DE102024205079A1 - Device and method for cleaning and testing the cleanliness of cavities in hollow components; lithography system - Google Patents

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) and comprising a housing (3) which is designed to create a clean room environment in the housing (3), as well as comprising a flushing medium and a conduit system (4) for conducting the flushing medium. The conduit system (4) is designed to accommodate 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). At least one particle counter (8) of the device (1) is provided behind the hollow component (2) as viewed in the flushing direction in order to detect particles in the flushing medium flushed out of the hollow component (2) as the flushing medium flows through.

Description

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

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

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

Components used in vacuum systems must meet certain cleanliness requirements, as contaminated components used in these vacuum systems can lead to the vacuum system becoming contaminated or soiled by particles and impurities deposited on or detached from the component, and can impair the vacuum created therein or the properties of the system. This applies in particular to systems used in connection with micro- or nanolithography, such as projection exposure systems for semiconductor lithography. Particularly in systems operated with extreme ultraviolet light (EUV light), components that do not meet the high cleanliness requirements can introduce contamination into the corresponding systems, thus not only compromising the required vacuum or the correspondingly adjusted gas atmosphere, but also contaminating and impairing other components of the system. In particular, contaminants such as particles can lead to transmission losses due to stray light or cause corresponding imaging errors and defective production.

It is therefore essential that parts and components used in corresponding EUV lithography systems are thoroughly cleaned and subjected to a cleanliness inspection in order to meet the defined specifications for particle contamination.

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

From the DE 10 2022 202 402 A1 For example, a method and a device for inspecting and cleaning surfaces of optical elements is known, which is based on a first nozzle arrangement for dispensing the cleaning agent and a second nozzle arrangement for sucking off cleaning agent and contamination.

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

Disadvantages of this and similar state-of-the-art solutions include the unavoidable contact of the probes or inspection/cleaning heads with the component and the only selective cleaning or testing.

Furthermore, there are also components with complex geometries, especially with cavities, i.e., hollow components that may be designed to conduct or transport gases or liquids. These cannot be cleaned and/or tested for cleanliness using currently known devices and methods, especially not in a way that is close to the application.

Until now, it has only been possible to clean and test individual parts of the hollow components or samples of the hollow components or samples of the corresponding material as examples, for example, using the methods mentioned above. However, this is error-prone and often not representative of the hollow component, particularly since contamination can occur during assembly of the individual parts of the hollow components and/or because the specific shape or geometry of the hollow component, as well as the influence of media flowing through the hollow component during operation, are not taken into account. This can sometimes lead to an inferior level of cleanliness, for example, if additional particles are detached from the hollow component by a fluid flow during subsequent operation.

The present invention is therefore based on the object 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.

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

The present invention is also based on the object of creating a method for cleaning components which is improved compared to the prior art, in particular the Cleaning and testing of hollow components under application-like conditions is possible.

According to the invention, this object is achieved by a method having the features mentioned in claim 14.

The present invention is further based on the object of creating a lithography system which is improved compared to the prior art, in particular by further reducing or minimizing the particle load by cleaning and testing hollow components of the lithography system under application-like conditions.

According to the invention, this object is achieved by a lithography system having the features mentioned in claim 15.

The device according to the invention for cleaning and testing the cleanliness of at least one hollow component having a cavity comprises a housing configured to create a cleanroom environment in the housing, and further comprises a flushing medium and a conduit system for conveying the flushing medium. The conduit system is configured to accommodate the hollow component and to allow the flushing medium to flow in a flushing direction from an inlet of the conduit system through the cavity of the hollow component to an outlet of the conduit system, wherein a first opening of the cavity is or can be detachably connected to the inlet, and a second opening of the cavity is or can be connected to the outlet. Furthermore, at least one particle counter of the device is provided downstream of the hollow component, viewed in the flushing direction, in order to detect particles in the flushing medium that have been flushed out of the hollow component as the flushing medium flows through.

The device can be 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.

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

The first opening of the hollow component can preferably be connected to the piping system on the inlet side, and the second opening of the hollow component can preferably be connected to the outlet side. However, the hollow component can also be connected to the inlet and the outlet via one and the same opening, wherein the first opening can be considered identical to the second opening.

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 to the piping system means that the hollow component can be connected to the piping system of the device for cleaning and checking for cleanliness, but is not permanently connected to it.

In particular, it can be provided that the hollow component, after being cleaned and tested by the device according to the invention, is integrated into another device or system, in particular into a vacuum system. The hollow component can, for example, be a component, assembly, or module of a lithography system, i.e., the hollow component is intended for integration into the lithography system, which requires a high degree of cleanliness.

