Device and method for cleaning and testing the cleanliness of cavities in hollow structural components; lithography system

Abstract

The invention relates to a device (1) for cleaning and testing the cleanliness of at least one hollow component (2) having a cavity (2a), comprising a housing (3) configured to create a cleanroom environment within the housing (3), and comprising a rinsing medium and a piping system (4) for conveying the rinsing medium. The piping system (4) is configured to accommodate the hollow component (2) and to allow the rinsing medium to flow in a rinsing direction from an inlet (5) of the piping system (4) through the cavity (2a) of the hollow component (2) to an outlet (6) of the piping system (4), wherein a first opening (7a) of the cavity (2a) is detachably connected to the inlet (5) and a second opening (7b) of the cavity (2a) is detachably connected to the outlet (6).At least one particle counter (8) of the device (1) is provided behind the hollow component (2) in the direction of flushing in order to detect particles flushed out of the hollow component (2) during the flow of the flushing medium.

Description

[0001] The invention relates to a device for cleaning and checking the cleanliness of at least one hollow component having a cavity.

[0002] The invention also relates to a method for cleaning and checking the cleanliness of at least two cavities in one or more hollow structural components.

[0003] The invention further relates to a lithography system, in particular a projection exposure system for semiconductor lithography.

[0004] Components used in vacuum systems must meet certain cleanliness requirements. Contaminated components used in these systems can lead to contamination of the vacuum system by particles and impurities deposited on or detaching from the component, potentially impairing the vacuum generated and / or the system's performance. This is particularly true for systems used in micro- or nanolithography, such as projection exposure systems for semiconductor lithography. Especially in systems operating with extreme ultraviolet (EUV) light, components that do not meet the stringent cleanliness requirements can introduce contaminants into the systems, potentially compromising not only the required vacuum but also the system's performance.The appropriately set gas atmosphere is not only affected, but other components of the system can also be contaminated and impaired. In particular, contaminants such as particles can lead to transmission losses due to scattered light or cause corresponding imaging errors with defective production.

[0005] It is therefore essential that components and parts used in corresponding EUV lithography systems are thoroughly cleaned and inspected for cleanliness to meet the defined particle contamination specifications.

[0006] Various devices or methods for cleaning components and / or for inspecting or checking the cleaning result are known from the prior art.

[0007] From DE 10 2022 202 402 A1, for example, a method and a device for inspecting and cleaning surfaces of optical elements are known, which is based on a first nozzle arrangement for dispensing the cleaning agent and a second nozzle arrangement for extracting cleaning agent and contaminants.

[0008] DE 10 2015 203 161 A1 discloses a method and a device for determining the contamination of surfaces, wherein a surface probe is used which is placed airtight on the component surface to be examined and which has a nozzle for providing a cleaning fluid and a suction connected to a particle counter.

[0009] Disadvantages of these and similar state-of-the-art solutions include the unavoidable contact of the probes or inspection / cleaning heads with the component and the fact that cleaning or testing is only performed at specific points.

[0010] Furthermore, there are also components with complex geometries, especially with cavities, i.e., hollow components, which may be designed to guide or direct gases or liquids. These cannot be cleaned and / or tested for cleanliness using previously known devices and methods, especially not in a way that is relevant to their intended application.

[0011] Currently, it is only possible to clean and test individual parts of the hollow components or samples of the hollow components or the corresponding material as examples, for instance using the methods mentioned above. However, this is prone to errors and often not representative of the hollow component, especially since contamination can occur again during the assembly of the individual parts and / or because the specific shape or geometry of the hollow component, as well as the influence of media flowing through it during operation, remains unaccounted for. This can sometimes lead to a substandard level of cleanliness, for example, if further particles are detached from the hollow component by a fluid flow during subsequent operation.

[0012] The present invention is therefore based on the objective of creating a device for cleaning components which is improved compared to the prior art, in particular enabling the cleaning and testing of hollow components under application-like conditions.

[0013] According to the invention, this object is achieved by a device having the features mentioned in claim 1.

[0014] The present invention also aims to create a method for cleaning components which is improved compared to the prior art, in particular enabling the cleaning and testing of hollow components under application-like conditions.

[0015] According to the invention, this problem is solved by a method with the features mentioned in claim 14.

[0016] The present invention further aims to create a lithography system which is improved compared to the prior art, in particular by a further reduction or minimization of particle contamination, by cleaning and testing hollow components of the lithography system under application-like conditions.

[0017] According to the invention, this problem is solved by a lithography system with the features mentioned in claim 15.

[0018] The device according to the invention for cleaning and testing the cleanliness of at least one hollow component comprising a cavity has a housing configured to create a cleanroom environment within the housing and also includes a rinsing medium and a piping system for conveying the rinsing medium. The piping system is configured to accommodate the hollow component and to allow the rinsing medium to flow in a rinsing direction from an inlet of the piping system through the cavity of the hollow component to an outlet of the piping system, wherein a first opening of the cavity is detachably connected to the inlet and a second opening of the cavity is detachably connected to the outlet. Furthermore, at least one particle counter of the device is provided downstream of the hollow component in the rinsing direction to detect particles flushed out of the hollow component during the flow of the rinsing medium.

[0019] The device is particularly suitable for one or more hollow components, each with one cavity. However, with appropriate design, the device can also be suitable for one or more hollow components, each with multiple cavities.

[0020] The respective hollow component has, in particular, at least one cavity and at least one, preferably two, openings, especially a first opening and a second opening. The openings can, for example, be designed as holes or slots. An example of a hollow component is a pipe or pipe section, or a duct or duct section. Preferably, the openings are used to connect the hollow component or the cavity to the piping system.

[0021] The first opening of the hollow component can preferably be connected to the piping system on the inlet side, and the second opening on the outlet side. However, the hollow component can also be connected to both the inlet and the outlet via one and the same opening, in which case the first and second openings can be considered identical.

[0022] It is preferably provided that the hollow component is replaceable. In particular, the detachable connection of the hollow component or the openings of the hollow component with the piping system means that the hollow component can be connected to the piping system of the device for the purpose of cleaning and testing for cleanliness, but is not permanently connected to it.

[0023] It can be provided, in particular, that the hollow component, after its cleaning and testing by the device according to the invention, is integrated into another device or system, especially a vacuum system. The hollow component can, for example, be a component, assembly, or module of a lithography system; that is, the hollow component is intended for integration into the lithography system, which necessitates a high degree of purity.

[0024] The housing can preferably be designed as a wash cabinet and / or a filter fan unit (FFU), which is further preferably located in a cleanroom. However, the housing can also be formed by the cleanroom itself.

