Device and method for cleaning the surface of a component and lithography system

Abstract

The invention relates to a device for cleaning a surface (1a) of a component (1), in particular a component (1) of a lithography system (100, 200), with at least one cleaning nozzle (2) for aspirating a medium (3) from the surface (1a), wherein a guide device (4) is provided which is configured to move the cleaning nozzle (2) without contact during cleaning at least along a section of the surface (1a).The cleaning nozzle (2) has a suction channel (5) with a suction opening (6) facing the surface (1a) of the component (1) for suctioning the medium (3), a Venturi nozzle (7) for generating a suction effect in the suction opening (6), a first pressurized gas connection (8) for the Venturi nozzle (7), an outlet opening (9) arranged downstream of the Venturi nozzle (7) for the outlet of the medium (3) suctioned from the surface (1a), a blow-out ring (10) radially surrounding the suction opening (6) with a plurality of blow-out openings (11) and a second pressurized gas connection (12) for supplying the blow-out openings (11) in the blow-out ring (10) with a pressurized gas. A gas jet directed towards the surface (1a) of the component (1) emerges from each of the vent openings (11), the gas jets being directed towards a longitudinal axis (13) of the extraction duct (5).

Description

The invention relates to an apparatus for cleaning a surface of a component, in particular a component of a lithography system.The invention further relates to a method for cleaning a surface of a component, in particular a component of a lithography system.The invention furthermore relates to a lithography system, in particular a projection exposure apparatus for semiconductor lithography, having an illumination system having a radiation source and an optical unit which has at least one optical component.Methods and devices for cleaning a surface of a component are known from the prior art in different embodiments and for different technical purposes.Particularly in the cleaning of an optical surface of a component, e.g. a lens or a mirror, high quality requirements are placed on the cleaning. It is also important to ensure that the surface is not damaged, in particular is not scratched, during cleaning or during the removal of a medium from the surface.Particularly high requirements for cleaning a surface of a component are met if the surface to be cleaned is the surface of a lens or a mirror of a lithography system, in particular an EUV or a DUV projection exposure apparatus.Lenses and mirrors for guiding and shaping radiation in projection exposure apparatuses are known from the general prior art. In the known lenses and mirrors, a surface of the optical component frequently guides and shapes the light waves incident on the optical component. In order to form an exact wavefront with desired properties, it is of particular importance in this case that the surface is not damaged and neither particles or foreign particles nor residues of a cleaning medium remain on the surface.Lithography systems, in particular projection exposure apparatus for semiconductor lithography, are known from the prior art, which use ultraviolet radiation, in particular DUV (deep ultra violet) and / or EUV (extreme ultra violet) light, in order to produce microlithography structures with the highest precision. In this case, the light of a radiation source is directed via a plurality of mirrors to a wafer to be exposed. An exact configuration of the surface shape of the mirror thereby contributes critically to the quality of the exposure.In order to meet the high accuracy requirements, it is known to use wet chemical cleaning processes during the production of the mirrors and the lenses.Ultrasonic cleaning systems or ultrasonic dipping systems are known for this purpose from the prior art, which enable automated cleaning and subsequent automated drying of the surface of the component.The prior art also discloses robot-assisted cleaning after polishing the surface of a component, in particular a mirror, in order to remove the removal and the polishing agent.However, situations may occur in the prior art in which automated ultrasonic cleaning with subsequent automated drying of a surface of a component, in particular of a mirror, is not possible, for example on processing machines in order to remove process media, or on already mounted components, in particular mirrors of EUV projection exposure apparatuses.In these cases, after the wet chemical cleaning, the surface is rubbed off with cloths to dry the component. In this case, in particular, a liquid medium which was used in the wet chemical cleaning process and which can be a liquid cleaning medium, a liquid rinsing medium or process auxiliary substances is to be removed. This can result in residues such as smearing of the cleaning medium and process auxiliary substances. In particular, when already finish-polished mirror or lens surfaces are cleaned, there is a risk of surface damage due to the rubbing of the surface with the wipes, as a result of which scratches can also be produced.It is also known from the prior art that particles or foreign particles have to be removed from the surface of the lens or of the mirror in order that the high accuracy requirements can be complied with. It may be necessary to remove particles or foreign particles both before and after the coating of the lens or of the mirror. It can also occur that in already finished lenses or mirrors particles must be removed from the surface before delivery or also during use by the customer, so that the high accuracy requirements placed on the optical components, for example of a projection exposure apparatus, can be fulfilled.When removing the particles, it is important to take care in particular that, on the one hand, the particle or the medium is removed without leaving any residue and, on the other hand, damage to the surface is avoided.The object of the present invention is therefore to provide a device for cleaning a surface of a component, in particular a component of a lithography system, with which a medium to be removed from the surface of the component can be removed without leaving any residue without the surface of the component being damaged.According to the invention, this object is achieved by a device having the features mentioned in claim 1.The present invention is further based on the object of providing a method for cleaning a surface of a component, in particular a component of a lithography system, which method makes it possible to remove a medium from the surface of the component without leaving any residue without the surface of the component being damaged.According to the invention, this object is achieved by a method having the features mentioned in claim 13.The present invention is furthermore based on the object of creating a lithography system, in particular a projection exposure apparatus for semiconductor lithography, which avoids the disadvantages of the prior art, in particular has reliably cleaned optical components.According to the invention, this object is achieved by a lithography system for semiconductor lithography having the features mentioned in claim 17.The device according to the invention for cleaning a surface of a component, in particular a component of a lithography system, has at least one cleaning nozzle for suctioning a medium from the surface. A guide device is provided which is configured to move the cleaning nozzle contactless during cleaning at least along a section of the surface. The cleaning nozzle has a suction channel with a suction opening facing the surface of the component for suctioning the medium, a Venturi nozzle for generating a suction effect in the suction opening, a first compressed gas connection for the Venturi nozzle, an outlet opening arranged after the Venturi nozzle in the flow direction for the outlet of the medium suctioned from the surface, a blow-out ring radially surrounding the suction opening with a plurality of blow-out openings, and a second compressed gas connection for supplying the blow-out opening in the blow-out ring with a pressurized gas. A gas jet directed onto the surface of the component exits from each of the blow-out openings. The gas jets are oriented in the direction of a longitudinal axis of the suction channel.The device according to the invention is particularly suitable when automated ultrasonic dip cleaning including drying cannot be used, for example on stand-up mirrors.It has been found that with the device according to the invention, a medium located on the surface of the component can be sucked off in a particularly