The housing can preferably be designed as a flushing cabinet and/or filter fan unit (FFU), which is further preferably located in a clean room. However, the housing can also be formed by the clean room itself.

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

The cleanroom environment meets the requirements of the European standard or DIN standard EN ISO 14644 and/or subsequent standards, preferably at least the ISO 6 specification or ISO class 6, more preferably at least the ISO 5 specification or

ISO Class 5. Accordingly, the cleanroom environment may, for example, preferably have less than 1,000,000 particles per m ³ with a size class of 0.1 micrometers and less than 8,320 particles per m ³ with a size class of 1 micrometer, more preferably less than 100,000 particles per m ³ with a size class of 0.1 micrometers and less than 832 particles per ^{m 3} with a A size class of 1 micrometer. The respective ISO classes define additional maximum particle counts per ^m³ for other particle size classes. For this and further details of the classification, please refer to EN ISO 14644. Similarly, the particle concentration or purity can also be classified based on the US Federal Standard 209E or similar standards for cleanrooms.

In particular, it is provided that at least the hollow component to be cleaned and tested is arranged in the designed cleanroom environment. The piping system and other components of the device can, if necessary, be arranged outside the cleanroom environment. However, all components of the device, apart from the housing itself, can also be arranged in the housing.

The selected flushing medium or fluid is preferably suitable for cleaning the hollow component in question. In particular, the flushing 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 liquid flushing medium can be selected.

The particles can, for example, be 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 flushing or when the flushing medium flows from or out of the hollow component.

It is within the scope of the invention to flush the particles out of the hollow component by the flow of the flushing medium or the flushing flow and then to measure, in particular count, the particles 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.

It can preferably be provided that the cleanliness is checked at the same time as the cleaning. However, it can also be provided that the cleanliness is checked after the cleaning has taken place. The device can also be suitable for checking the cleanliness of hollow components independently of the cleaning, for example if they have been cleaned by other means and/or if the last cleaning was some time ago, or the device can be suitable for cleaning hollow components independently of the inspection. However, the device is particularly suitable for both cleaning hollow components and checking them for cleanliness, whether simultaneously or sequentially.

The device may comprise additional components. In particular, the list of components that the device comprises, namely the housing, the flushing medium, the piping system, and the particle counter, is not intended to be exhaustive.

The device according to the invention, as described above, has proven particularly advantageous for cleaning and testing the cleanliness of cavities or inner sides or interiors of hollow components, in particular for particle cleaning and particle qualification.

The invention combines cleaning and cleanliness testing. In particular, cleanliness testing is enabled, on the one hand, on the cleaned hollow component itself, rather than using samples or specimens, and, on the other hand, under application-like or realistic conditions, in particular under atmospheric conditions rather than under vacuum, and in a flow-through rather than under static conditions. This makes cleanliness testing significantly more representative than the state of the art and, for hollow components, is only possible under application-like conditions. In addition, particle pollution is further reduced compared to conventional methods, especially since the rinsing flow used can at least largely remove particles that can be detached from the inner surface of the hollow components during the test.

Using the device according to the invention with a particle counter, the measurement or testing for cleanliness can be carried out contactlessly, which has proven particularly advantageous, preventing damage and/or contamination of the hollow component by the measuring unit. Furthermore, the measurement or testing using a particle counter is less selective than other measurement methods and thus provides a more meaningful average value regarding cleanliness.

The connection of the hollow component to the piping system provided by the inventive solution, for which openings in the hollow component are preferably used, also avoids the need to disassemble or dismantle the hollow component, i.e., for example, a cover of the hollow component does not have to be removed for cleaning and/or checking for cleanliness. This at least significantly reduces the risk of recontamination during reassembly or reassembly of the hollow component after conventional cleaning.

Advantageous or preferred embodiments and further developments of the device according to the invention result from the dependent claims and the following description.

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

In particular, the particle counter can be designed to detect particles as small as possible in order to enable the most accurate possible cleanliness check.

The particle counter can be a “Discrete Particle Counter” (DPC) or a “Condensation Particle Counter” (CPC).

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

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

It has proven advantageous to provide a control unit which 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 undercut.

This allows, in particular, the purging duration and/or the measurement time to be controlled. It may be advantageous to keep the purging duration as short as possible to save purging medium and/or time. Instead of determining the purging duration based on the particle counter's measurement results, a standardized purging duration can also be specified, after which the particle counter test may begin.

Once a sufficient level of cleanliness has been achieved, the flushing medium may be stopped. Cleanliness is preferably measured or assessed based on a specification predetermined or defined by the user. This specification may preferably be an ISO 1 specification or ISO Class 1 in 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 with a size class of over 0.1 micrometers. For further details on 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.

