Hose assembly, projection exposure system and process

Abstract

The invention relates to a hose assembly (40) comprising an elastic hose (30) which is connected at at least one end to a connection area of ​​a connector (31) and an outer tube (32) which surrounds the elastic hose (30) at least partially. A sleeve (33) is connected at a first end to at least one end of the outer tube (32) and at a second end to the connector (31). At least one additional sealing element (37) is provided in the connection area for additional sealing of the connection between the connection area and the elastic hose (30). The additional sealing element (37) comprises a compression element which, from the outside of the hose, presses the hose section connected to the connection area at least partially against a surface of the connection area.Furthermore, the invention relates to a projection exposure system for semiconductor lithography (1,101) equipped with the hose assembly (40) and a method for assembling a hose assembly (40).

Description

[0001] The invention relates to a tube assembly, in particular for use in a projection exposure system for semiconductor lithography, a projection exposure system and a method for assembling a tube assembly.

[0002] To enable ever-smaller feature sizes on semiconductor devices in accordance with Moore's Law, the demands on the systems used to manufacture them are also increasing, particularly projection exposure systems for semiconductor lithography. Current systems of this type feature cooling circuits for thermal stabilization of the optics and structures used.

[0003] The cooling lines or cooling channels used can be routed through both the optical elements used in the system and the structural components of the system. Typically, the structures to be cooled are connected to each other by pipe assemblies and networks, which in turn are attached to the structures of the system itself. Active cooling ensures both the highest possible heat dissipation and good controllability of the system. The flowing fluid also ensures improved heat transfer across the surfaces through which the fluid flows (forced convection).

[0004] Due to its high heat capacity and availability, water is typically used as the cooling medium; other fluids are also conceivable.

[0005] Especially in the development of water-cooled optical elements, their support structures, and infrastructure, pressure fluctuations / pulsations transported and transmitted via the fluid (e.g., water) play a crucial role in the performance of the overall system, especially the lithography optics, and the image quality on a wafer. These pressure waves, which propagate at the speed of sound in the fluid (e.g., approximately 1500 m / s in a reverberant environment such as stainless steel), are referred to below as WLA - Water Line Acoustics.

[0006] The sources or triggering mechanisms for WLA are diverse. One example is so-called flow-induced vibrations (FIV), which, depending on local geometric boundary conditions and the upstream and downstream boundary conditions, cause persistent periodic and random fluctuations in the flow, i.e., turbulence. These hydrodynamic fluctuations lead to the coupling of acoustic pressure waves, which propagate as WLA both downstream and upstream and, depending on the geometry of the cooling circuit, can lead to standing waves.

[0007] Another triggering mechanism is transmitted structural vibrations and the interaction between structural components and the fluid. Both the structural vibrations themselves and the interaction exhibit frequency-dependent amplitudes. For example, in current systems, structural vibrations are transmitted via pipe supports to the pipe wall and thus directly into the water column. Cooling channels directly incorporated into structural components can also absorb the structural vibration directly via the water itself. In addition, acoustic disturbances from the environment can also affect the water column. The induction of WLA by FIV occurs exclusively in a cooling system with active flow. The other mechanisms also occur in a system filled only with water, without active flow.Therefore, even a countermeasure such as switching off the active cooling and thus switching off the flow does not provide a complete remedy, only against FIV as a source.

[0008] The pressure and momentum fluctuations from the fluid (WLA) and the resulting forces on the cooling channel walls lead to a frequency-dependent dynamic excitation of the cooled components and the overall system. The sensitivity of the system components to incoming disturbances or vibrations also plays a role. In general, the pressure waves (WLA) are reflected differently in the cooling system depending on the geometric and acoustic boundary conditions as well as the materials used and lead to frequency-dependent force amplitudes that act on the system. These disturbances have a negative impact on system performance (e.g., critical frequencies for the position control of the optics or the deformation of the optical components due to pressure pulsations) and imaging accuracy.

[0009] To reduce the pressure fluctuations introduced into the fluid system to a specified level, (hardware) measures are required. These can be actively operated / controlled or, preferably, passive measures. One solution for reducing or suppressing pressure fluctuations in the fluid column (WLA) is hose assemblies made of viscoelastic materials with gas inclusions. An example of such a hose assembly is a so-called VE hose, as used in Fig. 3 is shown.

