KR20210121131A - A method for cleaning a vacuum system, a method for vacuum processing of a substrate, and an apparatus for vacuum processing a substrate - Google Patents

Abstract

A method for cleaning a vacuum chamber, in particular a vacuum chamber used in the manufacture of OLED devices, is described. The method comprises cleaning the interior of the vacuum chamber and at least one of the components inside the vacuum chamber with the active species at a pressure of ^{5*10 -3} mbar or less, in particular 1*10 ^{-4 mbar or less.}

Description

A method for cleaning a vacuum system, a method for vacuum processing of a substrate, and an apparatus for vacuum processing a substrate

[0001] Embodiments of the present disclosure relate to a method for cleaning a vacuum system, a method for vacuum processing a substrate, and an apparatus for vacuum processing a substrate. Embodiments of the present disclosure relate, inter alia, to methods and apparatuses used in the manufacture of organic light-emitting diode (OLED) devices.

Techniques for layer deposition on a substrate include, for example, thermal evaporation, physical vapor deposition (PVD), and chemical vapor deposition (CVD). Coated substrates can be used in several applications and in several technical fields. For example, coated substrates may be used in the field of organic light emitting diode (OLED) devices. OLEDs can be used in the manufacture of television screens for displaying information, computer monitors, mobile phones, other hand-held devices, and the like. An OLED device, such as an OLED display, may include one or more layers of organic material positioned between two electrodes that are deposited on a substrate.

OLED devices may include, for example, a stack of several organic materials that are evaporated in a vacuum chamber of a processing apparatus. Vacuum conditions inside the vacuum chamber and contamination inside the vacuum chamber affect the deposited material layers and the quality of OLED devices fabricated using these material layers.

[0004] For example, OLED device lifetime is affected by organic contaminants. Contamination may result from parts and materials used inside the vacuum and/or from cross-contamination during maintenance. Cleaning before or during production, ie removal of contamination, enables stable, high-quality production of OLED devices.

The duration or time for adequate cleaning (preventive maintenance (PM) restoration) to reach contamination levels suitable for production is an important resource. For the owner of a production system, every moment of tool downtime is costly. Thus, increasing cleaning efficiency and reducing cleaning time reduces production costs.

[0006] According to common practice, for example, the concentration of active species in plasma cleaning is increased by using higher vacuum levels, ie pressures close to atmospheric pressure. Further, for example document WO2018/197008 relates to pre-cleaning and remote plasma cleaning for cleaning at least part of a vacuum system. Plasma cleaning may be performed under vacuum. For example, the pressure may be 10 ^-2 mbar or less. Additionally, it is disclosed that for remote plasma cleaning the pressure can be in the range of ^{10 -2 mbar to 10 mbar.} It is beneficial to further improve the cleaning efficiency.

[0007] Accordingly, there is a need for a method and apparatus capable of improving the cleaning of the vacuum chamber and the vacuum conditions inside the vacuum chamber. The present disclosure specifically aims to reduce contamination so that the quality of layers of organic material deposited on a substrate can be improved.

[0008] In view of the above, a method for cleaning a vacuum chamber, in particular a method for cleaning a vacuum system used in the manufacture of OLED devices, a method for vacuum processing a substrate, and in particular a method for manufacturing OLED devices An apparatus for vacuum processing a substrate is provided. Additional aspects, advantages, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings.

According to one embodiment, there is provided a method for cleaning a vacuum chamber, in particular a vacuum chamber used in the manufacture of OLED devices. The method comprises cleaning at least one of a surface of the vacuum chamber and a component inside the vacuum chamber with the active species at a pressure of ^{5*10 -3} mbar or less, in particular 1*10 ^{-4 mbar or less.}

According to one embodiment, there is provided a method for cleaning a vacuum chamber, particularly a vacuum chamber used in the manufacture of OLED devices. The method includes determining an average distance of walls of a vacuum chamber; and cleaning at least one of the surfaces of the walls of the vacuum chamber and a component within the vacuum chamber with the active species at a pressure corresponding to an average free path length of 20% to 97% of the average distance of the walls.

According to one embodiment, there is provided a method for cleaning a vacuum chamber, in particular a vacuum chamber used in the manufacture of OLED devices. The method includes igniting a remote plasma source at a first pressure while the vacuum chamber has a second pressure less than a first pressure in the remote plasma source; and varying the pressure in the remote plasma source to a third pressure equal to or greater than the second pressure.

According to one embodiment, a method for cleaning a vacuum system having a first vacuum chamber and a second vacuum chamber is provided. The method comprises: cleaning a first vacuum chamber with an active species at a first pressure of less than 1 mbar; and cleaning the second vacuum chamber with the active species at a second pressure of less than 1 mbar different from the first pressure.

According to one embodiment, a method is provided for vacuum processing a substrate to fabricate OLED devices. The method includes a method for cleaning in accordance with any of the embodiments described herein, and depositing one or more layers of an organic material on a substrate.

