WO2019037874A1

WO2019037874A1 - Apparatus for evaporating material in a vacuum chamber and method for evaporating material in a vacuum chamber

Info

Publication number: WO2019037874A1
Application number: PCT/EP2017/071451
Authority: WO
Inventors: Christopher Jürgen HANSEN
Original assignee: Applied Materials, Inc.
Priority date: 2017-08-25
Filing date: 2017-08-25
Publication date: 2019-02-28
Also published as: CN109715847A

Abstract

An apparatus for evaporating material in a vacuum chamber is described. The apparatus includes a container for the material, the container being provided in the vacuum chamber; an ultrasonic source in contact with the container configured to generate an aerosol of the material; a distribution pipe for guiding the material; and a light source directing electromagnetic radiation in a region having the aerosol to evaporate the aerosol.

Description

APPARATUS FOR EVAPORATING MATERIAL IN A VACUUM CHAMBER AND METHOD FOR EVAPORATING MATERIAL IN A VACUUM CHAMBER

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to evaporation of materials. Embodiments of the present disclosure particularly relate to evaporation in a cold "crucible" and evaporation of sensitive materials, such as OLED materials. Embodiments of the present disclosure particularly relate to apparatuses for evaporating material in a vacuum chamber and methods for evaporating material in a vacuum chamber.

BACKGROUND

[0002] Several methods are known for depositing a material on a substrate. As an example, substrates may be coated by using an evaporation process, a physical vapor deposition (PVD) process, such as a sputtering process, a spraying process, etc., or a chemical vapor deposition (CVD) process. The process can be performed in a processing chamber of a deposition apparatus, where the substrate to be coated is located. A deposition material is provided in the processing chamber. Further, other processes like etching, structuring, annealing, or the like can be conducted in processing chambers.

[0003] For example, coating processes may be considered for large area substrates, e.g. in display manufacturing technology. Coated substrates can be used in several applications and in several technical fields. For instance, an application can be organic light emitting (OLED) panels. Further applications include insulating panels, microelectronics, such as semiconductor devices, substrates with thin film transistors (TFTs), color filters or the like. OLEDs are solid-state devices composed of thin films of (organic) molecules that create light with the application of electricity. As an example, OLED displays can provide bright displays on electronic devices and use reduced power compared to, for example, liquid crystal displays (LCDs). In the processing chamber, the organic molecules are generated (e.g., evaporated, sputtered, or sprayed etc.) and deposited as a layer on the substrates. The particles can, for example, pass through a mask having a boundary or a specific pattern to deposit material at positions on the substrate, e.g. to form an OLED pattern on the substrate.

[0004] Evaporation of material can be difficult for materials which are not stable over a long time in hard crucibles. For example, some materials utilized for OLED display manufacturing can degrade or degenerate over time in a crucible provided in a vacuum chamber having a source for evaporating the material. However, other materials may also suffer from degradation over time.

[0005] Accordingly, it is beneficial to provide improved concepts for evaporation of materials, particularly in vacuum chambers utilized for material deposition, for example on large area substrates.

SUMMARY

[0006] In light of the above, an apparatus for evaporating material in a vacuum chamber, a system for depositing material on a substrate in a vacuum chamber, a method for evaporating a material in a vacuum chamber, and a method of depositing a material onto a substrate in a vacuum chamber are provided.

[0007] According to one embodiment, an apparatus for evaporating material in a vacuum chamber is provided. The apparatus includes a container for the material, the container being provided in the vacuum chamber; an ultrasonic source in contact with the container configured to generate an aerosol of the material; a distribution pipe for guiding the material; and a light source directing electromagnetic radiation in a region having the aerosol to evaporate the aerosol.

