Arrangement comprising a microlithographic projection system and a wall element for thermal shielding, and projection exposure system

Abstract

The invention relates to an arrangement comprising a projection system (22) for microlithography and a wall element (28) for thermally shielding the projection system (22) with respect to a lighting system (10). The projection system (22) has an object field which can be illuminated by the lighting system (10) and optical elements (M1-M6) for imaging the object field into an image plane (21). The wall element (28) additionally comprises a passive shielding surface element (30) which is arranged in a transition region between a last beam portion (41) of the lighting system (10) and a first beam portion (42) of the projection system (22). According to the invention, the arrangement also has an active cooling element (31) which is positioned in the transition region and has a cooling surface (32) which extends at least partially along a surface area of the passive shielding surface element (30). With the aid of the active cooling element positioned in the transition region, a rate of change of the heat flow from the lighting system into the projection system can be significantly reduced.

Description

Arrangement comprising a microlithographic projection system and a wall element for thermal shielding and projection exposure system

[0001] The present patent application claims priority from German patent application DE 10 2024 204 451.2, filed on May 14, 2024, to which reference is made and whose content is fully incorporated herein (“incorporation by reference”). The present invention relates to an arrangement comprising a microlithographic projection system and a wall element for thermally shielding the projection system from an illumination system.

[0002] Microlithographic projection exposure systems, comprising an illumination system and a projection system, are used for the fabrication of microstructured components. Achieving high image quality depends not only on the quality of the individual optical elements of the projection system but also on their relative positions. To ensure these relative positions during operation of a projection exposure system, it is known to mount the individual optical elements of the projection system on a common support frame. The support frame and the optical elements are actively temperature-controlled at regular intervals to reduce changes in the image quality of the projection system due to thermal expansion of the optical elements or the support structure. For example, the support frame and / or optical elements can be permeated by channels for a thermofluid.By passing thermofluid through these channels at a predetermined flow rate and / or temperature, the temperature of the support frame and / or optical elements can be kept relatively constant. These measures are intended to minimize deformation of the support frame and / or optical elements during operation.

[0003] Furthermore, actuators can be provided between the support frame and the individual optical elements, allowing the position of each optical element relative to the support frame to be readjusted. In this way, minor temperature changes and resulting deformations of the support frame or optical elements, which cannot be completely ruled out, can be compensated for.

[0004] Despite the possibilities for actively cooling the optical elements or the support frame, as well as for readjusting the optical elements, image quality can deteriorate if the heat input into the projection system is too high. Increased heat input can originate particularly from the illumination system when using illumination radiation with very short wavelengths, as this radiation has higher energy and, moreover, a larger proportion of the energy tends to be absorbed by the optical elements of the illumination system. To reduce the heat input from the illumination system, it is generally known to place a wall element between the illumination system and the projection system for thermal shielding.

[0005] The object of the present invention is to provide an arrangement comprising a projection system for microlithography with a wall element for thermal shielding or a corresponding projection exposure system, which enables improved image quality.

[0006] This problem is solved by an arrangement according to claim 1, by a projection exposure system according to claim 14, and by the use of an active cooling element according to claim 15. Advantageous embodiments are described in the dependent claims.

[0007] The invention relates to an arrangement comprising a projection system for microlithography and a wall element for thermally shielding the projection system from an illumination system. The projection system comprises an object field that can be illuminated by the illumination system and optical elements for imaging the object field onto an image plane. The wall element comprises a passive shielding surface element arranged in a transition region between a final beam section of the illumination system and a first beam section of the projection system. According to the invention, the arrangement further includes an active cooling element positioned in the transition region, with a cooling surface that extends at least partially along a surface area of ​​the passive shielding surface element.

[0008] First, some terms used in this disclosure are explained. The active cooling element is designed to be actively cooled. In particular, heat energy can be actively extracted from the cooling surface. For example, the active cooling element can have at least one cooling channel for conveying a thermofluid, extending along the cooling surface. The cooling surface of the active cooling element is an outer surface of the active cooling element, which can be oriented towards a heat source, in particular towards the lighting system.

[0009] A lighting system typically comprises a plurality of optical elements with which a suitable illumination beam path is generated to illuminate the object field of the projection system. In one embodiment of the present disclosure, the last beam segment of the lighting system denotes the part of the beam path that lies between the object plane and the optical element of the lighting system immediately in front of the object plane in the beam path. The last beam section of the illumination system is, according to the invention, the part of the illumination beam path of the illumination system that is located between the object plane of the projection system and a faceted mirror of the illumination system that is the last with respect to the illumination beam path. Further optical elements that are not faceted mirrors may be present between the aforementioned last faceted mirror of the illumination beam path and the object plane without this affecting the definition of the last beam section. The first beam section of the projection system denotes the part of the beam path that is located between the object plane and the optical element of the projection system that is immediately downstream of the object plane in the beam path.The area between the last beam section of the lighting system and the first beam section of the projection system is also referred to as the transition area.

