Cooling device for cooling a position-sensitive component of a lithography system

Abstract

A cooling device (200) for cooling a position-sensitive component (102) of a lithography system (1), comprising a cooling line (206) with a liquid chamber (218) for conducting a cooling liquid (112) to the position-sensitive component (102) and a gas chamber (220) for receiving a gas (222), and an elastic separating membrane (224) which is arranged inside the cooling line (206) and separates the gas chamber (220) from the liquid chamber (218).

Description

[0001]Carl Zeiss SMT GmbH et al. 1 Cooling device for cooling a position-sensitive component of a lithography system. The present invention relates to a cooling device for cooling a position-sensitive component of a lithography system, a corresponding lithography system, and a method for operating a cooling device of a lithography system. The content of the priority application DE 102022125354.6 is incorporated in its entirety by reference. Microlithography is used to manufacture microstructured components, such as integrated circuits. The microlithography process is carried out using a lithography system that has an illumination system and a projection system.The image of a mask (reticle) illuminated by the illumination system is projected by the projection system onto a substrate coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system, for example a silicon wafer, in order to transfer the mask structure onto the light-sensitive coating of the substrate. Driven by the desire for ever smaller structures in the manufacture of integrated circuits, EUV lithography systems are currently being developed which use light with a wavelength in the range of 0.1 nm to 30 nm, in particular 13.5 nm. Since most materials absorb light at this wavelength, such EUV lithography systems must use reflective optics, i.e. mirrors, instead of the previously used refractive optics, i.e. lenses. Carl Zeiss SMT GmbH et al.2 The demands on the accuracy and precision of the imaging properties of lithography systems are constantly increasing. From a dynamic perspective, it is therefore important to minimize the influence of interference on the movement of various position-sensitive components of the lithography system. For example, very precise positioning of optical components, especially mirrors, of the lithography system is required. Dynamic interference excitations of optical components can be generated, for example, by the movement of other components of the lithography system or by acoustic interference. Acoustic interference is transmitted to position-sensitive components of the lithography system, for example, as pressure fluctuations of coolants in cooling lines of a cooling device of the lithography system.As the complexity of lithography systems continues to increase, further dynamic disturbances within and outside the system are to be expected, making additional mechanisms for suppressing or compensating for them desirable and necessary. Against this background, an object of the present invention is to provide an improved cooling device for a lithography system, a corresponding lithography system, and a method for operating a cooling device of a lithography system. According to a first aspect, a cooling device for cooling a position-sensitive component of a lithography system is proposed.The cooling device comprises: a cooling line with a liquid space for transporting a cooling liquid to the position-sensitive component and a gas space for receiving a gas, and an elastic separating membrane arranged within the cooling line, which separates the gas space from the liquid space. Carl Zeiss SMT GmbH et al. 3 By introducing a compressible gas volume within the cooling line, pressure fluctuations in the cooling liquid can be dampened. This can significantly reduce the propagation of pressure fluctuations via the cooling liquid. In particular, the elastic separating membrane is designed to deform and thereby change the volume of the liquid space at the expense of the volume of the gas space.For example, an increase in the pressure of the coolant, as seen in the cross-section of the cooling line, leads to a deformation of the separating membrane into the original gas space, so that the volume of the liquid space increases and, at the same time, the volume of the gas space decreases accordingly. Thus, an increase in the pressure of the coolant can be dampened by expanding the liquid in the liquid space and compressing the gas in the gas space. The same applies to a reduction in the pressure of the coolant in the liquid space of the cooling line, which leads to an increase in the volume of the gas space. This allows the gas in the gas space to expand and the coolant in the liquid space is compressed, thereby dampening the pressure reduction of the coolant. Accordingly, periodic pressure fluctuations in the coolant can also be dampened using the compressible gas volume.The position-sensitive component of the lithography system can be an optical or a mechanical component of the lithography system, e.g., a projection optics of the lithography system. The position-sensitive component is, in particular, a component that must be held in a precise position with only small tolerances during operation of the lithography system. Carl Zeiss SMT GmbH et al. 4 The position-sensitive component of the lithography system is, for example, a mirror of the lithography system, e.g., a mirror of the projection optics of the lithography system. The mirrors of a projection optics of an EUV lithography system are usually movably attached to a support frame by means of actuators in order to be able to precisely adjust the position of the respective mirror. The position-sensitive component of the lithography system can also be a frame structure that serves as a (e.g., optical) reference.The position-sensitive component can, for example, be a sensor frame of the lithography system, e.g., the projection optics of the lithography system. A sensor frame typically has a sensor device for measuring a current position of one or more optical components of the lithography system relative to the sensor frame. The sensor frame is mounted, for example, in a vibration-decoupled manner with respect to a support frame of the optical component(s). The sensor device comprises, for example, one or more sensors, such as interferometers and / or other measuring devices for detecting a position of the optical component(s). The optical component(s) can, for example, have reflector elements for reflecting light emitted by the sensors (e.g., laser light). For example, the one or more sensors serve to detect a position of the optical component(s) in six degrees of freedom.The six degrees of freedom include, in particular, three translational degrees of freedom (e.g., in three mutually perpendicular spatial directions) and three rotational degrees of freedom (e.g., with respect to a rotation around the three mutually perpendicular spatial directions). The proposed cooling device with the compressible gas volume integrated in the cooling line can dampen pressure fluctuations in the coolant, and transmission to the position-sensitive component can be reduced or avoided. Consequently, a greater precession of the position and thus of the optical properties or reference properties of the position-sensitive component can be achieved. Consequently, the imaging properties of the lithography system can be improved. Furthermore, interference excitation can be better compensated, even in increasingly complex lithography systems with an increasing number of interference sources.The lithography system is, for example, an EUV or DUV lithography system. EUV stands for "extreme ultraviolet" (EUV) and refers to a wavelength of the working light in the range of 0.1 nm to 30 nm, specifically 13.5 nm. Furthermore, DUV stands for "deep ultraviolet" (DUV) and refers to a wavelength of the working light between 30 nm and 250 nm. The EUV or DUV lithography system includes an illumination system and a projection system. In particular, with the EUV or DUV lithography system, the image of a mask (reticle) illuminated by the illumination system is projected by means of the projection system onto a substrate coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system, for example a silicon wafer, in order to transfer the mask structure onto the light-sensitive coating of the substrate.The cooling line is, for example, a pipe for conducting the coolant. The cooling line has, for example, a metal pipe and / or a stainless steel pipe. The cooling line can, for example, have a circular cross-section. The coolant is or comprises, for example, water. The cooling line serves, for example, to transport the coolant to and / or from the position-sensitive component. The cooling line serves, for example, to transport the coolant from a cooling unit of the cooling device to the position-sensitive component and / or from the Carl Zeiss SMT GmbH et al. 6 position-sensitive component (back) to the cooling unit. The cooling device can also have more than one cooling line. The cooling device serves, in particular, to avoid high temperatures and temperature fluctuations in the position-sensitive component.In particular, mirrors in an EUV lithography system (as an example of position-sensitive components) heat up due to the absorption of high-energy EUV radiation. The resulting high temperatures and temperature fluctuations in the mirror, and the associated thermal deformation of the mirror, can lead to wavefront aberrations and thus impair the imaging properties of the mirrors. To prevent thermally induced deformations, mirrors in the lithography system can be actively cooled. The cooling device can also be used (in addition to or instead of) cooling, for example, a sensor frame (as an example of a position-sensitive component). This can prevent the sensor frame from heating up due to thermal radiation. Thermal radiation is caused in particular by working light from the lithography system