advantageous manner without contact with the surface, for example by a cloth, being necessary. The cleaning nozzle can be moved by means of the guide device contactless at least along a section of the surface. Preferably, the cleaning nozzle can be moved at least along the section of the surface at which the medium to be sucked off is located. It can also be provided in a further advantageous manner that the guide device moves the cleaning nozzle along the entire section of the surface, in particular if the cleaning nozzle is used for drying a surface after wet chemical cleaning and a cleaning medium or a rinsing medium is to be suctioned off in the process.It has been shown that a particularly advantageous suction results if the cleaning nozzle has a Venturi nozzle or if the Venturi effect is used in the cleaning nozzle in such a way that a suction effect is generated in the suction opening facing the surface of the component. A Venturi nozzle is a component based on the principle of the Venturi effect. A constriction is provided at one location. The fluid (liquid or gas) flowing through the nozzle accelerates in the constriction and generates a negative pressure. This phenomenon is based on the principle of continuity and the Bernoulli equation. Due to the negative pressure in the constriction of the nozzle, a Venturi nozzle can suck in liquids or gases. It has been found that the medium to be sucked off according to the invention can be sucked off in a particularly advantageous manner by means of a Venturi nozzle. In addition, in the device according to the invention, it is provided that the suction opening or the suction channel is radially surrounded by a blow-out ring, which has a plurality of blow-out openings. The inventors have recognized that the suction output increases significantly by a pressurized gas being conducted from the blow-out openings onto the surface of the component, wherein the blow-out openings are aligned such that the gas jets aligned on the surface of the component are aligned in the direction of the (notionally extended) longitudinal axis of the suction channel.It is advantageous if the gas jets are oriented on the surface of the component in such a way that the gas jets enclose or delimit a preferably at least approximately circular-shaped effective region, so that the gas jets contribute to concentrating the medium to be sucked off onto a region around the longitudinal axis of the suction channel and thus centrally below the suction opening.The inventors have recognized that if the gas jets are aligned on the surface of the component in such a way that the gas jets are not aligned axially, i.e. parallel to the longitudinal axis of the suction channel, on the surface, but are instead inclined in the direction of the longitudinal axis or are aligned towards each other, a particularly advantageous suction results.It is advantageous here if the gas jets are not concentrated on a common point on the surface, but rather strike the surface radially around the longitudinal axis, preferably at least partially in the shape of a circle, so that the gas jets surround an area of action. From the location of the surface on which the gas jets impinge, the gas jets are deflected by the suction effect of the suction channel or the suction opening and sucked into the suction channel, whereby the medium to be sucked away is particularly advantageously entrained.The device according to the invention enables contactless cleaning, in particular also contactless drying after a wet chemical cleaning process. Charging of the surface of the component, such as in the case of frictional contact with the surface, for example a mirror surface, by means of which the deposition of particles is promoted, is avoided by the device according to the invention.The device according to the invention is suitable not only for drying after the wet chemical cleaning, but generally for suctioning off a medium, in particular also for suctioning off particles from the surface without creating scratches or wipers. The device according to the invention is also suitable in particular for sucking off a liquid medium, for example water. Additionally or alternatively, the device according to the invention can also be used to suck away particles, in particular also dry particles.The optimization, configuration and use of a cleaning nozzle utilizing the Venturi effect in such a way that it is used for suctioning off particles and liquids has proven to be particularly suitable.The outlet opening arranged after the Venturi nozzle in the flow direction for the outlet of the medium suctioned off from the surface allows it to be removed particularly advantageously. A line, preferably a hose, can preferably be connected to the outlet opening, through which line the medium, in particular a liquid medium or even particles, can be discharged.It has been found to be particularly suitable if the exhaust openings are arranged in an exhaust ring which radially surrounds the suction opening. However, other configurations are also possible here, preferably such that the blow-out openings radially surround the suction opening.The device according to the invention provides two or at least two compressed gas connections.The first compressed gas connection is provided for the Venturi nozzle for generating the suction effect in the suction opening. With respect to a longitudinal axis of the cleaning nozzle or a longitudinal axis of the suction channel, a central suction of the medium is preferably to be achieved.The second compressed gas connection serves to supply the blow-out openings in the blow-out ring, so that a gas under pressure can be aligned on the surface of the component, in particular in order to center the medium to be sucked off. The blow-out openings can also be referred to as media-collecting holes in the blow-out ring. It is also possible to provide a plurality of second compressed gas connections, in particular in such a way that in each case a group of blow-out openings or each blow-out opening is individually supplied with compressed gas from a second compressed gas connection. This could help improve the homogeneity of the gas jets exiting the respective exhaust openings. Furthermore, different pressures can optionally be selected in a targeted manner for individual suction openings or groups of suction openings. However, the inventors have recognized that it is sufficient to provide exactly one second compressed gas connection which supplies all the blow-out openings with the compressed gas.In a simple embodiment of the invention (not according to the invention), instead of a first and a second compressed gas connection, only one compressed gas connection can be provided, which supplies both the Venturi nozzle and the blow-out openings. However, this has proved to be less suitable, since the suction pressure cannot then be adjusted independently of the blowing-out pressure. At least, individual adjustment is not readily possible.The blow-out openings can be formed as holes or bores. However, the blow-out openings can also be slots which preferably extend along the circular path of the blow-out ring or concentrically. A mixture is also possible, i.e. a part of the blow-out openings are formed as holes, preferably as circular holes, and a part of the blow-out openings are formed as slots.According to the invention, it can furthermore be provided that the blow-out openings are oriented such that an angle α between the longitudinal axis of the suction channel and the gas jets is 10° to 80°, more preferably 20° to 70°, particularly preferably 30° to 60°, in particular 40° to 50°.These values have proven to be particularly suitable for centering the medium and thereby increasing the suction output.It has been found to be particularly suitable if the blow-out openings are oriented such that the gas jets emerging from the blow-out openings in the direction of the surface converge, but without encountering one point on the surface. Preferably, the gas jets enclose or surround an effective area. A center point of the area of action is preferably located on the longitudinal axis of the suction channel. The effective region preferably has a diameter which is smaller than the diameter of the suction opening, preferably smaller than 80% of the diameter of the suction opening, in particular smaller than 50% of the diameter of the suction opening.The orientation of the blow-out openings is preferably predefined to be rigid or invariable, wherein the range of action can be changed if necessary by the distance which the cleaning nozzle has from the surface of the component.The blow-out openings can be