[0010] Shown in Fig. 3 is a viscoelastic hose 30 arranged between two connecting pieces 31 of two cooling channels (not shown in the figure) and surrounded by an outer tube 32. The outer tube 32 is integrally connected on both sides to a sleeve designed as a weld-on sleeve 33. The ends of the hose 30 are each pushed onto a socket 34 of the connecting pieces 31 and are pressed from the outside by the inside of the weld-on sleeves 33 against the outside of the sockets, creating a certain sealing effect. A so-called gas chamber 35 is formed between the hose 30 and the outer tube 32.

[0011] In the illustrated combination of viscoelastic material and gas, permeation of water or another fluid used into the gas space 35 may occur. This permeation process depends primarily on the partial pressure difference between the fluid and the gas space 35. The partial pressure difference, in turn, depends directly on the temperature difference between the fluid volume and the gas space 35. Since the temperature in a projection exposure system is maintained very precisely at a constant value and the cooling fluid can simultaneously have a higher temperature, this permeation process is sometimes greatly accelerated.

[0012] In addition, the lower dew point causes condensation of the water vapor within the gas chamber 35. In addition to permeation, cooling fluid, particularly water, can enter the gas chamber 35 due to a leak at the connection point between the viscoelastic hose 30 and the weld-on sleeve 33. The penetrating fluid fills the gas chamber 35 over time. This must be avoided because water, in particular, exhibits significantly higher stiffness due to its low compressibility. This ultimately leads to the viscoelastic hose 30 no longer being able to expand freely, and the damping function of the entire VE hose is limited.

[0013] Various concepts are known from the prior art, particularly for detecting such harmful leaks. For example, European patent application EP 3 951 228 A1 discloses a hose assembly in which a two-part, suitably designed connector allows the tightness of the assembly to be tested at a material-to-material connection, particularly a laser weld seam, that is easily accessible from the outside. However, the solution presented in the cited document only improves the testability of the tightness of a hose assembly, not its tightness itself.

[0014] The object of the present invention is to provide a tube assembly, particularly for use in a projection exposure system for semiconductor lithography, with improved sealing. A further object of the present invention is to provide a projection exposure system for semiconductor lithography with improved fluid tightness and an assembly method for a tube assembly.

[0015] This object is achieved by a device and a method having the features of the independent claims. The subclaims relate to advantageous developments and variants of the invention.

[0016] A hose assembly according to the invention comprises an elastic hose connected at at least one end to a connection area of ​​a connector. The elastic hose can be selected according to the respective requirements, i.e., its nominal diameter and wall thickness can be adjusted accordingly. For example, both straight extruded hose sections and injection-molded hose sections with additional geometric elements are possible.

[0017] Furthermore, the hose assembly according to the invention comprises an outer tube which surrounds the elastic hose at least in sections and a sleeve which is connected at a first end to at least one end of the outer tube and at a second end to the connecting piece.

[0018] At least one additional sealing element is provided in the connection area to further seal the connection between the connection area and the elastic hose. The additional sealing element comprises a pressing element that presses the hose section connected to the connection area against a surface of the connection area, at least in sections, from the outside of the hose.

[0019] The improved sealing between the connection area and the elastic hose ensures that fluids, such as cooling water, cannot penetrate into the gas space between the outer tube and the elastic hose, which is important for the desired damping.

[0020] In particular, the pressing element can comprise at least one ring segment or be designed as a closed pressing ring. The cross-sectional geometry of the pressing element can be selected according to the specific requirements. Rectangular or round cross-sectional geometries are conceivable, for example.

[0021] In the case of a closed press ring, a particularly effective seal can be achieved due to the all-round pressure of the hose against the connection area.

[0022] The pressing element can be formed at least partially from an elastic material, in particular spring steel. Likewise, the pressing element can be formed at least partially from an SMA material. An SMA material is a shape memory material that changes its shape during a phase transition triggered, for example, by a temperature change.

[0023] For example, a ring made of such a material can change its radius, particularly by reducing it, when temperatures exceed or fall below a certain limit, thereby achieving the desired pressing effect. A particular advantage of this material is the comparatively high force that can be applied even with a small volume of material.