According to one embodiment, there is provided an apparatus for vacuum processing a substrate, in particular for manufacturing OLED devices. The apparatus comprises: a vacuum chamber; a remote plasma source coupled to the vacuum chamber, the remote plasma source having a process gas inlet, a conduit to the active species, and a process gas outlet; and a valve between the vacuum chamber and the remote plasma source positioned to open or close the conduit.

According to one embodiment, there is provided an apparatus for vacuum processing a substrate, in particular for manufacturing OLED devices. The apparatus includes a controller including a processor and a memory, the memory storing instructions that, when executed by the processor, cause the apparatus to perform a method according to embodiments of the present disclosure.

[0016] In such a way that the above-mentioned features of the present disclosure may be understood in detail, a more specific description of the disclosure briefly summarized above may be made with reference to embodiments. The accompanying drawings relate to embodiments of the present disclosure and are described below.
1A and 1B show flow diagrams of methods for cleaning a vacuum system used in the manufacture of OLED devices, in accordance with embodiments described herein.
2 shows a flow diagram of a method for vacuum processing of a substrate for manufacturing OLED devices, in accordance with embodiments described herein.
3 shows a schematic diagram of a system for vacuum processing a substrate to fabricate OLED devices, in accordance with embodiments described herein.
4 shows a schematic diagram of an apparatus for cleaning a vacuum chamber, according to embodiments described herein;
5 shows a flow diagram of a method for cleaning a vacuum system used in the manufacture of OLED devices, in accordance with embodiments described herein.
6 shows a graph comparing the cleaning efficiency of a standard cleaning process to that of a process according to embodiments of the present disclosure.

Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are illustrated in the drawings. Within the following description of the drawings, like reference numbers refer to like components. In general, only differences to individual embodiments are described. Each example is provided by way of explanation of the present disclosure, and is not meant to be limiting of the present disclosure. Additionally, features illustrated or described as part of one embodiment may be used with or with other embodiments to yield a still further embodiment. It is intended that the description cover such modifications and variations.

[0018] The vacuum conditions inside the vacuum chamber and the amount of contaminants, particularly organic contaminants, can greatly affect the quality of the material layers deposited on the substrate. In particular, for OLED mass production, the cleanliness of vacuum components greatly affects the lifetime of the manufactured device. Even electro-polished surfaces can still be too dirty for OLED device fabrication. Some embodiments of the present disclosure use plasma cleaning for vacuum cleaning, such as using a remote plasma source. For example, vacuum cleaning may be provided after a pre-clean procedure, such as as a final cleaning procedure for the vacuum system. Embodiments of the present disclosure relate to ultra clean vacuum (UCV) cleaning.

For example, plasma cleaning may be used to process parts or components of a vacuum chamber and/or vacuum system. For example, plasma cleaning may be performed under vacuum prior to process start or production start to improve cleanliness levels. The treatment may be carried out for a specified time period, for example, using a remote plasma of pure oxygen or oxygen mixtures with nitrogen or argon. Additionally or alternatively, hydrogen or hydrogen mixtures may be used.

According to embodiments of the present disclosure, the cleaning process uses very low vacuum levels. Very low vacuum levels can significantly increase cleaning efficiency, especially for large volume vacuum chambers. In contrast to the industry-standard for using higher vacuum levels to produce higher active species concentrations, the inventors of the present invention have developed the methods described herein to increase cleaning efficiency, as described in more detail below. It has been found that very low vacuum levels can be used as described above.

According to some embodiments of the present disclosure, there is provided a method for cleaning a vacuum chamber, particularly a vacuum chamber used in the manufacture of OLED devices. The method comprises cleaning the interior of the vacuum chamber and at least one of the components inside the vacuum chamber with the active species at a pressure of ^{5*10 -3} mbar or less, in particular 1*10 ^{-4 mbar or less.}

[0022] The cleanliness of the chamber or surface may be determined, for example, by contact angle measurement. As exemplarily shown in FIG. 6 , the dotted curve shows the cleaning efficiency of a standard cleaning process. For example, the contact angle may be reduced slightly to less than 10 within a time period of slightly greater than 70 hours. The solid line shows a cleaning process according to embodiments of the present invention. For example, a near-zero contact angle measured by vacuum exposure of a (110) silicon substrate can be reached in a very short time, such as in 10 hours or less or even 5 hours or less. The contact angle can be measured on a pre-cleaned (110) silicon substrate with a vacuum exposure of 16 hours in the cleaned chamber. The cleaning efficiency can be increased by at least a factor of ten or even several times of ten.

[0023] Compared to conventional cleaning strategies used in the OLED industry, such as “bake-out under vacuum,” embodiments of the present disclosure reduce and/or remove organic contaminants inside a vacuum chamber. To do so, it is not based on elevated temperatures. Bake-out is not a beneficial option, especially when having temperature-sensitive components, such as electronics, inside the system. Moreover, the use of active species according to embodiments of the present disclosure shows a cleaning efficiency several orders of magnitude higher compared to conventional strategies, and in particular also without a bake-out procedure.