aligned in such a way that the gas jets converge conically or conically. The cone, which results from the alignment of the gas jets, opens from the surface in the direction of the suction opening or runs in the direction of the surface of the component. It is preferably not provided here that the cone that the gas jets simulate has a tip. The gas jets preferably reproduce a truncated cone whose appearance depends, inter alia, on the size of the range of action. An opening angle of the cone of 30° to 90°, in particular of 40 to 60°, has proven to be particularly suitable for centering the medium and for increasing the suction output.According to the invention, it can be provided that the blow-out ring has two to twenty blow-out openings, preferably five to fifteen blow-out openings.The aforementioned number of blow-out openings has proven to be particularly suitable.It is advantageous if the blow-out openings are arranged with a uniform angular spacing along a circumferential circular path of the blow-out ring.It has been found to be suitable if the blow-out openings are arranged at a uniform angular spacing or a uniform spacing or uniformly along a circumferential circular path of the blow-out ring.According to the invention, it can also be provided that the blow-out ring has at least one ring arc free of blow-out openings with a central angle β of 30° to 90°, preferably of 30° to 60°, in particular of 40° to 60°, which has no blow-out openings.It has surprisingly been found to be advantageous if the blow-out ring has at least one ring arc free of blow-out openings, i.e. no blow-out openings are provided along an arc-shaped section of the blow-out ring, wherein the arc-shaped section has a central angle of 30° to 90°, preferably 30° to 60°, in particular 40° to 60°. In the region in which the blow-out ring has the blow-out openings, these are preferably arranged at a uniform angular spacing or at least predominantly at a uniform angular spacing.According to the invention, the blow-out ring can have two ring arches which are free of blow-out openings and are formed on the blow-out ring offset by 180°.The formation of two annular arches free of blow-out openings, which are formed at opposite points on the blow-out ring and which preferably have the same length or the same central angle β, has proven to be particularly suitable so that the guide device or the cleaning nozzle, in particular a robot head to which the cleaning nozzle is fastened, does not have to be rotated, in particular in the case of meandering travel of the surface, since one of the annular arches free of blow-out openings can always be moved in the direction of travel.The ring arches on the blow-out ring prevent redistribution of the components or the medium (liquid as well as particulate) to be removed from the surface. The annular arcs lead to the suction of the medium in front of the respective annular arc in the direction of travel (and thus to its suction), which is located outside the nozzle diameter or the diameter of the suction opening (i.e. in front of the nozzle or the suction opening in the direction of travel).It is advantageous if the pressure at the two compressed gas connections can be adjusted independently of one another.It has been found to be particularly suitable if the pressures at the two compressed gas connections, i.e. the first compressed gas connection and the second compressed gas connection, can be set independently of one another or a setting or regulation which is independent of one another is possible.According to the invention, it can be provided that a particle filter is inserted in the second compressed gas connection and / or a connected pressure line.It has been found to be particularly suitable if a particle filter is inserted in the second compressed gas connection and / or a connected pressure line. This prevents particles from being applied to the surface from the blow-out openings. The formation of a particle filter in the first compressed gas connection and / or a connected pressure line of the first compressed gas connection can, on the other hand, be dispensed with. The particle filter can preferably be designed, in particular if the surface to be cleaned is an optical surface, in particular a surface of a lens or a mirror, in particular of a lithography system, preferably an EUV or a DUV projection exposure apparatus, in such a way that particles with a size of 3 nm (and greater) can be filtered.It is advantageous if nitrogen or dried air, in particular XCDA, is used as the gas for supplying the second compressed gas connection.The aforementioned gases have proven to be particularly suitable for supplying the second compressed gas connection. In particular, it has been found that nitrogen is particularly suitable for blowing particles which are located on the surface of the component. Also, dried air, in particular air with the designation XCDA (Extreme Clean Dry Air), i.e. air suitable for clean rooms, has proven to be particularly suitable.Conventional air can be used for the first compressed gas connection for generating the Venturi effect.In particular if the surface to be cleaned is an optical surface of a lens or a mirror of an EUV or a DUV projection exposure apparatus, it can however also be advantageous for the second compressed gas connection if air with the designation XCDA is used.According to the invention, it can furthermore be provided that the guide device can be controlled in such a way that the distance between the cleaning nozzle and the surface of the component during cleaning is 5 mm to 100 mm, preferably 10 mm to 80 mm, in particular 10 mm to 50 mm.It has been found to be particularly suitable if the cleaning nozzle is moved in such a way that the distance between the cleaning nozzle and the surface of the component has the aforementioned values. An advantageous distance control can be effected, for example, by a model contour or by the fact that the guide device and / or the cleaning nozzle have sensors for determining or detecting the distance. The sensors can preferably be ultrasonic sensors.It can be advantageous if-if appropriate adapted to the medium to be sucked off-the alignment of the blowing openings and the distance between the cleaning nozzle, in particular an underside of the cleaning nozzle facing the surface of the component and the surface of the component are matched to one another. For this purpose, the above-mentioned values have proven to be particularly suitable.According to the invention, it can furthermore be provided that the guide device is moved along the surface of the component in a robot-assisted and / or automated manner.It has proven particularly suitable if the guide device is part of a robot, in particular a six-axis robot, or the guide device is preferably detachably fastened to a robot, in particular a six-axis robot. The guide device and / or optionally the robot as part of the guide device can be correspondingly configured in this case, such that the cleaning nozzle can be moved contactless during the cleaning at least along a section of the surface, preferably at a constant distance.According to the invention, it can be provided that the surface is an optical surface, in particular a surface of a lens or a mirror, in particular of a lithography system, preferably of an EUV or a DUV projection exposure apparatus.The device according to the invention is particularly suitable if the surface is the surface of a lens or a mirror of an EUV or a DUV projection exposure apparatus, in particular if it has been previously wet-chemically cleaned and is provided for drying the surface, i.e. for removing the medium which is located on the surface after cleaning, in particular a cleaning medium or a rinsing medium, by suction. However, the device according to the invention is also particularly suitable for sucking away particles before coating the surface of a lens or a mirror or even after coating. The apparatus according to the invention can advantageously also be used to clean lenses or mirrors of an EUV or DUV projection exposure apparatus, which are already used, directly at the customer or, if the lenses or the mirrors are returned for repair or for processing, with the aid of the apparatus according to the invention, in particular also in order to suck away particles.The device according to the invention and the method according to the invention are also particularly suitable for carrying out a cleaning with them after polishing an optical surface, in particular a surface of a lens or a mirror.The present invention also relates to a method for cleaning a surface of a component, in particular a component of a