[0008] According to one embodiment, an apparatus for evaporating material in a vacuum chamber is provided. The apparatus includes a container for the material, the container being provided in the vacuum chamber; an ultrasonic source in contact with the container configured to generate an aerosol of the material; a distribution pipe for guiding the material; and a charged particle beam source directing a charged particle beam in the region having the aerosol to evaporate the aerosol. [0009] According to another embodiment, an apparatus for evaporating a material in a vacuum chamber is provided. The apparatus includes a container for the material, the container being provided in the vacuum chamber; an ultrasonic source in contact with the container; and a light source or a charged particle beam source evaporating the material. [0010] According to another embodiment, a system for depositing material on a substrate in a vacuum chamber is provided. The system includes the vacuum chamber and an apparatus for evaporating material in the vacuum chamber. For example, the apparatus for evaporating material includes a container for the material, the container being provided in the vacuum chamber; an ultrasonic source in contact with the container; and a light source or a charged particle beam source evaporating the material.

[0011] According to another embodiment, a method for evaporating a material in a vacuum chamber is provided. The method includes providing the material in a container provided in the vacuum chamber; generating an aerosol of the material with ultrasound; and evaporating the aerosol of the material with electromagnetic radiation or a charged particle beam.

[0012] According to another embodiment, a method of depositing a material onto a substrate in a vacuum chamber is provided. The method includes evaporating the material in the vacuum chamber with a method providing the material in a container provided in the vacuum chamber; generating an aerosol of the material with ultrasound; and evaporating the aerosol of the material with electromagnetic radiation or a charged particle beam. The method of depositing further includes guiding the material towards the substrate with distribution pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following: shows an apparatus for evaporating a material in a vacuum chamber, for example an evaporation source for material according to embodiments of the present disclosure; shows a further apparatus for evaporating material in a vacuum chamber according to embodiments of the present disclosure and having an external light source; shows a yet further apparatus for evaporating material in a vacuum chamber according to embodiments of the present disclosure, and having a feeding mechanism for the material; shows a yet further apparatus for evaporating material in a vacuum chamber according to embodiments of the present disclosure; shows an apparatus, for example a substrate processing system including an evaporation source according to embodiments of the present disclosure; and shows a flowchart illustrating methods for evaporating material in a vacuum chamber according to embodiments of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0014] Reference will now be made in detail to the various embodiments of the 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 same components. Generally, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation. Further, 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.

[0015] FIG. 1 shows an apparatus for evaporating material, which is particularly suitable for evaporating material in a vacuum chamber. The apparatus can be a crucible for cold material evaporation. In FIG. 1 the evaporation source 100 is shown. The evaporation source 100 includes a container 110. The container includes the material to be evaporated in the evaporation source 100.

[0016] For example the material can be an organic material, particularly the organic material suitable for OLED manufacturing such as manufacturing of OLED displays. For example, organic materials can be provided in the container 110 as a powder. However, also other materials, i.e. non-organic materials, can be provided in the container 110 and can be evaporated by the evaporation source 100. Embodiments of the present disclosure provide an evaporation source or an apparatus for evaporating material, which is particularly beneficial for materials that may easily degrade or degenerate in a hot crucible, i.e. the crucible that is heated for material evaporation. Sensitive materials may degrade or degenerate, i.e. materials may not be stable, if held on an evaporation temperature of the materials. Accordingly, a hot crucible referred to herein is a crucible heated to temperatures for thermally evaporating the material, for example by providing a heater to the crucible. A cold crucible, including for example container 110, according to embodiments described herein is a crucible having a temperature, which is lower than the temperature at which intermolecular degeneration of the material happens. For example, the temperature of the material to be evaporated can be at least 50°C below the evaporation temperature of the material to be evaporated. Further, additionally or alternatively^ a cold crucible can be a crucible which is provided essentially at room temperature or at temperatures of 100°C or below.

[0017] The evaporation source 100 shown in FIG. 1 includes an ultrasonic source 120. The ultrasonic source 120 is in contact with the container 110. The ultrasonic source 120 generates an aerosol of the material provided in the container 110, for example, an organic material. The evaporation source 100 or the apparatus for evaporating material, respectively, is configured for evaporation in a vacuum chamber, e.g. an environment having a technical vacuum. For example, the pressure can be 10^" mbar or below, such as 10 -^"7 mbar to 10 -^"5 mbar. The ultrasonic source 120 excites the container 110. The excited container 110 excites the material provided in the container. Inventors of the present disclosure have found that the ultrasonic source 120 can excite the material to be evaporated under vacuum conditions. The aerosol generated by the ultrasonic source 120 is, for example provided in region 112.