[0024] According to embodiments of the present disclosure, an active species is released into or provided within the vacuum chamber, eg, to clean surfaces within the chamber. In-situ cleaning principles, such as cleaning the walls of a vacuum chamber and components within the vacuum chamber, can be very effective in cleaning microlayers, such as some monolayers. According to embodiments of the present disclosure, which may be combined with other embodiments described herein, the active species may be a chemically active species, such as excited molecules or atoms, for example to dissociate contaminating molecules. have.

[0025] A cleaning method according to embodiments of the present disclosure includes the creation of excited states of molecules, such as oxygen. Accordingly, reactive O, O3 and/or other active species may be provided. For example, the active species may be generated using plasma, particularly at a remote plasma source.

[0026] Some embodiments of the present disclosure may be further described in terms of a distribution strategy of active species within a vacuum chamber to be cleaned. In contrast to the strategy of industry-standard cleaning processes based on maximizing the number of active species for the cleaning process, embodiments of the present disclosure reduce the number of active species participating in the cleaning process. However, the efficiency of the active species is increased by changing the distribution of the active species within the vacuum chamber.

[0027] At each collision, plasma molecules (eg, O) may collapse into a steady state _{of O 2 .} O ₂ is non-reactive. Lower pressure results in lower densities and, therefore, reduced initial active species concentration. However, lower pressure increases the mean free path length of the excited molecules.

[0028] For example, the mean free path length can be calculated as follows:

[0029] The resulting values may be, for example ^{, about 6 m at 10 -3} Pa and correspondingly 6 mm at 1 Pa.

As explained above, the lifetime of chemically active species is limited. For example, due to each collision with other molecules in the vacuum, chamber walls, or surfaces of components, there is a probability that the active species will recombine with non-reactive molecules. At high pressures, for example above 1 mbar, the amount of atoms per volume is high. In addition, the average free path length, ie the average distance between collisions, is short. Thus, even if the initial concentration of the generated active species is high, the probability of reaching the distant surface of the large chamber is small.

[0031] Embodiments of the present disclosure as described herein utilize low pressure, which results in longer mean free path lengths of the active species. The mean free path length can be adjusted by varying the chamber pressure. The scattering properties continue to change from atom-atom (or molecule-molecular) collisions to atom-wall collisions (ie, line-of-sight scattering) when the chamber pressure is reduced.

For OLED chambers, an average wall-to-wall distance of 3 m can be provided. Therefore, the mean free path length of the active species can be less than 3 m to ensure a homogeneous distribution through scattering. Additionally, the mean free path length may be greater than or equal to 0.5 m to have good reach in the chamber. For example, according to some embodiments that may be combined with other embodiments described herein, ^{a base pressure of, for example, greater than or equal to 5*10 -5} mbar and/or ^{less than or equal to 9*10 -5} mbar may be provided. The average wall-to-wall distance or the average distance of walls may be defined, for example, as follows. A vacuum chamber typically has a bottom wall and a top wall having a vertical distance. Additionally, the vacuum chamber typically has two opposing sidewalls having a first horizontal distance and additional two opposing sidewalls having a second horizontal distance. For example, the average distance of the walls may be an average from a vertical distance, a first horizontal distance, and a second horizontal distance. The above refers to a rectangular parallelepiped-shaped vacuum chamber by way of example. For cylindrical chambers or chambers with trapezoidal cross-section, the average distance can be calculated in a similar way.

According to some embodiments, which may be combined with other embodiments described herein, a method is provided for cleaning a vacuum chamber, particularly a vacuum chamber used in the manufacture of OLED devices. The method includes determining an average distance of walls of a vacuum chamber; and cleaning at least one of the surfaces of the walls of the vacuum chamber and a component within the vacuum chamber with the active species at a pressure corresponding to an average free path length of 20% to 97% of the average distance of the walls.

1A shows a flow diagram of a method 100 , for example, for cleaning a vacuum system used in the manufacture of OLED devices according to embodiments described herein.

[0035] Method 100 includes cleaning with an active species at low pressures (block 110). For example, the active species may be generated using a plasma source, such as a remote plasma source and/or UV light. Plasma cleaning may be, for example, a final cleaning procedure prior to operating the vacuum system to deposit one or more layers of organic materials on a substrate, or may be a cleaning procedure during operation, such as at idle times. The term “final” should be understood to mean that no further cleaning procedures are performed after plasma cleaning.

[0036] In a remote plasma source, a gas such as a process gas is typically activated in a remote chamber remote from the vacuum chamber in which the cleaning process is to be performed. Such activation may be performed, for example, at a remote plasma source. Examples of remote plasmas used in embodiments of the present disclosure include, but are not limited to, remote plasmas of pure oxygen or nitrogen or mixtures of argon and oxygen.