[0024] The pressing element can also be plastically deformed by external force in such a way that no SMA material or elastic material is necessary.

[0025] Combinations of materials, for example a combination of a spring steel and an SMA material, are also conceivable for the pressing element depending on the application.

[0026] Additionally, at least one sealing rib can be formed on the outer circumference of the connector facing the elastic hose. Such a sealing rib locally increases the pressure between the connection area, hose, and sleeve, thus locally improving the sealing effect.

[0027] In an advantageous variant of the invention, the sealing rib is designed as a circumferential sealing rib.

[0028] It contributes to a further improvement of the sealing effect if several spaced-apart sealing ribs are present.

[0029] The desired damping effect of the hose assembly according to the invention can be further improved by pre-tensioning the elastic hose between two connectors. This ensures that the elastic hose runs freely inside the outer tube, i.e., in particular, without contact with the inner wall of the outer tube. This allows the elastic hose to initially move toward the inner wall of the outer tube without restriction in the event of pressure fluctuations.

[0030] The desired pre-tension can be achieved, for example, by the outer tube exerting a tensile force on the hose in the axial direction against the elasticity of the hose.

[0031] A method according to the invention for assembling a hose assembly comprises the following steps: - Provision of an elastic hose, two connectors, two sleeves and an outer tube - Arrangement of the elastic hose inside the outer tube - Tensile-resistant connection of the ends of the elastic hose with the connectors - Longitudinal stretching of the elastic hose to a specified value - Fixing the sleeves to the connecting pieces and the outer pipe in such a way that a longitudinal expansion of the hose is maintained

[0032] In the following, embodiments and variants of the invention are explained in more detail with reference to the drawings. Fig. 1 schematically shows in meridional section a projection exposure system for EUV projection lithography, Fig. 2 schematically shows in meridional section a projection exposure system for DUV projection lithography, Fig. 3 a representation of a hose assembly according to the prior art, Fig. 4 shows a representation of a first embodiment of the invention, Fig. 5 in the Fig. 5a and Fig. 5b an exemplary process of pressing the end section of the elastic hose, Fig. 6 in the Fig. 6a and Fig. 6b a possible method for assembling a hose assembly according to the invention, and Fig. 7 a flowchart of a method according to the invention.

[0033] In the following, with reference to the Fig. 1 describes, by way of example, the essential components of a projection exposure system 1 for microlithography. The description of the basic structure of the projection exposure system 1 and its components is not intended to be limiting.

[0034] One embodiment of an illumination system 2 of the projection exposure system 1 has, in addition to a radiation source 3, an 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. In this case, the illumination system does not include the light source 3.

[0035] A reticle 7 arranged in the object field 5 is illuminated. 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.

[0036] In the Fig. 1 shows a Cartesian xyz coordinate system for explanation. The x-direction is perpendicular to the plane of the drawing. The y-direction is horizontal and the z-direction is vertical. The scanning direction is in the Fig. 1 along the y-direction. The z-direction runs perpendicular to the object plane 6.

[0037] The projection exposure system 1 comprises a 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.

[0038] A structure on the reticle 7 is imaged onto a light-sensitive layer of a wafer 13 arranged in the image plane 12 in the region of the image field 11. The wafer 13 is held by a wafer holder 14. The wafer holder 14 can be displaced, in particular along the y-direction, via a wafer displacement drive 15. The displacement of the reticle 7, on the one hand, via the reticle displacement drive 9, and the displacement of the wafer 13, on the other hand, via the wafer displacement drive 15, can be synchronized with each other.

[0039] The radiation source 3 is an EUV radiation source. The radiation 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 has, in particular, a wavelength in the range between 5 nm and 30 nm. The radiation source 3 can be a plasma source, for example, an LPP source (laser produced plasma) or a DPP source (gas discharged produced plasma). It can also be a synchrotron-based radiation source. The radiation source 3 can be a free-electron laser (FEL).

[0040] The illumination radiation 16 emanating from the radiation source 3 is focused 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 (Gl), i.e., at angles of incidence greater than 45° relative to the normal direction of the mirror surface, 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.

[0041] 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 radiation source 3 and the collector 17, and the illumination optics 4.

[0042] The illumination optics 4 comprises 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 conjugated 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 are also referred to below as field facets. Of these facets 21, Fig. 1 only some examples are shown.