[0025] The housing serves, at least primarily, to create a cleanroom environment, i.e., a very clean or ultra-clean environment with as few particles as possible, in order to prevent contamination of the hollow component. For this purpose, the housing typically has an inlet and an outlet for purging the enclosed volume, especially with filtered or clean air.

[0026] The cleanroom environment preferably meets at least the ISO 6 specification or ISO class 6 within the framework of the European standard or DIN standard EN ISO 14644 and / or subsequent standards, and further preferably at least the ISO 5 specification or

[0027] ISO Class 5. Accordingly, the cleanroom environment should preferably contain fewer than 1,000,000 particles per m². 3 with a size class of 0.1 micrometers and less than 8,320 particles per m³ 3 with a size class of 1 micrometer, further preferably less than 100,000 particles per m² 3with a size class of 0.1 micrometers and less than 832 particles per 3 with a particle size class of 1 micrometer. Further maximum values ​​for particles per m³ are specified within the respective ISO classes. 3 Other particle size classes are defined. For this and further details of the classification, please refer to EN ISO 14644. Similarly, particle concentration or purity can also be classified based on US Federal Standard 209E or similar cleanroom standards.

[0028] It is specifically intended that at least the hollow component to be cleaned and tested is located within the designated cleanroom environment. The piping system and other components of the device may optionally be located outside the cleanroom environment. However, all components of the device, except for the housing itself, may also be located within the housing.

[0029] The selected rinsing medium or fluid is preferably suitable for cleaning the hollow component in question. In particular, the rinsing medium is preferably matched to the material of the hollow component. Depending on the intended subsequent use of the cleaned and tested component, a gaseous and / or a liquid rinsing medium can be selected.

[0030] The particles can be, for example, organic or inorganic particles that are deposited or adsorbed in the cavity or on the inside of the hollow component. They can also be particles that are only released during rinsing or when the rinsing medium flows in and out of the hollow component.

[0031] The invention aims to flush the particles out of the hollow component using the flow of the rinsing medium and then measure them, in particular count them, using the particle counter. The particle counter can also be configured to further analyze the particles, for example, with regard to their size or diameter.

[0032] It is preferable to have the cleanliness checked simultaneously with the cleaning process. Alternatively, the cleanliness can be checked after cleaning. Furthermore, the device can be suitable for checking the cleanliness of hollow components independently of the cleaning process, for example, if they have been cleaned elsewhere and / or if the last cleaning was some time ago. The device is particularly well-suited for both cleaning and checking the cleanliness of hollow components, whether simultaneously or sequentially.

[0033] The device may include further components. In particular, the list of components included in the device, namely the housing, the rinsing medium and the piping system, as well as the particle counter, is not exhaustive.

[0034] The device according to the invention, as described above, has proven to be particularly advantageous for cleaning and testing the cleanliness of cavities or inner surfaces or interiors of hollow components, especially for particle cleaning and particle qualification.

[0035] The invention combines cleaning and cleanliness testing. In particular, cleanliness testing is enabled, firstly, on the cleaned hollow component itself, instead of using samples, and secondly, under near-application or realistic conditions, especially under atmospheric conditions instead of under vacuum, and in a flow instead of under static conditions. This makes cleanliness testing significantly more representative compared to the prior art and makes it possible for hollow components to be tested under application-like conditions for the first time. Furthermore, particle contamination is further reduced compared to conventional methods, primarily because the rinsing flow used removes particles that can be detached from the inner surface of the hollow components, at least to a large extent, during the test.

[0036] Using the device according to the invention with particle counter, the measurement or testing for cleanliness can be carried out without contact, which avoids damage and / or contamination of the hollow component by the measuring unit and has proven to be particularly advantageous. Furthermore, the measurement or testing by a particle counter is less point-based than other measuring methods and thus provides a more meaningful average value regarding cleanliness.

[0037] The connection of the hollow component to the piping system provided by the solution according to the invention, preferably using openings in the hollow component, also avoids the need for disassembly or dismantling of the hollow component. This means, for example, that a cover of the hollow component does not need to be removed for cleaning and / or cleanliness testing. This significantly reduces the risk of recontamination during reassembly or reinstallation of the hollow component after conventional cleaning.

[0038] Advantageous or preferred embodiments and further developments of the device according to the invention will become apparent from the dependent claims and the following description.

[0039] Preferably, the particle counter is set up and configured to detect at least particles with a minimum diameter of 500 nm, preferably 100 nm, more preferably 50 nm, and particularly preferably 10 nm.

[0040] In particular, the particle counter can be designed to detect particles as small as possible in order to enable the most accurate possible testing of cleanliness.

[0041] The particle counter may be, in particular, a “Discrete Particle Counter” (DPC) or a “Condensation Particle Counter” (CPC).

[0042] Alternatively or additionally, the particle counter is designed and configured to determine the particle size distribution. This enables, among other things, further analysis of the achieved cleanliness, conclusions about the type of potentially remaining contaminants, and an evaluation of the cost-benefit ratio of the cleaning process.

[0043] It may be necessary to make a compromise between the detectable particle size and the possibility of determining a size distribution.

[0044] It has proven advantageous to have a control unit that stops the cleaning and / or testing as soon as the particle counter detects a defined specification, in particular as soon as a defined number of particles per volume is undershot.

[0045] This allows for precise control of the rinsing time and / or the measurement time. It can be advantageous to keep the rinsing time as short as possible to save rinsing medium and / or time. However, instead of determining the rinsing time based on the particle counter's measurement results, a standardized rinsing time can also be used, after which the particle counter test may only begin.

[0046] Once a sufficient level of cleanliness has been achieved, the rinsing medium can be stopped. Cleanliness is preferably measured or assessed according to a specification predetermined, defined, or specified by the user. This specification may preferably be an ISO 1 specification or ISO Class 1 within the framework of the European Standard or DIN standard EN ISO 14644 and / or subsequent standards. Accordingly, the particle concentration is preferably less than 10 particles per m³. 3 with a size class greater than 0.1 micrometers. For further details of the classification, please refer to EN ISO 14644. Similarly, the particle concentration or purity can also be classified based on US Federal Standard 209E or similar standards.

[0047] The cleanroom environment provided or created by the housing should preferably meet at least approximately the same specifications as the specification defined for cleaning the hollow component in order to avoid cross-contamination. If the hollow component is to achieve ISO Class 1, it may be sufficient for the cleanroom environment to meet ISO Class 5 or 6.

[0048] It may be provided that the hollow component is tightly connected to the piping system, the piping system having a drain for the removal of excess flushing medium that is not routed through the particle counter and / or the outlet.

