of the plurality of separate masking units so as not to follow thermally induced movements of the remaining masking units.

In some embodiments, which may be combined with other embodiments described herein, at least one shielding unit of the plurality of separate shielding units 60 may be connected to a single distribution pipe so as to thermally expand and contract with the single distribution pipe in a length direction of the single distribution pipe, in particular so as to move relative to other shielding units connected to the single distribution pipe when the single distribution pipe thermally contracts or expands.

The main emission direction of the nozzles of the distribution pipe 106 may be inclined with respect to the main emission direction of the nozzles of the second distribution pipe 107 and/or the third distribution pipe 108. For example, the main emission direction may be inclined such that the plume of evaporated source material emitted from the distribution pipe 106 may overlap with the plume of evaporated source material emitted from the second distribution pipe 107 and/or from the third distribution pipe 108. In some embodiments, the distribution pipes are arranged such that their main emission directions may substantially intersect on the surface of the substrate. Plumes emitted from different distribution pipes in the cross-section may be directed to substantially the same area on the substrate.

In some embodiments, one of the distribution tubes, such as distribution tube 106, may be configured to deposit a primary material and at least one other distribution tube, such as second distribution tube 107, may be configured to deposit a secondary material, such as a dopant.

Fig. 5 shows the evaporation source 20 according to embodiments described herein in a cross-sectional view, wherein this cross-section extends in the length direction of the distribution tube 106. The length direction of the distribution pipe may be a vertical direction.

In some embodiments, the second distribution pipe 107 and/or the third distribution pipe 108 may extend substantially parallel to the distribution pipe 106 on both sides of the distribution pipe 106, as shown in fig. 4.

The distribution pipe 106 comprises a plurality of nozzles 22, which nozzles 22 are arranged adjacent to each other in the length direction of the distribution pipe. A first nozzle 402 and a second nozzle 404 of the plurality of nozzles are shown in fig. 5. A first plume 403 of evaporated source material is emitted by the first nozzle 402, while a second plume 405 of evaporated source material is emitted by the second nozzle 404.

A shielding device 30 is arranged downstream of the plurality of nozzles to shape the plumes of evaporated source material emitted from the plurality of nozzles. The shielding device 30 may comprise a plurality of individual shielding units, wherein one shielding unit 61 of the plurality of shielding units is illustrated in fig. 5.

The shielding unit 61 includes a first hole 406 and a second hole 408, and the first hole 406 and the second hole 408 may be configured according to any one of the above embodiments. The first holes 406 are configured to individually shape the first plumes 403 emitted from the first nozzle 402, and the second holes 408 are configured to individually shape the second plumes 405 emitted from the second nozzle 404.

The shielding unit 61 may comprise more than two holes, for example three, four or five holes, of the plurality of holes arranged in a line. The holes may be connected by a support structure, such as a sheet element. The apertures of the shielding unit 61 may be configured for individually shaping the plumes of evaporated source material of three, four or five adjacent nozzles, which are arranged adjacent to each other along the length direction of the distribution pipe 106.

The distribution pipe may comprise 10 or more nozzles arranged in a linear arrangement. Thus, more than one shielding unit, e.g. two, three or more shielding units, may be fixed to the distribution pipe in a linear arrangement.

Each of the plurality of separate shielding units may be mechanically fixed to a single distribution pipe of the two or more distribution pipes of the evaporation source. The shielding units may be mechanically and/or thermally decoupled from each other such that a relative movement between the individual shielding units may be feasible. Accordingly, the shielding units may move relative to each other when the distribution pipe to which the shielding units are fixed is extended or contracted.

