TECHNICAL FIELD

[0001] The embodiments of the present disclosure relate to deposition rate measurement devices and methods of measuring deposition rates of evaporated materials, particularly evaporated organic materials. Further, the present disclosure relates to deposition sources including deposition rate measurement devices as well as to deposition apparatuses having such deposition sources, particularly for production of optoelectronic devices, e.g. organic light-emitting diodes (OLEDs).

BACKGROUND

[0002] Organic evaporators are a tool for the production of organic light- emitting diodes (OLEDs). OLEDs are a special type of light-emitting diode in which the emissive layer comprises a thin-film of certain organic compounds. OLEDs are used in the manufacture of television screens, computer monitors, mobile phones, other hand-held devices, etc., for displaying information. OLEDs can also be used for general space illumination. The range of colors, brightness, and viewing angles possible with OLED displays is greater than that of traditional LCD displays because OLED pixels directly emit light and do not involve a back light. Therefore, the energy consumption of OLED displays is considerably less than that of traditional LCD displays. Further, the fact that OLEDs can be manufactured onto flexible substrates results in further applications.

[0003] The functionality of an OLED depends on the coating thickness of the organic material. This thickness has to be within a predetermined range. In the production of OLEDs, the deposition rate at which the coating with organic material is effected is controlled to lie within a predetermined tolerance range. In other words, the deposition rate of an organic evaporator has to be controlled thoroughly in the production process. [0004] Accordingly, for OLED applications but also for other evaporation processes, a high accuracy of the deposition rate over a comparably long time is needed. There is a plurality of measurement systems for measuring the deposition rate of evaporators available. However, these measurement systems suffer from either insufficient accuracy and/or insufficient stability over the desired time period.

[0005] For example, a Quartz Crystal microbalance (QCM) correlates the frequency of an oscillating quartz crystal with the mass of the material deposited on the QCM. Upon deposition of material on the QCM, the oscillation frequency changes. A deposition rate is determined based on the changing oscillation frequency. A QCM can be considered highly sensitive to the change in mass. Yet, saturation of the QCM and difficulties to measure reliably over a long time period results in frequent maintenance and/or long maintenance times.

[0006] Accordingly, there is a continuing demand for providing improved deposition rate measurement systems, deposition rate measurement methods, particularly for deposition sources for depositing evaporated material, e.g. employed in deposition apparatuses for the production of optoelectronic devices, such as organic light-emitting diodes (OLEDs).

SUMMARY

[0007] in view of the above, a measurement assembly for measuring a deposition rate of evaporated material and a method of measuring a deposition rate according to the independent claims are provided. Additionally, a deposition rate sensor unit including a measurement assembly according to embodiments described herein, a deposition source including a measurement assembly according to embodiments described herein, and a deposition apparatus including at least one deposition source according to embodiments described herein are provided. Further, a method of manufacturing a device including using at least one of the methods of measuring a deposition rate according to embodiments of the present disclosure, the deposition rate sensor unit according to embodiments of the present disclosure, the deposition source according to embodiments of the present disclosure, and the deposition apparatus according embodiments of the present disclosure is provided. Yet further, a method of retrofitting a deposition source is provided, the method including providing the deposition source with a measurement assembly according embodiments of the present disclosure.

[0008] Further advantages, features, aspects and details are apparent from the dependent claims, the description and drawings.

[0009] According to an aspect of the present disclosure, a measurement assembly for measuring a deposition rate of evaporated material is provided. The measurement assembly includes a capacitor arranged within a deposition compartment. The deposition compartment has an inlet for providing evaporated material to a first capacitor plate of the capacitor and to a second capacitor plate of the capacitor.

[0010] According to a further aspect of the present disclosure, a deposition rate sensor unit is provided. The deposition rate sensor unit includes two or more measurement assemblies according to any embodiments described herein. The two or more measurement assemblies are mounted on a movable element, particularly a rotatable element.