[0049] In particular, the connection between the piping system and the hollow component at the first and second openings of the cavity must be tight and free of leaks. This ensures that particles in the flushing flow are captured particularly effectively. The drain prevents overpressure in the piping system or the hollow component, which could damage the system or component. The drain can, for example, be designed as a pressure relief valve.

[0050] The connection to the opening(s) of the cavity of the hollow component can preferably be adapted to the shape of the respective opening. This can optionally already be the case in the unconnected or unattached state. The connections can preferably be standardized. The connection(s) can be sealed, if required, by means of sealing rings or other sealing agents.

[0051] The design with a tight connection, i.e., where the hollow component is tightly connected to the piping system, is particularly suitable when the flushing medium is liquid. However, this design can also be used with a gaseous flushing medium.

[0052] It may also be suitable if the hollow component is connected to the piping system with a leakage, preferably with a connection to the piping system adapted to the shape of the first opening and / or the second opening of the cavity.

[0053] The connection should preferably only be essentially adapted to the shape of the respective opening, so that leakage can occur at the connection or transition.

[0054] In this design, the connection to the piping system is not completely sealed due to a loose connection and may exhibit leakage; that is, rinsing medium may escape from the piping system or the hollow component at the interface. This design is therefore particularly suitable for gaseous rinsing media, and preferably, any escaping rinsing medium is carried away via the housing outlet during rinsing of the enclosed volume, thus using the same mechanism by which the cleanroom environment is typically maintained.

[0055] The design with a customized connection is particularly suitable when the openings of the hollow component or cavity have an unusual shape or when no standardized connections, such as pipe clamps, are available for connecting the openings to the piping system. For this purpose, the connection can be made of electropolished stainless steel or other, preferably smooth, materials.

[0056] If the leakage alone is not sufficient to prevent overpressure, an additional drain and / or pressure relief valve should be provided, analogous to the tight connection described above.

[0057] Preferably, the device is designed and configured to clean and inspect multiple cavities and / or multiple hollow components. This can involve at least one hollow component with multiple cavities and / or multiple hollow components, each with at least one cavity.

[0058] In a simple, but not preferred, embodiment, it may be provided to connect at least two hollow components one after the other to the piping system, in particular in one and the same pipe section, so that the flushing medium can flow from one of the hollow components into the other hollow component(s).

[0059] It is particularly advantageous if the piping system is designed and configured to guide the flushing medium simultaneously or alternately through at least two hollow components, wherein the piping system divides into a corresponding number of pipe sections after the inlet, and wherein one of the hollow components is connected in each pipe section.

[0060] This makes it possible to clean and / or test multiple hollow components in parallel, at least partially, which can lead to efficiency gains in terms of time and / or costs.

[0061] It may be preferable to pass the rinsing medium simultaneously through at least two, in particular all, hollow components, especially to maximize the cleaning effect or to optimize the cleaning time.

[0062] It may also be provided that the pipe sections, viewed in the direction of flushing, are rejoined or converge before the outlet or before the particle counter.

[0063] The shared use of a particle counter can be particularly advantageous for testing multiple hollow components or for detecting particles that have been flushed out of different hollow components. This can be achieved by connecting the particle counter sequentially and / or alternately to the corresponding pipe sections of different hollow components.

[0064] In a preferred embodiment, the piping system between the hollow components and the particle counter has a distribution valve, wherein, depending on the position of the distribution valve, the proportion of the rinsing medium which is guided through a selected hollow component and the associated piping section can be supplied to the particle counter.

[0065] This allows the same particle counter to be used sequentially and / or alternately for different hollow components. Instead of a distribution valve, a separate particle counter could also be provided for each hollow component; however, this is generally less costly.

[0066] Even if flushing medium is routed through those pipe sections that are temporarily disconnected from the particle counter by the distribution valve, it is intended that this medium be diverted elsewhere. This can be achieved, for example, through any existing drain(s), through leaking or loose connections, and / or through a bypass line that bypasses the particle counter.

[0067] Furthermore, a second distribution valve may be provided, which is arranged between the inlet and the hollow component, in particular to direct the flushing medium only through one or selected pipe sections and the hollow components connected to them.

[0068] Preferably, the piping system has at least one flow meter or flow controller, and preferably one flow meter per pipe section, if pipe sections are provided. This serves to monitor the flushing parameters, for example to ensure the correct measuring conditions for the particle counter.

[0069] It has proven particularly suitable if the inlet has a filter or particle filter for filtering the flushing medium. This ensures, in particular, that no particles or new contaminants are introduced into the hollow component or cavity by the flushing medium.

[0070] The rinsing medium can be gaseous, preferably nitrogen, carbon dioxide, and / or dry, purified air. Gaseous rinsing medium is particularly suitable for gas-carrying hollow components, i.e., those hollow components which, after cleaning and testing, are intended to carry gases.

[0071] Dry, purified air can refer specifically to "Extreme Clean Dry Air" (XCDA). The use of dry or purified air or compressed air may also be sufficient in some cases.

[0072] Alternatively, the rinsing medium can be liquid, preferably purified water and / or water with cleaning additives. Liquid rinsing medium is particularly suitable for fluid-carrying hollow components, i.e., those hollow components which, after cleaning and testing, are intended to carry liquids.

[0073] Purified water can be, in particular, distilled and / or demineralized and / or particle-free water, preferably with the highest possible purity level. Cleaning additives can include, for example, suitable detergents or solvents.

[0074] Preferably, the selected rinsing medium is similar to the medium that the hollow component is intended to carry or conduct after cleaning and testing, or during subsequent operation, if this is provided for. The invention is also applicable to hollow components that are not intended to carry any medium, or neither a gaseous nor a liquid medium or fluid, during subsequent operation.

[0075] A flushing flow rate of the flushing medium between 10 l / min and 300 l / min, preferably between 30 l / min and 200 l / min, may be particularly suitable.

[0076] In particular, the flow rate of the flushing medium should be within a range that allows the particle counter to function properly and / or where turbulence in the flushing medium is negligible or tolerable. The optimal flow rate may depend on the specific flushing medium.

[0077] The control unit can alternatively or additionally be set up and designed to monitor or control the flushing flow and / or to control the distributor valve(s), in addition to controlling the flushing duration and / or the measuring time.

[0078] An indicator light may be provided to show whether the cleaning and testing process is still in progress or has already been completed. This indicator light could, for example, glow red or green.