[0018] A light source, such as a laser 130 is provided. The light source emits an electromagnetic radiation to evaporate the aerosol in the region 112. According to some modifications, a charged particle beam source can be provided to evaporate the aerosol in the region 112. For example, the charged particle beam source can be an electron source. According to embodiments described herein, and aerosol is generated and evaporated by a light source. The evaporated material is provided in a distribution pipe 140. The distribution pipe 140 includes one or more openings 142 to guide the evaporated material into a vacuum chamber and/or on a substrate.

[0019] According to some embodiments, and as exemplarily shown in FIG. 1, electromagnetic radiation provided, for example, by a laser 130, can enter the region 112, i.e., an evaporation zone, from one side. According to additional or alternative modifications, the laser 130 or elements for guiding the electromagnetic radiation into the evaporation zone, for example mirrors or optical fibers, can be provided at two or more sides of the region 112. A light source directs electromagnetic radiation in the region between the container and a distribution pipe 140 to evaporate the aerosol. The region 112, i.e. evaporation zone can also be part of the container or part of the distribution pipe, i.e. the evaporation zone at or adjacent to a junction between the container and the distribution pipe.

[0020] According to embodiments described herein, the distribution pipe 140 can be a linear distribution pipe having a plurality of openings 142. Further, as exemplarily illustrated in FIG. 1, the distribution pipe 140 has a length 145 and an inner volume 144.

Surprisingly, the inventors have found that even for a linear distribution pipe, i.e. evaporation source 100 extending along one dimension of a substrate such as a large area substrate, sufficient partial pressure of evaporated material can be provided in the linear distribution pipe to provide a uniform deposition along the length of the linear source. [0021] The partial pressure of the evaporated material, which is for example one order of magnitude higher in the inner volume 144 of the distribution pipe as compared to the vacuum chamber surrounding the distribution pipe, can be controlled by at least two parameters for embodiments of the present disclosure. Firstly, the excitation of the ultrasonic source can be adapted for generating a suitable amount of aerosol. Secondly, the intensity of the light source, such as laser 130, can be adapted for evaporating the material to provide an evaporation rate. A yet further, third parameter, which will be discussed in more detail with respect to FIG. 3, can be feeding of material into the container 110.

[0022] According to embodiments of the present disclosure, an apparatus for evaporating material in a vacuum chamber is provided. For example, the material can be an organic material, such as material that may easily degenerate in a hot crucible. The apparatus includes a container for the material provided in the vacuum chamber, an ultrasonic source in contact with the container and a light source, such as a laser evaporating the organic material. According to yet further embodiments, which can be combined with other embodiments described herein, the ultrasonic source can be configured to generate an aerosol of the material, for example the organic material. Further, the apparatus may include a distribution pipe for guiding the evaporated material and a laser directing mission in an area between the container and the distribution pipe to evaporate the aerosol generated by the ultrasonic source. [0023] The material, which is to be evaporated, can be carried in a crucible, such as a cold crucible, i.e. the container. The material in the crucible or container is provided in an ultrasound zone. In the ultrasound zone, the ultrasound will make a dust-like cloud of the material. An aerosol is generated. The dust-like cloud, i.e. the aerosol is evaporated for example, the material passes through the laser, i.e. the region with the Admitted electromagnetic radiation, and is evaporated. The laser may evaporate the aerosol instantaneously. The crucible or the container, thus, the material in the container can stay cold and the material does not degenerate.

[0024] The embodiments described herein can be utilized for coating large area substrates, e.g., for display manufacturing. The substrates or substrate receiving areas for which the apparatuses and methods described herein are provided can be large area substrates. For example, a large area substrate or carrier can be GEN 4.5, which corresponds to about 0.67 m² substrates (0.73x0.92m), GEN 5, which corresponds to about 1.4 m² substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m² substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7m² substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m² 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. For example, for OLED display manufacturing, half sizes of the above mentioned substrate generations, including GEN 6, can be coated by evaporation of an apparatus for evaporating material. The half sizes of the substrate generation may result from some processes running on a full substrate size, and subsequent processes running on half of a substrate previously processed.