[0011] According to another aspect of the present disclosure, a deposition source for depositing evaporated material is provided. The deposition source includes an evaporation crucible for providing evaporated material. Additionally, the deposition apparatus includes a distribution assembly in fluid communication with the evaporation crucible. The distribution assembly has one or more outlets provided along the length of the distribution assembly for providing evaporated material to a substrate. Further, the deposition apparatus includes a measurement assembly according to any embodiments described herein, particularly a deposition rate sensor unit according to any embodiments described herein.

[0012] According to a further aspect of the present disclosure, a deposition apparatus for applying material to a substrate in a vacuum chamber at a deposition rate is provided. The deposition apparatus includes at least one deposition source according to any embodiments described herein. [0013] According to a further aspect of the present disclosure, a method of measuring a deposition rate is provided. The method includes depositing evaporated material onto a first capacitor plate of a capacitor and onto a second capacitor plate of the capacitor. Further, the method includes measuring the change of capacitance of the capacitor.

[0014] According to another aspect of the present disclosure, a method of manufacturing a device is provided. The method includes using at least one of the measurement assembly according to any embodiments described herein, the deposition rate sensor unit according to any embodiments described herein, the deposition source according to any embodiments described herein, the deposition apparatus according to any embodiments described herein, and the method of measuring a deposition rate according to any embodiments described herein.

[0015] According to a yet further aspect of the present disclosure, a method of retrofitting a deposition source is provided. The method includes providing the deposition with a measurement assembly according to any embodiments described herein.

[0016] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing the described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed at methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] So that the manner in which the above recited features of the disclosure described herein can be understood in detail, a more particular description, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

FIGS. 1A and IB show schematic views of a measurement assembly for measuring a deposition rate of evaporated material according to embodiments of the present disclosure;

FIGS. 2 and 3 show schematic views of a measurement assembly for measuring a deposition rate of evaporated material according to further embodiments described herein;

FIG. 4 shows a schematic view of a deposition rate sensor unit according to embodiments of the present disclosure;

FIG. 5 shows a schematic view of a deposition rate sensor unit according to further embodiments described herein;

FIGS. 6A to 6C shows a schematic view of a deposition source according to embodiments described herein;

FIG. 7 shows a schematic view of a deposition apparatus according to embodiments described herein;

FIG. 8 shows a block diagram for illustrating a method of measuring a deposition rate according to embodiments described herein;

FIG. 9 shows a block diagram for illustrating a method of manufacturing a device according to embodiments described herein; and

FIG. 10 shows a block diagram for illustrating a method of retrofitting a deposition source according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0018] 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. In the following, 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 of the disclosure. 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.

[0019] With exemplary reference to FIGS. 1A and IB, a measurement assembly 100 for measuring a deposition rate of evaporated material 13 according to the present disclosure is described. According to embodiments which can be combined with other embodiments described herein, the measurement assembly 100 includes a deposition compartment 110 and a capacitor 120. The capacitor 120 is arranged within the deposition compartment 110. The deposition compartment 110 has an inlet 115 for providing evaporated material to the capacitor 120. In particular, the inlet is configured such that evaporated material can be provided to a first capacitor plate 121 of the capacitor 120 as well as to a second capacitor plate 122 of the capacitor 120. The evaporated material 13 is exemplarily indicated by dotted arrows.

[0020] FIG. 1A shows the measurement assembly 100 before material is deposited on the capacitor plates and FIG. IB shows the measurement assembly 100 with deposited material 14 on the capacitor plates. It is to be noted that when material is deposited on the capacitor plates, the capacitance of the capacitor changes due to the fact that a dielectric is added resulting in current and voltage changes in a given circuit. In other words, when evaporated material 13 is deposited on the first capacitor plate 121 and/or the second capacitor plate 122, a layer thickness of deposited material 14 on the first capacitor plate 121 and/or the second capacitor plate 122 increases over time, resulting in a change of capacitance. Accordingly, by measuring the capacitance of the capacitor over time, the deposition rate can be measured.