[0037] Pre-clean to clean at least a portion of the vacuum system and plasma cleaning, such as using a remote plasma source to clean at least a portion of the vacuum system, may be used for the various components of the vacuum system. In some implementations, the pre-clean and plasma cleaning each include cleaning of a vacuum chamber. For example, cleaning each includes cleaning of one or more inner walls of the vacuum chamber. Additionally or alternatively, cleaning may include cleaning of one or more components within a vacuum chamber of the vacuum system. The one or more components may be selected from the group consisting of mechanical components, movable components, drives, valves, and any combination thereof. For example, the mechanical components may be any components provided inside a vacuum chamber, such as movable components used to operate a vacuum system. Exemplary movable components include, but are not limited to, valves such as gate valves. Drives include drives used for transport of substrates and/or carriers in a vacuum system, drives or actuators for substrate and/or mask alignment, valves separating adjacent vacuum zones or chambers, such as a gate drives for valves, and the like.

[0038] According to some embodiments that may be combined with other embodiments described herein, a method for cleaning, such as method 100, is performed after a maintenance procedure of a vacuum system or parts of a vacuum system. In particular, post-maintenance pre-cleaning, such as wet cleaning, may not be sufficient to achieve adequate cleanliness levels for OLED mass production. A cleaning procedure after pre-cleaning, ie, plasma cleaning, can ensure cleanliness levels that can improve the quality of layers of organic materials deposited during a deposition process, such as a thermal evaporation process. Plasma cleaning can also be used to prevent recontamination caused by outgassing of polymers (o-rings, cables, etc.) during production or system idle time.

[0039] The term “maintenance procedure” may be understood to mean that the vacuum system is not operated so that it can perform various tasks such as servicing and/or initial installation of the vacuum system or parts of the vacuum system. . The maintenance procedure may be performed periodically, for example at predetermined service intervals.

[0040] In some implementations, the cleaning is selected from the group consisting of a load lock chamber, a cleaning chamber, a vacuum deposition chamber, a vacuum processing chamber, a transfer chamber, a routing module, and any combination thereof. in one or more (vacuum) chambers of

As described above, embodiments of the present disclosure refer to a cleaning process at low pressures, particularly low pressures that may be adapted to the size and optionally geometry of the vacuum chamber to be cleaned. Display manufacturing, such as manufacturing of OLED displays, is performed on large area substrates. For example, the size of the substrate may be 0.67 m ² or more, such as 1 m ^{2 or} more.

[0042] The systems described herein can be used, for example, for evaporation on large area substrates for OLED display manufacturing. Specifically, substrates on which systems according to embodiments described herein are provided are large area substrates. For example, the large area substrate or carrier may have a GEN 4.5 corresponding to a surface area of ^{about 0.67 m 2 (0.73×0.92 m), a GEN 5 corresponding to a surface area of about 1.4 m 2} (1.1 m×1.3 m), and a GEN 5 corresponding to a surface area of about 2.7 m ² ( GEN 6 corresponding to a surface area of 1.5 m × 1.8 m), ^{GEN 7.5 corresponding to a surface area of approximately 4.29 m 2} (1.95 m × 2.2 m), and GEN corresponding to a surface area of approximately 5.7 m ² (2.2 m × 2.5 m) 8.5, or even GEN 10, corresponding to a surface area of ^{about 8.7 m 2 (2.85 m×3.05 m).} Even larger generations, such as GEN 11 and GEN 12 and corresponding surface areas, can be implemented similarly. Half sizes of GEN generations can also be offered in OLED display manufacturing.

[0043] According to embodiments of the present disclosure, depending on the size of the chamber, improved pressure levels for cleaning with active species can be provided. Thus, lower pressures can be advantageously used for larger chambers. For smaller chambers, the pressure may be higher corresponding to a shorter mean free path length.

[0044] According to still further embodiments, which may be combined with other embodiments described herein, the inventors' findings, such as wafer processing or wafer inspection, similarly apply to vacuum chambers in the semiconductor industry. It may be possible. As the chambers can typically be smaller, the pressures can be higher. In particular, embodiments that refer to optimizing the mean free path length according to the mean chamber wall distance are applicable for smaller vacuum chambers. Additionally, additionally or alternatively, improvement or optimization of additional cleaning parameters may similarly be applied to semiconductor fabrication.

FIG. 1B shows a flow diagram of a method 100 , for example, for cleaning a vacuum system used in the manufacture of OLED devices according to embodiments described herein.

[0046] The method 100 includes determining an average distance of the walls of the vacuum chamber as described above (block 120), and performing a cleaning with the active species at low pressures (block 110). )) is included. A low pressure corresponds to an average free path length of 20% to 97% of the average distance of the walls.

Yet further additional embodiments that may optionally be combined with other embodiments described herein are adaptive process used for cleaning conditions at low pressures, eg, as described herein. refer to parameters.