[0025] The term "substrate" as used herein may particularly embrace substantially inflexible substrates, e.g., a wafer, slices of transparent crystal such as sapphire or the like, or a glass plate. However, the present disclosure is not limited thereto and the term "substrate" may embrace flexible substrates such as a web or a foil. The term "substantially inflexible" is understood to distinguish over "flexible". Specifically, a substantially inflexible substrate can have a certain degree of flexibility, e.g. a glass plate having a thickness of 0.5 mm or below, wherein the flexibility of the substantially inflexible substrate is small in comparison to the flexible substrates.

[0026] A substrate may be made of any material suitable for material deposition. For instance, the substrate may be made of 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, metal or any other material or combination of materials which can be coated by a deposition process.

[0027] FIG. 2 illustrates yet further embodiments of an apparatus for evaporating material in the cold crucible. FIG. 2 shows an evaporation source 100 in a vacuum chamber 210. The light source, for example laser 130, can be provided outside of the vacuum chamber 210. The electromagnetic radiation emitted from the laser 130 can be guided through an optical fiber 232. For example, a mirror 234 can reflect the electromagnetic radiation into the region 112, i.e. an evaporation zone of the evaporation source 100. [0028] As shown exemplarily in FIGS. 1 and 2, the ultrasonic source 120 can be provided on two sides of the container 110 or the crucible, respectively. One ultrasonic source 120 can be provided at one side of the container 110. The ultrasonic source 120 is in contact with the container 110. Two or more ultrasonic sources 120 can be provided around the container 110.

[0029] According to embodiments of the present disclosure, the apparatus for evaporating material includes an ultrasonic region, in which ultrasound excites material in the container. The material to be evaporated is provided as an aerosol. Further, an evaporation region is provided, in which electromagnetic radiation, for example light emitted from a laser evaporates the aerosol of the material to be evaporated. A laser can evaporate the aerosol instantaneously.

[0030] According to some embodiments, that can be combined with other embodiments described herein, the light source or the laser can be a line laser. A laser can include optical elements to generate a line of electromagnetic radiation (rather than spot). Yet further, additionally or alternatively, a mirror can be provided to move the laser spot or a laser line within the evaporation zone. According to yet further embodiments, which can be combined with other embodiments described herein, an electron beam may be utilized instead of electromagnetic radiation. However, for sensitive materials like some organic materials, an e-beam may also deteriorate or destroy the material. For sensitive materials electromagnetic radiation may be beneficial.

[0031] FIG. 3 illustrates yet further embodiments of an evaporation source 100. Material can be carried into the crucible or container, for example from the bottom, with a screw conveyor 330. Alternatively, other feeding mechanisms for the material to the evaporated can be utilized. Providing material into the container with a feeding mechanism is particularly beneficial in light of the fact that a further parameter for controlling the amount of evaporated material can be provided. By controlling the feeding mechanism, i.e. the amount of material fed into the container, the amount of aerosol can be further controlled. Accordingly, uniformity of a deposition with a line source, particularly a vertical line source having evaporation at the bottom, i.e. below the distribution pipe can be further improved. [0032] According to embodiments described herein, it has been found that the combination of an ultrasonic region with a laser region providing a cold crucible can be utilized for a vertical line source having an evaporation zone below a distribution pipe 140. A vertical line source for evaporation material can be utilized for depositing material on vertically oriented substrates, particularly large area substrates. Considering the increasing substrate sizes of displays, such as substrate sizes of 1.4 m² and above and a continuous increase in substrate sizes, vertical substrate orientation reduces the footprint of a processing system. Vertical processing systems, particularly for evaporation processes, such as processes for OLED manufacturing, are distinct from horizontal processing. On the one hand, pixel masks (FFM, fine metal masks) with a pixel accuracy of a few microns, result in major differences of vertical processing systems as compared to horizontal processing systems. On the other hand, as described with respect to embodiments described herein, vertical evaporation sources having a uniform evaporation along the length (see for example length 145 in FIG. 1) of the distribution pipe result in further differences of vertical processing systems as compared to horizontal processing systems. It has been found that a combination of ultrasonic aerosol generation with, e.g., laser evaporation can provide a uniform evaporation rate along the length of an evaporation line source. Yet, embodiments of the present disclosure may also be utilized for horizontal systems and/or point sources, wherein the benefit of avoiding degeneration of materials in a hot crucible applies.