[0079] The invention also relates to a method for cleaning and testing the cleanliness of at least two cavities in one or more hollow components for use in a cleanroom environment. At least the following steps are provided: (a) Connecting the hollow components in separate sections of a piping system, wherein a first opening of the cavity of the respective hollow component is detachably connected to an inlet of the piping system and a second opening of the cavity of the respective hollow component is detachably connected to an outlet of the piping system, so that a flushing medium can flow in a flushing direction through the cavities of the hollow components from the inlet to the outlet; (b) Guiding the flushing medium through the hollow components and the associated pipe sections; (c) Controlling a distribution valve located downstream of the hollow components when viewed in the direction of flushing, such that the portion of the flushing medium which has passed through a selected hollow component and the associated pipe section is fed to a particle counter; (d) Detecting and characterizing particles flushed out of the hollow component during the flow of the flushing medium; (e) Iteratively repeat steps (c) and (d) to check all hollow components successively; and (f) Stopping the rinsing medium as soon as the particle counter detects or has detected a defined specification for all hollow components, in particular as soon as a defined number of particles per volume is undershot.

[0080] This method can advantageously be carried out using a device according to the invention, wherein the device should in particular be designed for connecting at least two cavities or hollow components. This also results in a preferred design of the method and its steps. Nevertheless, the method can also be implemented independently of the device.

[0081] The advantages and preferred variants of the method according to the invention will become apparent from the description of the device according to the invention analogously.

[0082] This method is particularly suitable for two or more hollow components, each with one cavity. However, it is equally suitable for one or more hollow components, each with at least two cavities. A hollow component can optionally be connected to more than one pipe section; for example, each cavity of the hollow component can be connected to a separate pipe section.

[0083] The cleanroom environment can be, for example, a rinsing cabinet and / or a cleanroom, wherein the cleanroom environment is characterized in particular by a comparatively low particle load. Preferably, the cleanroom environment encloses at least the hollow component(s) in order to prevent unwanted contamination of the hollow component(s) and thus not to jeopardize the cleaning result.

[0084] The connection of the hollow components according to step (a) can be tight or leakage-prone. The connection can preferably be made at two openings of the respective hollow component. It can be particularly advantageous if the connection is adapted to the shape of the hollow component or its openings.

[0085] In step (b), the rinsing medium can preferably be guided or flowed through several hollow components simultaneously. The rinsing medium can be gaseous or liquid. It can also be provided that the rinsing medium flows through only one or the selected hollow component at a time, which is preferably also tested for particles. A second distribution valve can be suitable for this purpose.

[0086] The (first) distribution valve, in its use according to step (c), serves in particular to assign the measurement results from step (d) to a specific hollow component. Alternatively, a particle counter can be provided for each hollow component and / or pipe section.

[0087] The characterization and analysis of the detected particles in step (d) can include, in particular, counting the particles, determining their individual or average size, and / or determining a particle size distribution. A particle counter is particularly suitable for this purpose.

[0088] It may be provided that the respective hollow component is first flushed for a defined or standardized flushing duration by passing the flushing medium through it according to step (b), and only then are any flushed-out particles detected and characterized according to step (d). Preferably, however, the flushing duration can be determined based on the characterization of the particles, in particular by stopping the flushing and / or the detection or characterization as soon as a defined specification, such as a defined number of particles per volume, is not reached.

[0089] For steps (e) and (f), the distributor valve is preferably switched to another hollow component or pipe section, analogous to step (c), which has not yet been tested and / or has not yet reached the defined specification, if the hollow component under test according to step (d) has reached the defined specification.

[0090] The steps of the procedure can be carried out or performed at least partially in parallel, for example steps (b) and (d). The sequence of the steps can be changed if necessary. Furthermore, individual steps and / or groups of steps can be repeated iteratively if necessary. Additional steps and / or intermediate steps may also be provided within the procedure.

[0091] The invention further relates to a lithography system, in particular a projection exposure system for semiconductor lithography, with an illumination system for illuminating a reticle arranged in an object field. It is provided that at least one hollow component of the lithography system, in particular a gas-carrying hollow component near the reticle, is cleaned and tested for cleanliness before its integration into the lithography system by means of a device according to the preceding description and / or by means of a method according to the preceding description.

[0092] The advantages of the lithography system according to the invention become apparent from the description of the device and method according to the invention. In the context of semiconductor lithography, the advantages of increased cleanliness and reduced contamination, for example in a gas stream or flow directed through the hollow component onto the reticle, photomask, or projection template, can become particularly evident by improving transmission and increasing image quality.

[0093] The lithography system could be, in particular, an EUV projection exposure system for semiconductor lithography, especially microlithography. However, it could also be a DUV projection exposure system or another type of projection exposure system.

[0094] It is specifically not intended that the device itself is integrated into the lithography system or that the process is carried out on the hollow component within the lithography system. It is intended that the hollow component is cleaned using a device and / or a method according to the invention before being integrated or installed in the lithography system. Preferably, the number of handling steps from cleaning using the device and / or the method to integration into the lithography system is as small as possible, and the handling steps should also take place in a clean environment.

[0095] Analogous to the use of the device and / or method according to the invention for hollow components of a lithography system, as described above, in a more general sense, an application of the invention to hollow components of any type of vacuum system with the corresponding advantages is also conceivable.

[0096] Features described in connection with one of the subject matter of the invention, in particular those given by the device, method, or lithography system according to the invention, can also be advantageously implemented for the other subject matter of the invention. Likewise, advantages mentioned in connection with one of the subject matter of the invention can also be understood to relate to the other subject matter of the invention.

[0097] It should be noted that designations such as "first" or "second" etc. are primarily used for the purpose of distinguishing between the respective device or process features and are not necessarily intended to indicate that features are mutually dependent or related to each other.

[0098] Exemplary embodiments of the invention are described in more detail below with reference to the drawing.

[0099] The figures each show preferred embodiments in which individual features of the present invention are combined with one another. Features of an embodiment can also be implemented independently of the other features of the same embodiment and can therefore be readily combined by a person skilled in the art to form further meaningful combinations and subcombinations with features of other embodiments.

[0100] In the figures, functionally identical elements are provided with the same reference numerals.

[0101] They show: Fig. 1 an EUV projection exposure system in meridional section; Fig. 2 a schematic representation of an embodiment of the device according to the invention; Fig. 3 a basic view of an exemplary hollow structural component; and Fig. 4 a basic view of another exemplary hollow component.

[0102] The following will first refer to Fig. 1. The essential components of an EUV projection exposure system 100 for microlithography are described as an example of a lithography system. The description of the basic structure of the EUV projection exposure system 100 and its components is not intended to be restrictive.