[0048] In particular, for the manufacture of OLED devices, the quality of the vacuum in the vacuum chamber and the contamination in the vacuum chamber greatly affect device performance. In particular, the lifetime of manufacturing devices can be dramatically reduced by contamination. Accordingly, the surfaces inside the vacuum chambers require frequent cleaning. Processing chambers, fabrication chambers, transfer chambers, transfer chambers, storage chambers, and assembly chambers are susceptible to contamination. Human interaction with the inner surfaces of such chambers introduces organic and inorganic contaminants that are absorbed by the surfaces of the chambers and/or surfaces of the components.

Although wet cleaning processes of interior surfaces by human operators can be time-consuming and labor-intensive, wet cleaning is beneficial in removing micro-contaminants such as solvent received use, particles, etc. . Additionally, human operators may introduce additional organic contaminants into the system, and some services may not be efficiently reached by human operators.

[0050] According to embodiments of the present disclosure, a wet cleaning process may be introduced to remove microcontaminants. An in-situ cleaning process may be provided following a wet cleaning process or other pre-clean process according to embodiments described herein.

As described above, reduced pressure, which determines the mean free path length of active species, is one parameter for improving cleaning efficiency. The pressure determines the concentration of active species reaching the contaminated surfaces, eg the concentration of active species responsible for cleaning efficiency. The active species may be a fraction of the total process gas in the vacuum chamber. By setting the chamber pressure and thus the mean free path length, given a constant pumping rate, the number of active species reaching the contaminated surfaces is defined. By increasing the pumping rate, the operating pressure (and mean free passage) can be maintained when increasing the inlet flow.

According to some embodiments that may be combined with other embodiments described herein, the inlet flow may be increased without reducing the activation efficiency of the plasma.

FIG. 2 shows a flow diagram of a method 200 for vacuum deposition on a substrate for manufacturing OLED devices, display devices, or semiconductor devices. The method may be particularly useful for OLED devices given their sensitivity to organic contaminants. Method 200 may include, for example, aspects of a method for cleaning a vacuum system used in the manufacture of OLED devices according to the present disclosure.

[0054] The method 200 performs cleaning at least a portion of a vacuum system (block 110), and depositing one or more layers of a material, such as an organic material, on a substrate (block 210). including the steps of

Plasma cleaning according to embodiments of the present disclosure can significantly improve the cleanliness level and/or cleaning efficiency of a vacuum system. Plasma cleaning can result in near-zero contact angles in 5 hours or less from cleaning to vacuum chambers for large area substrates. The contact angle can be measured on a pre-cleaned (110) silicon substrate with a vacuum exposure of 16 hours in the cleaned chamber.

3 shows a portion of a processing system 300 for vacuum deposition on a substrate, such as for manufacturing OLED devices, according to embodiments described herein.

In FIG. 3 , the process modules 310 are coupled to the routing module 320 . The maintenance module 340 may be coupled to the process module. Transport module 330 provides a route along a transport direction from a first routing module to a second routing module (not shown). Each of the modules may have one or more vacuum chambers. Additionally, the transport module may provide two or more tracks, such as four transport tracks 352 , where the carrier may be moved from one of the routing modules. As shown in FIG. 3 , the transport direction along the routing module and/or transport module may be a first direction. Additional routing modules may be coupled to additional process modules (not shown). 3 , gate valves 305 may be provided along a first direction between neighboring modules or vacuum chambers, respectively, eg between a transport module and an adjacent routing module and along a second direction, respectively. can The gate valves 305 may be closed or open to provide a vacuum seal between the vacuum chambers. The presence of the gate valve may depend on the application of the processing system, eg, the type, number and/or sequence of layers of organic material deposited on the substrate. Accordingly, one or more gate valves may be provided between the transfer chambers.

According to typical embodiments, the first transport track 352 and the second transport track 352 are configured for contactless transport of a substrate carrier and/or a mask carrier to reduce contamination in vacuum chambers. . In particular, the first transport track and the second transport track may comprise a drive structure and holding assembly configured for contactless translation of the substrate carrier and/or the mask carrier.

As illustrated in FIG. 3 , in the first routing module 320 , two substrates 301 are rotated. The two transport tracks on which the substrates are positioned are rotated to align in the first direction. Thus, the two substrates on the transport tracks are provided in a position to be transported to the transport module and an adjacent additional routing module.

According to some embodiments that may be combined with other embodiments described herein, the transport tracks of the transport track arrangement may extend from the vacuum process chamber into the vacuum routing chamber, ie, different from the first direction. It may be oriented in a second direction. Accordingly, one or more of the substrates may be transferred from the vacuum process chamber to an adjacent vacuum routing chamber. Additionally, as illustratively shown in FIG. 3 , a gate valve 305 that may be opened for transport of one or more substrates may be provided between the process module and the routing module. Accordingly, it should be understood that the substrate may be transferred from the first process module to the first routing module, from the first routing module to the additional routing module, and from the additional routing module to the additional process module. Accordingly, several processes, such as the deposition of various layers of organic material on a substrate, can be performed without exposing the substrate to an undesired environment, such as an atmospheric environment or a non-vacuum environment.