[0021] Accordingly, compared to the state of the ait, an improved deposition rate measurement system is provided. In particular, with the deposition rate measurement assembly according to embodiments described herein, problems associated with deposition rate measurement systems including Quartz Crystal microbalances (QCMs) are at least partially or even completely overcome. For instance, QCMs may have issues in terms of measurement quality and measurement reliability. More specifically, exemplary issues of QCMs are a relatively fast saturation time resulting in increased maintenance downtimes. By employing a measurement assembly having a capacitor for measuring the deposition rate as described herein, the saturation time can be increased, particularly approximately up to ten times, compared to saturation times of QCMs. Further, it has been found that the deposition rate measurement assembly according to embodiments described herein beneficially shows less signal losses and provides more stable readings, compared to QCMs. Another advantage of the deposition rate measurement assembly according to embodiments described herein is that, compared to conventional deposition rate measurement systems, the number of parts are less and spare parts are even easier to replace, resulting in less overall production downtime. Further, it is has been found that capacitance measurement for determining deposition rates is highly repeatable, such that the measurement assembly as described herein beneficially provides for more stable readings compared to conventional deposition rate measurement systems using QCMs.

[0022] Further, embodiments of the measurement assembly according to the present disclosure can be utilized for measuring deposition rates in-situ during material deposition in vacuum deposition chambers. In particular, the measurement assembly according to embodiments described herein can be used for evaporation sources and specifically for evaporation sources for organic materials, for which highly accurate deposition rate measurements are advantageous. Accordingly, embodiments as described herein provide for improved in-situ deposition rate measurements with better measurement quality and reliability.

[0023] Before various further embodiments of the measurement assembly are described in more detail, some aspects with respect to some terms used herein are explained. [0024] In the present disclosure, a“measurement assembly for measuring a deposition rate of evaporated material” can be understood as an assembly having a measurement device for conducting a deposition rale measurement.

[0025] In the present disclosure, the term“evaporated material” may refer to an evaporated material suitable for deposition on a substrate, e.g. for display production. For instance, the evaporated material can be an evaporated organic material, particularity suitable for OLED production. For example, organic materials may have an evaporation temperature of about 100°C to about 600°C. It is to be understood that embodiments of the present disclosure are not limited to organic materials and other materials, e.g. metals, may be used. Accordingly, the “evaporated material” may also refer to evaporated metal materials, e.g. having an evaporation temperature of about 300°C to about 1500°C. Accordingly, the evaporated material may be an inorganic material or an organic material that can be deposited on a substrate to form an optically active layer of a display device, e.g. an OLED device. The material may be deposited as a continuous layer or in a predetermined pattern, e.g. by using a mask such as a fine metal mask (FMM) having a plurality of openings for creating a plurality of pixels on the substrate. Examples of evaporated materials include one or more of the following: metals such as silver, magnesium, aluminum, calcium, barium, gold, ytterbium, cesium or other materials such as ITO, NPD, Alq3, and Quinacridone.

[0026] In the present disclosure, a“deposition compartment” can be understood as a compartment, casing, housing, or chamber of a deposition rate measurement assembly in which the deposition rate measurement device, e.g. a capacitor as described herein, is arranged. In particular, the“deposition compartment” as described herein has an inlet such that evaporated material can be provided to the deposition rate measurement device. The inlet can be an opening or aperture provided in a wall of the deposition compartment. Accordingly, the deposition compartment provides a confined space into which evaporated material can be provided for carrying out deposition rate measurements.

[0027] With exemplary reference to FIG. 2, according to embodiments which can be combined with other embodiments described herein, the inlet 115 has an inlet axis 15. The inlet axis 15 is arranged between the first capacitor plate 121 and the second capacitor plate 122. In particular, the first capacitor plate 121 and the second capacitor plate 122 may be symmetrically arranged with respect to the inlet axis 15.

[0028] As exemplarily shown in FIG. 2, according to embodiments which can be combined with other embodiments described herein, the first capacitor plate 121 has a first detector surface 123 and the second capacitor plate 122 has a second detector surface 124. Typically, the first detector surface 123 and the second detector surface 124 are substantially parallel to each other. In particular, the first detector surface 123 may be parallel to the inlet axis 15. Accordingly, the second detector surface 124 may be parallel to the inlet axis 15.