[0043] 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.

[0044] As is known, for example, from DE 10 2008 009 600 A1, the first facets 21 themselves can also be composed of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 20 can, in particular, be designed as a microelectromechanical system (MEMS system). For details, reference is made to DE 10 2008 009 600 A1.

[0045] Between the collector 17 and the deflecting mirror 19, the illumination radiation 16 runs horizontally, i.e. along the y-direction.

[0046] 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 1 614 008 B1, and US Pat. No. 6,573,978.

[0047] 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.

[0048] The second facets 23 can also be macroscopic facets, which can, for example, be round, rectangular, or hexagonal, or alternatively facets composed of micromirrors. Reference is also made to DE 10 2008 009 600 A1 in this regard.

[0049] The second facets 23 can have planar or alternatively convex or concave curved reflection surfaces.

[0050] The illumination optics 4 thus form a double-faceted system. This basic principle is also known as a honeycomb condenser (fly's eye integrator).

[0051] It may be advantageous to arrange the second facet mirror 22 not exactly in a plane that is optically conjugated to a pupil plane of the projection optics 10. In particular, the pupil facet mirror 22 can be arranged tilted relative to a pupil plane of the projection optics 10, as described, for example, in DE 10 2017 220 586 A1.

[0052] With the help of the second facet mirror 22, the individual first facets 21 are imaged into the object field 5. The second facet mirror 22 is the last beam-forming mirror or actually the last mirror for the illumination radiation 16 in the beam path before the object field 5.

[0053] 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 into 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 comprise one or two mirrors for normal incidence (NI mirrors, normal incidence mirrors) and / or one or two mirrors for grazing incidence (GI mirrors, grazing incidence mirrors).

[0054] The illumination optics 4 has in the version shown in the Fig. 1, after the collector 17 there are exactly three mirrors, namely the deflection mirror 19, the field facet mirror 20 and the pupil facet mirror 22.

[0055] 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.

[0056] 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 usually only an approximate imaging.

[0057] 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.

[0058] In the Fig. In the example shown in Figure 1, the projection optics 10 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve, or a different number of mirrors M1 are also possible. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 is a doubly obscured optic. The projection optics 10 has an image-side numerical aperture that is greater than 0.5 and can also be greater than 0.6, for example, 0.7 or 0.75.

[0059] Reflection surfaces of the mirrors Mi can be designed as freeform surfaces without a rotational symmetry axis. Alternatively, the reflection surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one rotational symmetry axis of the reflection surface shape. The mirrors Mi, like the mirrors of the illumination optics 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.

[0060] The projection optics 10 has a large object-image offset in the y-direction 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 can be approximately as large as a z-distance between the object plane 6 and the image plane 12.

[0061] The projection optics 10 can, in particular, be anamorphic. It has, in particular, different magnifications βx, βy in the x- and y-directions. The two magnifications βx, βy of the projection optics 10 are preferably (βx, βy) = (+ / - 0.25, + / - 0.125). A positive magnification β means imaging without image inversion. A negative sign for the magnification β means imaging with image inversion.

[0062] The projection optics 10 thus leads to a reduction in the ratio 4:1 in the x-direction, i.e. in the direction perpendicular to the scanning direction.

[0063] The projection optics 10 results in a reduction of 8:1 in the y-direction, i.e. in the scanning direction.

[0064] Other magnifications are also possible. Magnifications with the same sign and absolutely identical in the x and y directions, for example, with absolute values ​​of 0.125 or 0.25, are also possible.

[0065] The number of intermediate image planes in the x- and y-directions in the beam path between the object field 5 and the image field 11 can be the same or can vary 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 are known from US 2018 / 0074303 A1.

[0066] Each of the pupil facets 23 is assigned to exactly one of the field facets 21 to form a respective illumination channel for illuminating the object field 5. This can, in particular, result in illumination according to the Köhler principle. The far field is divided into a plurality of object fields 5 using the field facets 21. The field facets 21 generate a plurality of images of the intermediate focus on the pupil facets 23 assigned to them.

[0067] The field facets 21 are each imaged onto the reticle 7 by an associated pupil 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.

[0068] By arranging the pupil facets, 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 pupil facets 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.

[0069] 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.

[0070] 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.