3 further illustrates the masks 303 and substrates 301 within the process module 310 . A deposition source 309 may be provided between the masks and/or substrates, respectively.

Each vacuum chamber of the modules shown in FIG. 3 includes a remote plasma source 350 . For example, a remote plasma source may be mounted to the chamber wall of the vacuum chamber. Illustratively, the chamber wall may be an upper chamber wall. Although the processing system 300 shows vacuum chambers with remote plasma sources in each chamber, the processing system may include at least one remote plasma source 350 . In particular, the processing system 300 may include a first vacuum chamber having a first remote plasma source 350 and a second vacuum chamber having a second remote plasma source 350 .

For example, the remote plasma source 350 of the process module 310 is coupled to the vacuum chamber. A controller coupled to the remote plasma source is configured to perform plasma cleaning in accordance with embodiments of the present disclosure. In particular, the controller may be configured to implement, for example, a method for cleaning a vacuum system or vacuum chamber used in the manufacture of the OLED devices of the present disclosure. An exemplary vacuum chamber with a remote plasma source is described in greater detail with respect to FIG. 4 .

[0064] One or more vacuum pumps, such as turbopumps and/or cryo-pumps, for creating a technical vacuum inside the vacuum chamber, for example one or more tubes, such as bellow tubes through the vacuum chamber. The controller may further be configured to control one or more vacuum pumps, such as to reduce the pressure in the vacuum chamber prior to the plasma cleaning procedure.

[0065] The term “vacuum” as used throughout the present disclosure may be understood to mean a technical vacuum having, for example, a vacuum pressure of less than 10 mbar. The pressure in the vacuum chamber may be from 10 ^-3 mbar to about 10 ^-7 mbar, specifically from 10 ^-4 mbar to 10 ^-5 mbar, especially for vacuum chambers for processing large area substrates.

As shown in FIG. 3 , the vacuum processing system 300 may have a plurality of different modules. Each module may have at least one vacuum chamber. Vacuum chambers may be of different sizes and geometries. As described above, according to some embodiments of the present disclosure, which may be combined with other embodiments described herein, the cleaning efficiency of cleaning with an active species is determined by determining the mean free path length as the size of the vacuum chamber. and by adapting the geometry. A good compromise can be determined between atomic-atom collisions to increase the homogeneity of the distribution of the active species in the vacuum chamber, ie atomic-wall collisions with sufficient reach of the active species in the chamber. Choosing a beneficial trade-off between different scattering mechanisms greatly increases cleaning efficiency.

Thus, according to some embodiments, the pressure in the vacuum chamber during cleaning with the active species may be individually adapted for two or more vacuum chambers in the vacuum processing system. The mean free path length is improved or optimized for individual chamber sizes and/or chamber geometries. According to one embodiment, a method for cleaning a vacuum system having a first vacuum chamber and a second vacuum chamber is provided. The method includes cleaning the first vacuum chamber with the active species at a first pressure of less than 1 mbar, and cleaning the second vacuum chamber with the active species at a second pressure of less than 1 mbar different from the first pressure. including the steps of

[0068] According to embodiments of the present disclosure, cleaning with, for example, an active species of a remote plasma source can be very efficient. A typical remote plasma source has a pressure range for ignition of the source. For example, ignition of a remote plasma source is possible at a pressure of at least 0.05 mbar, such as between 0.1 mbar and 1.5 mbar. A remote plasma source, and thus a volume in which active species are generated within the remote plasma source, is coupled to the vacuum chamber. Accordingly, the chamber pressure of the vacuum chamber can be raised to the ignition pressure of the remote plasma source, which is connected to the vacuum chamber after ignition, and cleaning conditions with reduced pressures are created. Pumping the vacuum chamber takes additional time and can limit cleaning applications to times immediately following preventive maintenance. A cleaning procedure that does not increase the chamber pressure of the vacuum chamber to be cleaned will allow more frequent cleaning. Embodiments illustratively described with respect to FIG. 4 below allow for a highly efficient cleaning process even during short interruptions or idle times. Thus, during production, control of recontamination and overall level of contamination can be provided. Consistent high quality OLED devices can be ensured. Accordingly, embodiments described herein also allow for efficient cleaning of contamination, as idle times during short interruptions can be used for remote plasma cleaning.

4 shows an apparatus 400 for vacuum processing a substrate. For example, the substrate may be a large area substrate or a semiconductor industrial wafer as described herein. In particular, the apparatus for vacuum processing may be configured for or included in a processing system for manufacturing OLED devices. The apparatus includes a vacuum chamber 410 . The vacuum chamber 410 may be evacuated using a vacuum pump 420 . In particular, for OLED processes, the vacuum pump may be a cryopump. A remote plasma source 350 is coupled to the vacuum chamber 410 . According to some embodiments, a remote plasma source may be coupled to an upper wall of the vacuum chamber.