[0029] With exemplary reference to FIG. 2, according to embodiments which can be combined with other embodiments described herein, the first capacitor plate 121 can be provided on a first side wall 11 of the deposition compartment 110. The second capacitor plate 122 can be provided on a second side wall 12 of the deposition compartment 110. In particular, the first capacitor plate 121 may cover the first side wall 11. The second capacitor plate 122 may cover the second capacitor plate 122.

[0030] According to embodiments which can be combined with other embodiments described herein, the measurement assembly may further include a vacuum compartment 130, as exemplarily shown in FIG. 3. For instance, the vacuum compartment 130 can be at least partially provided around the deposition compartment 110. From FIG. 3 it is to be understood that the vacuum compartment 130 is typically configured to provide a closed space 16 between the outer walls of the deposition compartment 110 and the inner walls of the vacuum compartment 130.

[0031] As exemplarily shown in FIG. 3, the vacuum compartment 130 typically includes a first electrical connection 131 connected to the first capacitor plate 121. Further, typically the vacuum compartment 130 includes a second electrical connection 132 connected to the second capacitor plate 122. Accordingly, beneficially the electrical connections are protected from evaporated material. Accordingly, signal losses can be reduced or even eliminated.

[0032] Accordingly, measurement assemblies according to embodiments of the present disclosure can be configured to measure a deposition rate of material in a vacuum deposition chamber. A deposition process is provided in a vacuum chamber. For example, the deposition process can be an evaporation process or another physical vapor deposition process or can be a CVD process. Measurement assemblies according to embodiments of the present disclosure can be provided and can operate in the vacuum chamber, for example, under a technical vacuum. A technical vacuum may be considered to have a pressure of 1 mbar or below, such as 1*10 ^-3 mbar or below or 1*10 ^-5 mbar or below. As described herein, a deposition rate signal can be provided by measuring a change of capacitance of a capacitor as described herein.

[0033] Further, as exemplarily shown in FIG. 3, the first electrical connection 131 and the second electrical connection 132 may extend through the wall of the vacuum compartment 130. Accordingly, respective air-tight sealings may be provided at the locations of the vacuum compartment wall through which the first electrical connection 131 and the second electrical connection 132 extend. Typically, the wall of the vacuum compartment 130 through which the first electrical connection 131 and the second electrical connection 132 extend is a vacuum compartment wall not exposed to evaporated material during a deposition rate measurement.

[0034] With exemplary reference to FIG. 4, a deposition rate sensor unit 200 according to the present disclosure is described. According to embodiments which can be combined with other embodiments described herein, the deposition rate sensor unit 200 includes two or more measurement assemblies as described herein. FIG. 4 shows a deposition rate sensor unit 200 having a first measurement assembly 100 A and a second measurement assembly 100B. The two or more measurement assemblies are mounted on a movable element 210, particularly a rotatable element. For instance, the rotatable element may rotate around a rotation axis 25, as exemplarily shown in FIG. 4. As exemplarily shown in FIG. 4, for measuring a deposition rate of evaporated material, at least one of the two or more measurement assemblies may be positioned in front of a measurement outlet 325 providing the evaporated material 13. Typically, the measurement outlet 325 is provided at a deposition source, for instance a deposition source as described with reference to FIGS. 6A to 6C.

[0035] With exemplary reference to FIG. 5, according to embodiments which can be combined with other embodiments described herein, the deposition rate sensor unit 200 includes a motor 220 connected to the movable element 210. In particular, the motor 220 can be connected to the movable element via a shaft 225. For instance, the motor 220 may be an indexer motor. As exemplarily shown in FIG. 5, the two or more measurement assemblies are typically arranged at an equal distance with respect to a rotation axis 25 corresponding to the longitudinal axis of the shaft 225. For instance, the two or more measurement assemblies can be arranged on a circle having a radius R from the rotation axis 25. Accordingly, a “revolver-type” deposition rate sensor unit can be provided having die advantage that the measurement assemblies can be exchanged quickly, such that downtimes for maintenance can be reduced.