The cleanroom environment ensured or created by the housing should preferably meet at least approximately the same specifications as those defined for cleaning the hollow component 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.

It can be provided that the hollow component is tightly connected to the piping system, wherein the piping system has a drain for discharging excess flushing medium which is not passed through the particle counter and/or the outlet.

In particular, the connection between the piping system and the hollow component is sealed and leak-free at the first and second openings of the cavity. This allows particles in the flushing flow to be captured particularly effectively. The drain serves to prevent overpressure in the piping system or hollow component, which could damage the piping system or hollow component. The drain can be designed, for example, as a pressure relief valve.

The connection to the opening(s) in the cavity of the hollow component can preferably be adapted to the shape of the respective opening. This can be the case even in the unconnected or unattached state. These connections can preferably be standardized. The connection(s) can be sealed using sealing rings or other sealing means if necessary.

The design with a tight connection, i.e., 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.

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

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.

In this design, the connection to the piping system with a loose connection is not completely sealed or may leak, i.e., flushing medium may escape from the piping system or the hollow component at the transition. This design is therefore particularly suitable for gaseous flushing media, with the preferred provision for any escaping flushing medium to be removed via the housing outlet when flushing the volume enclosed within the housing, i.e., using the same mechanism as is typically used to maintain a cleanroom environment.

The design with a customized connector is particularly suitable when the openings in the hollow component or cavity have an unusual shape, or when no standardized connectors, such as pipe clamps, are available to connect the openings to the piping system. For this purpose, the connector can be made of electropolished stainless steel or other materials that are as smooth as possible.

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

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

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

It is particularly advantageous if the line system is designed and constructed to conduct the flushing medium simultaneously or alternately through at least two hollow components, wherein the line system is divided into a corresponding number of line sections after the inlet, and wherein one of the hollow components is connected in each of the line sections.

This makes it possible to clean and/or test several hollow components at least partially in parallel, which can lead to efficiency improvements in terms of time and/or costs.

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

It can further be provided that the line sections are reunited or converge before the outlet or before the particle counter, as viewed in the flushing direction.

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. The particle counter can be connected sequentially and/or alternately to the corresponding pipe sections of different hollow components.

In a preferred embodiment, the line system between the hollow components and the particle counter has a distribution valve, wherein, depending on the position of the distribution valve, the portion of the flushing medium which is guided through a selected hollow component and the associated line section can be fed to the particle counter.

This makes it possible to use the same particle counter consecutively and/or alternately for different hollow components. Instead of a distribution valve, a separate particle counter could also be provided for each hollow component, but this is usually not cost-effective.

If flushing medium is also routed through those pipe sections that are temporarily not connected to the particle counter via the distribution valve, it is intended that it be diverted elsewhere. This can occur, for example, through the existing drain(s), through leaky or loose connections, and/or through a bypass line that bypasses the particle counter.

Furthermore, a further (second) distribution valve may be provided, which is arranged between the inlet and the hollow component, in particular in order to guide flushing medium only through one or selected line sections and the hollow components connected to them.

Preferably, the piping system has at least one flow meter or flow controller, more preferably one flow meter per line section, if line sections are provided. This serves to control the purging parameters, for example, to ensure the correct measuring conditions for the particle counter.

It has proven particularly suitable for the inlet to be equipped with 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.

The purging medium can be gaseous, preferably nitrogen, carbon dioxide, and/or dry, purified air. Gaseous purging media are particularly suitable for gas-conducting hollow components, i.e., hollow components intended to conduct gases after cleaning and testing.

Dry, purified air can be understood in particular as "Extreme Clean Dry Air" (XCDA). In some cases, the use of dry or purified air or compressed air may also be sufficient.

Alternatively, the rinsing medium can be liquid, preferably purified water and/or water with cleaning additives. Liquid rinsing medium is particularly suitable for liquid-conducting hollow components, i.e., hollow components intended to conduct liquids after cleaning and testing.

Purified water can, in particular, be 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.

Preferably, the selected flushing medium is similar to the medium that the hollow component is intended to carry after cleaning and testing or during subsequent operation, if this is intended. 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.

A flushing flow 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.

In particular, the flushing flow of the flushing medium should be within a range where the particle counter is functional and/or where turbulence in the flushing medium is negligible or tolerable. The optimal flushing flow may depend on the flushing medium.

As an alternative or in addition to controlling the flushing duration and/or the measuring time, the control unit can also be configured and designed to monitor or control the flushing flow and/or to control the distribution valve(s).

An indicator light may be provided to indicate whether the cleaning and testing process is still in progress or has already been completed. For this purpose, the indicator light may, for example, glow red or green.