The remote plasma source 350 includes an enclosure 450 in which plasma is generated and a plasma generator 451 . For the production of active species, a process gas inlet 452 is provided in the enclosure 450 . During operation, a process gas, such as an oxygen containing process gas or a hydrogen containing process gas, may be provided to the remote plasma source via the process gas inlet 452 . For example, the process gas may include oxygen and at least one of nitrogen and argon. A valve 455 may be provided between the remote plasma source 350 and the vacuum chamber 410 . For example, valve 455 may be included in flange 453 connecting remote plasma source 350 with vacuum chamber 410 .

The valve 455 allows having different pressures in the vacuum chamber 410 and the enclosure 450 of the remote plasma source 350 . Thus, the remote plasma source 350 may be ignited at a relatively high pressure while the vacuum chamber 410 is maintained at a relatively low pressure. In accordance with some embodiments that may be combined with other embodiments described herein, a bypass for valve 455 is provided. The bypass 456 allows fluid communication between the enclosure 450 and the vacuum chamber 410 . With valve 455 in the closed position, process gas flow through process gas inlet 452 will change the pressure within enclosure 450 without having an outlet for incoming process gas flow. The size of the bypass allows for differential pumping between the enclosure 450 and the vacuum chamber 410 .

Thus, in accordance with embodiments described herein, a process gas outlet is advantageously provided in addition to the conduit 457 connecting the remote plasma source and the vacuum chamber. The process gas outlet may be a bypass 456 . According to additional or alternative modifications that may be combined with other embodiments described herein, the process gas outlet may also be a pump 425 coupled to a remote plasma source. A process gas outlet in addition to conduit 457 allows creating stable ignition conditions for the remote plasma source. After ignition of the remote plasma source, valve 455 in conduit 457 may be opened. The active species may be provided to the vacuum chamber 410 from the enclosure of a remote plasma source. Conduit 457 may be an additional portion of flange 453 .

[0073] Some embodiments of the present disclosure use bypass to create ignition conditions in a remote plasma source with little effect on chamber pressure. After opening a corresponding, eg, associated, bypass valve, improved cleaning conditions according to embodiments of the present disclosure can be reached almost immediately.

[0074] A remote plasma source (RPS) is connected to the vacuum chamber using a flange. A valve capable of isolating the vacuum chamber and the remote plasma source unit, such as a pendulum valve, may be incorporated into the flange. According to some embodiments that may be combined with other embodiments described herein, for example, a small tube with a variable orifice is attached to the top of the flange (RPS side) and the bottom of the flange (chamber side). A small tube bypasses the valve.

[0075] For ignition of the plasma inside the RPS unit, the valve is closed and the inlet flow is streamed into the RPS unit. A small bypass ensures a constant pressure inside the plasma unit for ignition. After the plasma has stabilized, the valve may be opened. Active species generated by the plasma inside the remote plasma source can migrate directly into the chamber for cleaning.

[0076] In view of the above, according to one embodiment, there is provided an apparatus for vacuum processing of a substrate, particularly for manufacturing OLED devices. The apparatus includes a vacuum chamber and a remote plasma source coupled to the vacuum chamber. The remote plasma source has a process gas inlet, a conduit to the active species, and a process gas outlet. For example, a conduit may connect the enclosure of a remote plasma source and a vacuum chamber. A process gas outlet and conduit may be included in the flange of the remote plasma source. The apparatus further includes a valve between the vacuum chamber and the remote plasma source positioned to open or close the conduit. According to some embodiments, the apparatus may further include a bypass for a conduit connecting the process gas outlet and the vacuum chamber.

4 shows a controller 490 . A controller 490 is coupled to a vacuum pump 420 and a remote plasma source 350 . The controller 490 may include a central processing unit (CPU), memory, and, for example, support circuits. To facilitate control of an apparatus for processing a substrate, the CPU may be one of any type of general-purpose computer processor that may be used in an industrial setting to control various chambers and sub-processors. The memory is coupled to the CPU. The memory or computer-readable medium may be one or more readily available memory devices, such as random access memory, read-only memory, floppy disk, hard disk, or any other form of digital storage, either local or remote. . Support circuits may be coupled to the CPU to support the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry and related subsystems, and the like. Inspection process instructions, and/or instructions for creating a notch in an electronic device provided on a substrate, are generally stored in memory as a software routine commonly known as a recipe. The software routines may also be stored and/or executed by a second CPU (not shown) located remotely from hardware controlled by the CPU. The software routines, when executed by the CPU, transform the general purpose computer into a special purpose computer (controller) that controls device operations, such as controlling the vacuum pump 420 and remote plasma source 350 in particular. Although the methods and/or processes of this disclosure are discussed as being implemented as software routines, some of the method steps disclosed herein may be performed in hardware as well as by a software controller. Thus, embodiments may be implemented in software running on a computer system, and in hardware as an application specific integrated circuit or other type of hardware implementation, or in a combination of software and hardware. The controller may execute or perform a method for processing a substrate and/or cleaning a vacuum chamber, such as for display manufacturing in accordance with embodiments of the present disclosure.