[0036] According to embodiments which can be combined with other embodiments described herein, the deposition rate sensor unit 200 further includes an atmospheric box 230, as exemplarily shown in FIG. 5. Typically, the motor 220 is arranged inside the atmospheric box 230, whereas the two or more measurement assemblies are arranged outside the atmospheric box 230. As shown in FIG. 5, the shaft 225 typically extends through an opening 231 in a wall of the atmospheric box. The opening 231 may include an air-tight sealing configured for sealing the interface between the wall of the atmospheric box and the shaft 225 extending there through.

[0037] Further, according to embodiments which can be combined with other embodiments described herein, the deposition rate sensor unit 200 may further include an electronic unit 240. In particular, the electronic unit 240 may be provided inside the atmospheric box 230. The electronic unit 240 can be configured for controlling the motor 220. Accordingly, as indicated in FIG. 5, the electronic unit 240 is typically configured for providing a control signal CS to the motor 220. Additionally or alternatively, the electronic unit 240 can be configured for evaluating a signal provided from respective capacitors of the two or more measurement assemblies for determining a deposition rate. Accordingly, as indicated in FIG. 5, the electronic unit 240 is typically configured for receiving and analyzing a first signal SI of the first measurement assembly 100 A and a second signal S2 of the second measurement assembly 100B.

[0038] With exemplary reference to FIGS. 6A to 6C, a deposition source 300 according to the present disclosure is described. The deposition source 300 includes an evaporation crucible 310 for providing evaporated material. Accordingly, the deposition source may also be referred to as evaporation source herein. Additionally, the deposition source 300 includes a distribution assembly 320 in fluid communication with the evaporation crucible 310, e.g. by a vapor conduit 332. For instance, the vapor conduit 332 can be at a lower end of the distribution assembly 320. The distribution assembly 320 includes one or more outlets 322 provided along the length of the distribution assembly for providing evaporated material to a substrate. Further, the deposition source 300 includes a measurement assembly 100 according to any embodiments described herein. In particular, the deposition source 300 includes a deposition rate sensor unit 200 according to any embodiments described herein.

[0039] Accordingly, a deposition source 300 is provided for which the deposition rate can be measured with improved measurement quality, improved measurement reliability and at a high accuracy.

[0040] In die present disclosure, an“evaporation crucible” may be understood as a device or a reservoir providing or containing the material to be deposited. Typically, the crucible may be heated for evaporating the material to be deposited on the substrate. Accordingly, the crucible typically includes heaters for heating the material to be evaporated.

[0041] In the present disclosure, a“distribution assembly” may be understood as a distribution pipe for guiding and distributing the evaporated material or as one or more point sources which can be arranged along a vertical axis. In particular, the distribution pipe or the one or more point sources may be configured for providing evaporated material from an evaporator to an outlet (such as nozzles or openings) in the distribution pipe or the one or more point sources. For instance, in the case of a distribution assembly in the form of a distribution pipe, the distribution pipe can be a linear distribution pipe extending in a longitudinal direction. For example, the distribution pipe may include a pipe having the shape of a cylinder, wherein the cylinder may have a circular, triangular or square-like bottom shape or any other suitable bottom shape.

[0042] According to some embodiments, which can be combined with other embodiments described herein, the length of the distribution pipe may correspond to a height of a substrate onto which material is to be deposited in a deposition apparatus. Alternatively, the length of the distribution pipe may be longer than the height of the substrate onto which material is to be deposited, for example at least by 10% or even 20%. Accordingly, a uniform deposition at the upper end of the substrate and/or the lower end of the substrate can be provided. For example, the length of the distribution pipe can be 1.3 m or above, for example 2.5 m or above.

[0043] According to embodiments, which can be combined with other embodiments described herein, the evaporation cmcible 310 may be provided at the lower end of the distribution assembly 320, particularly the distribution pipe. The material, e.g. an organic material, can be evaporated in the evaporation crucible 310. The evaporated material may enter the distribution assembly 320 at the bottom of the distribution assembly and may be guided essentially sideways through the plurality of outlets 322 in the distribution assembly 320, e.g. towards an essentially vertical substrate. As exemplarily shown in FIGS. 6A to 6C, the measurement assembly 100 may be provided at an upper portion of the distribution assembly.