lithography system, according to which at least one cleaning nozzle is moved along the surface in an automated and / or robot-assisted manner, wherein the cleaning nozzle is designed such that it generates a suction effect by a Venturi effect, as a result of which a medium is suctioned from the surface through a suction opening into a suction channel of the cleaning nozzle, wherein the cleaning nozzle has outflow openings which radially surround the suction opening, wherein a respective gas jet directed onto the surface of the component emerges from the outflow openings during the suction, wherein the outflow openings are aligned such that the gas jets are aligned in the direction of a longitudinal axis of the suction channel.The contactless method according to the invention for cleaning a surface of a component has proven to be particularly suitable for suctioning a medium from the surface. It has been shown that a particularly high suction performance results from the fact that a suction effect is generated by the Venturi effect and this suction effect is further supported by the fact that blow-out openings are provided, from which a gas jet directed onto the surface of the component respectively exits during the suction, wherein the gas jets preferably enclose or surround an effective region in which the medium to be sucked off is located on the surface. For this purpose, an alignment of the blow-out openings has proven to be such that the gas jets converge conically or conically or are aligned on the longitudinal axis of the suction channel.According to the invention, it can furthermore be provided that the method is used for cleaning an optical surface, in particular a surface of a lens or a mirror, in particular of a lithography system, preferably an EUV or a DUV projection exposure apparatus.An application of the method according to the invention for cleaning a surface of a lens or a mirror of an EUV or a DUV projection exposure apparatus is particularly suitable.According to the invention, it can furthermore be provided that firstly a wet chemical cleaning of the surface is carried out, wherein the medium to be sucked off is a liquid cleaning medium and / or a liquid rinsing medium and / or a process auxiliary agent, which is sucked off by means of the cleaning nozzle after the wet chemical cleaning of the surface.The configuration of the method according to the invention such that it firstly includes a wet chemical cleaning of the surface or firstly a wet chemical cleaning of the surface is carried out and then the medium is suctioned off by means of the cleaning nozzle has proven to be particularly suitable. This results in an especially advantageous cleaning of a surface without the risk that the surface, in particular an optical surface, is damaged by contact. It has been shown that, in particular, a liquid medium can be suctioned off particularly advantageously with the method according to the invention.According to the invention, it can furthermore be provided that the medium to be sucked off is a particle which is located on the surface, in particular a coated surface of a lens or a mirror, in particular an EUV or a DUV projection exposure apparatus, wherein the gas stream flowing out of the blow-out openings encloses an action region within which the particle to be sucked off is located.It has been shown that the method according to the invention can also be used particularly advantageously in order to suck off a medium which is a particle, in particular also a dry particle. The method according to the invention has proven to be particularly suitable for removing particles, in particular from sensitive surfaces. This is particularly important, especially in the case of surfaces of a lens or of a mirror, in particular of an EUV or DUV projection exposure apparatus. The method according to the invention is suitable not only for removing particles from the surface before or after coating it, but also for cleaning already completed lenses or mirrors, in particular also lenses or mirrors, which are in use.The present invention also relates to a lithography system, in particular a projection exposure apparatus for semiconductor lithography, having an illumination system having a radiation source and an optical unit which has at least one optical component. According to the invention, it is provided that at least one of the optical components, in particular a lens or a mirror, is at least partially cleaned by means of the device according to the invention and / or by means of the method according to the invention.Features which have been described in connection with one of the subject matters of the invention, namely given by the apparatus, 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 which have been 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.In addition, it should be pointed out that terms such as "comprising", "having" or "having" do not exclude other features or steps. Further, terms such as "a" or "the" that indicate a singular number of steps or features do not exclude a plurality of features or steps - and vice versa.In a heuristic embodiment of the invention, however, it can also be provided that the features introduced in the invention with the terms "comprising", "having" or "with" are listed in the end. Accordingly, one or more enumerations of features within the scope of the invention may be considered as completed, for example considered for each claim. The invention can consist, for example, exclusively of the features mentioned in claim 1.It should be noted that terms such as "first" or "second", etc. are used primarily for reasons of distinguishability of respective device or method features and are not necessarily intended to indicate that features are mutually related or are related to one another.Exemplary embodiments of the invention are described in more detail below with reference to the drawings.The figures each show preferred exemplary embodiments in which individual features of the present invention are shown in combination with one another. Features of an exemplary embodiment can also be implemented separately from the other features of the same exemplary embodiment and can accordingly be easily combined with features of other exemplary embodiments by a person skilled in the art to form further meaningful combinations and sub-combinations.In the figures, functionally identical elements are provided with the same reference numerals.The following are shown: FIG. 1 shows an EUV projection exposure apparatus in meridional section; FIG. 2 shows a DUV projection exposure apparatus; FIG. 3 shows a schematic illustration of an apparatus according to the invention with a cleaning nozzle and a guide device which sucks a medium from a surface of a component which is illustrated only in sections; FIG. 4 shows a schematic perspective view of a cleaning nozzle from a viewing direction in which the suction opening can be seen; FIG. 5 is a schematic illustration from below of a cleaning nozzle; FIG. 6 is a schematic side view of a cleaning nozzle; and FIG. 7 is a cross-section through a cleaning nozzle.In the following, first of all, with reference to FIG. 1, the essential components of an EUV projection exposure apparatus 100 for microlithography are described by way of example as an example of a lithography system. The description of the basic design of the EUV projection exposure apparatus 100 and its components should not be understood here as restrictive.An illumination system 101 of the EUV projection exposure apparatus 100 has, in addition to a radiation source 102, an illumination optical unit 103 for illuminating an object field 104 in an object plane 105. In this case, 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.For the purpose of explanation, a Cartesian xyz-coordinate system is drawn in FIG. 1. The x-direction extends perpendicularly into the plane of the drawing. The y-direction runs horizontally and the z-direction runs vertically. The scanning direction runs along the y-direction in FIG. 1. The z-direction runs perpendicular to the object plane 105.The EUV projection exposure apparatus 100 comprises a projection optical unit 109. The projection optical unit 109 serves for imaging the object field 104 into an image field 110 in an image plane 111. The image plane 111 extends parallel to the object plane 105. Alternatively, an angle different from 0° is also possible between the object plane 105 and the image plane 111.A structure on the reticle 106 is imaged onto a light-sensitive layer of a wafer 112 arranged in the region of the image field 110 in the image plane 111. The wafer 112 is held by a wafer holder 113. The wafer holder 113 is displaceable in particular along the y-direction via a wafer displacement drive 114. The displacement of the reticle 106 via the reticle displacement drive 108 on the one hand and of the wafer 112 via the wafer displacement drive 114 on the other hand can take place in synchronization with one another.