The shielding unit 61 may be fixed to the distribution pipe 106 so as to be thermally decoupled from the distribution pipe 106. For example, the shielding unit 61 may be held at a distance from the distribution pipe 106 by one or more spacer elements 411, the spacer elements 411 may be arranged between the shielding unit and the distribution pipe. The spacer elements 411 may be configured as support sections which are arranged between the nozzles of the distribution pipe. The spacer element 411 may provide a small contact area in order to reduce the heat flow from the distribution pipe 106 towards the shielding unit 61. For example, the contact area of the spacer element 411 may be 1mm ² Or less, in particular 0.25mm ² Or smaller. The shielding unit 61 may be fixed to the distribution pipe 106 by one or more fixing members, such as screws, which may be made of metal having low thermal conductivity.

The length of the shielding unit 61 in the length direction of the distribution pipe may be 20cm or less, particularly 10cm or less. Due to the small length of the shielding unit, the shielding unit may follow thermally induced local movements of the distribution pipe 106, such as expansion or contraction movements. For example, when the dispensing tube is expanded, a first shielding unit fixed to the dispensing tube may be moved away from a second shielding unit fixed to the same dispensing tube. When the distribution pipe is retracted, the first shielding unit fixed to the distribution pipe may move toward the second shielding unit fixed to the same distribution pipe.

In some embodiments, which can be combined with other embodiments described herein, the shielding unit 61 is firmly fixed to the distribution pipe at a single fixing portion along the length direction of the shielding unit, for example at the central portion of the shielding unit. In other positions, the shielding unit 61 may be fixed to the distribution pipe 106 in order to provide a relative movement between the shielding unit and the distribution pipe. For example, in the embodiment shown in fig. 5, the first end 412 of the shielding unit 61 and the second end 413 of the shielding unit 61 may be movably fixed to the distribution pipe, for example, by a fixing element, such as a screw, which penetrates through a slot that may be disposed in the shielding device. In some embodiments, the slots may provide a gap between the distribution pipe and the shielding unit in a length direction of the shielding unit of more than 0.01mm and less than 0.5mm, for example about 0.1 mm.

Fig. 6 shows in perspective view a shielding device 500 for an evaporation source according to embodiments described herein. The screening arrangement is constructed as a single component and does not comprise a plurality of separate screening units. The shielding device 500 comprises a plurality of apertures, wherein each aperture of the plurality of apertures is configured as a passage surrounded by a shielding wall, wherein each aperture of the plurality of apertures is configured to individually shape a plume of evaporated source material emitted from a single associated nozzle of the evaporation source.

The shielding device 500 is configured to be mounted to an evaporation source having three distribution pipes. Thus, the screening arrangement 500 comprises three vertically arranged hole columns arranged next to each other in a support structure, such as a sheet element. Those holes of the central hole pillar may be offset relative to the outer pillar. This allows a more compact arrangement of three distribution pipes adjacent to each other.

The holes are respectively arranged as oval channels. Thus, a first maximum emission angle of the plume of evaporated source material exiting the apertures in the vertical direction is greater than a second maximum emission angle of the plume of evaporated source material exiting the apertures in the horizontal direction.

Fig. 7 shows in perspective view a shielding unit 600 of the shielding device for an evaporation source according to embodiments described herein. The shading device according to embodiments described herein may comprise a plurality of separate shading units 600, for example three or more, in particular 12 or more shading units 600.

The shielding unit 600 may comprise two or more holes and/or ten or less holes, in particular five holes. Each aperture may be configured as a channel surrounded by a shielding wall, such as a perimeter wall. Circular channels, in particular circular channels, save space and are easy to manufacture. Due to the rotational symmetry, a circular arc shaped channel may have other advantages: the evaporated source material may hit the shielding wall at the same impact angle in the circumferential direction. During deposition, the evaporated source material can be uniformly accumulated on the shield wall in the circumferential direction. Cleaning of the shielding unit may become easier.

The apertures of the shielding unit 600 may be arranged in a straight line with a distance between adjacent apertures of 1cm or more and 5cm or less, in particular about 2 cm. The shelter unit 600 may be constructed as a one-piece (one-piece) part, wherein the apertures may be connected by a support structure 612, the support structure 612 being for example an elongated sheet element. The shielding unit 600 may have a width of 3cm or less, 2cm or less, or even 1cm or less.