[0071] The projection optics 10 can, in particular, have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

[0072] The entrance pupil of the projection optics 10 cannot usually be precisely illuminated with the pupil facet mirror 22. When the projection optics 10 images the center of the pupil facet mirror 22 telecentrically onto the wafer 13, the aperture rays often do not intersect at a single point. However, a surface can be found in which the pairwise determined distance of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugate to it in spatial space. In particular, this surface exhibits a finite curvature.

[0073] It is possible that the projection optics 10 have different entrance pupil positions for the tangential and sagittal beam paths. In this case, an imaging element, in particular an optical component of the transmission optics, should be provided between the second facet mirror 22 and the reticle 7. With the help of this optical element, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

[0074] In the Fig. In the arrangement of the components of the illumination optics 4 shown in Figure 1, the pupil facet mirror 22 is arranged in a surface conjugated to the entrance pupil of the projection optics 10. The field facet mirror 20 is arranged tilted relative to the object plane 6. The first facet mirror 20 is arranged tilted relative to an arrangement plane defined by the deflection mirror 19.

[0075] The first facet mirror 20 is arranged tilted to an arrangement plane which is defined by the second facet mirror 22.

[0076] Fig. 2 shows a schematic meridional section of another projection exposure system 101 for DUV projection lithography, in which the invention can also be used.

[0077] The structure of the projection exposure system 101 and the principle of imaging is comparable to that in Fig. 1 described structure and procedure. Identical components are provided with a 100 Fig. 1 raised reference numerals, the reference numerals in Fig. So 2 start with 101.

[0078] In contrast to a Fig. 1, due to the longer wavelength of the DUV radiation 116 used as useful light in the range from 100 nm to 300 nm, in particular from 193 nm, refractive, diffractive and / or reflective optical elements 117, such as lenses, mirrors, prisms, cover plates and the like, can be used in the DUV projection exposure system 101 for imaging or for illumination.The projection exposure system 101 essentially comprises an illumination system 102, a reticle holder 108 for receiving and precisely positioning a reticle 107 provided with a structure, by means of which the later structures on a wafer 113 are determined, a wafer holder 114 for holding, moving and precisely positioning this wafer 113 and a projection lens 110 with a plurality of optical elements 117, which are held via mounts 118 in a lens housing 119 of the projection lens 110.

[0079] The illumination system 102 provides DUV radiation 116 required for imaging the reticle 107 on the wafer 113. A laser, a plasma source, or the like can be used as the source for this radiation 116. The radiation 116 is shaped in the illumination system 102 via optical elements such that the DUV radiation 116, upon impinging on the reticle 107, exhibits the desired properties with regard to diameter, polarization, wavefront shape, and the like.

[0080] The structure of the subsequent projection optics 101 with the lens housing 119 does not differ in principle from that in Fig. 1 and is therefore not described further.

[0081] Fig. Figure 4 shows, in a first embodiment of the invention, a part of a hose assembly 40, such as is used, for example, with a cooling system of one of the Fig. 1 or Fig. 2. It goes without saying that a hose assembly 40 according to the invention can be used at a wide variety of suitable locations in a projection exposure system 1,101.

[0082] The figure shows a connecting piece 31 connected to an elastic hose 30 via a nozzle 34. The elastic hose 30 is guided inside an outer pipe, which in the example shown is designed as a corrugated pipe 32. In the area of ​​the connecting piece 31, the outer pipe, which in the example shown is designed as a corrugated pipe 32, is connected to a sleeve 33 which surrounds the nozzle 34 and the elastic hose 30 pushed over the nozzle 34 up to a shoulder 36 of the connecting piece 31. The sleeve 33 can be integrally connected, in particular welded, to the connecting piece 31 and the outer pipe 32. Other joining techniques such as threads or adhesive bonds are also possible. A fluid-tight, in particular gas-tight, connection between the outer pipe 32, the sleeve 33 and the connecting piece 31 is essential.