being absorbed by mirror surfaces or structural elements.Other heat sources can be, for example, actuators and heating heads. With the help of the cooling device, a stable temperature environment can be created for the sensor frame. This allows a position measurement of the mirror or the multiple mirrors to be carried out with greater accuracy using the sensor device held by the sensor frame. The cooling device further comprises, for example, a cooling unit for cooling the coolant, one or more pumps for generating a required coolant flow rate of the coolant, and one or more valves for controlling the coolant flow. A specific coolant flow rate is required for cooling, which is realized via a pump system. This leads to dynamic disturbance excitation, because each pump generates local pressure fluctuations.These are transmitted through the entire cooling circuit via coolant sound (waterborne sound, longitudinal waterborne sound wave). Furthermore, any cross-sectional change and any deflection of the fluid line, as well as any valve installed in the cooling circuit, can represent a source of disturbance that causes local pressure fluctuations in the fluid. This type of dynamic disturbance is also called flow-induced vibrations (FIV). The disturbance is transmitted to the cooled, position-sensitive component via waterborne sound. This causes the position of the position-sensitive component to deviate from a desired position. In particular, a pressure surge from the coolant acts on surfaces of the cooled, position-sensitive component. The pressure surge is converted into a force at the surfaces it acts on.Due to this force, the position of the position-sensitive component deviates from the target position. The liquid space of the cooling line is arranged inside the cooling line and is used for the flow of the coolant. Furthermore, the gas space is arranged inside the cooling line and is used to hold a gas. Due to the elastic separating membrane, which separates the liquid space from the gas space, the volume of the liquid space and the gas space is variable. Consequently, the elastic separating membrane causes the volume of the coolant and the volume of the gas to be variable. During operation of the cooling device, e.g. during operation of the lithography system, the liquid space, as seen in the cross-section of the cooling line, is completely filled with the coolant. Furthermore, for example, the gas space, as seen in the cross-section of the cooling line, is completely filled with the gas.The elastic separation membrane is particularly designed to form a gas bubble together with a gas contained in the gas space. The gas bubble is, for example, an axial gas bubble with respect to a central longitudinal axis of the liquid line. The elastic separation membrane is, in particular, (reversibly) deformable to adapt the volume of the liquid space and thus of the cooling liquid to a pressure of the cooling liquid in the liquid space. The elastic separation membrane is, for example, liquid-tight and / or gas-tight. The elastic separation membrane comprises, for example, an (e.g., thin-walled) elastic material. A material for the elastic separation membrane includes, for example, polyurethane, silicone, rubber, natural rubber, silicone rubber, fluororubber, and / or another elastic material. Fluororubber is particularly well suited for use in vacuum due to its resistance to aging and low outgassing.A material for the elastic separation membrane can, for example, also comprise a fluorothermoplastic, such as tetrafluoroethylene, hexafluoropropylene and / or vinylidene fluoride. In addition to compressing the gas volume separated thereby, the elastic material (e.g., a highly dampened polymer) can provide further damping of pressure fluctuations in the cooling liquid. Carl Zeiss SMT GmbH et al. 9 The gas space can be a closed gas space for accommodating a gas in a static state. Alternatively, the gas space can also be part of a gas circuit in which the gas flows through the gas space during operation. For example, in this case, a gas flow can be realized using a gas pump. The gas is, for example, a gas that includes air, ultrapure room air, helium and / or one or more noble gases. In embodiments, the cooling device comprises a gas that is accommodated in the gas space.For example, in these embodiments the gas space is a closed gas space in which the gas remains (e.g. permanently). In embodiments the cooling line with the integrated gas volume is designed to dampen and / or suppress pressure fluctuations in the coolant in a frequency range of 1 to 2 kHz, 1 to 1 kHz, 1 to 800 Hz, 1 to 500 Hz, 1 to 400 Hz, 1 to 200 Hz, 1 to 100 Hz and / or 50 to 150 Hz. According to one embodiment the elastic separating membrane is a pressure membrane which is designed to deform when the pressure of the coolant changes so that a volume of the gas space changes accordingly. In particular when the pressure of the coolant changes the separating membrane deforms in accordance with the pressure change. As a result the gas in the gas space is in particular compressed or expands. Carl Zeiss SMT GmbH et al.10 According to a further embodiment, the gas space separated by the elastic separating membrane is rotationally symmetrical when viewed in the cross-section of the cooling line. Due to a rotationally symmetrical design of the gas space and thus of the gas volume, all forces acting on the gas bubble formed by the separating membrane and the gas in the gas space balance each other out, resulting in a force-free system. According to a further embodiment, the liquid space and the gas space separated from the liquid space by the elastic separating membrane are arranged coaxially when viewed in the cross-section of the cooling line. This enables even better damping of pressure fluctuations caused by the gas volume. According to a further embodiment, the gas space is an internal gas space or an external gas space when viewed in the cross-section of the cooling line and with respect to the liquid space.The advantage of an internal gas space and thus an internal compressible gas volume is that the gas volume is located where the greatest flow velocity of the coolant occurs. This makes damping of pressure fluctuations in the coolant particularly effective. The advantage of an external gas space is that the gas space is easier to access from the outside and thus the gas can be filled and / or refilled more easily. For example, the gas can be fed into the gas space via an opening and / or a valve in a wall of the cooling line. Carl Zeiss SMT GmbH et al. 11 In an internal gas space, for example, the gas space is delimited exclusively by the separating membrane and not by an inner wall of the cooling line. In an external gas space, for example, the gas space is delimited by both the separating membrane and an inner wall of the cooling line.According to a further embodiment, the cooling device has an elastic hose enclosing the elastic separating membrane for forming the gas space. This enables a particularly simple realization of a gas volume integrated into a cooling line. For example, the gas space is formed inside the hose (an example of an internal gas space). The liquid space is then formed correspondingly outside the hose (e.g., between an outer side of the hose and an inner wall of the cooling line). Alternatively, the gas space can also be formed outside the hose (an example of an external gas space) (e.g., between an outer side of the hose and an inner wall of the cooling line). The liquid space is then formed correspondingly inside the hose.According to a further embodiment, the cooling device has at least one spacer arranged between the elastic separating membrane and an inner wall of the cooling line. Carl Zeiss SMT GmbH et al. 12 The at least one spacer can improve the arrangement of the elastic separating membrane within the cooling line, for example even during operation of the cooling device. For example, a movement of the elastic separating membrane within the cooling line, in particular during operation of the cooling device, can be restricted (without, however, restricting deformation of the elastic separating membrane). For example, a position of the gas space relative to the liquid space can be limited. For example, a rotationally symmetrical and / or coaxial arrangement of the gas space relative to the liquid space can be maintained (e.g. substantially) even during operation.The at least one spacer is arranged, for example, in the gas space or in the liquid space. The cooling device can also have a plurality of spacers. The plurality of spacers can be arranged (e.g. radially) at a longitudinal position of the cooling line and / or (e.g. spaced apart from one another) at a plurality of longitudinal positions of the cooling line. According to a further embodiment, the cooling device has a plurality of spacers which are formed by knobs arranged on an outer side of the elastic separating membrane. The knobs (e.g. projections) protrude in particular from an outer side of the elastic separating membrane, e.g. in the direction of the inner wall of the cooling line and / or in a radial direction of the cooling line. The knobs can, for example, be made of the same material as the separating membrane. The separating membrane with the knobs can, for example, also be manufactured in one piece. Carl Zeiss SMT GmbH et al.13 According to a further embodiment, the cooling device has fastening means for fastening the elastic separating membrane to an inner wall of the cooling line. This allows a position of the separating membrane within the cooling line to be restricted and / or fixed. The fastening means can, for example, also comprise or form the at least one spacer. According to a further embodiment, the cooling device has a device for adjusting a pressure of a gas in the gas space. This allows a gas pressure (preload pressure) of a gas in the gas space and thus a damping frequency of the gas volume to be specifically adjusted. The set gas pressure is in particular