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 may be a plasma source, for example a LPP (Laser Produced Plasma) source or a DPP (Gas Discharged Produced Plasma) source. It can also be a synchrotron-based radiation source. The radiation source 102 may 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 may be a collector having one or more ellipsoidal and / or hyperbolic reflective surfaces. The illumination radiation 115 can be applied to the at least one reflection surface of the collector 116 in the grazing incidence ("Grazing Incidence", GI), that is to say with angles of incidence greater than 45°, or in the normal incidence ("Normal Incidence", NI), that is to say with angles of incidence less than 45°. The collector 116 can be structured and / or coated on the one hand for optimizing its reflectivity for the useful radiation 115 and on the other hand for suppressing false light.Downstream of the collector 116, the illumination radiation 115 propagates through an intermediate focus in an intermediate focus plane 117. The intermediate focus plane 117 may represent a separation between a radiation source module comprising the radiation source 102 and the collector 116, and the illumination optics 103.The illumination optical unit 103 comprises a deflection mirror 118 and, downstream thereof, a first facet mirror 119 in the beam path. The deflecting mirror 118 can be a planar deflecting mirror or alternatively a mirror having an effect influencing the beam beyond the pure deflecting effect. Alternatively or additionally, the deflecting mirror 118 can be designed as a spectral filter which separates a used light wavelength of the illumination radiation 115 from false light of a wavelength deviating therefrom. If the first facet mirror 119 is arranged in a plane of the illumination optical unit 103 which is optically conjugate to the object plane 105 as a field plane, this is also referred to as a field facet mirror. The first facet mirror 119 comprises a multiplicity of individual first facets 120, which are also referred to below as field facets. Of these facets 120, only some are illustrated by way of example in FIG. 1.The first facets 120 can be designed as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or part-circular edge contour. The first facets 120 can be embodied as planar facets or alternatively as convexly or concavely curved facets.As is known, for example, from DE 10 2008 009 600 A1, the first facets 120 themselves can also each be composed of a multiplicity of individual mirrors, in particular a multiplicity of micromirrors. The first facet mirror 119 can be designed, in particular, as a microelectromechanical system (MEMS system). For details, reference is made to DE 10 2008 009 600 A1.Between the collector 116 and the deflection mirror 118, the illumination radiation 115 extends horizontally, that is to say along the y-direction.In the beam path of the illumination optical unit 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 optical unit 103, this is also referred to as pupil facet mirror. The second facet mirror 121 can also be arranged at a distance from a pupil plane of the illumination optical unit 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 US 2006 / 0132747 A1, EP 1 614 008 B1 and U.S. Pat. No. 6,573,978.The second facet mirror 121 comprises a plurality of second facets 122. The second facets 122 are also referred to as pupil facets in the case of a pupil facet mirror.The second facets 122 can likewise be macroscopic facets, which can be round, rectangular or else hexagonally bordered, for example, or alternatively facets composed of micromirrors. In this respect, reference is likewise made to DE 10 2008 009 600 A1.The second facets 122 may have planar or alternatively convexly or concavely curved reflection surfaces.The illumination optics 103 thus form a double faceted system. This basic principle is also referred to as a fly eye integrator ("Fly's Eye Integrator").It may be advantageous not to arrange the second facet mirror 121 exactly in a plane which is optically conjugate to a pupil plane of the projection optical unit 109.With the aid 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 beam-forming mirror or indeed the last mirror for the illumination radiation 115 in the beam path in front of the object field 104.In a further embodiment of the illumination optics 103, not shown, a transmission optics can be arranged in the beam path between the second facet mirror 121 and the object field 104, which in particular contributes 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, which are arranged one behind the other in the beam path of the illumination optics 103. The transmission optics can comprise in particular one or two mirrors for normal incidence (NI) mirrors and / or one or two mirrors for strobing incidence (GI) mirrors.In the embodiment shown in FIG. 1, the illumination optical unit 103 has exactly three mirrors downstream of the collector 116, namely the deflecting mirror 118, the field facet mirror 119 and the pupil facet mirror 121.In a further embodiment of the illumination optical unit 103, the deflecting mirror 118 can also be omitted, so that the illumination optical unit 103 can then have exactly two mirrors downstream of 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 optical unit into the object plane 105 is regularly only an approximate imaging.The projection optical unit 109 comprises a plurality of mirrors Mi, which are numbered in accordance with their arrangement in the beam path of the EUV projection exposure apparatus 100.In the example illustrated in FIG. 1, the projection optical unit 109 comprises six mirrors M 1 to M 6. Alternatives with four, eight, ten, twelve or another number of mirrors Mi are also possible. The next to last mirror M 5 and the last mirror M 6 each have a passage opening for the illumination radiation 115. The projection optical unit 109 is a double-obscured optical unit. The projection optics 109 has an image-side numerical aperture which is greater than 0.5 and which can also be greater than 0.6 and which can be, for example, 0.7 or 0.75.Reflection surfaces of the mirrors Mi can be designed as free-form surfaces without a rotational symmetry axis. Alternatively, the reflection surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflection surface shape. The mirrors Mi, like the mirrors of the illumination optical unit 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 may 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 may be the same or may be different depending on the embodiment of the projection optical unit 109. Examples of projection optics with different numbers of such intermediate images in the x and y directions are known from US 2018 / 0074303 A1.In each case one of the pupil facets 122 is assigned exactly to one of the field facets 120 for forming in each case an illumination channel for illuminating the object field 104. This can result in particular in illumination according to the Kohler principle. The far field is split into a plurality of object fields 104 with the aid 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 them in each case.The field facets 120 are imaged onto the reticle 106 in each case by an associated pupil facet 122 in a manner overlapping one another in order 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%. The field uniformity can be achieved by superimposing different illumination channels.By arranging the pupil facets, the illumination of the entry pupil of the projection optical unit 109 can be geometrically defined. By selecting the illumination channels, in particular the subset of the pupil facets which guide light, the intensity distribution in the entry pupil of the projection optical unit 109 can be adjusted. This intensity distribution is also referred to as illumination setting.A likewise preferred pupil uniformity in the region of sections of an illumination pupil of the illumination optical unit 103 that are illuminated in a defined manner can be achieved by redistribution of the illumination channels.Further aspects and details of the illumination of the object field 104 and in particular of the entry pupil of the projection optical unit 109 are described below.The projection optical unit 109 can have, in particular, a homocentric entry pupil. This can be accessible. It may also be inaccessible.The entry pupil of the projection optical unit 109 cannot be illuminated exactly with the pupil facet mirror 121 as a rule. In an image of the projection optical unit 109 which images the center of the pupil facet mirror 121 telecentrically onto the wafer 112, the aperture beams often do not intersect at a single point. However, an area can be found in which the paired distance of the aperture beams becomes minimum. This surface represents the entry pupil or a surface in the spatial domain which is conjugated to it. In particular, this surface exhibits a finite curvature.It can be that the projection optics 109 have different positions of the entrance pupil for the tangential and for the sagittal beam path. 