[0083] At the end section of the elastic hose 30, a press ring 37 is arranged as an additional sealing element, which presses the elastic hose 30 from the outside against an outer circumference of the nozzle 34 and thus ensures an improved seal between the nozzle 34 and the elastic hose 30. The force required for pressing can be applied, for example, by first expanding an elastic press ring 37 using a suitable tool and then pushing it over the end section of the elastic hose 30. The tool is then removed so that the press ring 37 can contract. It is also conceivable to form the press ring 37 from a shape memory material, a so-called SMA material, which undergoes a phase transition upon reaching a certain temperature, which manifests itself in a change in shape, for example, in a reduction in radius.

[0084] Furthermore, it is conceivable to plastically deform the, for example, metallic press ring 37 by applying an external force in the radial direction, whereby the elastic hose 30 is permanently pressed against the nozzle 34.

[0085] Although a press ring 37 is shown in the example shown, it is also possible to use a combination of ring segments or a wire section bent into a loop.

[0086] Furthermore, the figure shows a circumferential sealing rib 38 on a slope of the nozzle 34 (not separately designated in the figure). The sealing rib 38 serves to further seal between the nozzle 34 and the elastic hose 30. It is advantageous if the sealing rib 38 is arranged as far out as possible on the hose-side end of the nozzle 34 in order to achieve the seal already at the beginning of the gap 39 between the nozzle 34 and the hose 30, so that any fluid that may pass through the sealing rib 38 still has a comparatively long way to go in the gap 39 to reach the end of the hose section pushed over the nozzle 34. In particular, the sealing rib 38 prevents residual water from remaining in the gap 39 between the elastic hose 30 and the nozzle 34, which could potentially lead to crevice corrosion.

[0087] In the example shown, only one circumferential sealing rib 38 is shown. It goes without saying that combinations of several sealing ribs, possibly even those that are not completely circumferential, can also be useful and advantageous depending on the application.

[0088] Fig. 5 shows in the Fig. 5a and Fig. 5b the process of pressing the end portion of the elastic hose 30 against the outside of the nozzle 34. The reference numerals in Fig. 5 correspond to the Fig. 4. The reference numbers used here show Fig. 5a shows the state in which the compression ring 37 is expanded and pushed over the end section of the hose 30. As already mentioned, the expansion can be achieved, for example, using a suitable tool or a suitable phase state of a shape memory material. Likewise, the compression ring 37 can initially have a larger circumference and be plastically deformed by a suitable tool, so that the circumference decreases and the compression ring 37 presses the elastic hose 30 against the connector 34.

[0089] Fig. Figure 5b shows the state after removal of the tool or after the corresponding phase transition of the shape memory material. The press ring 37 now presses the end section from the outside against the circumference of the nozzle 34, thus creating the required seal.

[0090] Fig. 6 shows in the Fig. 6a and Fig. 6b shows a possible method for assembling a hose assembly 40 according to the invention. Fig. Figure 6a shows a state in which the elastic hose 30 has already been guided over the nozzles 34 of the connecting pieces 31 and secured thereto by means of the compression rings 37. The connecting pieces 31 can be held by a suitable device (not shown in the figure) in such a way that a certain preload acts on the elastic hose 30. In this state, the two sleeves 33 are still axially displaceable in a hollow cylindrical section of the outer tube, which is designed as a corrugated tube 32 with corrugated areas 41.

[0091] Fig. Figure 6b shows the fully assembled state of the hose assembly 40. The sleeves 33 are now guided over the connecting pieces 34 and, in particular, also over the compression rings 37. In a known manner, the geometry of the sleeves 33 and the connecting pieces 34 is selected such that the section of the elastic hose 30 located between a sleeve bevel 42 and a connecting piece bevel 43 is pressed against the connecting piece 34 by the sleeve 33, which leads to a further improvement in the seal.

[0092] In the Fig. In the state shown in Figure 6b, the sleeves 33 can be welded, glued, or screwed to both the connecting piece 31 and the outer tube 32. In this case, the comparatively rigid outer tube 32 serves not only to create a sealed cavity between the outer tube 32 and the hose 30, but also to pre-tension the elastic hose 30. This also prevents the elastic hose 30 from partially contacting the inside of the outer tube 32 on its outer side, thereby at least partially losing its damping effect on vibrations in the fluid.