1. (a) Anschließen der Hohlbauteile in jeweils einem separaten Leitungsabschnitt eines Leitungssystems, wobei eine erste Öffnung des Hohlraums des jeweiligen Hohlbauteils mit einem Einlass des Leitungssystems sowie eine zweite Öffnung des Hohlraums des jeweiligen Hohlbauteils mit einem Auslass des Leitungssystems lösbar verbunden wird, so dass ein Spülmedium in einer Spülrichtung durch die Hohlräume der Hohlbauteile von dem Einlass zu dem Auslass fließen kann;
2. (b) Leiten des Spülmediums durch die Hohlbauteile und die zugehörigen Leitungsabschnitte;
3. (c) Ansteuern eines in Spülrichtung betrachtet hinter den Hohlbauteilen angeordneten Verteilerventils derart, dass der Anteil des Spülmediums, welcher durch ein ausgewähltes Hohlbauteil und den zugehörigen Leitungsabschnitt geleitet wurde, einem Partikelzähler zugeführt wird;
4. (d) Detektieren und charakterisieren von beim Durchfluss des Spülmediums aus dem Hohlbauteil herausgespülten Partikeln;
5. (e) Iteratives wiederholen der Schritte (c) und (d), um alle Hohlbauteile nacheinander zu prüfen; und
6. (f) Stoppen des Spülmediums, sobald der Partikelzähler eine definierte Spezifikation für alle Hohlbauteile feststellt bzw. festgestellt hat, insbesondere sobald jeweils eine definierte Partikelzahl pro Volumen unterschritten wird.

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:

1. (a) connecting the hollow components in a separate line section of a line system, wherein a first opening of the cavity of the respective hollow component is detachably connected to an inlet of the line system and a second opening of the cavity of the respective hollow component is detachably connected to an outlet of the line 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;
2. (b) passing the flushing medium through the hollow components and the associated pipe sections;
3. (c) controlling a distribution valve arranged behind the hollow components 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 and the associated line section is fed to a particle counter;
4. (d) detecting and characterising particles flushed out of the hollow component during the flow of the flushing medium;
5. (e) Iteratively repeating steps (c) and (d) to test all hollow components one after the other; and
6. (f) Stop the flushing medium as soon as the particle counter reaches a defined specification for all Hollow components are or have been identified, particularly as soon as a defined number of particles per volume is exceeded.

This method can advantageously be carried out using a device according to the invention, wherein the device should be designed in particular 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.

The advantages and preferred variants of the method according to the invention result analogously from the description of the device according to the invention.

The method is particularly suitable for two or more hollow components, each with one cavity. However, the method is also suitable for one or more hollow components, each with at least two cavities. A hollow component can be connected to more than one line section if necessary; for example, each of the cavities of the hollow component can be connected to a separate line section.

The cleanroom environment can be formed, for example, by a sink cabinet and/or a cleanroom, with the cleanroom environment being characterized in particular by a comparatively low particle load. The cleanroom environment preferably encloses at least the hollow component(s) to prevent unwanted contamination of the hollow component(s) and thus not jeopardize the cleaning result.

The connection of the hollow components according to step (a) can be tight or leak-proof. 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.

In step (b), the flushing medium can preferably be directed or guided or flow through several hollow components simultaneously. The flushing medium can be gaseous or liquid. It can also be provided that the flushing 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.

The (first) distribution valve, when used after 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 line section.

The characterization or analysis of the detected particles in step (d) may, in particular, comprise counting the particles, determining the respective size or average size of the particles, and/or determining a size distribution of the particles. A particle counter is particularly suitable for this purpose.

It can be provided that the respective hollow component is first rinsed for a defined or standardized rinsing time by passing the rinsing medium through it according to step (b), and only then are any particles that may have been rinsed out detected and characterized according to step (d). However, the rinsing time can preferably be determined based on the characterization of the particles, in particular by stopping the rinsing and/or detection or characterization as soon as a defined specification, such as a defined number of particles per volume, is undercut.

For steps (e) and (f), the distribution valve is preferably switched over, analogously to step (c), to another hollow component or another line section which has not yet been tested and/or has not yet reached the defined specification when the defined specification has been reached for the hollow component being tested according to step (d).

The steps of the method can be carried out or executed at least partially in parallel with one another, 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. Furthermore, further steps and/or intermediate steps can be provided within the framework of the method.

The invention further relates to a lithography system, in particular a projection exposure system for semiconductor lithography, comprising 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-conducting hollow component near the reticle, is cleaned and checked for cleanliness prior to its integration into the lithography system using a device according to the preceding description and/or using a method according to the preceding description.