[0103] An illumination system 101 of the EUV projection exposure system 100 comprises, in addition to a radiation source 102, an illumination optic 103 for illuminating an object field 104 in an object plane 105. A reticule 106 arranged in the object field 104 is exposed. The reticule 106 is held by a reticule holder 107. The reticule holder 107 can be moved, particularly in a scanning direction, by means of a reticule displacement drive 108.

[0104] In Fig. Figure 1 shows a Cartesian xyz coordinate system for illustrative purposes. The x-direction runs perpendicular to the plane of the drawing. The y-direction runs horizontally, and the z-direction runs vertically. The scan direction runs in Fig. 1 along the y-direction. The z-direction runs perpendicular to the object plane 105.

[0105] The EUV projection exposure system 100 comprises a projection optic 109. The projection optic 109 serves to image the object field 104 onto an image field 110 in an image plane 111. The image plane 111 is parallel to the object plane 105. Alternatively, an angle other than 0° between the object plane 105 and the image plane 111 is also possible.

[0106] A structure on the reticulum 106 is imaged onto a photosensitive layer of a wafer 112 located in the image plane 111 within the image field 110. The wafer 112 is held by a wafer holder 113. The wafer holder 113 can be displaced, particularly along the y-direction, via a wafer transfer drive 114. The displacement of the reticulum 106 via the reticulum transfer drive 108 and of the wafer 112 via the wafer transfer drive 114 can be synchronized.

[0107] Radiation source 102 is an EUV radiation source. Specifically, radiation source 102 emits EUV radiation 115, which is also referred to as useful radiation or illumination radiation. The useful radiation 115 has a wavelength in the range between 5 nm and 30 nm. Radiation source 102 can be a plasma source, for example, an LPP source (laser-produced plasma) or a DPP source (gas-discharged produced plasma). It can also be a synchrotron-based radiation source. Radiation source 102 can be a free-electron laser (FEL).

[0108] The illumination radiation 115, emanating from the radiation source 102, is focused by a collector 116. The collector 116 can be a collector with one or more ellipsoidal and / or hyperboloid reflective surfaces. The at least one reflective surface of the collector 116 can be illuminated with the illumination radiation 115 at grazing incidence (GI), i.e., with angles of incidence greater than 45°, or at normal incidence (NI), i.e., with angles of incidence less than 45°. The collector 116 can be structured and / or coated, both to optimize its reflectivity for the useful radiation 115 and to suppress stray light.

[0109] After the collector 116, the illumination radiation 115 propagates through an intermediate focus in an intermediate focal plane 117. The intermediate focal plane 117 can represent a separation between a radiation source module, comprising the radiation source 102 and the collector 116, and the illumination optics 103.

[0110] The illumination optics 103 comprise a deflecting mirror 118 and, downstream in the beam path, a first faceted mirror 119. The deflecting mirror 118 can be a planar deflecting mirror or, alternatively, a mirror with an effect that influences the beam shape beyond the mere deflection effect. Alternatively or additionally, the deflecting mirror 118 can be designed as a spectral filter that separates a useful wavelength of the illumination radiation 115 from stray light of a different wavelength. If the first faceted mirror 119 is arranged in a plane of the illumination optics 103 that is optically conjugate to the object plane 105 as the field plane, it is also referred to as a field faceted mirror. The first faceted mirror 119 comprises a plurality of individual first facets 120, which are also referred to as field facets in the following. Of these facets 120, the following are in the Fig. 1 only some examples are shown.

[0111] The first facets 120 can be designed as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or semicircular border contour. The first facets 120 can be designed as planar facets or alternatively as convexly or concavely curved facets.

[0112] As is known, for example, from DE 10 2008 009 600 A1, the first facets 120 can themselves each be composed of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 119 can in particular be designed as a microelectromechanical system (MEMS system). For details, reference is made to DE 10 2008 009 600 A1.

[0113] Between the collector 116 and the deflecting mirror 118, the illumination radiation 115 runs horizontally, i.e. along the y-direction.

[0114] In the beam path of the illumination optics 103, a second faceted mirror 121 is arranged downstream of the first faceted mirror 119. If the second faceted mirror 121 is arranged in a pupil plane of the illumination optics 103, it is also referred to as a pupil faceted mirror. The second faceted mirror 121 can also be arranged at a distance from a pupil plane of the illumination optics 103. In this case, the combination of the first faceted mirror 119 and the second faceted mirror 121 is also referred to as a specular reflector. Specular reflectors are known from US 2006 / 0132747 A1, EP 1 614 008 B1, and US 6,573,978.

[0115] The second facet mirror 121 comprises a plurality of second facets 122. In the case of a pupil facet mirror, the second facets 122 are also referred to as pupil facets.

[0116] The second facets 122 can also be macroscopic facets, which may, for example, have round, rectangular, or hexagonal edges, or alternatively, facets composed of micromirrors. Reference is also made to DE 10 2008 009 600 A1 in this regard.

[0117] The second facets 122 can have planar or alternatively convex or concave curved reflective surfaces.

[0118] The illumination optics 103 thus form a double-faceted system. This basic principle is also known as a fly's eye integrator.

[0119] It may be advantageous not to arrange the second faceted mirror 121 exactly in a plane which is optically conjugate to a pupil plane of the projection optics 109.

[0120] With the aid of the second faceted mirror 121, the individual first facets 120 are imaged into the object field 104. The second faceted mirror 121 is the last beam-shaping, or indeed the last, mirror for the illumination radiation 115 in the beam path before the object field 104.

[0121] In another embodiment of the illumination optics 103, not shown, a transmission optic can be arranged in the beam path between the second facet mirror 121 and the object field 104, which contributes in particular to imaging the first facets 120 into the object field 104. The transmission optic can have exactly one mirror, or alternatively two or more mirrors, which are arranged one behind the other in the beam path of the illumination optics 103. The transmission optic can in particular comprise one or two mirrors for normal incidence (NI mirrors, "normal incidence" mirrors) and / or one or two mirrors for grazing incidence (GI mirrors, "grazing incidence" mirrors).

[0122] The lighting optic 103, in the version that is in the Fig. Figure 1 shows exactly three mirrors after the collector 116, namely the deflecting mirror 118, the field facet mirror 119 and the pupil facet mirror 121.

[0123] In a further embodiment of the illumination optics 103, the deflection mirror 118 can also be omitted, so that the illumination optics 103 can then have exactly two mirrors after the collector 116, namely the first facet mirror 119 and the second facet mirror 121.

[0124] The imaging of the first facets 120 by means of the second facets 122 or with the second facets 122 and a transmission optic into the object plane 105 is regularly only an approximate imaging.