[0093] Fig. 7 shows a method according to the invention for assembling a hose assembly with the following steps: - Provision of an elastic hose, two connectors, two sleeves and an outer tube - Arrangement of the elastic hose inside the outer tube - Tensile-resistant connection of the ends of the elastic hose with the connectors - Longitudinal stretching of the elastic hose to a specified value - Fixing the sleeves to the connecting pieces and the outer pipe in such a way that a longitudinal expansion of the hose is maintained

[0094] It goes without saying that the variants shown in the figures above are merely exemplary. It is also possible to combine the partial aspects shown in the figures. List of reference symbols 1 projection exposure system 2 Lighting system 3 Radiation source 4 Lighting optics 5 Object field 6 Object level 7 reticles 8 reticle holders 9 Reticle displacement drive 10 Projection optics 11 Image field 12 Image plane 13 wafers 14 wafer holders 15 Wafer relocation drive 16 EUV radiation 17 Collector 18 Intermediate focal plane 19 Deflecting mirrors 20 facet mirrors 21 facets 22 facet mirrors 23 facets 30 hose 31 connecting piece 32 outer tube 33 sleeve 34 nozzles 35 Gas room 36 paragraph 37 Press ring 38 Sealing rib 39 gap 40 Hose assembly 41 Well area 42 sleeve bevel 43 nozzle slope 101 Projection exposure system 102 Lighting system 107 reticles 108 reticle holders 110 Projection optics 113 wafers 114 wafer holders 116 DUV radiation 117 optical element 118 versions 119 lens housings M1-M6 mirrors QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] EP 3 951 228 A1

[0013] DE 10 2008 009 600 A1 [0044, 0048] US 2006 / 0132747 A1

[0046] EP 1 614 008 B1

[0046] US 6,573,978

[0046] DE 10 2017 220 586 A1

[0051] US 2018 / 0074303 A1

[0065]

Claims

[1] Hose assembly (40) comprising - an elastic hose (30) which is connected at least at one end to a connection area of a connection piece (31) - an outer tube (32) which surrounds the elastic hose (30) at least in sections - a sleeve (33) connected at a first end to at least one end of the outer tube (32) and at a second end to the connecting piece (31) characterized by that at least one additional sealing element (37) is present in the connection area for additional sealing of the connection between the connection area and the elastic hose (30), wherein the additional sealing element (37) comprises a pressing element which presses the hose section connected to the connection area at least in sections against a surface of the connection area from an outer side of the hose. [2] Hose assembly (40) according to claim 1, characterized bythat the pressing element (37) comprises at least one ring segment. [3] Hose assembly (40) according to claim 1, characterized by that the pressing element (37) is designed as a closed pressing ring. [4] Hose assembly (40) according to one of claims 1 to 3, characterized by that the pressing element (37) is at least partially made of an elastic material, in particular a spring steel. [5] Hose assembly (40) according to one of claims 1 to 4, characterized by that the pressing element (37) is at least partially made of an SMA material. [6] Hose assembly (40) according to one of claims 1 to 5, characterized by that the pressing element (37) is at least partially made of a plastically deformable material. [7] Hose assembly (40) according to one of claims 1 to 6, characterized bythat at least one sealing rib (38) is formed on an outer circumference of the connecting piece (31) facing the elastic hose (30). [8] Hose assembly (40) according to claim 7, characterized by that the sealing rib (38) is designed as a circumferential sealing rib. [9] Hose assembly (40) according to one of claims 7 or 8, characterized by that several sealing ribs (38) spaced apart from one another are present. [10] Hose assembly (40) according to one of claims 1 to 9, characterized by that the elastic hose (30) is pre-tensioned and arranged between two connecting pieces (31). [11] Hose assembly according to claim 10, characterized by that the prestressing is achieved by the outer tube (32) exerting a tensile force on the hose (30) in the axial direction against the elasticity of the hose (30). [12] Projection exposure system (1,101) for semiconductor lithography with a tube assembly (40) according to one of the preceding claims. [13] A method for assembling a hose assembly (40), comprising the following steps: - Provision of an elastic hose (30), two connecting pieces (31), two sleeves (33) and an outer tube (32) - Arrangement of the elastic hose (30) within the outer tube (32) - Tensile connection of the ends of the elastic hose (30) with the connectors (31) - Longitudinal stretching of the elastic hose (30) to a specified value - Fixing the sleeves (33) to the connecting pieces (31) and the outer tube (32) in such a way that a longitudinal expansion of the hose (30) is maintained.

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