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

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

In particular, it is not intended that the device itself be integrated into the lithography system or that the method be carried out on the hollow component in the lithography system. It is intended that the hollow component has been cleaned by means of a device and/or a method according to the invention before it is integrated or installed into the lithography system. Preferably, the number of handling steps from cleaning by means of 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.

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

Features described in connection with one of the subject matters of the invention, specifically the device according to the invention, the method according to the invention, or the lithography system according to the invention, can also be advantageously implemented for the other subject matters of the invention. Likewise, advantages mentioned in connection with one of the subject matters of the invention can also be understood to relate to the other subject matters of the invention.

It should be noted that terms such as “first” or “second” etc. are used primarily for reasons of distinguishing between respective device or process features and are not necessarily intended to indicate that features are mutually dependent or related to one another.

In the following, embodiments of the invention are described in more detail with reference to the drawing.

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

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

• 1 eine EUV-Projektionsbelichtungsanlage im Meridionalschnitt;
• 2 eine prinzipmäßige Darstellung einer Ausführungsform der erfindungsgemäßen Vorrichtung;
• 3 eine prinzipmäßige Ansicht eines exemplarischen Hohlbauteils; und
• 4 eine prinzipmäßige Ansicht eines weiteren exemplarischen Hohlbauteils.

They show:

• 1 an EUV projection exposure system in meridional section;
• 2 a schematic representation of an embodiment of the device according to the invention;
• 3 a schematic view of an exemplary hollow component; and
• 4 a schematic view of another exemplary hollow component.

In the following, with reference to 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 should not be understood as limiting.

An illumination system 101 of the EUV projection exposure system 100 comprises, in addition to a radiation source 102, an illumination optics 103 for illuminating an object field 104 in an object plane 105. A reticle 106 arranged in the object field 104 is exposed. The reticle 106 is held by a reticle holder 107. The reticle holder 107 can be displaced, in particular in a scanning direction, via a reticle displacement drive 108.

In 1 For explanation purposes, a Cartesian xyz coordinate system is shown. The x-direction runs perpendicular to the drawing plane. The y-direction runs horizontally and the z-direction runs vertically. The scanning direction runs in 1 along the y-direction. The z-direction runs perpendicular to the object plane 105.

The EUV projection exposure system 100 comprises a projection optics 109. The projection optics 109 serves to image the object field 104 into an image field 110 in an image plane 111. The image plane 111 runs 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.

A structure on the reticle 106 is imaged onto a light-sensitive layer of a wafer 112 arranged in the image plane 111 in the region of the image field 110. The wafer 112 is held by a wafer holder 113. The wafer holder 113 can be displaced, in particular along the y-direction, via a wafer displacement drive 114. The displacement of the reticle 106, on the one hand, via the reticle displacement drive 108, and the wafer 112, on the other hand, via the wafer displacement drive 114, can be synchronized with each other.

The radiation source 102 is an EUV radiation source. The radiation source 102 emits, in particular, EUV radiation 115, which is also referred to below as useful radiation or illumination radiation. The useful radiation 115 has, in particular, a wavelength in the range between 5 nm and 30 nm. The 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. The radiation source 102 can be a free-electron laser (FEL).

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 hyperboloidal reflection surfaces. The at least one reflection surface of the collector 116 can be exposed to the illumination radiation 115 at grazing incidence (GI), i.e., at angles of incidence greater than 45°, or at normal incidence (NI), i.e., at angles of incidence less than 45°. The collector 116 can be structured and/or coated, on the one hand, to optimize its reflectivity for the useful radiation 115 and, on the other hand, to suppress stray light.

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.

The illumination optics 103 comprises a deflecting mirror 118 and, downstream of this in the beam path, a first facet mirror 119. The deflecting mirror 118 can be a flat deflecting mirror or, alternatively, a mirror with a beam-influencing effect beyond the pure deflection effect. Alternatively or additionally, the deflecting mirror 118 can be designed as a spectral filter that separates a useful light wavelength of the illumination radiation 115 from stray light of a different wavelength. If the first facet mirror 119 is arranged in a plane of the illumination optics 103 that is optically conjugated to the object plane 105 as the field plane, it is also referred to as a field facet mirror. The first facet mirror 119 comprises a plurality of individual first facets 120, which are also referred to below as field facets. Of these facets 120, 1 only a few examples are shown.

The first facets 120 can be designed as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or partially circular edge contour. The first facets 120 can be designed as flat facets or, alternatively, as convexly or concavely curved facets.

As for example from the DE 10 2008 009 600 A1 As is known, the first facets 120 themselves can also 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 referred to.

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

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

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.

The second facets 122 may also be macroscopic facets, which may, for example, be round, rectangular or hexagonal, or alternatively facets composed of micromirrors. In this regard, reference is also made to the DE 10 2008 009 600 A1 referred to.