a gas pressure in a rest state (i.e., an undeformed state) of the separating membrane. A damping effect of the gas volume depends in particular on a relative pressure between the gas pressure of the gas volume and a pressure of the liquid.According to a further embodiment, the cooling device has two or more elastic separating membranes arranged within the cooling line, which correspondingly form two or more gas chambers separated from one another and from the liquid chamber. By providing a plurality of separate (e.g. closed) gas chambers and thus gas volumes, pressure fluctuations can be dampened even more specifically. For example, a gas pressure of a gas in the plurality of gas chambers can differ from one another, so that pressure surges with different frequencies can be dampened. Carl Zeiss SMT GmbH et al. 14 For example, gas chambers and thus gas volumes can also be specifically designed for individual position-sensitive components. For example, a gas pressure of a gas in a respective gas chamber can be specifically adjusted to dampen a disturbance excitation of a respective position-sensitive component.For example, a respective gas space can be arranged adjacent to and, with respect to a flow direction of the cooling liquid, (e.g., immediately) upstream of a respective position-sensitive component. According to a further embodiment, the two or more gas spaces are separated from one another and from the liquid space, as seen in the cross-section of the cooling line, and / or the two or more gas spaces are separated from one another and from the liquid space with respect to a flow direction of the cooling liquid. According to a further embodiment, the two or more gas spaces are separated from one another and from the liquid space with respect to a flow direction of the cooling liquid, the cooling device has a gas in each of the two or more gas spaces, and the respective gases have different pressures from one another.For example, the cooling device comprises one or more devices designed to adjust the pressure of a gas in the respective gas space. This allows, for example, a gas pressure and thus a damping frequency to be specifically adjusted in each gas space. According to a further embodiment, the cooling device has a foam-like and / or sponge-like element with a plurality of bubbles and an elastic material surrounding the plurality of bubbles, wherein the gas space is formed by the plurality of bubbles of the foam-like and / or sponge-like element, and the separating membrane is formed by the elastic material surrounding the plurality of bubbles. The foam-like and / or sponge-like element can provide the gas space separated by the separating membrane in an alternative manner.According to a further embodiment, the cooling device is designed so that a cooling liquid flows through the cooling line in a flow direction, and a diameter of the cooling line tapers along the flow direction. By changing the shape of the cooling line, the flow velocity of the cooling liquid can be influenced and a frequency range of the damping can thus be set. For example, the diameter of the cooling line tapers uniformly along the flow direction. For example, the cooling line extends (e.g. straight) in a longitudinal direction and the cooling liquid flows along the longitudinal direction through the cooling line. For example, the diameter of the cooling line tapers along the longitudinal direction. Alternatively, the cooling line can also be curved, e.g., also run helically (often also called spirally).For example, the diameter of the cooling line tapers along the helically curved cooling line. According to a second aspect, a lithography system, in particular an EUV lithography system, is proposed. The lithography system comprises a cooling device as described above. Carl Zeiss SMT GmbH et al. 16 The lithography system has, for example, at least one position-sensitive component. According to a third aspect, a method for operating a cooling device is proposed. The cooling device serves to cool a position-sensitive component of a lithography system. The cooling device has a cooling line with a liquid space for transporting a cooling liquid to the position-sensitive component and a gas space for receiving a gas, and an elastic separating membrane arranged within the cooling line, which separates the gas space from the liquid space.The method comprises the steps: a) flowing a cooling liquid through the liquid space of the cooling line, and b) changing a volume of the liquid space by deforming the elastic separating membrane in response to a pressure change of the cooling liquid in the liquid space. Changing a volume of the liquid space means in particular changing a volume of the cooling liquid in the liquid space. The position-sensitive component is preferably a position-sensitive component of a projection optics of the lithography system (projection exposure system). However, the position-sensitive component can also be a position-sensitive component of an illumination system of the lithography system. According to a fourth aspect, a temperature control device for temperature control of a position-sensitive component of a lithography system is proposed. The temperature control device comprises: Carl Zeiss SMT GmbH et al.17 a liquid line with a liquid space for transporting a temperature control liquid to the position-sensitive component and a gas space for receiving a gas, and an elastic separating membrane arranged within the liquid line, which separates the gas space from the liquid space. With the help of the temperature control device, a thermal condition of the position-sensitive component can be influenced. In particular, the position-sensitive component can be temperature-controlled, i.e., cooled or heated, using the temperature control device. Accordingly, the temperature control device is a cooling device or a heating device. Furthermore, the temperature control liquid is a cooling liquid or a heating liquid. As far as the present application refers to cooling device, cooling, cooling liquid, cooling line, method for operating a cooling device, etc.When "a" is spoken of, a heating device, heating, heating fluid, heating line, method for operating a heating device, etc. can also be used accordingly. "A" is not necessarily to be understood as being limited to exactly one element. Rather, multiple elements, such as two, three or more, can also be provided. Any other counting word used here is also not to be understood as implying a restriction to the exact number of elements stated. Rather, numerical deviations upwards and downwards are possible, unless otherwise stated. The embodiments and features described for the cooling device (first aspect) apply accordingly to the other aspects (second, third and fourth aspects) and vice versa. Carl Zeiss SMT GmbH et al.18 Further possible implementations of the invention also include combinations of features or embodiments described above or below with regard to the exemplary embodiments, which are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention. Further advantageous embodiments and aspects of the invention are the subject of the subclaims and the exemplary embodiments of the invention described below. The invention is explained in more detail below using preferred embodiments with reference to the attached figures. Fig. 1 shows a schematic meridional section of a projection exposure system for EUV projection lithography; Fig. 2 shows a positioning system with an optical component of the projection exposure system from Fig. 1 according to one embodiment; Fig.3 shows a cooling device for cooling the optical component from Fig. 2 according to one embodiment, wherein the cooling device comprises a cooling line device with an integrated compressible gas volume; Fig. 4 shows a functional principle of the cooling line device from Fig. 3 in a cross-sectional view; Fig. 5 shows a cross-sectional view of the cooling line device from Fig. 3, wherein an elastic separating membrane of the cooling line device is in a rest state; Carl Zeiss SMT GmbH et al. 19 Fig. 6 shows a view similar to Fig. 5, wherein the elastic separating membrane is in an elastically deformed state; Fig. 7 shows a cross-sectional view of a further embodiment of the cooling line device of the cooling device from Fig. 3; Fig. 8 shows a cross-sectional view of a further embodiment of the cooling line device of the cooling device from Fig. 3; Fig.9 shows a cross-sectional view of a further embodiment of the cooling line device of the cooling device from Fig. 3; Fig. 10 shows a cross-sectional view of a further embodiment of the cooling line device of the cooling device from Fig. 3, wherein the separating membrane of the cooling line device has spacers; Fig. 11 shows a perspective view of a further embodiment of the cooling line device of the cooling device from Fig. 3, wherein the cooling line device has fastening means according to a first variant; Fig. 12 shows a perspective view of a further embodiment of the cooling line device of the cooling device from Fig. 3, wherein the cooling line device has fastening means according to a second variant; Fig. 13 shows a cross-sectional view of a further embodiment of the cooling line device of the cooling device from Fig. 3; Fig.14 shows a side view of a further embodiment of the cooling line device of the cooling device from Fig. 3; Carl Zeiss SMT GmbH et al. 20 Fig. 15 shows a side view of a further embodiment of the cooling line device of the cooling device from Fig. 3; and Fig. 16 shows a flow diagram of a method for operating a cooling device of a projection exposure system according to one embodiment. In the figures, identical or functionally equivalent elements have been provided with the same reference numerals, unless stated otherwise. Furthermore, it should be noted that the representations in the figures are not necessarily to scale. Fig. 1 shows an embodiment of a projection exposure system 1 (lithography system), in particular an EUV lithography system.One embodiment of