The support structure 612 may include one or more holes at a first end 613 and one or more holes at a second end 614 opposite the first end 613 for securing the shielding unit to the distribution tube, e.g., via screws or bolts. In some embodiments, other holes may be disposed between the holes, respectively.

Each aperture of the masking unit 600 may be configured to individually shape a plume of evaporated source material emitted from a single associated nozzle of the evaporation source.

In some embodiments described herein, the holes of the shielding unit 600 may have a diameter of between 3mm and 25mm, in particular between 5mm and 15mm, respectively. The small diameter of the holes of the masking unit may improve deposition accuracy. However, small hole diameters tend to be more prone to clogging, which can reduce deposition efficiency and deposition uniformity.

Several embodiments of operating evaporation sources as described herein are provided for maintaining high deposition accuracy for long periods of time while clogging of the apertures can be avoided.

A method of operating the evaporation source 20 is described with reference to fig. 8A and 8B.

The methods described herein include depositing evaporated source material on a substrate 10, as shown in fig. 8A. The deposition of evaporated source material comprises guiding the evaporated source material in the main emission direction X towards the substrate 10, wherein part of the evaporated source material is blocked by a shielding device 30, which shielding device 30 is arranged between the nozzles and the substrate 10 for individually shaping the plumes of evaporated source material.

During deposition, the masking device 30 may be maintained at a first temperature, which may be a low temperature, such as a temperature below 150 ℃, in particular a temperature of 100 ℃ or lower, or a temperature of 50 ℃ or lower. For example, during deposition, the surface of the shielding means facing the substrate may be kept at a temperature of 100 ℃ or less in order to reduce the heat radiation towards the mask and/or towards the substrate. In some embodiments, the masking device 30 may be actively or passively cooled during deposition, for example, by cooling channels or by a thermoelectric cooling device fitted to the masking device.

Since the surface of the shielding device 30 can be kept at a low temperature, the evaporated source material blocked by the shielding device can condense on and adhere to the shielding device. The hole diameter may become small and there may be a risk of clogging.

According to several methods described herein, the deposition phase depicted in FIG. 8A may be followed by a cleaning phase depicted in FIG. 8B, wherein at least a portion of the source material accumulated on the masking device 30 is removed from the masking device by heating the masking device to a second temperature higher than the first temperature. The screening device may be heated at least locally, in particular in a surface section of the screening device having accumulated source material. For example, the shielding walls around the plurality of apertures 32 of the shielding device may be heated, as some evaporated source material is generally blocked by the shielding walls around the apertures.

In some embodiments, the shielding device may be at least locally heated during cleaning to a temperature above the evaporation temperature of the source material, for example a temperature above 100 ℃, or a temperature above 200 ℃, in particular a temperature of 300 ℃ or more. The attached source material may be released from the masking device and re-evaporated. Thus, the screening device can be cleaned.

In some embodiments, the masking device 30 faces the substrate 10 during deposition, while the masking device 30 does not face the substrate 10 during heating. Therefore, deposition of the re-evaporation source material on the substrate from the shielding device can be avoided. Furthermore, thermal expansion of the mask and/or the substrate due to thermal radiation from the heated shielding means can be avoided.

In some embodiments, which can be combined with other embodiments described herein, the emission of evaporated source material through the nozzle can be stopped during cleaning. For example, during cleaning phase II, the nozzle may be turned off or evaporation may stop. The loss of source material can be reduced.

In some embodiments, which can be combined with other embodiments described herein, the deposition apparatus can be set into a maintenance position II for cleaning. In particular, after deposition, the deposition apparatus can be brought from the deposition position I, in which the holes of the masking device are directed towards the substrate 10, into the maintenance position II, in which the holes of the masking device are not directed towards the substrate.