The second facets 122 may have planar or alternatively convex or concave curved reflection surfaces.

The illumination optics 103 thus forms a double-faceted system. This basic principle is also referred to as the fly's eye integrator.

It may be advantageous not to arrange the second facet mirror 121 exactly in a plane which is optically conjugated to a pupil plane of the projection optics 109.

With the help of the second facet mirror 121, the individual first facets 120 are imaged into the object field 104. The second facet mirror 121 is the last bundle-forming mirror or actually the last mirror for the illumination radiation 115 in the beam path before the object field 104.

In a further, not shown embodiment of the illumination optics 103, a transmission optics can be arranged in the beam path between the second facet mirror 121 and the object field 104, which transmission optics contributes in particular to the imaging of the first facets 120 into the object field 104. The transmission optics can have exactly one mirror, but alternatively also two or more mirrors arranged one behind the other in the beam path of the illumination optics 103. The transmission optics 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).

The illumination optics 103 has in the version shown in the 1 As shown, after the collector 116 there are exactly three mirrors, namely the deflection mirror 118, the field facet mirror 119 and the pupil facet mirror 121.

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.

The imaging of the first facets 120 by means of the second facets 122 or with the second facets 122 and a transmission optics into the object plane 105 is usually only an approximate imaging.

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

In the 1 In the example shown, the projection optics 109 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve, or a different number of mirrors M1 are also possible. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 115. The projection optics 109 are doubly obscured optics. The projection optics 109 have 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.

Reflection surfaces of the mirrors Mi can be designed as freeform surfaces without a rotational symmetry axis. Alternatively, the reflection surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one rotational symmetry axis of the reflection 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.

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.

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

Each of the pupil facets 122 is assigned to exactly one of the field facets 120 to form a respective illumination channel for illuminating the object field 104. This can, in particular, result in illumination according to the Köhler principle. The far field is divided into a plurality of object fields 104 using the field facets 120. The field facets 120 generate a plurality of images of the intermediate focus on the pupil facets 122 assigned to them.

The field facets 120 are each imaged onto the reticle 106 by an associated pupil facet 122, superimposed on one another, to illuminate the object field 104. The illumination of the object field 104 is, in particular, as homogeneous as possible. It preferably has a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

By arranging the pupil facets, the illumination of the entrance pupil of the projection optics 109 can be geometrically defined. By selecting the illumination channels, in particular the subset of the 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.

A likewise preferred pupil uniformity in the area of defined illuminated sections of an illumination pupil of the illumination optics 103 can be achieved by redistributing the illumination channels.

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

The projection optics 109 can, in particular, have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

The entrance pupil of the projection optics 109 cannot usually be precisely illuminated with the pupil facet mirror 121. When the projection optics 109 images 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 in which the pairwise determined distance of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugate to it in spatial space. In particular, this surface exhibits a finite curvature.

It is possible that the projection optics 109 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 facet mirror 121 and the reticle 106. With the help of this optical component, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

At the 1 In the illustrated arrangement of the components of the illumination optics 103, the pupil facet mirror 121 is arranged in a surface conjugated 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 deflection mirror 118.

The first facet mirror 119 is arranged tilted to an arrangement plane defined by the second facet mirror 121.

The use of the invention is not limited to use in projection exposure systems 100, in particular not with the described structure. The invention is suitable for any lithography systems or microlithography systems, but in particular for projection exposure systems with the described structure. The invention is also suitable for EUV projection exposure systems which have a lower image-side numerical aperture than that used in connection with 1 described, and do not have an obscured mirror M5 and/or M6. In particular, the invention is also suitable for EUV projection exposure systems having an image-side numerical aperture of 0.25 to 0.5, preferably 0.3 to 0.4, particularly preferably 0.33.

The invention may also be suitable for DUV projection exposure systems. An exemplary DUV projection system may be DE 10 2022 200 205 B3 from the applicant.

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.

The following figures and embodiments represent the invention by way of example and highly schematic. The invention is not to be understood as being limited to a specific design.

The 2 shows a schematic representation or a flow chart 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 3 and 4 is shown as an example.

The device 1 has a housing 3, which is configured to create a clean room environment in the housing 3. In addition, the device 1 has a flushing medium and a conduit system 4 for conducting 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 or through the respective cavities 2a of the hollow components 2 to an outlet 6 of the conduit system 4. For this purpose, a first opening 7a of the respective cavity 2a is detachably connected to the inlet 5, and a second opening 7b of the respective 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(s) 2, viewed in the flushing direction, in order to detect particles in the flushing medium that are flushed out of the hollow component(s) 2 during the flow of the flushing medium. The arrows in the 2 symbolize the flushing direction of the flushing medium.