an illumination system 2 of the projection exposure system 1 has, in addition to a light or radiation source 3, illumination optics 4 for illuminating an object field 5 in an object plane 6. In an alternative embodiment, the light source 3 can also be provided as a separate module from the rest of the illumination system 2. In this case, the illumination system 2 does not include the light source 3. A reticle 7 arranged in the object field 5 is exposed. The reticle 7 is held by a reticle holder 8. The reticle holder 8 can be displaced, in particular in a scanning direction, via a reticle displacement drive 9. For the purpose of explanation, a Cartesian coordinate system with an x-direction x, a y-direction y and a z-direction z is shown in Fig. 1. The x-direction x runs perpendicular into the drawing plane. The y-direction y runs horizontally and the z-direction z runs vertically.The scanning direction in Carl Zeiss SMT GmbH et al. 21 of Fig. 1 runs along the y-direction y. The z-direction z runs perpendicular to the object plane 6. The projection exposure system 1 comprises projection optics 10. The projection optics 10 serves to image the object field 5 into an image field 11 in an image plane 12. The image plane 12 runs parallel to the object plane 6. Alternatively, an angle other than 0° between the object plane 6 and the image plane 12 is also possible. A structure on the reticle 7 is imaged onto a light-sensitive layer of a wafer 13 arranged in the region of the image field 11 in the image plane 12. The wafer 13 is held by a wafer holder 14. The wafer holder 14 can be displaced via a wafer displacement drive 15, in particular along the y-direction y.The displacement of the reticle 7, on the one hand, via the reticle displacement drive 9, and the wafer 13, on the other hand, via the wafer displacement drive 15, can be synchronized with each other. The light source 3 is an EUV radiation source. The light source 3 emits, in particular, EUV radiation 16, which is also referred to below as useful radiation, illumination radiation, or illumination light. The useful radiation 16 has, in particular, a wavelength in the range between 5 nm and 30 nm. The light source 3 can be a plasma source, for example, an LPP source (Laser Produced Plasma, plasma generated with the aid of a laser) or a DPP source (Gas Discharged Produced Plasma, plasma generated by means of a gas discharge). It can also be a synchrotron-based radiation source. The light source 3 can be a free-electron laser (FEL).Carl Zeiss SMT GmbH et al. 22 The illumination radiation 16 emanating from the light source 3 is bundled by a collector 17. The collector 17 can be a collector with one or more ellipsoidal and / or hyperboloidal reflection surfaces. The at least one reflection surface of the collector 17 can be exposed to the illumination radiation 16 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 17 can be structured and / or coated, on the one hand, to optimize its reflectivity for the useful radiation and, on the other hand, to suppress stray light. After the collector 17, the illumination radiation 16 propagates through an intermediate focus in an intermediate focal plane 18.The intermediate focal plane 18 can represent a separation between a radiation source module, comprising the light source 3 and the collector 17, and the illumination optics 4. The illumination optics 4 comprise a deflecting mirror 19 and, downstream of this in the beam path, a first facet mirror 20. The deflecting mirror 19 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 19 can be designed as a spectral filter that separates a useful light wavelength of the illumination radiation 16 from stray light of a different wavelength. If the first facet mirror 20 is arranged in a plane of the illumination optics 4 that is optically conjugate to the object plane 6 as the field plane, it is also referred to as a field facet mirror.The first facet mirror 20 comprises a plurality of individual first facets 21, which can also be referred to as field facets. Only a few of these first facets 21 are shown in Fig. 1 as examples. Carl Zeiss SMT GmbH et al. 23 The first facets 21 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 21 can be designed as flat facets or alternatively as convexly or concavely curved facets. As is known, for example, from DE 102008009600 A1, the first facets 21 themselves can each also be composed of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 20 can be designed, in particular, as a microelectromechanical system (MEMS system). For details, see DE 102008009600 A1.Between the collector 17 and the deflecting mirror 19, the illumination radiation 16 runs horizontally, i.e., along the y-direction y. In the beam path of the illumination optics 4, a second facet mirror 22 is arranged downstream of the first facet mirror 20. If the second facet mirror 22 is arranged in a pupil plane of the illumination optics 4, it is also referred to as a pupil facet mirror. The second facet mirror 22 can also be arranged at a distance from a pupil plane of the illumination optics 4. In this case, the combination of the first facet mirror 20 and the second facet mirror 22 is also referred to as a specular reflector. Specular reflectors are known from US 2006 / 0132747 A1, EP 1614 008 B1, and US 6,573,978. The second facet mirror 22 comprises a plurality of second facets 23. In the case of a pupil facet mirror, the second facets 23 are also referred to as pupil facets. Carl Zeiss SMT GmbH et al.24 The second facets 23 can also be macroscopic facets, which can, for example, be round, rectangular, or hexagonal in shape, or alternatively, facets composed of micromirrors. Reference is also made to DE 102008009600 A1 in this regard. The second facets 23 can have flat or, alternatively, convex or concavely curved reflection surfaces. The illumination optics 4 thus forms a double-faceted system. This basic principle is also referred to as a fly's eye integrator. It can be advantageous not to arrange the second facet mirror 22 exactly in a plane that is optically conjugate to a pupil plane of the projection optics 10. In particular, the second facet mirror 22 can be arranged tilted relative to a pupil plane of the projection optics 10, as described, for example, in DE 102017220586 A1.With the help of the second facet mirror 22, the individual first facets 21 are imaged in the object field 5. The second facet mirror 22 is the last bundle-forming or actually the last mirror for the illumination radiation 16 in the beam path in front of the object field 5. In a further embodiment of the illumination optics 4 (not shown), a transmission optics can be arranged in the beam path between the second facet mirror 22 and the object field 5, which transmission optics contributes in particular to the imaging of the first facets 21 in the object field 5. 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 4. The transmission optics can in particular have one or two mirrors for Carl Zeiss SMT GmbH et al.25 normal incidence (NI mirror, Normal Incidence Mirror) and / or one or two mirrors for grazing incidence (GI mirror, Grazing Incidence Mirror). In the embodiment shown in Fig. 1, the illumination optics 4 has exactly three mirrors after the collector 17, namely the deflection mirror 19, the first facet mirror 20 and the second facet mirror 22. In a further embodiment of the illumination optics 4, the deflection mirror 19 can also be omitted, so that the illumination optics 4 can then have exactly two mirrors after the collector 17, namely the first facet mirror 20 and the second facet mirror 22. The imaging of the first facets 21 by means of the second facets 23 or with the second facets 23 and a transmission optics into the object plane 6 is generally only an approximate imaging.The projection optics 10 comprises a plurality of mirrors Mi, which are numbered according to their arrangement in the beam path of the projection exposure system 1. In the example shown in Fig. 1, the projection optics 10 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or a different number of mirrors Mi are also possible. The projection optics 10 is a doubly obscured optic. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 has an image-side numerical aperture that is greater than 0.5 and can also be greater than 0.6 and can be, for example, 0.7 or 0.75. Carl Zeiss SMT GmbH et al. 26 Reflecting 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 axis of rotational symmetry of the reflection surface shape. The mirrors Mi, just like the mirrors of the illumination optics 4, can have highly reflective coatings for the illumination radiation 16. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon. The projection optics 10 has a large object-image offset in the y-direction y between a y-coordinate of a center of the object field 5 and a y-coordinate of the center of the image field 11. This object-image offset in the y-direction y can be approximately as large as a z-distance between the object plane 6 and the image plane 12. The projection optics 10 can, in particular, be anamorphic. In particular, it has different image scales βx, βy in the x and y directions x, y.The two image scales βx, βy of the projection optics 10 are preferably (βx, βy) = (+ / - 0.25, + / - 0.125). A positive image scale β means an image without image inversion. A negative sign for the image scale β means an image with image inversion. The projection optics 10 thus leads to a reduction in the ratio 4:1 in the x-direction x, i.e., in the direction perpendicular to the scanning direction. The projection optics 10 leads to a reduction of 8:1 in the y-direction y, i.e., in the scanning direction. Carl Zeiss SMT GmbH et al. 27 Other image scales are also possible. Even image scales with the same sign and absolutely the same in the x and y directions x, y, for example with absolute values ​​of 0.125 or 0.25, are possible.The number of intermediate image planes in the x- and y-directions x, y in the beam path between the object field 5 and the image field 11 can be the same or can be different, depending on the design of the projection optics 10. Examples of projection optics with different numbers of such intermediate images in the x- and y-directions x, y are known from US 2018 / 0074303 A1. Each of the second facets 23 is assigned to exactly one of the first facets 21 to form a respective illumination channel for illuminating the object field 5. This can result in particular in illumination according to the Köhler principle. The far field is broken down into a plurality of object fields 5 with the aid of the first facets 21. The first facets 21 generate a plurality of images of the intermediate focus on the second facets 23 assigned to them.The first facets 21 are each imaged onto the reticle 7 by an associated second facet 23, superimposed on one another, to illuminate the object field 5. The illumination of the object field 5 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 second facets 23, the illumination of the entrance pupil of the projection optics 10 can be geometrically defined. By selecting the illumination channels, in particular the subset of the second facets 23 that guide light, the intensity distribution in the entrance pupil of the projection optics 10 can be adjusted. This intensity distribution is also referred to as the illumination setting or illumination pupil filling.A likewise preferred pupil uniformity in the area of ​​defined illuminated sections of an illumination pupil of the illumination optics 4 can be achieved by redistributing the illumination channels. Further aspects and details of the illumination of the object field 5 and in particular of the entrance pupil of the projection optics 10 are described below. The projection optics 10 can in particular have a homocentric entrance pupil. This can be accessible. It can also be inaccessible. The entrance pupil of the projection optics 10 cannot usually be illuminated precisely with the second facet mirror 22. When the projection optics 10 images the center of the second facet mirror 22 telecentrically onto the wafer 13, the aperture rays often do not intersect at a single point. However, an area can be found in which the pairwise determined distance of the aperture rays is minimal.This surface represents the entrance pupil or a surface conjugated to it in spatial space. In particular, this surface exhibits a finite curvature. The projection optics 10 may 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 22 and the reticle 7. With the aid of this optical element, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account. Carl Zeiss SMT GmbH et al. 29 In the arrangement of the components of the illumination optics 4 shown in Fig. 1, the second facet mirror 22 is arranged in a surface conjugated to the entrance pupil of the projection optics 10. The first facet mirror 20 is tilted relative to the object plane 6.The first facet mirror 20 is arranged tilted relative to an arrangement plane defined by the deflecting mirror 19. The first facet mirror 20 is arranged tilted relative to an arrangement plane defined by the second facet mirror 22. Fig. 2 shows a positioning system 100 with an optical component 102 (as an example of a position-sensitive component) according to one embodiment. The optical component 102 is, for example, a mirror of the projection exposure system 1 (lithography system), in particular the projection optics 10, from Fig. 1. The optical component 102 is, for example, one of the mirrors M1-M6. In the following, the optical component 102 is described as a mirror; in other examples, however, it may also be an optical component other than a mirror. As shown in Fig.2, the mirror 102 includes a coating 104 having an optically active surface 106. The mirror 102 also includes a substrate 108.Cooling lines 110 are arranged in the substrate 108, through which a cooling liquid 112, such as water, is passed to actively cool the mirror 102. Cooling the mirror 102 serves to prevent thermal deformation of the mirror 102, even upon exposure to high-energy EUV radiation 16 (Fig. 1). The mirror 102 is movably attached to a support frame 116 by means of an actuator device 114. The actuator device 114 has, for example, several Carl Zeiss SMT GmbH et al. 30 actuators 118 and a drive unit (not shown). The actuator device 114 serves, for example, to position the mirror 102 with respect to six degrees of freedom (translation in the X, Y, and Z directions and rotation about the X, Y, and Z directions). The positioning system 100 further comprises a sensor device 120 for detecting a current position of the mirror 102. The sensor device 120 is only schematically indicated in Fig. 2.The sensor device 120 has one or more sensors, such as interferometers. The sensors of the sensor device 120 are attached, for example, to a sensor frame (not shown). The sensor frame is attached, for example, in a vibration-decoupled manner to the support frame 116. For example, a current position of the mirror 102 is detected using laser beams 122. Figure 3 shows a cooling device 200 for cooling the mirror 102. The cooling device has a cooling circuit 202. The cooling device 200 comprises a cooling unit 204 for cooling a cooling liquid 112 (Fig. 2) and cooling lines 206, 110 for transporting the cooling liquid 112. The cooling device 200 also comprises one or more pumps 208 for generating a required coolant flow rate of the cooling liquid 112. The cooling device 202 further comprises one or more valves 210 for controlling the cooling flow.The cooling device 200 can be used to cool several components of the lithography system 1. By way of example, the mirror 102 from Fig. 2 is shown in Fig. 3 as a cooled component. The cooling lines 110 (Fig. 2), which are arranged in the mirror substrate 108, are schematically shown in Fig. 3. Furthermore, two further mirrors 102' and 102" - similar to the mirror 102 from Fig. 2 - are shown in Fig. 3 as further cooled components. Carl Zeiss SMT GmbH et al. 31 Pumps of the cooling device 200, such as the pump 208, cause local pressure fluctuations in the liquid 112, thereby generating a dynamic disturbance excitation. These pressure fluctuations are transmitted through the entire cooling circuit 202 via longitudinal water sound waves.Furthermore, cross-sectional changes (not shown) of the cooling line 206, deflections 212 of the cooling line 206, and valves 210 of the cooling device 200 can also represent sources of interference that cause local pressure fluctuations of the liquid 112. Such acoustic interference is transmitted to the cooled optical component 102, 102', 102" (the mirror 102, 102', 102") by water sound. This can lead to a change in the position of the respective mirror 102, 102', 102", so that the actual position of the respective mirror 102, 102', 102" deviates from a desired position. In the example shown in Fig. 3 and the following description, the cooling device 200 serves, by way of example, to cool the mirrors 102, 102', 102".In other examples, however, the cooling device 200 can also be used to cool other position-sensitive components, such as other mirrors and / or a sensor frame (not shown) of the projection exposure system 1 (lithography system). To dampen pressure fluctuations of the cooling liquid 112, the cooling device 200 comprises a cooling line device 214 with an integrated compressible gas volume 216. In particular, the cooling line device 214 comprises the cooling line 206 or a section of the cooling line 206, a liquid space 218 for the cooling liquid 112 to flow through, and a gas space 220 for receiving a gas 222 (gas volume 216). Furthermore, the cooling line device 214 comprises an elastic separating membrane 224 which separates the gas space 220 from the liquid space 218. Carl Zeiss SMT GmbH et al. 32 Fig.4 illustrates a functional principle of the cooling line device 200' from Fig.3.On the left side of Fig. 4, a cooling line device 214' is shown with a cooling line 206' and an elastic separating membrane 224' arranged in the cooling line 206', which is in a rest state. In particular, the elastic separating membrane 224' on the left side of Fig. 4 is in a relaxed, undeformed state. The elastic separating membrane 224' separates the cooling liquid 112 in the liquid space 218' from the gas 222 in the gas space 220'. A volume of the cooling liquid 112 is VF1 in the rest state, and a volume of the gas 222 is VG1 in the rest state. On the right side of Fig. 4, the cooling line device 214' with the elastic separating membrane 224' is shown in a state in which the elastic separating membrane 224' is in an elastically deformed state. By increasing the pressure of the cooling liquid 112, the separating membrane 224' was deformed, so that the volume V. F2of the liquid space 218' has increased and at the same time the volume VG2 of the gas space 220' has decreased accordingly. Thus, an increase in pressure of the cooling liquid 112 can be dampened by expanding the liquid 112 and compressing the gas 222 in the gas space 220'. The dashed line in Fig. 4 illustrates a deformation of the separating membrane 224' in the event of a reduction in pressure of the cooling liquid 112 in the liquid space 218', which would lead to an increase in the volume of the gas space 220'. Accordingly, periodic pressure fluctuations of the cooling liquid 112 can also be dampened using the compressible gas bubble 216'. Fig. 5 shows a cross-sectional view of the cooling line device 214 from Fig. 3 along line VV. In this embodiment, the elastic separation membrane 224 is a tube 226, in whose interior 228 the gas 220 is located. Thus, the gas space 220 is an internal Carl Zeiss SMT GmbH et al.33 Gas space 220. The liquid space 218, through which the cooling liquid 112 flows, is formed between an outer wall 230 of the hose 226 and an inner wall 232 of the cooling line 206. Furthermore, in this embodiment, the gas space 220 is arranged and configured rotationally symmetrically with respect to the cooling line 206. In particular, the gas space 220, the liquid space 