[0125] The projection optics 109 comprise a plurality of mirrors Mi, which are numbered according to their arrangement in the beam path of the EUV projection exposure system 100.

[0126] In the Fig. In the example shown, the projection optics 109 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve, or any other number of mirrors Mi are also possible. The penultimate mirror M5 and the last mirror M6 each have an aperture for the illumination radiation 115. The projection optics 109 is a double-obscured optic. The projection optics 109 has an image-side numerical aperture that is greater than 0.5 and can also be greater than 0.6, for example, 0.7 or 0.75.

[0127] The reflective surfaces of the mirrors Mi can be designed as freeform surfaces without an axis of rotational symmetry. Alternatively, the reflective surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflective surface shape. The mirrors Mi, like the mirrors of the illumination optics 103, can have highly reflective coatings for the illumination radiation 115. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

[0128] The projection optics 109 has a large object-image offset in the y-direction between a y-coordinate of a center of the object field 104 and a y-coordinate of the center of the image field 110. This object-image offset in the y-direction can be approximately as large as a z-distance between the object plane 105 and the image plane 111.

[0129] The number of intermediate image planes in the x- and y-directions in the beam path between the object field 104 and the image field 110 can be the same or, depending on the design of the projection optics 109, can differ. Examples of projection optics with different numbers of such intermediate images in the x- and y-directions are known from US 2018 / 0074303 A1.

[0130] Each of the pupil facets 122 is assigned to exactly one of the field facets 120 to form an illumination channel for illuminating the object field 104. This can result, in particular, in illumination according to Köhler's principle. The far field is divided into a multitude of object fields 104 by means of the field facets 120. The field facets 120 generate a plurality of images of the intermediate focus on the pupil facets 122 assigned to each of them.

[0131] The field facets 120 are each superimposed on the reticulum 106 by an associated pupil facet 122 to illuminate the object field 104. The illumination of the object field 104 is particularly homogeneous. It preferably exhibits a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

[0132] The illumination of the entrance pupil of the projection optics 109 can be geometrically defined by the arrangement of the pupil facets. By selecting the illumination channels, in particular the subset of pupil facets that guide light, the intensity distribution in the entrance pupil of the projection optics 109 can be adjusted. This intensity distribution is also referred to as the illumination setting.

[0133] Another preferred pupil uniformity in the area of ​​defined illuminated sections of an illumination pupil of the illumination optics 103 can be achieved by a redistribution of the illumination channels.

[0134] Further aspects and details of the illumination of the object field 104 and, in particular, the entrance pupil of the projection optics 109 are described below.

[0135] The projection optic 109 can, in particular, have a homocentric entrance pupil. This may be accessible. It may also be inaccessible.

[0136] The entrance pupil of the projection optics 109 cannot always be illuminated exactly by the pupil facet mirror 121. When the projection optics 109 image the center of the pupil facet mirror 121 telecentrically onto the wafer 112, the aperture rays often do not intersect at a single point. However, a surface can be found where the pairwise determined separation of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugate to it in real space. In particular, this surface exhibits a finite curvature.

[0137] The projection optics 109 may have different entrance pupil positions for the tangential and sagittal beam paths. In this case, an imaging element, in particular an optical component of the transmission optics, should be provided between the second faceted mirror 121 and the reticle 106. This optical component will allow the different positions of the tangential and sagittal entrance pupils to be taken into account.

[0138] In the Fig. In the arrangement of the components of the illumination optics 103 shown in Figure 1, the pupil facet mirror 121 is arranged in a plane conjugate to the entrance pupil of the projection optics 109. The first field facet mirror 119 is arranged tilted relative to the object plane 105. The first facet mirror 119 is arranged tilted relative to an arrangement plane defined by the deflecting mirror 118.

[0139] The first faceted mirror 119 is arranged at an angle to an arrangement plane defined by the second faceted mirror 121.

[0140] The use of the invention is not limited to use in projection exposure systems 100, particularly not with the described setup. The invention is suitable for any lithography or microlithography systems, but especially for projection exposure systems with the described setup. The invention is also suitable for EUV projection exposure systems, which have a lower image-side numerical aperture than those associated with Fig. 1 as described, and do not have an obscured mirror M5 and / or M6. In particular, the invention is also suitable for EUV projection exposure systems which have an image-side numerical aperture of 0.25 to 0.5, preferably 0.3 to 0.4, particularly preferably 0.33.

[0141] The invention may also be suitable for DUV projection exposure systems. An exemplary DUV projection system can be found, for example, in DE 10 2022 200 205 B3 of the applicant.

[0142] It should be noted that the invention can also be used completely independently of lithography systems or projection exposure systems, in particular for any vacuum systems.

[0143] The following figures and embodiments illustrate the invention in an exemplary and highly schematic way. The invention is not to be understood as limited to a specific design.

[0144] The Fig. Figure 2 shows a schematic representation or flowchart of an embodiment of the device 1 according to the invention for cleaning and checking the cleanliness of at least one hollow component 2 having a cavity 2a, as described in more detail below. Fig. 3 and Fig. 4 is shown as an example.

[0145] The device 1 comprises a housing 3, which is configured to create a cleanroom environment within the housing 3. The device 1 also includes a rinsing medium and a piping system 4 for conveying the rinsing medium. The piping system 4 is configured to accommodate the hollow component 2 and to allow the rinsing medium to flow in a rinsing direction from an inlet 5 of the piping system 4 through the cavity 2a of the hollow component 2, or through the respective cavities 2a of the hollow components 2, to an outlet 6 of the piping system 4. For this purpose, a first opening 7a of each cavity 2a is detachably connected to the inlet 5, and a second opening 7b of each cavity 2a is detachably connected to the outlet 6.

[0146] At least one particle counter 8 of the device 1 is provided downstream of the hollow component(s) 2, viewed in the direction of flushing, in order to detect particles flushed out of the hollow component(s) 2 during the flow of the flushing medium. The arrows in the Fig. 2 symbolizes the direction of the rinsing medium.

[0147] In the Fig. Figure 2 shows such an embodiment of the device 1, which is designed for cleaning and testing several, in particular six, hollow components 2. The cleaning and / or testing can be carried out at least partially in parallel or simultaneously, or sequentially, and optionally iteratively. In another embodiment, the device 1 can also be designed to hold only one hollow component 2.

[0148] The housing 3 can, as is common practice in rinsing cabinets and cleanrooms, have an inlet and an outlet for rinsing the enclosed volume, particularly with filtered or clean air, to create or maintain the cleanroom environment. These are not shown in the drawing. It should also be noted that, as an alternative to the design according to the Fig. 2 may be sufficient if only the hollow component(s) 2 are enclosed by the housing 3 or the cleanroom environment.