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 aid of this optical component, the different position of the tangential entry pupil and of the sagittal entry pupil can be taken into account.In the arrangement of the components of the illumination optical unit 103 illustrated in FIG. 1, the pupil facet mirror 121 is arranged in a surface conjugate to the entry pupil of the projection optical unit 109. The first field facet mirror 119 is arranged tilted with respect to the object plane 105. The first facet mirror 119 is arranged tilted with respect to an arrangement plane which is defined by the deflecting mirror 118.The first facet mirror 119 is arranged tilted with respect to an arrangement plane which is defined by the second facet mirror 121.FIG. 2 shows an exemplary DUV projection exposure apparatus 200. The DUV projection exposure apparatus 200 has an illumination system 201, a device, referred to as a reticle stage 202, for receiving and exactly positioning a reticle 203, by means of which the later structures on a wafer 204 are determined, a wafer holder 205 for holding, moving and exactly positioning the wafer 204, and an imaging device, namely a projection optical unit 206, having a plurality of optical elements, in particular lenses 207, which are held via mounts 208 in an objective housing 209 of the projection optical unit 206.Alternatively or additionally to the lenses 207 shown, various refractive, diffractive and / or reflective optical elements, including mirrors, prisms, end plates and the like, can be provided.The basic functional principle of the DUV projection exposure apparatus 200 provides that the structures introduced into the reticle 203 are imaged onto the wafer 204.The illumination system 201 provides a projection beam 210 in the form of electromagnetic radiation required for imaging the reticle 203 onto the wafer 204. A laser, a plasma source or the like can be used as the source for this radiation. The radiation is shaped in the illumination system 201 via optical elements such that the projection beam 210 has the desired properties with regard to diameter, polarization, shape of the wavefront and the like when incident on the reticle 203.An image of the reticle 203 is generated by means of the projection beam 210 and is transmitted to the wafer 204 in a correspondingly reduced manner by the projection optical unit 206. In this case, the reticle 203 and the wafer 204 can be moved synchronously, with the result that regions of the reticle 203 are imaged onto corresponding regions of the wafer 204 in a virtually continuous manner during a so-called scanning operation.Optionally, an air gap between the last lens 207 and the wafer 204 may be replaced by a liquid medium having a refractive index greater than 1.0. The liquid medium can be, for example, high-purity water. Such a structure is also referred to as immersion lithography and has an increased photolithographic resolution.The use of the invention is not restricted to use in projection exposure apparatuses 100, 200, in particular also not having the described structure. The invention is suitable for cleaning any desired surfaces of a component, in particular a component of a lithography system or microlithography system, but in particular for components of projection exposure apparatuses, having the described structure. The invention is also suitable for EUV projection exposure apparatuses which have a smaller image-side numerical aperture than that described in connection with FIG. 1 and also have no obscured mirror M 5 and / or M 6. In particular, the invention is also suitable for EUV projection exposure apparatuses which have an image-side numerical aperture of 0.25 to 0.5, preferably 0.3 to 0.4, particularly preferably 0.33. The invention and the following exemplary embodiments are furthermore not to be understood as being limited to a specific design.The following figures illustrate the invention merely by way of example and in a highly schematic manner.The device according to the invention, as illustrated in principle on the basis of the exemplary embodiments according to FIGS. 3 to 7, is suitable for cleaning a surface 1 aof any desired component 1.The device according to the invention has at least one cleaning nozzle 2 for suctioning a medium 3 from the surface 1 aof the component 1. The medium 3 can be, for example, a liquid, as shown in principle in FIG. 3, or else a particle, as shown in FIGS. 6 and 7, for example.In the exemplary embodiment, the device according to the invention has exactly one cleaning nozzle 2, but the device can also have a plurality of cleaning nozzles 2 or a plurality of devices according to the invention can be provided in order to suck medium 3 from a surface 1 a simultaneously or successively.In the exemplary embodiment, the surface 1 ais an optical surface 1 aor a reflective surface, in particular a surface of a lens or of a mirror, in particular of a lithography system, preferably of an EUV or a DUV projection exposure apparatus 100, 200.The device according to the invention also has, as shown in FIG. 3, a guide device 4.The guide device 4 is configured to move the cleaning nozzle 2 contactless during cleaning at least along a portion of the surface 1 a. In the exemplary embodiment, the cleaning nozzle 2 is moved over the entire surface 1 ato suck away the medium 3 there. However, it can also be provided that the cleaning nozzle 2 is moved by means of the guide device 4 only along the section of the surface 1 ain which the presence of a medium 3 to be sucked off has been previously determined.The guide device 4 can preferably be controlled in such a way that the distance between the cleaning nozzle 2 and the surface 1 aof the component 1 during cleaning is 5 mm to 100 mm, preferably 10 mm to 80 mm, in particular 10 mm to 50 mm.The guide device 4 can preferably be moved along the surface 1 aof the component 1 in a robot-assisted and / or automated manner.In the exemplary embodiment, the guide device 4 is designed as a six-axis robot, or the guide device 4 can be part of a six-axis robot.As can be seen in particular from the sectional view of FIG. 7, the cleaning nozzle 2 according to the invention has a suction channel 5 with a suction opening 6 facing the surface 1 aof the component 1 for suctioning the medium 3. Furthermore, the cleaning nozzle 2 has a Venturi nozzle 7 for generating a suction effect in the suction opening 6, a first compressed gas connection 8 for the Venturi nozzle 7, an outlet opening 9 arranged after the Venturi nozzle 7 in the flow direction for the outlet of the medium 3 sucked off from the surface 1 a, a blow-out ring 10 radially surrounding the suction opening 6 and having a plurality of blow-out openings 11 and a second compressed gas connection 12 for supplying the blow-out openings 11 with a pressurized gas.A view from below of the cleaning nozzle 2 with a schematic illustration of the blow-out ring 10 with the blow-out openings 11 can be seen from FIG. 5.A gas jet directed onto the surface 1 aof the component 1 flows out of each of the blow-out openings 11, wherein the gas jets are oriented in the direction of a longitudinal axis 13 of the suction duct 5.The term longitudinal axis 13 of the suction channel 5 is to be understood here in such a way that it is not only located within the suction channel 5, but is correspondingly extended. The feature that the gas jets are oriented in the direction of the longitudinal axis 13 of the suction channel 5 is intended to define that the gas jets, starting from the suction openings 6, do not run parallel to the longitudinal axis 13 of the suction channel 5 or the cleaning nozzle 2 downward in the direction of the surface 1 a, but rather are inclined somewhat radially inward. This is also illustrated in principle in FIGS. 6 and 7, wherein the gas jets which emerge from the blow-out openings 11 are illustrated in dashed lines.The blow-out openings 