218, and the cooling line 206 are arranged coaxially to one another. In Fig. 5, a central axis of the cooling line 206 is designated by reference symbol A1, a central axis of the liquid space 218 is designated by reference symbol A2, and a central axis of the gas space 220 is designated by reference symbol A3. In Fig. 5, the elastic separating membrane 224 (i.e., the hose 226) is in a resting state. A volume of the gas 222 is V. G1 ' and a volume of the cooling liquid 112 is V F1'. Fig. 6 shows the cooling line device 214 from Fig. 5, wherein the elastic separating membrane 224 is in an elastically deformed state. Due to an increase in the pressure of the cooling liquid 112, the separating membrane 224 was deformed such that the volume VF2' of the liquid space 218 increased and, at the same time, the volume V G2' of the gas space 220 has decreased accordingly. In particular, a diameter D of the hose 226, which has the separating membrane 224, has decreased. Due to the rotational symmetry, the pressure increase of the cooling liquid 112 acts evenly on the hose 226. As a result, a pressure increase of the cooling liquid 112 by compressing the gas 222 in the gas space 220 can be well dampened. Fig. 7 shows a cross-sectional view of a further embodiment of a cooling line device 314 of a cooling apparatus 300 of the lithography system 1. The cooling line device 314 comprises a cooling line 306 with a gas space 320 located externally with respect to a liquid space 318. In particular, a separating membrane 324 in this embodiment is designed in the form of a hose 326. This is another example of a rotationally symmetric gas space 220. Fig.8 shows a cross-sectional view of another embodiment of a cooling line device 414 of a cooling apparatus 400 of the lithography system 1. The cooling line device 414 comprises a cooling line 406 with two coaxially arranged separation membranes 424 and 424'. It can also be said that the two separation membranes 424 and 424' are concentric when viewed in the cross-section of the cooling line 406. In this embodiment, three spaces are created which are separated from one another by means of the two separating membranes 424 and 424' in the cross-section of the cooling line 406: two gas spaces 420 and 420' for receiving a gas 222 and a liquid space 418 for the cooling liquid 112 to flow through. In particular, the liquid space 418, which is annular in cross-section, is in contact from both sides, i.e. both on its inner side 434 and on its outer side 436, with a respective gas space 420 and gas space 420' for pressure equalization.In a variant (not shown) of the embodiment of Fig. 8, an annular gas space can also be flanked by two liquid spaces. Fig. 9 shows a cross-sectional view of a further embodiment of a cooling line device 514 of a cooling apparatus 500 of the lithography system 1. The cooling line device 514 comprises a cooling line 506 with two separating membranes 524 and 524', each in the form of a hose 526, 526'. In contrast to the embodiment in Fig. 8, the separating membranes 524 and 524' are not arranged coaxially when viewed in cross-section, but next to one another. Each of the hoses 526, 526' is filled with a gas 222 to provide a compressible gas volume 516, 516' for damping Carl Zeiss SMT GmbH et al. 35 pressure fluctuations of the cooling liquid 112. The embodiment shown in Fig. 9 is an example of two internal gas spaces 520, 520'. In a variant (not shown) of the embodiment of Fig.9, two liquid spaces formed within the tubes 526, 526' can also be provided. Furthermore, a gas space arranged between an outer wall 530, 530' of the tubes 526, 526' and an inner wall 532 of the cooling line 506 can be provided. Fig. 10 shows a cross-sectional view of a further embodiment of a cooling line device 614 of a cooling apparatus 600 of the lithography system 1. The cooling line device 614 is a variant of the cooling line device 214 shown in Fig. 5. The cooling line device 614 according to the embodiment of Fig. 10 differs from the cooling line device 214 according to the embodiment of Fig. 5 in that a plurality of spacers 638 are arranged on the separating membrane 624. By way of example, three of the spacers 638 shown are provided with a reference numeral in Fig. 10.The spacers 638 are arranged, in particular, between an outer wall 630 of the elastic separating membrane 624 and an inner wall 632 of the cooling line 606. For example, the spacers 638 are formed by studs 640 arranged on the outer wall 630 of the elastic separating membrane 624. The studs 640 can, in particular, be formed from the same material as the elastic separating membrane 624. For example, the studs can also be formed integrally with the elastic separating membrane 624. Fig. 11 shows a perspective view of a further embodiment of a cooling line device 714 of a cooling apparatus 700 of the lithography system 1. The cooling line device 714 comprises, in particular, fastening means 742 for fastening the elastic separating membrane 724 to an inner wall 732 of the cooling line 706. The elastic separating membrane 724 is designed, in particular, in the form of a tube 726.Furthermore, the fastening means 742 comprise, for example, a pipe clamp 744 arranged around the hose 726 and clamped to the hose 726. The fastening means 742 also comprise, for example, a strut and / or a web 746 connecting the pipe clamp 744 to an inner wall 732 of the cooling line 706. In particular, the strut / web 746 is attached on one side to the pipe clamp 744 and on its other side to the inner wall 732 of the cooling line 706. The strut / web 746 particularly represents an example of a spacer that holds the hose 726 in position within the liquid space 718 filled with the cooling liquid 112. Fig. 12 shows a perspective view of a further embodiment of a cooling line device 814 of a cooling apparatus 800 of the lithography system 1. The cooling line device 814 has fastening means 842 according to a further variant.The fastening means 842 comprise struts 844 arranged between an outer wall 830 of the separating membrane 824 and an inner wall 832 of the cooling line 806. The struts are arranged, in particular, radially. Five struts are shown as an example in Fig. 12, three of which have been provided with a reference numeral. Fig. 12 shows an internal gas space 820 surrounded by an annular liquid space 818; however, this arrangement can also be reversed, so that an external gas space and an internal liquid space are present. The embodiments of the cooling line devices 214, 214', 214", 314, 414, 514, 614, 714 and 814 shown in Figures 3 to 12 can be combined with one another in many ways. For example, the spacers 638 shown in Figure 10, the fastening means 742 shown in Figure 11 and the fastening means 842 shown in Figure 12 can be combined with each other in connection with Figures 3 to 12.3 to 9 can be combined. Carl Zeiss SMT GmbH et al. 37 Figures 8 and 9 show two examples of cooling line devices 414 and 514 in which more than one separating membrane 424, 524 is provided in order to provide more than one gas space 420, 520 for damping pressure fluctuations of the cooling liquid 112, as seen in the cross-section of the cooling line 406, 506. In particular, two separating membranes 424 and 424' or 524 and 524' are shown in each case for forming two gas spaces 420 and 420' or 520 and 520', respectively. However, more than two separating membranes can also be provided such that more than two gas spaces are provided, as seen in the cross-section of the cooling line 406, 506. As shown in Fig.3, additionally or alternatively, more than two separating membranes 224, 224" may be provided such that they are separated from one another and from the liquid space 218 with respect to a flow direction R of the cooling liquid 112. Furthermore, the cooling device 200 may have two or more gas spaces 220, 220" that are separated from the liquid space 218 by means of the two or more separating membranes 224, 224". The two or more gas spaces 220, 220" are separated from one another and from the liquid space 218, in particular with respect to the flow direction R of the cooling liquid 112. In each of the two or more gas spaces 220, 220", a gas 222, 222" is accommodated, wherein the gases 222, 222" may have different pressures P, P". The pressures P, P" refer in particular to pressures of the gases 222, 222" (preload pressures) in a resting state of the separating membrane 224, 224".By providing several gas volumes 216, 216" with different preload pressures P, P" in the cooling circuit 202, pressure fluctuations of the cooling liquid 112 in the cooling circuit 202 can be specifically dampened. In particular, a frequency range of a damping can be set by adjusting the preload pressure P, P" of the respective gas volume 216, 216". Carl Zeiss SMT GmbH et al. 38 For example, low-frequency pressure surges can be dampened by a first gas volume 216 in the cooling circuit 202 in Fig. 3. For example, it is known that excitations from the water cabinet tend to be of a low-frequency nature. Therefore, the first gas volume 216 can be specifically designed for low-frequency suppression and this can be realized as close to the water cabinet as possible. Furthermore, higher-frequency pressure surges can be dampened, for example, by a second gas volume 216" in the cooling circuit 202 in Fig.3.For this purpose, in particular, the preload pressure P" of the second gas volume 216" is set to a higher value than the preload pressure P of the first gas volume 216. It is known that the position control of the mirrors 102 results in a sensitive frequency range between approximately 50 and 150 Hz. This would allow the second gas volume 216" to be arranged directly in front of the actively controlled and cooled mirrors 102, which exhibits good suppression precisely in this frequency range. For example, a cascading of the pressure damping in the cooling circuit 202 can also be realized in this way. During cascading, for example, seen in the flow direction R of the cooling liquid 112, pressure fluctuations with