[0149] It is advantageous if the particle counter 8 is configured and designed to detect at least particles with a minimum diameter of 500 nm, preferably 100 nm, more preferably 50 nm, and particularly preferably 10 nm. It can also be advantageous if the particle counter 8 is configured and designed to determine the size distribution of the particles.

[0150] Preferably, a control unit is provided which stops the cleaning and / or testing as soon as the particle counter 8 detects a defined specification, in particular as soon as a defined number of particles per volume is undershot. The control unit is not shown in the drawing.

[0151] The hollow component 2 can be tightly connected to the piping system 4, wherein the piping system 4 has a drain for discharging excess flushing medium that is not routed through the particle counter 8 and / or the outlet 6. Alternatively, the hollow component 2 can be connected to the piping system 4 via a leakage point, wherein preferably a connection to the piping system 4 is provided that is adapted, at least substantially, to the shape of the first opening 7a and / or the second opening 7b of the cavity 2a.

[0152] A particularly suitable embodiment of the device 1 is one in which the piping system 4 is configured and designed to guide the flushing medium simultaneously or alternately through at least two hollow components 2, wherein the piping system 4 divides into a corresponding number of piping sections 4a after the inlet 5, and wherein one of the hollow components 2 is connected in each of the piping sections 4a. Fig. Figure 2 shows this as an example for six hollow components 2, whereby the conductor system 4 is divided into six conductor sections 4a analogous to a parallel circuit.

[0153] Such a design is particularly advantageous in combination with the fact that the piping system 4 between the hollow components 2 and the particle counter 8 has an optional distribution valve 9, wherein, depending on the position of the distribution valve 9, the portion of the flushing medium which is guided through a selected hollow component 2 and the associated piping section 4a can be supplied to the particle counter 8. In the Fig. Figure 2 shows the distribution valve 9 schematically and only as an example circuit symbol. Similarly, another (second) distribution valve can be provided between the inlet 5 and the hollow components 2, but this is not shown.

[0154] The piping system 4 preferably has at least one flow meter 10, and more preferably one flow meter 10 per piping section 4a. The flushing flow rate of the flushing medium preferably has a flow rate between 10 l / min and 300 l / min, and more preferably between 30 l / min and 200 l / min.

[0155] The rinsing medium can be gaseous, preferably nitrogen, carbon dioxide, and / or dry purified air. Alternatively, the rinsing medium can be liquid, preferably purified water and / or water with cleaning additives. Preferably, the inlet 5 has a suitable filter 11 for filtering the selected rinsing medium.

[0156] After cleaning and testing, the hollow component 2 can preferably be removed from the device 1 in order to put it to its intended use.

[0157] In the Fig. 3 and the Fig. Figure 4 shows a basic view of an exemplary hollow component 2 with a cavity 2a. The hollow component 2 according to the Fig. 3 is essentially designed as a pipe (section) or channel (section) with round openings 7a, 7b at both ends. This could, for example, be a cooling channel, the flushing medium for its cleaning preferably being liquid. The hollow component 2 according to the Fig. In contrast, part 4 is box-shaped and has a round first opening 7a and a slit-shaped second opening 7b. The second opening 7b is shown hatched in both figures. The first opening 7a, which is obscured due to perspective, as well as hidden edges of the respective hollow component 2, are drawn with dashed lines. The hollow component 2 can also be designed differently than shown in the figures. Fig. 3 and Fig. Figure 4 shows a cavity 2a and at least one, preferably two, openings 7a, 7b. The openings 7a, 7b can have any shape.

[0158] The Fig. Sections 2 to 4 also serve to disclose a method according to the invention for cleaning and testing the cleanliness of at least two cavities 2a in one or more hollow structural components 2 for use in a cleanroom environment. The method includes at least the following steps: (a) Connecting the hollow components 2 in separate pipe sections 4a of a pipe system 4, wherein a first opening 7a of the cavity 2a of the respective hollow component 2 is detachably connected to an inlet 5 of the pipe system 4 and a second opening 7b of the cavity 2a of the respective hollow component 2 is detachably connected to an outlet 6 of the pipe system 4, so that a flushing medium can flow in a flushing direction through the cavities 2a of the hollow components 2 from the inlet 5 to the outlet 6; (b) Guiding the flushing medium through the hollow components 2 and the associated pipe sections 4a; (c) Controlling a distribution valve 9 located behind the hollow components 2 in the direction of flushing such that the portion of the flushing medium which has passed through a selected hollow component 2 and the associated pipe section 4a is fed to a particle counter 8; (d) Detecting and characterizing particles flushed out of the hollow component 2 during the flow of the flushing medium; (e) Iteratively repeat steps (c) and (d) to check all hollow components 2 successively; and (f) Stopping the rinsing medium as soon as the particle counter 8 detects a defined specification for all hollow components 2, in particular as soon as a defined number of particles per volume is undershot.

[0159] The steps can be varied in their order and / or can be carried out at least partially simultaneously. Further steps and / or intermediate steps may also be provided. The method described above and variants thereof can be carried out particularly advantageously using a device 1 according to the invention. Reference is made to the preceding description.

[0160] The Fig. Figure 2 schematically illustrates the device 1 or the method using six hollow components 2 as examples, each with a cavity 2a and each cavity having two openings 7a, 7b. It should be noted that the six hollow components 2 may be identical or different. Furthermore, after their respective cleaning and testing, the six hollow components 2 may be intended for further use for different purposes and / or for integration into different devices or systems, in particular vacuum systems.

[0161] The Fig. References 1 to 4 further serve to disclose a lithography system according to the invention, in particular a projection exposure system 100 for semiconductor lithography. The lithography system according to the invention includes, among other things, an illumination system 101 for illuminating a reticle 106 arranged in an object field 104. It is provided that at least one hollow component 2 of the lithography system, in particular a gas-carrying hollow component 2 near the reticle 106, is cleaned and tested for cleanliness before its integration into the lithography system by means of a device 1 according to the preceding description and / or by means of a method according to the preceding description.

[0162] The lithography system or projection exposure unit 100 for semiconductor lithography can, in particular, be an EUV projection exposure unit for microlithography according to the Fig. 1 act as described above. The hollow component 2 provided in the context of this invention is in the Fig. 1 not shown. The lithography system could alternatively be a DUV projection exposure system, which is not shown in the drawing, or another type of projection exposure system.