As used herein, a "deposition position" may be a state of the deposition apparatus in which the deposition apparatus is ready to direct evaporated source material toward the substrate. For example, the nozzles of the evaporation source and the apertures of the shielding device may face the substrate or the deposition area of the deposition apparatus.

As used herein, a "maintenance position" may be a state of the deposition apparatus in which it is not suitable for directing evaporated source material towards the substrate. For example, the nozzles of the evaporation source and the apertures of the shielding device may not face the substrate or the deposition area of the deposition apparatus. Setting the deposition apparatus from the deposition position into the maintenance position may comprise a movement, for example a rotational movement, of the evaporation source. In some embodiments, setting the deposition apparatus into the maintenance position may comprise moving the evaporation source into a position in which the heating device 50 is arranged to heat the shielding device, and/or the shielding device faces the material collection unit 40, the material collection unit 40 being e.g. a shielding wall.

In some embodiments, setting the deposition apparatus into the maintenance position II may include relative movement between the evaporation source 20 and the material collection unit 40. For example, in the embodiment shown in fig. 8A and 8B, the evaporation source 20 is moved from the deposition position I shown in fig. 8A to the maintenance position II shown in fig. 8B, wherein the shielding device 30 is guided towards the material collection unit 40 in the maintenance position II.

Moving the evaporation source to the maintenance position II may comprise rotating the evaporation source 20 by a rotation angle, in particular a rotation angle α of 20 ° or more, more in particular a rotation angle from 60 ° to 120 °. In the embodiment shown in fig. 8B, the evaporation source is rotated by a rotation angle of about 90 ° from the deposition position I to the maintenance position II.

The shielding device 30 may be heated in the maintenance position II, in which the shielding device 30 faces the material collection unit 40. The material collection unit 40 may be provided as a wall element, such as a condensation wall or a shielding wall. As shown in fig. 8B, the wall element may be curved. The distance between the wall element and the shielding means may remain substantially constant during the rotational movement of the evaporation source. Furthermore, due to the curved shape of the wall element, the wall element can act as a shield against evaporated source material emitted from the evaporation source 20 during substantially the entire rotational movement of the evaporation source 20. For example, the wall element may extend over an angle of 45 ° or more, in particular an angle of 90 ° or more, with respect to the rotation axis of the evaporation source.

In some embodiments, cleaning may comprise heating the shielding device for a period of 1 second or more, in particular for a period of 10 seconds or more. Longer heating periods may result in better cleaning results, but may delay the evaporation process. Good cleaning results can be achieved by heating for a period of between 1 and 60 seconds.

After cleaning, the evaporated source material may be deposited on the substrate or other substrate continuously. Before continuing the deposition, in some embodiments, the evaporation source can be brought back from the maintenance position II to the deposition position I or to other deposition positions. For example, the evaporation source may be rotated by an angle (- α) back to the deposition position I, or the evaporation source may be further rotated in the same rotational direction, for example by another angle α, to bring the evaporation source to other deposition positions.

In some embodiments, which can be combined with other embodiments described herein, deposition and cleaning can be performed alternately. For example, the masking device may be post-cleaned during a predetermined deposition period, respectively, and after cleaning, deposition may continue, respectively. In some embodiments, cleaning of the masking device may be performed after the evaporated source material has been deposited on each substrate, or after a predetermined number of substrates have been coated, for example after 2 substrates, 4 substrates, or more substrates have been coated. In some embodiments, the cleaning of the masking device may be performed after a deposition operation of minutes, hours, or days, respectively. The period of time before cleaning is performed may depend on the size and shape of the apertures of the shielding device, the distance between the outlets of the evaporation sources and the shielding device, and the temperature of the surface of the shielding device during deposition. For example, cleaning may be performed after depositing evaporated source material on each substrate or after a deposition period of up to several hours, respectively.

In some embodiments, the accumulation of source material on the shade device may be measured, and cleaning may be performed after a predetermined accumulation has been reached. Clogging of these apertures of the shielding device can be avoided and a constant plume of evaporated source material impinging on the substrate can be obtained.