[0044] In particular, as exemplarily shown in FIGS. 6 A to 6C, the distribution assembly 320 includes a measurement outlet 325. Typically, the measurement outlet 325 is arranged at an end of the distribution assembly 320. The measurement outlet 325 is configured for directing evaporated material to the measurement assembly 100. Accordingly, the measurement assembly may be arranged at an end of the distribution assembly. According to an example, the measurement outlet 325 may be provided at a lop wall 321 of the distribution assembly 320, as exemplarily shown in FIG. 6A. Accordingly, the measurement assembly 100 may be provided above the top wall 321, particularly above the measurement outlet 325. Alternatively, the measurement outlet 325 may be provided at a back wall 323 of the distribution assembly 320, as exemplarily shown in FIG. 6B. Accordingly, alternatively the measurement assembly 100 may be provided behind the measurement outlet 325 provided in the back wall 323.

[0045] In the present disclosure, a“measurement outlet” may be understood as an opening or aperture through which evaporated material can be provided to a measurement device, e.g. a measurement assembly according to embodiments described herein. Further, in the present disclosure, a“measurement outlet” may be understood as an opening or aperture which is provided in a wall, particularly a top wall or a back side wall, of a distribution assembly (e.g. a distribution pipe) of a deposition source as described herein.

[0046] FIG. 6C shows a perspective view of a deposition source 300 according to embodiments described herein. As exemplarily shown in FIG. 6, the distribution assembly 320 may be a distribution pipe designed in a triangular shape. A triangular shape of the distribution pipe may be beneficial in the case that two or more distribution pipes are arranged next to each other. In particular, a triangular shape of the distribution pipe makes it possible to bring the outlets of neighboring distribution pipes close to each other. This allows for achieving an improved mixture of different materials from different distribution pipes, e.g. for the case of the co-evaporation of two, three or even more different materials.

[0047] According to embodiments, which can be combined with other embodiments described herein, the distribution pipe may include walls, for example side walls 324 and a back wall 323 at the back side. The distribution pipe may be heated, e.g. by one or more heating elements 315. The heating elements 315 may be mounted or attached to the walls of the distribution pipe. According to some embodiments, which can be combined with other embodiments described herein, the deposition source 300 may include a shield 305. The shield 305 may reduce the heat radiation towards the deposition area. Further, the shield 305 may be cooled by one or more cooling elements 316. For example, the one or more cooling elements 316 may be mounted to the shield 305 and may include a conduit for cooling fluid.

[0048] With exemplary reference to FIG. 7, a deposition apparatus 400 for applying material to a substrate 433 in a vacuum chamber 410 at a deposition rate according to the present disclosure is described. According to embodiments which can be combined with other embodiments described herein, the deposition apparatus 400 includes at least one deposition source 300 according to embodiments described herein. In particular, the at least one deposition source 300 may be an evaporation source and is provided in the vacuum chamber 410. For example, the at least one deposition source 300 may be provided on a track, e.g. a linear guide 420. The track or the linear guide 420 may be configured for a translational movement of the deposition source 300. Accordingly, according to embodiments which can be combined with other embodiments described herein, a drive for the translational movement can be provided for the deposition source 300, at the track and/or the linear guide 420, within the vacuum chamber 410. According to embodiments which can be combined with other embodiments described herein, a first valve 405, for example a gate valve, may be provided which allows for a vacuum seal to an adjacent vacuum chamber (not shown in FIG. 7). The first valve can be opened for transport of the substrate 433 or a mask 432 into the vacuum chamber 410 or out of the vacuum chamber 410.

[0049] According to some embodiments, which can be combined with other embodiments described herein, a further vacuum chamber, such as maintenance vacuum chamber 411 may be provided adjacent to the vacuum chamber 410, as exemplarily shown in FIG. 7. Accordingly, the vacuum chamber 410 and the maintenance vacuum chamber 411 may be connected with a second valve 407.

[0050] As exemplarily shown in FIG. 7, two substrates may be supported on respective transportation tracks within the vacuum chamber 410. Further, two tracks for providing masks thereon can be provided. Accordingly, during coating the substrate 433 can be masked by respective masks. For example, the mask may be provided in a mask frame 431 to hold the mask 432 in a predetermined position.