11 are oriented such that an angle α between the longitudinal axis 13 of the suction channel 5 and the gas jets is 10° to 80°, more preferably 20° to 70°, particularly preferably 30° to 60°, in particular 40° to 50°.The angle α is illustrated by way of example in FIG. 6. For this purpose, an auxiliary line is drawn adjacent to the right-hand gas jet, which line runs parallel to the longitudinal axis 13 and with the aid of which the angle α between the longitudinal axis 13 and the gas jet impinging on the surface 1 ais specified.In the exemplary embodiment, it is provided that the gas jets which emerge from the blow-out openings 11 do not converge on the surface at one point, but preferably at least partially enclose an area of action. The alignment of the gas jets thereby achieves that the medium 3 to be sucked off is centered, so that it is preferably located at a location which lies on the longitudinal axis 13 of the suction channel 5, whereby the suction is optimized.In FIGS. 6 and 7, the dashed line illustration of the gas jets represents that the gas or the gas jets emerging from the exhaust openings 11 are sucked into the exhaust opening 6 or into the exhaust duct 5 after they have struck the surface 1 aof the component 1, due to the suction effect which results from the Venturi nozzle 7. The suction effect is shown with the dashed arrow in FIG. 7. The suction along the suction channel 5 is symbolized by the single arrow shown in bold.In FIG. 7 or correspondingly in FIG. 6, it is provided that the blow-out openings 11 are arranged in the blow-out ring 10 or the gas jets emerge from the blow-out openings 11 in such a way that the effective region, which the gas jets enclose when the gas jets strike the surface 1 aof the component 1, is at least partially circular. The gas jets preferably surround the longitudinal axis 13 radially and at the same distance from the longitudinal axis 13.The gas jets are preferably oriented such that they would converge at a point of the longitudinal axis 13 which is located below the surface 1 aof the component 1 (not illustrated in FIGS. 6 and 7, but easily conceivable).In the exemplary embodiment, it is preferably provided that the blow-out ring 10 has two to twenty blow-out openings 11, preferably five to fifteen blow-out openings 11.In one exemplary embodiment, the blow-out openings 11 can be arranged along a circular path of the blow-out ring 10, preferably at a uniform angular distance from one another.It has been shown that it is particularly advantageous if the blow-out ring 10 has at least one ring bend 14 free of blow-out openings with a central angle β of 30° to 90°, preferably of 30° to 60°, in particular of 40° to 60°, which has no blow-out openings 11. In the exemplary embodiment, the blow-out ring 10 has two ring arches 14 free of blow-out openings. This is illustrated in principle in FIG. 5. It has been shown that by such an arrangement, undesired lateral splashing of the medium to be sucked off, in particular if this is a liquid, can be reduced. The cleaning nozzle 2 is preferably moved along the surface 1 ain such a way that one of the annular arches 14 free of blow-out openings is located in each case in the travel direction or in the front in the travel direction. In FIG. 5, the direction of travel of the cleaning nozzle 2 in a first direction and in an opposite second direction is illustrated by means of an arrow. The robot-supported guide device 4 can thus travel along the surface 1 aof the component 1, preferably in meandering fashion, without the need to rotate the cleaning nozzle 2, wherein one of the arches 14 is always located at the front in the direction of travel.In principle, it is also possible, in particular within the scope of the method according to the invention, for the formation of a blow-out ring 10 to be dispensed with and for the blow-out openings 11 to be arranged in another radial manner, preferably with a uniform angular spacing and preferably also with the formation of at least one annular arc free of blow-out openings, around the outlet opening 9 or the suction duct 5.However, it has proven to be advantageous if the blow-out openings 11 are arranged in a blow-out ring 10.In the exemplary embodiment, it is provided that the pressure at the two compressed gas connections 8, 12 can be adjusted independently of one another.The compressed gas connection 12, which supplies the blow-out openings 11 with a pressurized gas, is preferably connected to a section of the blow-out ring 10, which preferably has an annular distributor space in order to supply the blow-out openings 11 with the pressurized gas.A particle filter 15 (see FIG. 7 ) can be inserted in the second compressed gas connection 12 and / or a connected pressure line 12 a(which is illustrated in principle in FIG. 3 ). The particulate filter 15 may be configured to filter particulates having a size of 3 nm and larger.In the exemplary embodiment, nitrogen or dried air, in particular XCDA, is provided as the gas for supplying the second compressed gas connection 12. Conventional air or particularly preferably XCDA is preferably provided for the first compressed gas connection 8.FIG. 3 also shows, in principle, a pressure line 8a which is connected to the first compressed gas connection 8 for the Venturi nozzle 7. Furthermore, FIG. 3 illustrates in principle an outlet line 9 awhich is connected to the outlet opening 9 from which the suctioned-off medium 3 exits.The lines 8 a, 9 aand 12 acan preferably be designed as hoses.In a manner not shown in more detail, it can be provided that the cleaning nozzle 2 and / or the guide device 4 has sensors, preferably ultrasonic sensors, with the aid of which the distance between the cleaning nozzle 2 and the surface 1 acan be adjusted and / or monitored and / or corrected and / or regulated.In the exemplary embodiment, it is provided that a constriction 7 aof the Venturi nozzle 7 can be adjusted. For this purpose, it is provided in the exemplary embodiment that the cleaning nozzle 2 has a housing 16, into which a tubular element 17, which forms the suction channel 5, is preferably screwed. The screw-in depth allows the gap or the constriction 7 ato be adjusted. The tubular member 17 may be suitably sealed from the housing 16. A thread is only shown in principle in FIG. 7 and is not designated.It should be noted that the configuration of the Venturi nozzle 7 with a housing 16 and a tubular element 17 and also the possibility of setting the constriction 7 acan also be solved in another way in terms of design, but the design has proven particularly suitable. The narrowing 7 acan also be adjusted, for example, with the aid of a spring and / or a magnet, in particular an electromagnet, and in particular without a thread.In FIG. 7, the compressed gas connection 8 is closed by a plug 18. After removal of the plug 18, a pressure line 8a, not shown in FIG. 7, can be connected accordingly, so that an annular space 19 between the tubular element 17 and the housing 16 can be supplied with a pressurized gas. From the annular chamber 19 the pressurized gas then flows through the constriction 7a, whereby the Venturi effect is produced. The constriction 7 ais configured in such a way that the gas flowing out of the annular space 19 or out of the compressed gas connection 8 is conducted in the arrow direction into the suction channel 5, as a result of which the suction effect (see the dashed arrow in FIG. 7 ) is then generated and the medium 3 to be sucked off is sucked off.The exemplary embodiment also serves to disclose a method according to the invention for cleaning a surface 1 aof a component 1, in particular a component 1 of a lithography system, in particular an EUV or a DUV projection exposure apparatus 100, 200. In the context of the method, provision is made for a cleaning nozzle 2 to be moved along the surface 1 aof the component 1 in an automated and / or robot-assisted manner.The method according to the invention is suitable in particular for cleaning an optical surface 1 aor a reflective surface, in particular a surface 1 aof a component 1, which is a lens or a mirror, in particular a lens or a mirror of a lithography system, preferably an EUV or a DUV projection exposure apparatus 100, 200.In the context of the method according to the invention, firstly a wet chemical cleaning of the surface 1 acan be provided or carried out. The liquid cleaning medium used in the wet chemical cleaning and / or a liquid rinsing medium and / or a process auxiliary can then be suctioned off according to the invention by means of the cleaning nozzle after the wet chemical cleaning of the surface.The method according to the