To reduce the heat load on the substrate caused by the heated shutter, the shutter may be allowed to cool down after cleaning. For example, after cleaning and before continuing deposition, the masking device may be cooled to a first temperature, such as a temperature of 150 ℃ or less, or a temperature of 100 ℃ or less. In some embodiments, the heating device 50 configured for heating the shutter during cleaning is turned off for a predetermined period of time before continuing deposition. In some embodiments, the masking device is passively or actively cooled after cleaning and/or prior to continued deposition. Furthermore, the masking device may additionally or alternatively be passively or actively cooled during deposition. Passive cooling may include cooling by a cooling fluid. Active cooling may include cooling by an active cooling element, such as a thermoelectric cooling element, a Peltier element, or a piezoelectric cooling element.

Fig. 9 is a flow chart illustrating a method for depositing evaporated source material on a substrate 10 in a vacuum chamber. In block 1010, the evaporated source material is directed through a plurality of nozzles of one or more distribution pipes of the evaporation source, wherein each nozzle of the plurality of nozzles generates a plume of evaporated source material that propagates toward the substrate. In block 1020, the plumes of evaporated source material are individually shaped by a plurality of apertures of a masking device.

Shaping the plume may include blocking at least a portion of the plume with the holes. Over time, the evaporated source material may adhere to the pores, which may result in a reduction in the diameter of the pores.

In an operational block 1030, the masking device may be cleaned by at least partially heating the masking device in a maintenance position of the deposition apparatus. The heating may cause the accumulated source material to re-evaporate from the masking device. After cleaning, deposition may continue.

In some embodiments, cleaning may be performed periodically.

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 objects, including making and using any devices or systems and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, the non-mutually 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 included within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. An evaporation source (20) for depositing evaporated source material on a substrate, comprising:

one or more distribution tubes (106) extending substantially vertically and having a plurality of nozzles (22); and

a shielding device (30) comprising a plurality of apertures (32), wherein at least one aperture of the plurality of apertures (32) is configured to individually shape a plume (318) of evaporated source material emitted from a single associated nozzle;

cooling means for actively or passively cooling the shutter means (30) during deposition; and

heating means for cleaning the screening means during a cleaning phase,

wherein the at least one aperture is configured as a channel surrounded by a peripheral wall (34), and

wherein the outlet of each nozzle protrudes at least partially into the shielding device (30).

2. The evaporation source according to claim 1, wherein the circumferential wall (34) is configured to block the plume (318) of the evaporated source material having an emission angle larger than a first maximum emission angle (θ) with respect to a main emission direction (X) in a first cross section, and wherein the circumferential wall (34) is configured to block the plume (318) of the evaporated source material having an emission angle larger than a second maximum emission angle (β) with respect to the main emission direction (X) in a second cross section, the second cross section being perpendicular to the first cross section.

3. The evaporation source according to claim 2, wherein the first cross section is a horizontal plane, the second cross section is a vertical plane, the first maximum emission angle (θ) is an angle from 10 ° to 45 °, and the second maximum emission angle is an angle from 15 ° to 60 °.

4. The evaporation source according to claim 2 or 3, wherein the first maximum emission angle (θ) is smaller than the second maximum emission angle.

5. The evaporation source according to any of claims 1 to 3, wherein the shielding device is detachably fixed to one of the distribution pipes by means of a fixing element.

6. The evaporation source according to any of claims 1 to 3, wherein the nozzle does not contact the shielding device (30).

7. The evaporation source according to any of claims 1 to 3, wherein the length of the circumferential wall in the main emission direction (X) varies along the circumferential direction.

8. The evaporation source according to claim 7, wherein the circumferential wall (34) has a first length (T1) in a first cross section comprising the main emission direction (X), and the circumferential wall (34) has a second length (T2) in a second cross section comprising the main emission direction (X) and extending perpendicular to the first cross section, the second length (T2) being smaller than the first length (T1).