[0051] According to some embodiments, which can be combined with other embodiments described herein, the substrate 433 may be supported by a substrate support 426, which can be connected to an alignment unit 412. The alignment unit 412 may adjust the position of the substrate 433 with respect to the mask 432. As exemplarily shown in FIG. 7, the substrate support 426 may be connected to the alignment unit 412. Accordingly, the substrate may be moved relative to the mask 432 in order to provide for a proper alignment between the substrate and the mask during deposition of the material, which may be beneficial for high quality display manufacturing. Alternatively or additionally, the mask 432 and/or the mask frame 431 holding the mask 432 can be connected to the alignment unit 412. Accordingly, either the mask 432 can be positioned relative to the substrate 433 or the mask 432 and the substrate 433 can both be positioned relative to each other.

[0052] As shown in FIG. 7, the linear guide 420 may provide a direction of the translational movement of the deposition source 300. A mask 432 may be provided on both sides of the deposition source 300. The masks may extend essentially parallel to the direction of the translational movement. Further, the substrates at the opposing sides of the deposition source 300 can also extend essentially parallel to the direction of the translational movement. As exemplarily shown in FIG. 7, the deposition source 300 provided in the vacuum chamber 410 of the deposition apparatus 400 may include a support 402 which may be configured for the translational movement along the linear guide 420. For example, the support 402 may support three evaporation crucibles and three distribution pipes provided over the evaporation crucibles. Accordingly, the vapor generated in the evaporation crucible can move upwardly and out of the one or more outlets of the distribution pipe and be provided to the substrate.

[0053] With exemplary reference to the block diagram shown in FIG. 8, a method 500 of measuring a deposition rate according to embodiments of the present disclosure is described. According to embodiments which can be combined with other embodiments described herein, the method 500 includes depositing (represented by block 501 in FIG. 8) evaporated material onto a first capacitor plate 121 of a capacitor 120 and onto a second capacitor plate 122 of the capacitor 120. Additionally, the method 500 includes measuring (represented by block 502 in FIG. 8) the change of capacitance of the capacitor. In particular, it is to be understood that the method 500 of measuring a deposition rate may be carried out by using a measurement assembly 100 according to embodiments described herein.

[0054] With exemplary reference to the block diagram shown in FIG. 9, a method 600 of manufacturing a device according to embodiments of the present disclosure is described. The method 600 includes using (represented by block 601 in FIG. 9) at least one of the measurement assembly 100 according to embodiments described herein, the deposition rate sensor unit 200 according to embodiments described herein, the deposition source 300 according to embodiments described herein, the deposition apparatus 400 according to embodiments described herein, and the method 500 of measuring a deposition rate according to embodiments described herein.

[0055] With exemplary reference to the block diagram shown in FIG. 10, a method 700 of retrofitting a deposition source is described. The method 700 includes providing (represented by block 701 in FIG. 10) the deposition source with a measurement assembly 100 according to any embodiments described herein. Accordingly, beneficially existing deposition sources can be as described herein.

[0056] In view of the embodiments described herein, it is to be understood that compared to the state of the art, an improved measurement assembly for measuring a deposition rate of evaporated material and an improved method of measuring a deposition rate are provided. Further, an improved deposition rate sensor unit, an improved deposition source, and an improved deposition apparatus are provided. In particular as described herein, with embodiments of the present disclosure, problems associated with measuring deposition rates by using QCMs are at least partially or even completely overcome. More specifically, embodiments of the present disclosure provide for increased saturation times, less signal losses, high repeatability and more stable readings. Further, compared to the slate of the art, the number of parts and spare parts are less and easier to replace in embodiments described herein. Moreover, embodiments of the present disclosure provide for a reduction of overall costs as well as a reduction of production downtime compared to the state of the art.

[0057] This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any apparatus or system and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

[0058] While the foregoing is directed to embodiments, other and further embodiments may be devised without departing from the basic scope, and the scope is determined by the claims that follow.