[0033] The apparatuses and methods according to the present disclosure can be used for vertical substrate processing. Therein, the substrate is vertically oriented during processing of the substrate, i.e. the substrate is arranged parallel to a vertical direction as described herein, i.e. allowing possible deviations from exact verticality. A small deviation from exact verticality of the substrate orientation can be provided, for example, because a substrate support with such a deviation might result in a more stable substrate position or a reduced particle adherence on a substrate surface. An essentially vertical substrate may have a deviation of +- 15° or below from the vertical orientation. Accordingly, embodiments of the present disclosure can refer to a direction being vertical +-15°, when reference to a vertical substrate orientation is made. [0034] In FIG. 3, a feeding mechanism, such as a screw conveyor 330, shown to feed the material from the material feeding region 312, which is in communication with an atmospheric box 310. The atmospheric box 310 can be adjacent to or connected with the evaporation source 100. The atmospheric box 310 can, for example, provide electric feedthroughs or feedthroughs for other media like cooling fluids for the evaporation source 100. The atmospheric box 310 can be in fluid communication with the atmosphere outside of the vacuum chamber. The material inlet can be provided, for example, through the atmospheric box 310. Material to be evaporated can be provided in the feeding region 312. The material can be fed from the feeding region 312 by a feeding mechanism into the container 110. As the material enters the crucible or container, it enters the ultrasonic sound. In the ultrasonic sound a dust-like cloud or aerosol of the material is generated. The dust-like cloud of material or the aerosol of material is evaporated by, e.g. the laser 130. The crucible or container and, thus, the material provided to be evaporated in the evaporation source can stay cold. Stability of the material i.e., no degeneration or degradation of the material, can be improved.

[0035] FIG. 4 illustrates yet further embodiments of an apparatus for evaporating material. FIG. 4 shows an evaporation source 100 being line source having a linear distribution pipe 140. The laser 130 or allied source in general, can admit the electromagnetic radiation into the evaporation zone, for example, region 112, through the distribution pipe 140. For example, the light of a laser can be scanned from the top of the distribution pipe over a surface of the region 112. According to yet further modifications, a feeding mechanism, such as screw conveyor 330 described with respect to FIG. 3 or other modifications of ultrasonic excitation or light evaporation can be combined with electromagnetic radiation through the top of the distribution pipe, as exemplarily shown in FIG. 4.

[0036] As exemplarily shown in FIG.5, a support 574 of an evaporation source 100 can support three crucibles or containers 110. The container is configured to enclose material for evaporating the material to be deposited on a substrate. The evaporated material can be guided in vapor distribution elements or vapor distribution pipes 140. The vapor distribution elements or vapor distribution pipes can direct the evaporated material onto a substrate mounted on the carrier of a carrier assembly 510. [0037] FIG. 5 shows a deposition source assembly facing a substrate of the upper carrier assembly 510. The deposition source assembly can be moved along a substrate mounted on the carrier of the carrier assembly. For example, the deposition source assembly can include one or more line sources. The line sources can be provided by the distribution pipes 140, e.g. a plurality of openings in each of the distribution pipes. A combination of providing a line source and a movement of the deposition source assembly allows for depositing material on a rectangular substrate, such as large area substrate for display manufacturing. According to further alternatives, distribution pipes of a deposition source assembly may include one or more point sources, which can be moved along a substrate surface.

[0038] Besides the translation of the deposition source assembly, the deposition source assembly may also rotate the deposition sources such that the deposition sources are directed towards a substrate of the lower carrier assembly 510 shown in FIG. 5. Accordingly, a carrier assembly 510 can be loaded out of and into the vacuum chamber 552 at a first position of the upper and lower position shown in FIG. 5 while the substrate of a carrier assembly on the corresponding other position of the upper and lower position shown in FIG. 5 can be processed. After processing of the corresponding other substrate, loading of a new substrate, for example on the carrier assembly 510, can be completed. After rotation of the one or more deposition sources of the evaporation source 100 a substrate, which has been loaded at the first position of the upper and lower position shown in FIG. 5 can be processed. Similarly, during processing (e.g. layer deposition) of a substrate in the first position, unloading and loading of another substrate in the other position can be conducted.