low frequencies are first damped (e.g., by the first gas volume 216). Subsequently, in the flow direction R, pressure fluctuations with higher frequencies are then dampened (e.g., by the second gas volume 216"). In Fig.3 shows, by way of example, two gas volumes 216, 216" with different preload pressures P, P" and thus different damping properties. However, more than two gas volumes 216, 216" with different preload pressures P, P" and damping properties can also be provided in the cooling circuit 202. Carl Zeiss SMT GmbH et al. 39 In addition, gas volumes 216, 216" can also be specifically adapted to the damping requirements of individual position-sensitive components 102, 102', 102". In Fig. 3, the three gas volumes 216", which are connected upstream of the three optical components 102, 102', 102" in the flow direction R, have an equal preload pressure P". However, a respective preload pressure P" of a gas volume 216" can also be specifically adapted to the damping requirements of a respective optical component 102, 102', 102". As shown in Fig.3, the cooling device 200 may comprise one or more devices 250 for adjusting a pressure P, P" of the gas 222, 222" of one or more gas volumes 216, 216". By means of the one or more pressure adjusting devices 250, damping properties of closed gas volumes 216, 216" can be selectively adjusted over the entire cooling circuit 202. For example, the preload pressures P, P" are set before commissioning of the cooling device 200 and / or the lithography system 1. Although not shown in Figures 4 to 12, the embodiments of the cooling devices 300, 400, 500, 600, 700, 800 may also comprise one or more devices similar to the device 250 (Fig. 3) for setting a pressure of the gas 222 in one or more gas spaces 320, 420, 420', 520, 520', 620, 720, 820.In Figures 3 to 12, closed gas spaces 320, 420, 420', 520, 520', 620, 720, 820 are shown, as viewed in the flow direction R. However, in other examples, a single gas space can also be guided through the entire cooling circuit 202. Carl Zeiss SMT GmbH et al. 40 Fig. 13 shows a cross-sectional view of a further embodiment of a cooling line device 914 of a cooling apparatus 900 of the lithography system 1. The cooling apparatus 900 comprises a cooling line 906 with a liquid space 918, a gas space 920, and a separating membrane 924 separating the liquid space 918. According to this embodiment, the cooling apparatus 900 further comprises a foam-like and / or sponge-like element 952. The foam-like and / or sponge-like element 952 comprises a plurality of bubbles 954 (gas bubbles 954) and an elastic material 956 surrounding the plurality of bubbles 954.The gas space 920 is formed in particular by the plurality of bubbles 954 of the foam-like and / or sponge-like element 952. Furthermore, the elastic material 956 surrounding the plurality of bubbles 954 forms the separation membrane 924. Fig. 14 shows a side view of another embodiment of a cooling line device 1014 of a cooling apparatus 1000 of the lithography system 1. The cooling apparatus 1000 comprises a cooling line 1006. Although not visible in Fig. 14, the cooling line 1006—like the cooling lines described above—has a liquid space, a gas space, and a separation membrane separating the liquid space. According to this embodiment, the cooling apparatus 1000 is configured for a cooling liquid to flow through the cooling line 1006 in a flow direction R. Furthermore, a diameter D1 of the cooling line 1006 tapers (e.g., uniformly) along the flow direction R.The reference symbol D1 denotes a first diameter and D2 a second diameter which is smaller than the first diameter D1. By tapering the cooling line diameter D1, the flow velocity of the cooling liquid can be influenced. In this way, a frequency range for damping pressure waves of the cooling liquid can be set. Carl Zeiss SMT GmbH et al. 41 In the example shown in Fig. 14, the cooling line 1006 extends rectilinearly in a longitudinal direction L, and the cooling liquid flows along the longitudinal direction L through the cooling line 1006. In other words, the flow direction R and the longitudinal direction L are arranged parallel to one another here. In Fig. 14, the diameter D1 of the cooling line 1006 tapers along the longitudinal direction L. Fig. 15 shows a further variant of a cooling line 1114 of a cooling device 1100 that tapers along a flow direction R' of a cooling liquid.The cooling line 1114 in Fig. 15 is, in particular, curved. In the example shown, the cooling line 1114 is shaped in a helical W. The diameter D1 of the cooling line 1114 tapers along the helically curved W cooling line 1114. The reference symbol D1' denotes a first diameter and D2' a second diameter that is smaller than the first diameter D1'. In the following, with reference to Fig. 16, a method for operating a cooling device 200, 200', 300, 400, 500, 600, 700, 800, 900, 1000, 1100 (Figs. 4 to 15) of a projection exposure apparatus 1 (Fig. 1) according to one embodiment is described. The cooling device 200, 200', 300, 400, 500, 600, 700, 800, 900, 1000, 1100 serves to cool a position-sensitive component 102, 102', 102" (Fig.3) of the projection exposure system 1 (Fig.1).The cooling device 200, 200', 300, 400, 500, 600, 700, 800, 900, 1000, 1100 comprises a cooling line device 214, 214', 314, 414, 514, 614, 714, 814, 914, 1014, 1114 (Fig. 4 to 15) with a cooling line 206, 206', 306, 406, 506, 606, 706, 806, 906, 1006, 1106. The cooling line device 214, 214', 314, 414, 514, 614, 714, 814, 914, 1014, 1114 also comprises a liquid space 218, 218', 318, 418, 518, 618, 718, 818, 918 for transporting a cooling liquid 112 to the position-sensitive component 102, 102', 102". To dampen pressure fluctuations of the cooling liquid 112, the cooling line device 214, 214', 314, 414, 514, 614, 714, 814, 914, 1014, 1114 also comprises one or more gas spaces 220, 220', 320, 420, 420', 520, 520', 620, 720, 820, 920 for absorbing a gas 222.The respective gas space 220, 220', 320, 420, 420', 520, 520', 620, 720, 820, 920 is separated from the liquid space 218, 218', 318, 418, 518, 618, 718, 818, 918 by means of an elastic separating membrane 224, 224', 324, 424, 424', 524, 524', 624, 724, 824, 924. In a first step S1 of the method, the cooling liquid 112 flows through the liquid space 218, 218', 318, 418, 518, 618, 718, 818, 918 of the cooling line 206, 206', 306, 406, 506, 606, 706, 806, 906, 1006, 1106. In a second step S2 of the method, a volume VF1 of the liquid space 218, 218', 318, 418, 518, 618, 718, 818, 918 (and thus a volume V F1of the cooling liquid 112) by deforming the elastic separating membrane 224, 224', 324, 424, 424', 524, 524', 624, 724, 824, 924. In particular, the volume VF1 of the liquid space 218, 218', 318, 418, 518, 618, 718, 818, 918 is changed in response to a change in pressure of the cooling liquid 112. By changing the volume VF1 of the liquid space 218, 218', 318, 418, 518, 618, 718, 818, 918 and thus of the cooling liquid 112, a change in pressure, e.g. B. a pressure fluctuation, of the cooling liquid 112 can be dampened. This can reduce or prevent the transmission of a pressure fluctuation to the position-sensitive component 102, 102', 102". Although the present invention has been described using exemplary embodiments, it can be modified in many ways. Carl Zeiss SMT GmbH et al.43 LIST OF REFERENCE SYMBOLS 1 Projection exposure system 2 Illumination system 3 Light source 4 Illumination optics 5 Object field 6 Object plane 7 Reticle 8 Reticle holder 9 Reticle displacement drive 10 Projection optics 11 Image field 12 Image plane 13 Wafer 14 Wafer holder 15 Wafer displacement drive 16 Illumination radiation 17 Collector 18 Intermediate focal plane 19 Deflecting mirror 20 First facet mirror 21 First facet 22 Second facet mirror 23 Second facet 100 Positioning system 102, 102', 102" Optical component 104 Coating 106 Optically active surface 108 Substrate Carl Zeiss SMT GmbH et al.44 110, 110', 110" Cooling line 112 Cooling liquid 114 Actuator device 116 Support frame 118 Actuator 120 Sensor device 122 Laser beam 200 Cooling device 202 Cooling circuit 204 Cooling unit 206 Cooling line 208 Pump 210 Valve 212 Deflection 214, 214' Cooling line device 216, 216', 216" Gas volume 218, 218' Liquid space 220, 220', 220" Gas space 222, 222" Gas 224, 224', 224" Separating membrane 226 Hose 228 Interior 230 Outer wall 232 Inner wall 250 Device (pressure adjustment device) 300 Cooling device 306 Cooling line 314 Cooling line device 316 Gas volume 318 Liquid space Carl Zeiss SMT GmbH et al.45 320 Gas space 324 Separating membrane 326 Hose 400 Cooling device 406 Cooling line 414 Cooling line device 416 Gas volume 418 Liquid space 420, 420' Gas space 424, 424' Separating membrane 434 Inside 436 Outside 500 Cooling device 506 Cooling line 514 Cooling line device 516 Gas volume 518 Liquid space 520 Gas space 524, 524' Separating membrane 526, 526' Hose 530, 530' Outer wall 532 Inner wall 600 Cooling device 606 Cooling line 614 Cooling line device 616 Gas volume 618 Liquid space 620 Gas space 624 Separating membrane 630 Outer wall Carl Zeiss SMT GmbH et al.46 632 Inner wall 638 Spacer 640 Stud 700 Cooling device 706 Cooling line 714 Cooling line device 716 Gas volume 718 Liquid space 720 Gas space 724 Separating membrane 726 Hose 732 Inner wall 742 Fastener 744 Pipe clamp 746 Web / strut 800 Cooling device 806 Cooling line 814 Cooling line device 816 Gas volume 818 Liquid space 820 Gas space 824 Separating membrane 830 Outer wall 832 Inner wall 842 Fastener 844 Strut 900 Cooling device 906 Cooling line 914 Cooling line device 918 Liquid space Carl Zeiss SMT GmbH et al. 47 920 Gas space 924 Separating membrane 952 Element 954 Bladder 956 Material 1000 Cooling device 1006 Cooling line 1100 Cooling device 1106 Cooling line A1-A3 Axis D Diameter D1, D1' Diameter D2, D2' Diameter L Longitudinal direction M1-M6 Level P, P" Pressure R, R' Flow direction S1-S2 Process steps VF1, VF1' Volume V. F2 , V F2 ' Volume V G1 , V G1' Volume VG2, VG2' Volume W Spiral shape X direction Y direction Z direction