invention is also suitable when the medium to be sucked off is a particle, in particular a dry particle, which is located on the surface, in particular a coated surface 1 aof a lens or a mirror, in particular an EUV or a DUV projection exposure apparatus 100, 200. The gas stream flowing out of the blow-out openings 11 preferably includes an effective region within which the particle to be sucked off is located.The present exemplary embodiment also serves to disclose a lithography system, in particular a projection exposure apparatus for semiconductor lithography, having an illumination system 101, 201, having a radiation source 102 and having an optical unit 103, 109, 206 which has at least one optical component 116, 118, 119, 120, 121, 122, Mi, 207. It is provided that at least one of the optical components 116, 118, 119, 120, 121, 122, Mi, 207 is at least partially cleaned by means of the device according to the invention and / or by means of the method according to the invention.List of reference characters1 Component 1 aSurface 2 Cleaning nozzle 3 Medium 4 Guide device 5 Suction channel 6 Suction opening 7 Venturi nozzle 7 a Verengung 8 First compressed gas connection for the Venturi nozzle 8 a Druckleitung line 9 Outlet opening 9 a Austritts line 10 Exhaust ring 11 Exhaust opening 12 Second compressed gas connection (for the exhaust openings) 12 a Druckleitung line 13 Longitudinal axis 14 Exhaust-opening-free annular arc 15 Particle filter 16 Housing 17 Tubular element 18 Plug 19 Annular space 100 EUV projection exposure apparatus 101 Illumination system 102 Radiation source 103 Illumination optical unit 104 Object field 105 Object plane 106 Reticle 107 Reticle holder 108 Reticle displacement drive 109 Projection optical unit 110 Image field 111 Image plane 112 Wafer 113 Wafer holder 114 Wafer displacement drive 115 EUV / usable / illumination radiation 116 Collector 117 intermediate focal plane 118 deflection 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 200 DUV projection exposure apparatus 201 illumination system 202 reticle stage 203 reticle 204 wafer 205 wafer holder 206 projection optical unit 207 lens 208 mount 209 objective housing 210 projection beam Mi mirrorReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2008 009 600 A1 [0096, 0100]US 2006 / 0132747 A1

[0098] EP 1 614 008 B1

[0098] U.S. Pat. No. 6,573,978

[0098] US 2018 / 0074303 A1

[0113]

Claims

Device for cleaning a surface (1a) of a component (1), in particular a component (1) of a lithography system (100, 200), having at least one cleaning nozzle (2) for suctioning a medium (3) from the surface (1a), wherein a guide device (4) is provided, which is configured to move the cleaning nozzle (2) contactless during cleaning at least along a section of the surface (1a), and wherein the cleaning nozzle (2) has a suction channel (5) with a suction opening (6) facing the surface (1a) of the component (1) for suctioning the medium (3), a Venturi nozzle (7) for generating a suction effect in the suction opening (6), a first compressed gas connection (8) for the Venturi nozzle (7), an outlet opening (9) arranged downstream of the Venturi nozzle (7) in the flow direction for the outlet of the medium (3) sucked off from the surface (1a), an exhaust ring (10), radially surrounding the exhaust opening (6), having a plurality of exhaust openings (11), and a second compressed gas connection (12) for supplying the exhaust openings (11) in the exhaust ring (10) with a gas under pressure, wherein a gas jet directed onto the surface (1a) of the component (1) exits from each of the exhaust openings (11), wherein the gas jets are oriented in the direction of a longitudinal axis (13) of the exhaust channel (5).Device according to claim 1, characterised in that the blow-out openings (11) are oriented such that an angle (α) between the longitudinal axis (13) of the suction channel (5) and the gas jets is 10° to 80°, more preferably 20° to 70°, particularly preferably 30° to 60°, in particular 40° to 50°.Device according to claim 1 or 2, characterised in that the blow-out ring (10) has two to twenty blow-out openings (11), preferably five to fifteen blow-out openings (11).Device according to one of Claims 1 to 3, characterized in that the blowing-out openings (11) are arranged at a uniform angular spacing along a circumferential circular path of the blowing-out ring (10).Device according to one of Claims 1 to 3, characterized in that the blow-out ring (10) has at least one annular bend (14) which is free of blow-out openings and has a central angle β of 30° to 90°, preferably of 30° to 60°, in particular of 40° to 60°, and has no blow-out openings (11).Device according to claim 5, characterised in that the blow-out ring (10) has two ring arches (14) free from blow-out openings, which are formed on the blow-out ring (10) offset by 180°.Device according to one of Claims 1 to 6, characterized in that the pressure at the two compressed-gas connections (8, 12) can be adjusted independently of one another.Device according to one of Claims 1 to 7, characterized in that a particle filter (15) is inserted in the second compressed gas connection (12) and / or a connected pressure line (12a).Device according to one of Claims 1 to 8, characterized in that nitrogen or dried air, in particular XCDA, is used as the gas for supplying the second compressed-gas connection (12).Device according to one of Claims 1 to 9, characterized in that the guide device (4) can be controlled in such a way that the distance between the cleaning nozzle (2) and the surface (1a) of the component (1) during cleaning is 5 mm to 100 mm, preferably 10 mm to 80 mm, in particular 10 mm to 50 mm.Device according to one of Claims 1 to 10, characterized in that the guide device (4) can be moved along the surface (1a) of the component (1) in a robot-assisted and / or automated manner.Apparatus according to one of Claims 1 to 11, characterized in that the surface (1a) is an optical surface, in particular a surface (1a) of a lens or of a mirror, in particular of a lithography system, preferably of an EUV or a DUV projection exposure apparatus (100, 200).Method for cleaning a surface (1a) of a component (1), in particular a component (1) of a lithography system (100, 200), according to which at least one cleaning nozzle (2) is moved along the surface (1a) in an automated and / or robot-assisted manner, wherein the cleaning nozzle (2) is designed and operated in such a way that it generates a suction effect by a Venturi effect, as a result of which a medium (3) is suctioned off from the surface (1a) through a suction opening (6) into a suction channel (5) of the cleaning nozzle (3), wherein the cleaning nozzle (2) has blowing-off openings (11) which radially surround the suction opening (6), wherein a gas jet directed onto the surface (1a) of the component (1) in each case emerges from the blowing-off openings (11) during the suction, wherein the blowing-off openings (11) are aligned in such a way, the gas jets are oriented in the direction of a longitudinal axis (13) of the suction channel (5).Method according to claim 13, characterised in that the method is used for cleaning an optical surface (1a), in particular a surface (1a), a lens or a mirror, in particular a lithography system, preferably an EUV or a DUV projection exposure apparatus (100, 200).Method according to Claim 13 or 14, characterized in that firstly a wet-chemical cleaning of the surface (1a) is carried out, wherein the medium (3) to be sucked off is a liquid cleaning medium and / or a liquid rinsing medium and / or a process auxiliary agent which is sucked off by means of the cleaning nozzle (2) after the wet-chemical cleaning of the surface (1a).Method according to claim 13 or 14, characterised in that the medium (3) to be sucked off is a particle which is located on the surface (1a), in particular a coated surface (1a) of a lens or a mirror, in particular an EUV or a DUV projection exposure apparatus (100, 200), wherein the gas stream flowing out of the blow-out openings (11) encloses an effective region within which the particle to be sucked off is located.Lithography system, in particular a projection exposure apparatus (100, 200) for semiconductor lithography, having an illumination system (101, 201) having a radiation source (102) and an optical unit (103, 109, 206) which has at least one optical component (116,118,119,120,121,122,Mi,207), characterized in that at least one of the optical components (116,118,119,120,121,122,Mi,207) is cleaned at least partially by means of a device according to one of Claims 1 to 12 and / or by means of a method according to one of Claims 13 to 16.

Images