[0039] According to embodiments, the speed of the deposition source assembly along the source transportation direction may be controlled for controlling the deposition rate. The speed of the deposition source assembly can be adjusted in real-time under the control of a controller. The adjustment can be provided for compensating a deposition rate change. A speed profile may be defined. The speed profile may determine the speed of the deposition source assembly at different positions. The speed profile may be provided to or stored in the controller. The controller may control the drive system such that the speed of the deposition source assembly is in accordance with the speed profile. Accordingly, a real- time control and adjustment of the deposition rate can be provided, so that the layer uniformity can be further improved. A translational movement of the deposition source assembly along the source transportation direction, as considered according to embodiments described herein, allows for a high coating precision, in particular a high masking precision during the coating process, since the substrate and the mask can remain stationary during coating.

[0040] According to yet further embodiments, which can be combined with other embodiments described herein, the instantaneous evaporation of the aerosol in the evaporation zone by, e.g., a laser can further be controlled to improve uniform deposition on a substrate provided on a carrier assembly 510. The evaporation source 100 can be moved in the vacuum chamber by magnetic levitation transport system, i.e. a contactless transport system. The contactless transport system reduces particle generation in the vacuum chamber that may occur by a source movement. Further, the contactless transport system enables improved control of the speed profile of a deposition source assembly, i.e. the evaporation source 100. Accordingly, the contactless transport system of a deposition source assembly, for example, the evaporation source 100, and evaporation of a material with a cold crucible as described herein, can - particularly in combination - improve uniformity of a layer of the material deposited on a substrate.

[0041] As shown in FIG. 5, a mask 512 can be provided between the evaporation source 100, i.e. a deposition source assembly, and a substrate of a carrier assembly 510. FIG. 5 shows a first mask 512 in an upper position, i.e. in a position between the evaporation source and the upper carrier assembly 510 and a second mask 512 in the lower position, i.e. in a position between the evaporation source and the lower carrier assembly 510.

[0042] According to embodiments described herein a mask can be an edge exclusion mask or can be a shadow mask for depositing a pattern on a substrate. According to embodiments described herein, the mask can be supported by a mask carrier. Accordingly, an alignment of a mask and substrate may also be provided with reference to the mask carrier. According to embodiments described herein, vertical substrate processing of large area substrate can be provided. Particularly for pattern masks, e.g. fine metal masks (FFM) requiring a precision of a few microns over the area of the large area substrate, an alignment system including at least one of a magnetic levitation system of a carrier assembly 510 and a mask carrier, and a mechanical alignment system for relative alignment of the substrate carrier and mask carrier can be provided.

[0043] FIG. 5 shows moving levitated carrier assemblies in a processing apparatus. Movement of levitated carrier assemblies allows for higher positioning precision as compared to movement of the carrier assemblies, which are mechanically supported, i.e. not supported without contact that is a mechanical contact on e.g. substrate transport rollers. Particularly, levitated carrier assembly movement allows for a high position in substrate positioning in a transport direction and/or a vertical direction. The positioning precision of carrier assemblies allows for an improved alignment of a substrate supported by a carrier of a carrier assembly relative to the mask 512. The alignment can be improved to provide for a precision for some mask configurations or can be improved to allow for a reduced complexity of a separate alignment system for some other mask configurations.

[0044] The apparatuses and methods according to the present disclosure can be used for vertical substrate processing. Therein, the substrate is vertically oriented during processing of the substrate, i.e. the substrate is arranged parallel to a vertical direction as described herein, i.e. allowing possible deviations from exact verticality. A small deviation from exact verticality of the substrate orientation can be provided, for example, because a substrate support with such a deviation might result in a more stable substrate position or a reduced particle adherence on a substrate surface. An essentially vertical substrate may have a deviation of +- 15° or below from the vertical orientation. Accordingly, embodiments of the present disclosure can refer to a direction being vertical +-15°, wherein reference to a substrate orientation is made.