[0163] If the hollow component 2 is designed to guide a gas in the lithography system, a gaseous rinsing medium is preferably selected for cleaning and / or cleanliness testing. Similarly, for a hollow component 2 designed to guide a liquid in the lithography system, a liquid rinsing medium is preferably selected. Reference symbol list 1 Device 2 Hollow component 2a Cavity 3 Enclosures (cleanroom environment) 4. Pipe system 4a Line section 5 Admission 6 Outlet 7a First opening 7b Second opening 8 particle counters 9 distributor valve 10 flow meters 11 filters 100 EUV projection exposure system 101 Lighting system 102 Radiation source 103 Lighting optics 104 Object field 105 Object level 106 reticles 107 reticle holders 108 Reticle displacement drive 109 Projection optics 110 image field 111 Image plane 112 wafers 113 wafer holders 114 Wafer relocation drive 115 EUV / useful / illumination radiation 116 collector 117 Intermediate focal plane 118 deflecting mirrors 119 first facet mirror / field facet mirror 120 first facets / field facets 121 second facet mirror / pupil facet mirror 122 second facets / pupil facets Mi Mirror QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 202 402 A1

[0007] DE 10 2015 203 161 A1

[0008] DE 10 2008 009 600 A1 [0112, 0116] US 2006 / 0132747 A1

[0114] EP 1 614 008 B1

[0114] US 6,573,978

[0114] US 2018 / 0074303 A1

[0129] DE 10 2022 200 205 B3

[0141] Cited non-patent literature

[0000] DIN standard EN ISO 14644

[0026] Framework of the European Standard or DIN standard EN ISO 14644

[0046]

Claims

[1] Device (1) for cleaning and testing the cleanliness of at least one hollow component (2) having a cavity (2a), comprising a housing (3) which is configured to form a clean room environment in the housing (3), and comprising a flushing medium and a conduit system (4) for conveying the flushing medium, wherein the conduit system (4) is configured to receive the hollow component (2) and to allow the flushing medium to flow in a flushing direction from an inlet (5) of the conduit system (4) through the cavity (2a) of the hollow component (2) to an outlet (6) of the conduit system (4), wherein a first opening (7a) of the cavity (2a) is detachably connected to the inlet (5) and a second opening (7b) of the cavity (2a) is detachably connected to the outlet (6), and wherein at least one particle counter (8) of the device (1) is provided behind the hollow component (2) as viewed in the flushing direction,to detect particles in the flushing medium that are flushed out of the hollow component (2) as the flushing medium flows. [2] Device (1) according to claim 1, wherein the particle counter (8) is arranged and designed to detect at least particles with a minimum diameter of 500 nm, preferably of 100 nm, more preferably of 50 nm, particularly preferably of 10 nm. [3] Device (1) according to claim 1 or 2, wherein the particle counter (8) is arranged and designed to determine a size distribution of the particles. [4] Device (1) according to claim 1, 2 or 3, wherein a control unit is provided which stops the cleaning and / or the testing as soon as the particle counter (8) detects a defined specification, in particular as soon as a defined number of particles per volume is undershot. [5] Device (1) according to one of claims 1 to 4, wherein the hollow component (2) is tightly connected to the line system (4), and wherein the line system (4) has an outlet for discharging excess rinsing medium which is not passed through the particle counter (8) and / or the outlet (6). [6] Device (1) according to one of claims 1 to 4, wherein the hollow component (2) is connected to the line system (4) with a leak, and wherein preferably a connection to the line system (4) is provided which is adapted to the shape of the first opening (7a) and / or the second opening (7b) of the cavity (2a). [7] Device (1) according to one of claims 1 to 6, wherein the line system (4) is arranged and designed to guide the flushing medium simultaneously or alternately through at least two hollow components (2), wherein the line system (4) is divided into a corresponding number of line sections (4a) after the inlet (5), and wherein one of the hollow components (2) is connected in each of the line sections (4a). [8] Device (1) according to claim 7, wherein the line system (4) between the hollow components (2) and the particle counter (8) has a distribution valve (9), and wherein, depending on the position of the distribution valve (9), the portion of the rinsing medium which is guided through a selected hollow component (2) and the associated line section (4a) can be fed to the particle counter (8). [9] Device (1) according to one of claims 7 or 8, wherein the line system (4) has at least one flow meter (10), preferably one flow meter (10) per line section (4a). [10] Device (1) according to one of claims 1 to 9, wherein the inlet (5) has a filter (11) for filtering the rinsing medium. [11] Device (1) according to one of claims 1 to 10, wherein the flushing medium is gaseous, preferably nitrogen, carbon dioxide and / or dry purified air. [12] Device (1) according to one of claims 1 to 10, wherein the rinsing medium is liquid, preferably purified water and / or water with cleaning additives. [13] Device (1) according to one of claims 1 to 12, wherein a flushing flow of the flushing medium is between 10 l / min and 300 l / min, preferably between 30 l / min and 200 l / min. [14] Method for cleaning and checking the cleanliness of at least two cavities (2a) in one or more hollow components (2) for use in a clean room environment, wherein at least the following steps are provided: (a) connecting the hollow components (2) in a separate line section (4a) of a line system (4), wherein a first opening (7a) of the cavity (2a) of the respective hollow component (2) is detachably connected to an inlet (5) of the line system (4) and a second opening (7b) of the cavity (2a) of the respective hollow component (2) is detachably connected to an outlet (6) of the line system (4), so that a flushing medium can flow in a flushing direction through the cavities (2a) of the hollow components (2) from the inlet (5) to the outlet (6); (b) guiding the flushing medium through the hollow components (2) and the associated line sections (4a); (c) controlling a distributor valve (9) arranged behind the hollow components (2) as viewed in the flushing direction in such a way that the portion of the flushing medium which has been passed through a selected hollow component (2) and the associated line section (4a) is fed to a particle counter (8); (d) detecting and characterising particles flushed out of the hollow component (2) during the flow of the flushing medium; (e) Iteratively repeating steps (c) and (d) to test all hollow components (2) one after the other; and (f) Stopping the flushing medium as soon as the particle counter (8) detects a defined specification for all hollow components (2), in particular as soon as a defined number of particles per volume is undercut. [15] Lithography system, in particular projection exposure system (100) for semiconductor lithography, with an illumination system (101) for illuminating a reticle (106) arranged in an object field (104), characterized by that at least one hollow component (2) of the lithography system, in particular a gas-conducting hollow component (2) near the reticle (106), is cleaned and checked for cleanliness by means of a device (1) according to one of claims 1 to 13 and / or by means of a method according to claim 14 before its integration into the lithography system.

Images