[0078] According to embodiments described herein, a method for vacuum processing of a substrate may be performed using computer programs, software, computer software products and interrelated controllers, the controllers including a CPU, a memory , a user interface, and input and output devices that communicate with corresponding components of the apparatus.

FIG. 5 shows a flow diagram illustrating additional methods 500 in accordance with embodiments described herein. The method 500 is for cleaning a vacuum chamber, particularly a vacuum chamber used in the manufacture of OLED devices. The method includes igniting the remote plasma source at a first pressure (see block 510 ) while the vacuum chamber has a second pressure lower than the first pressure in the remote plasma source. The method further includes varying the pressure in the remote plasma source to a third pressure equal to or higher than the second pressure, such as slightly higher (see block 520 ). For example, some methods that may be combined with other methods described herein include igniting a remote plasma source at a first pressure, and at least 10 times less than the first pressure, particularly at least 1000 times less than the first pressure. reducing the pressure in the remote plasma source to a smaller second pressure.

[0080] While the foregoing relates to embodiments of the present disclosure, other and additional embodiments of the disclosure may be devised without departing from the basic scope of the disclosure, the scope of which is to follow determined by the claims.

Claims (16)

A method for cleaning a vacuum chamber, in particular a vacuum chamber used in the manufacture of OLED devices, comprising:
a vacuum chamber comprising cleaning at least one of a surface of the vacuum chamber and a component inside the vacuum chamber with an active species at a pressure of 5*10 ^-3 mbar or less, in particular 1*10 ^{-4 mbar or less} method for cleaning. According to claim 1,
wherein the active species is generated using a remote plasma source. 3. The method of claim 2,
igniting the remote plasma source at a first pressure; and
reducing the pressure in the remote plasma source to a second pressure that is at least 10 times less than the first pressure, in particular at least 1000 times less than the first pressure. 4. The method of claim 3,
Plasma cleaning comprises cleaning one or more inner walls of the vacuum chamber. 5. The method according to any one of claims 1 to 4,
wherein the process gas for generating the active species comprises oxygen. 6. The method of claim 5,
The process gas for producing the active species comprises at least 90 Vol.-% oxygen and at least 2 Vol.-% argon, in particular the process gas comprises about Vol.-95% oxygen and about Vol.-5% argon. A method for cleaning a vacuum chamber comprising: 7. The method according to any one of claims 1 to 6,
wherein the method is performed after a maintenance procedure of a vacuum system or parts of the vacuum system. A method for cleaning a vacuum chamber, in particular a vacuum chamber used in the manufacture of OLED devices, comprising:
determining an average distance of the walls of the vacuum chamber; and
cleaning at least one of a surface of the vacuum chamber and a component inside the vacuum chamber with an active species at a pressure corresponding to an average free path length of at least 20% and in particular no more than 97% of the average distance of the walls; A method for cleaning a vacuum chamber. 9. The method of claim 8,
wherein the active species is generated using a remote plasma source. A method for cleaning a vacuum chamber, in particular a vacuum chamber used in the manufacture of OLED devices, comprising:
igniting the remote plasma source at the first pressure while the vacuum chamber has a second pressure lower than the first pressure in the remote plasma source; and
reducing the pressure in the remote plasma source to a third pressure equal to or greater than the second pressure. A method for cleaning a vacuum system having a first vacuum chamber and a second vacuum chamber, the method comprising:
cleaning the first vacuum chamber with an active species at a first pressure of less than 1 mbar; and
cleaning the second vacuum chamber with an active species at a second pressure of less than 1 mbar different from the first pressure. A method for vacuum processing a substrate to fabricate OLED devices, comprising:
12. A method for cleaning according to any one of claims 1 to 11; and
and depositing one or more layers of organic material on the substrate. In particular, an apparatus for vacuum processing a substrate for manufacturing OLED devices, comprising:
vacuum chamber;
a remote plasma source coupled to the vacuum chamber, the remote plasma source having a process gas inlet, a conduit for active species, and a process gas outlet; and
and a valve between the vacuum chamber and the remote plasma source positioned to open or close the conduit. 14. The method of claim 13,
and a bypass to the conduit connecting the process gas outlet and the vacuum chamber. 15. The method of claim 13 or 14,
Further comprising a controller comprising a processor and memory,
wherein the memory stores instructions that, when executed by the processor, cause the apparatus to perform a method according to any one of claims 1 to 13. In particular, an apparatus for vacuum processing a substrate for manufacturing OLED devices, comprising:
A controller comprising a processor and memory;
wherein the memory stores instructions that, when executed by the processor, cause the apparatus to perform a method according to any one of claims 1 to 13.

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