[0045] Embodiments described herein relate to contactless levitation, transportation and/or alignment of a deposition source assembly or deposition source. The term "contactless" as used throughout the present disclosure can be understood in the sense that a weight of the deposition source assembly is not held by a mechanical contact or mechanical forces, but is held by a magnetic force. Specifically, the deposition source assembly is held in a levitating or floating state using magnetic forces instead of mechanical forces. As an example, the apparatus described herein may have no mechanical element, such as a mechanical rail, supporting the weight of the deposition source assembly, i.e., while being in mechanical contact with the mechanical rail. In some implementations, there can be no mechanical contact between the deposition source assembly and the rest of the apparatus at all during movement of the deposition source assembly or deposition source past a substrate.

[0046] FIG. 5 shows an apparatus 500 for processing a substrate in a vacuum chamber. The vacuum chamber 552 can for example have a chamber wall 553. The gate valve 562 can be provided in the chamber wall 553. The gate valve can be opened to load a carrier assembly 510 into and out of the vacuum chamber 552. One or more guiding structures 570 are provided. The one or more guiding structures can include a plurality of active magnetic units 575. FIG. 5 shows an embodiment of an apparatus 500 having two gate valves 562 and two guiding structures 570. Accordingly, two carrier assemblies 510 can be loaded and unloaded from the vacuum chamber 552, for example, alternating or simultaneously. Loading and unloading the carrier assemblies 510 alternatingly has the advantage that a processing tool, for example a deposition source, can process a substrate of a carrier assembly while another substrate of another carrier assembly is unloaded or loaded, respectively. Accordingly, the throughput of the apparatus 500 can be increased.

[0047] As shown in FIG. 5, the apparatus 500 can further include a maintenance chamber 554, which may for example be a further vacuum chamber. The maintenance chamber 554 can be separated from the vacuum chamber 552 by a further gate valve 564. According to one embodiment, which can be combined with other embodiments described herein, the apparatus 500 can be a deposition apparatus. A deposition source assembly or evaporation source 100 can be moved along a track 572. The track 572 or a portion of the track 572 can extend into the maintenance chamber 554 in order to move the deposition source assembly from the vacuum chamber 552 into the maintenance chamber 554. Moving the evaporation source 100 into the maintenance chamber has the advantage that the evaporation source can be maintained outside of the vacuum chamber 552. For example, after the further gate valve 564 has been closed, the maintenance chamber 554 can be vented to have maintenance access to the evaporation source while the vacuum chamber 552 can stay evacuated. According to some embodiments, a second evaporation source can be in operation in the vacuum chamber 552 while the evaporation source can be maintained in the maintenance chamber 554. Additionally or alternatively, the reduced number of times at which the vacuum chamber 552 needs to be vented results in a cleaner environment in the vacuum chamber 552.

[0048] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, the evaporation source can include support 574. The support 574 can include drive units to move the evaporation source along the track 572. The support 574 can further include magnetic units to levitate the evaporation source. One or more containers 110, distribution pipes 140, ultrasonic sources and light sources can be included in the evaporation source.

[0049] For example, co-evaporation of two or more organic materials, for example 3 materials can be provided. Each of the organic materials is provided in a container 110 having an ultrasonic zone. The ultrasonic zone is in contact with an ultrasonic source configured to generate an aerosol. The aerosol is guided in an evaporation zone, for example, region 112 (see FIG. 1) in which electromagnetic radiation, for example, from a laser, evaporates the aerosol to generate evaporated material to be deposited on a substrate. [0050] According to embodiments described herein, cold evaporation is provided. The cold evaporation with an ultrasonic source and a laser can be supported by thermal heating. For example a material, such as an organic material may be stable over a sufficiently long time at an elevated temperature, wherein the elevated temperature is below the evaporation temperature. Accordingly, in addition to evaporation of an aerosol, heating of the material and/or the aerosol can be provided to support evaporation with the electromagnetic radiation.

[0051] As shown in FIG. 5, co-evaporation can be provided, wherein two or more different materials, for example organic materials, are evaporated to deposit a layer on a substrate. According to some embodiments, one of the two or more different materials can be evaporated with the thermal evaporation process and another one of the two or more different materials can be evaporated with a cold evaporation process.