In the 2 Such an embodiment of the device 1 is shown, 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 provided for receiving only one hollow component 2.

To create or ensure the clean room environment, as is generally the case with flushing cabinets and clean rooms, the housing 3 may have an inlet and an outlet for flushing the enclosed volume, in particular with filtered or clean air. These are not shown in the drawing. It should also be noted that, as an alternative to the design according to the 2 may be sufficient if only the hollow component(s) 2 is/are enclosed by the housing 3 or the clean room environment.

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 may also be advantageous if the particle counter 8 is configured and designed to determine a size distribution of the particles.

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.

The hollow component 2 can be tightly connected to the conduit system 4, wherein the conduit 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 conduit system 4 with a leak, wherein preferably a connection to the conduit system 4 is provided that is at least substantially adapted to the shape of the first opening 7a and/or the second opening 7b of the cavity 2a.

A particularly suitable embodiment of the device 1 is one in which the line system 4 is designed and constructed to conduct 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 to each of the line sections 4a. 2 This is shown as an example for six hollow components 2, whereby the line system 4 is divided into six line sections 4a analogously to a parallel circuit.

Such a configuration is particularly advantageous in combination with the fact that the line 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 line section 4a can be fed to the particle counter 8. In the 2 The distribution valve 9 is shown schematically and merely as an example as a circuit symbol. Similarly, a further (second) distribution valve can be provided between the inlet 5 and the hollow components 2, although this is not shown.

The line system 4 can preferably have at least one flow meter 10, more preferably one flow meter 10 per line section 4a. A flushing flow of the flushing medium can preferably be between 10 l/min and 300 l/min, preferably between 30 l/min and 200 l/min.

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

After cleaning and testing, the hollow component 2 can preferably be dismantled or removed from the device 1 in order to use it for its intended purpose.

In the 3 and the 4 A schematic view of an exemplary hollow component 2 with a cavity 2a is shown. The hollow component 2 according to the 3 is essentially designed as a pipe (section) or channel (section) with round openings 7a, 7b at each end. This can be, for example, a cooling channel, wherein the flushing medium for cleaning it is preferably liquid. The hollow component 2 according to the 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 hidden due to the perspective, as well as hidden edges of the respective hollow component 2 are shown in dashed lines. The hollow component 2 can also be designed differently than shown in the 3 and 4 is shown, provided it has a cavity 2a and at least one, preferably two openings 7a, 7b. The openings 7a, 7b can have any shape.

1. (a) Anschließen der Hohlbauteile 2 in jeweils einem separaten Leitungsabschnitt 4a eines Leitungssystems 4, wobei eine erste Öffnung 7a des Hohlraums 2a des jeweiligen Hohlbauteils 2 mit einem Einlass 5 des Leitungssystems 4 sowie eine zweite Öffnung 7b des Hohlraums 2a des jeweiligen Hohlbauteils 2 mit einem Auslass 6 des Leitungssystems 4 lösbar verbunden wird, so dass ein Spülmedium in einer Spülrichtung durch die Hohlräume 2a der Hohlbauteile 2 von dem Einlass 5 zu dem Auslass 6 fließen kann;
2. (b) Leiten des Spülmediums durch die Hohlbauteile 2 und die zugehörigen Leitungsabschnitte 4a;
3. (c) Ansteuern eines in Spülrichtung betrachtet hinter den Hohlbauteilen 2 angeordneten Verteilerventils 9 derart, dass der Anteil des Spülmediums, welcher durch ein ausgewähltes Hohlbauteil 2 und den zugehörigen Leitungsabschnitt 4a geleitet wurde, einem Partikelzähler 8 zugeführt wird;
4. (d) Detektieren und charakterisieren von beim Durchfluss des Spülmediums aus dem Hohlbauteil 2 herausgespülten Partikeln;
5. (e) Iteratives wiederholen der Schritte (c) und (d), um alle Hohlbauteile 2 nacheinander zu prüfen; und
6. (f) Stoppen des Spülmediums, sobald der Partikelzähler 8 eine definierte Spezifikation für alle Hohlbauteile 2 feststellt, insbesondere sobald jeweils eine definierte Partikelzahl pro Volumen unterschritten wird.

The 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 components 2 for use in a cleanroom environment. The method includes at least the following steps:

1. (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;
2. (b) guiding the flushing medium through the hollow components 2 and the associated line sections 4a;
3. (c) controlling a distribution 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;
4. (d) detecting and characterising particles flushed out of the hollow component 2 during the flow of the flushing medium;
5. (e) Iteratively repeating steps (c) and (d) to test all hollow components 2 one after the other; and
6. (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.