Claims

Carl Zeiss SMT GmbH et al. 48 PATENT CLAIMS 1. Cooling device (200) for cooling a position-sensitive component (102) of a lithography system (1), comprising a cooling line (206) with a liquid space (218) for transporting a cooling liquid (112) to the position-sensitive component (102) and a gas space (220) for receiving a gas (222), and an elastic separating membrane (224) arranged within the cooling line (206) and separating the gas space (220) from the liquid space (218).

2. Cooling device according to claim 1, wherein the elastic separating membrane (224) is a pressure membrane which is configured to deform upon a pressure change of the cooling liquid (112), so that a volume (VG1', VG2') of the gas space (220) changes accordingly.

3. Cooling device according to claim 1 or 2, wherein the gas space (220) separated by the elastic separating membrane (224) is rotationally symmetrical when viewed in the cross-section of the cooling line (206).Cooling device according to one of claims 1 to 3, wherein the liquid space (218) and the gas space (220) separated from the liquid space (218) by the elastic separating membrane (224) are arranged coaxially as seen in the cross-section of the cooling line (206).

5. Cooling device according to one of claims 1 to 4, wherein the gas space (220, 320) is an internal gas space (220) or an external gas space (320) as seen in the cross-section of the cooling line (206, 306) and with respect to the liquid space (218, 318). Carl Zeiss SMT GmbH et al. 49 6. Cooling device according to one of claims 1 to 5, comprising an elastic hose (226) surrounding the elastic separating membrane (224) for forming the gas space (220).

7. Cooling device according to one of claims 1 to 6, comprising at least one spacer (638) arranged between the elastic separating membrane (624) and an inner wall (632) of the cooling line (606).

8. Cooling device according to claim 7, comprising a plurality of spacers (638) which are formed by knobs (640) arranged on an outer side (630) of the elastic separating membrane (624).

9. Cooling device according to one of claims 1 to 8, comprising fastening means (742, 842) for fastening the elastic separating membrane (724, 824) to an inner wall (732, 832) of the cooling line (706, 806).

10. Cooling device according to one of claims 1 to 9, comprising a device (250) for adjusting a pressure (P) of a gas (222) in the gas space (220). 11.Cooling device according to one of claims 1 to 10, comprising two or more elastic separating membranes (224, 224", 424, 424', 524, 524') arranged within the cooling line (206, 406, 506), which correspondingly form two or more gas spaces (220, 220", 420, 420', 520, 520') separated from one another and from the liquid space (218, 418, 518).

12. Cooling device according to claim 11, wherein the two or more gas spaces (420, 420', 520, 520'), seen in the cross section of the cooling line (406, 506), are separated from one another and from the liquid space (318, 518), and / or. Carl Zeiss SMT GmbH et al. 50 the two or more gas spaces (220, 220") are separated from one another and from the liquid space (218) with respect to a flow direction (R) of the cooling liquid (112).

13. Cooling device according to claim 11 or 12, wherein the two or more gas spaces (220, 220") are separated from one another and from the liquid space (218) with respect to a flow direction (R) of the cooling liquid (112), the cooling device (200) has a gas (222, 222") in each of the two or more gas spaces (220, 220"), and the respective gases (222, 222") have different pressures (P, P") from one another. 14.Cooling device according to one of claims 1 to 13, comprising a foam-like and / or sponge-like element (952) with a plurality of bubbles (954) and an elastic material (956) surrounding the plurality of bubbles (954), wherein the gas space (920) is formed by the plurality of bubbles (954) of the foam-like and / or sponge-like element (952), and the separating membrane (924) is formed by the elastic material (956) surrounding the plurality of bubbles (954).

15. Cooling device according to one of claims 1 to 14, wherein the cooling device is configured such that a cooling liquid (112) flows in a flow direction (R) through the cooling line (206, 1006, 1106), and a diameter (D1, D1') of the cooling line (206, 1006, 1106) tapers along the flow direction (R).

16. Lithography system (1), in particular an EUV lithography system, comprising a cooling device (200) according to one of claims 1 to 15. 17.Method for operating a cooling device (200) for cooling a position-sensitive component (102) of a lithography system (1), wherein the. Carl Zeiss SMT GmbH et al. 51 Cooling device (200) has a cooling line (206) with a liquid space (218) for transporting a cooling liquid (112) to the position-sensitive component (102) and a gas space (220) for receiving a gas (222) and an elastic separating membrane (224) arranged within the cooling line (206) and separating the gas space (220) from the liquid space (218), and wherein the method comprises the steps of: a) flowing (S1) through the liquid space (218) of the cooling line (206) with a cooling liquid (112), and b) changing (S2) a volume (VF1', VF2') of the liquid space (218) by deforming the elastic separating membrane (224) in response to a pressure change of the cooling liquid (112) in the liquid space (218).

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