[0052] According to embodiments of the present disclosure, methods for evaporating material in a vacuum chamber are provided. Fig. 6 shows a flowchart illustrating a method for evaporating material in a vacuum chamber. In box 602 the material to be evaporated is provided in a container. The container is provided in the vacuum chamber. An aerosol of the material is generated with ultrasound (see box 604). According to box 606 the aerosol is evaporated with electromagnetic radiation. According to some embodiments, which can be combined with other embodiments described herein, the electromagnetic radiation can be light from a laser. For example, the light can be provided in an evaporation zone. The evaporation zone can be at the lower end of the distribution pipes or below the distribution pipe.

[0053] According to yet further embodiments, which can be combined with other embodiments described herein, the ultrasound for aerosol generation can be provided with an ultrasonic source in contact with the container.

[0054] Methods for evaporating material can be utilized for methods of depositing the material on a substrate in a vacuum chamber. The cold evaporation process as described herein, can be provided. The evaporated material can be guided with a distribution pipe, for example a linear distribution pipe having a plurality of openings. The distribution pipe guides the waiver towards the substrate in the vacuum chamber. For example, the linear distribution pipe and/or the substrate can be essentially vertically oriented. According to some embodiments, the substrate can be a large area substrate, for example for manufacturing of OLED displays.

[0055] While the foregoing is directed to embodiments of the disclosure, other and further embodiments may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. An apparatus for evaporating material in a vacuum chamber, comprising: a container for the material, the container being provided in the vacuum chamber; an ultrasonic source in contact with the container configured to generate an aerosol of the material; a distribution pipe for guiding the material; and a light source directing electromagnetic radiation in a region having the aerosol or a charged particle beam source directing a charged particle beam in the region having the aerosol, to evaporate the aerosol.

2. The apparatus according to claim 1, wherein the light source includes a laser.

3. The apparatus according to any of claims 1 to 2, wherein the electromagnetic radiation is provided in the region having the aerosol from two or more sides.

4. The apparatus according to any of claims 1 to 3, wherein the region having the aerosol is provided below the distribution pipe, at a lower end of the distribution pipe, between the container and the distribution pipe, or at an upper end of the container.

5. An apparatus for evaporating a material in a vacuum chamber, comprising: a container for the material, the container being provided in the vacuum chamber; an ultrasonic source in contact with the container; and a light source or a charged particle beam source evaporating the material.

6. The apparatus according to claim 5, further comprising a distribution pipe.

7. The apparatus according to any of claims 1 to 6, wherein the ultrasonic source excites a wall of the container.

8. The apparatus according to claim 7, wherein the ultrasonic source excites the wall of the container at two or more positions.

9. The apparatus according to any of claims 1 to 8, further comprising: a feeding mechanism to feed the material in the container.

10. The apparatus according to claim 9, wherein the feeding mechanism is a screw conveyor.

11. A system for depositing material on a substrate in a vacuum chamber, comprising: an apparatus for evaporating material according to any of claims 1 to 10.

12. The system according to claim 11, wherein the distribution pipe is provided in a linear evaporation source.

13. The system according to any of claims 11 to 12, wherein the linear evaporation source is oriented substantially vertically.

14. The system according to claim 12, further comprising: a contactless transport system for the linear evaporation source.

15. A method for evaporating a material in a vacuum chamber, comprising: providing the material in a container provided in the vacuum chamber; generating an aerosol of the material with ultrasound; and evaporating the aerosol of the material with electromagnetic radiation or a charged particle beam.

16. The method according to claim 15, wherein the electromagnetic radiation is light emitted from a laser.

17. The method according to any of claims 15 to 16, wherein the ultrasound is provided with an ultrasonic source in contact with the container.

18. A method of depositing a material onto a substrate in a vacuum chamber, comprising: evaporating the material in the vacuum chamber with a method according to any of claims 15 to 17; and guiding the material towards the substrate with a distribution pipe.

19. The method according to claim 18, wherein the material is an organic material and the substrate is an essentially vertically oriented large area substrate.