The sequence of the steps can be varied and/or at least partially performed simultaneously. Additional steps and/or intermediate steps can also be provided. The method described above and variants of this method can be carried out in a particularly advantageous manner using a device 1 according to the invention. Reference is made to the above description.

The 2 1 schematically illustrates the device 1 or the method by way of example for six hollow components 2, each with a cavity 2a, each with two openings 7a, 7b. It should be noted that the six hollow components 2 can be identical or different. Furthermore, after their respective cleaning and testing, the six hollow components 2 can, if necessary, be intended for further use for different purposes and/or for integration into different devices or systems, in particular vacuum systems.

The 1 to 4 further serve to disclose a lithography system according to the invention, in particular a projection exposure apparatus 100 for semiconductor lithography. The lithography system according to the invention comprises, inter alia, 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-conducting hollow component 2 near the reticle 106, is provided with by means of a device 1 according to the above description and/or by means of a method according to the above description and checked for cleanliness.

The lithography system or projection exposure apparatus 100 for semiconductor lithography can in particular be an EUV projection exposure apparatus for microlithography according to the 1 as described above. The hollow component 2 provided in the context of this invention is shown in the 1 not shown. Alternatively, the lithography system may be a DUV projection exposure system, which is not shown in the drawing, or another type of projection exposure system.

If the hollow component 2 is a hollow component 2 intended for conducting a gas in the lithography system, a gaseous flushing medium is preferably selected for cleaning and/or checking for cleanliness. Similarly, for a hollow component 2 intended for conducting a liquid in the lithography system, a liquid flushing medium is preferably selected.

List of reference symbols

1

device

2

Hollow component

2a

cavity

3

Housing (clean room environment)

4

piping system

4a

Line section

5

inlet

6

Outlet

7a

First opening

7b

Second opening

8

particle counter

9

distribution valve

10

flow meter

11

filter

100

EUV projection exposure system

101

lighting system

102

Radiation source

103

Lighting optics

104

Object field

105

Object level

106

Reticle

107

Reticle holder

108

Reticle displacement drive

109

Projection optics

110

Image field

111

Image plane

112

wafers

113

Wafer holder

114

Wafer relocation drive

115

EUV / useful / illumination radiation

116

collector

117

Intermediate focal plane

118

Deflecting mirror

119

first facet mirror / field facet mirror

120

first facets / field facets

121

second facet mirror / pupil facet mirror

122

second facets / pupil facets

Wed

Mirror

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• 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

• DIN standard EN ISO 14644 [0026]
• Framework of the European standard or DIN standard EN ISO 14644 [0046]

Claims (15)

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 line system (4) for conducting the flushing medium, wherein the line 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 line system (4) through the cavity (2a) of the hollow component (2) to an outlet (6) of the line 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, in order to to detect particles flushed out of the hollow component (2) in the flushing medium. Device (1) according to Claim 1 , wherein the particle counter (8) is designed and constructed to detect at least particles having a minimum diameter of 500 nm, preferably 100 nm, more preferably 50 nm, particularly preferably 10 nm. 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. 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. Device (1) according to one of the Claims 1 until 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 flushing medium which is not passed through the particle counter (8) and/or the outlet (6). Device (1) according to one of the Claims 1 until 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). Device (1) according to one of the Claims 1 until 6 , wherein the line system (4) is set up 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). 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 flushing medium which is conducted through a selected hollow component (2) and the associated line section (4a) can be fed to the particle counter (8). Device (1) according to one of the 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). Device (1) according to one of the Claims 1 until 9 , wherein the inlet (5) has a filter (11) for filtering the flushing medium. Device (1) according to one of the Claims 1 until 10 , wherein the flushing medium is gaseous, preferably nitrogen, carbon dioxide and/or dry purified air. Device (1) according to one of the Claims 1 until 10 , wherein the rinsing medium is liquid, preferably purified water and/or water with cleaning additives. Device (1) according to one of the Claims 1 until 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. Method for cleaning and testing 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 distribution valve (9) arranged downstream of the hollow components (2) as viewed in the flushing direction in such a way that the portion of the flushing medium which was passed through a selected hollow component (2) and the associated line 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 repeating steps (c) and (d) in order to check all hollow components (2) one after the other; and (f) stopping the flushing medium as soon as the particle counter (8) determines a defined specification for all hollow components (2), in particular as soon as a defined number of particles per volume is undershot in each case. 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 in that at least one hollow component (2) of the lithography system, in particular a gas-conducting hollow component (2) near the reticle (106), is illuminated by means of a device (1) according to one of the Claims 1 until 13 and/or by means of a procedure according to Claim 14 cleaned and checked for cleanliness.

Images