9. The evaporation source of claim 7, wherein the length of the circumferential wall (34) continuously changes from the first length (T1) in the first cross section to the second length (T2) in the second cross section.

10. The evaporation source according to claim 9, wherein a front end (35) of the circumferential wall (34) has a wavy shape along the circumferential direction.

11. The evaporation source according to any of claims 1 to 3, wherein the at least one aperture is configured as a circular arc channel, a circular channel or an oval channel.

12. The evaporation source according to claim 11, wherein the at least one aperture has a diameter greater than or equal to 3mm and less than or equal to 25 mm.

13. The evaporation source according to any of claims 1 to 3, wherein the shielding device (30) comprises a plurality of separate shielding units (60), wherein each shielding unit of the plurality of separate shielding units (60) comprises at least one aperture of the plurality of apertures (32).

14. The evaporation source according to claim 13, wherein at least one of the plurality of separate shielding units (60) comprises two, three, four, five or more of the plurality of apertures (32) arranged in a straight line.

15. The evaporation source according to claim 14, wherein the at least one shielding unit comprises the apertures arranged in a line with a distance between adjacent apertures of greater than or equal to 1cm and less than or equal to 5 cm.

16. The evaporation source according to claim 14, wherein the at least one shielding unit is connected to a single distribution pipe of the one or more distribution pipes (106).

17. The evaporation source according to claim 16, wherein the at least one shielding unit is configured to follow thermal expansion and contraction of the single distribution pipe in a length direction of the single distribution pipe.

18. The evaporation source of claim 13, comprising two or more distribution pipes (106) arranged adjacent to each other, wherein each shielding unit of the plurality of separate shielding units (60) is mechanically fixed to a single distribution pipe of the one or more distribution pipes and comprises two or more apertures of the plurality of apertures (32) for individually shaping the plumes of evaporated source material of two or more adjacent nozzles of the plurality of nozzles (22).

19. The evaporation source according to claim 13, wherein at least one shielding unit of the plurality of separated shielding units (60) is mechanically decoupled from the remaining shielding units of the plurality of separated shielding units (60).

20. The evaporation source according to claim 13, wherein at least one shielding unit of the plurality of separate shielding units (60) is thermally decoupled from the one or more distribution pipes.

21. The evaporation source according to claim 20, wherein the at least one shielding unit is held at a distance from the one or more distribution pipes (106) by one or more spacer elements (411).

22. A shielding device (30) for an evaporation source (20) according to claim 1, the shielding device comprising:

a plurality of separate shielding units (60), wherein each shielding unit of the plurality of separate shielding units (60) comprises one or more apertures configured as passages surrounded by a peripheral wall (34), wherein each aperture of the one or more apertures is configured to individually shape a plume (318) of evaporated source material emitted from a single associated nozzle of the evaporation source;

heating means for cleaning the screening means during a cleaning phase,

wherein the nozzle protrudes into the one or more apertures of the shielding device.

23. A method for depositing an evaporated source material on a substrate (10) in a vacuum chamber, comprising:

providing an evaporation source (20), the evaporation source (20) comprising one or more distribution pipes (106) and a shielding device (30), the one or more distribution pipes (106) having a plurality of nozzles, the shielding device (30) comprising a plurality of apertures (32), the one or more distribution pipes extending substantially vertically;

directing an evaporated source material through the plurality of nozzles (22), wherein each nozzle of the plurality of nozzles (22) generates a plume of evaporated source material that is delivered towards the substrate (10);

shaping the plume of evaporated source material by a plurality of apertures (32) of a shielding device (30), wherein at least one of the apertures (32) is configured as a passage surrounded by a peripheral wall (34), and wherein an outlet of each nozzle at least partially protrudes into the shielding device (30);

actively or passively cooling the shutter during deposition; and

heating the shutter device during a cleaning phase to clean the shutter device.