[0010] The passive shielding element is located in the aforementioned transition area. It may have a recess through which the beam path can pass to transition from the illumination system to the projection system. Furthermore, the passive shielding element may be positioned such that an imaginary connecting plane, linking the last beam segment of the illumination system with the first beam segment of the projection system, intersects the passive shielding element. The passive shielding element serves, in particular, to passively reduce the transfer of radiant heat from the illumination system to the projection system, i.e., without active temperature control.A section of the wall element that serves to separate the lighting system from the projection system and is equipped with means for active cooling (such as cooling channels) is not considered a passive shielding surface element within the scope of this disclosure.

[0011] The passive shielding element has a surface area that is significantly larger than its thickness measured perpendicular to this area. The passive shielding element can, in particular, be designed as a sheet metal part. The passive shielding element can be connected to other parts of the wall element. The wall thickness of the passive shielding element can, in one embodiment, be between 0.2 mm and 15 mm, in particular between 0.5 mm and 4 mm.

[0012] In the transition zone between the illumination system and the projection system, space is typically limited, as the final beam segment of the illumination system usually strikes the object plane (or a photomask located there, for example) at an acute angle and is reflected. Accordingly, the passive shielding element was regularly designed with a thin material thickness for space reasons. Since a vacuum or very low pressure is typically maintained within the projection exposure system during operation, it was previously assumed that a thin-walled passive shielding element would be sufficient to adequately reduce the heat transfer mode of thermal radiation prevalent under these pressure conditions, so that, if necessary, with the aid of the compensation means present in the projection system (i.e., with the aid of active temperature control of the optical elements or...).(of the support frame as well as the readjustment of the optical elements) ensures high image quality.

[0013] However, within the scope of the invention it was recognized that, particularly when using very small wavelengths, under certain circumstances the rate of change of the heat flow from the lighting system to the projection system can increase to such an extent that the compensation means present in the projection system can no longer counteract it sufficiently. Furthermore, it was recognized that the rate of change of the heat flux can be significantly reduced by positioning an active cooling element in the transition region between the beam path and the passive shielding element, with its cooling surface extending along the passive shielding element. In particular, due to its orientation along the shielding element, the cooling surface can effectively absorb heat and dissipate it, for example, via a thermofluid conveyed through a cooling channel, thereby significantly reducing the rate of change of the heat flux. In this way, the time constant of the heat transfer can be increased to such an extent that potential positional changes of the optical elements can be adequately counteracted by means of active temperature control or readjustment of the optical element positions.

[0014] In one embodiment, the active cooling element is positioned on the side of the passive shielding element facing the projection system. Heat radiation emanating from the passive shielding element can then be effectively absorbed and dissipated by the active cooling element, thus reducing heat input into the optical elements of the projection system. In an alternative embodiment, the active cooling element can also be positioned on the side of the passive shielding element facing the illumination system. In this case, the heat input into the passive shielding element can be reduced, thereby also reducing the rate of change of the heat flux.

[0015] In one embodiment, the active cooling element has at least one cooling channel extending along the cooling surface. In this case, the cooling element may have suitable connections for supplying a thermofluid. It may be provided that an existing projection system- The system is retrofitted by providing an active cooling element. In this case, it is possible to connect existing conveying equipment for pumping the thermofluid to the active cooling element.

[0016] Furthermore, the cooling surface can be essentially aligned parallel to the passive shielding element, and in particular, a contour of the cooling surface can be adapted to a contour of the passive shielding element. The features described above enable effective heat absorption and dissipation, thus effectively reducing changes in heat flow. The cooling surface, i.e., the surface of the cooling element facing the heat source, can have an area between 100 cm². 2 and 5000 cm 2 , especially between 600 cm 2 and 1000 cm 2 The thickness of the active cooling element (measured perpendicular to the cooling surface) can be between 2 mm and 20 mm, in particular between 4 mm and 15 mm.

[0017] The cooling surface can, in principle, be in complete or partial thermal contact with at least a portion of the passive shielding element. However, full thermal contact is not strictly necessary. It may be sufficient if the heat extraction element is merely positioned adjacent to the passive shielding element. The heat extraction element can, for example, be attached to the passive shielding element using fasteners.

[0018] The active cooling element can be made of a thermally conductive material, in particular a metal. Furthermore, the active cooling element can have a through-hole aligned along the cooling surface, forming at least part of a cooling channel. Through-holes also allow for cooling in an active cooling element with low thermal conductivity. A plurality of cooling channels can be implemented so that the cooling surface can be effectively cooled. The active cooling element can, in particular, have at least two through-holes. The through-holes can be fluidly connected to each other by a distribution element in the region of a side surface of the active cooling element. A side surface is defined as a boundary surface that is at an angle to the cooling surface, where the angle can be essentially 90°. It is also possible that at least one through-hole opening into a side surface of the active cooling element is designed for, or used for, the supply or discharge of the thermofluid.

[0019] In an alternative embodiment, the active cooling element comprises two surface components with corresponding contours, which are joined together over their surface. At least one of the surface components has an embossed feature, such that the embossing between the surface components forms at least a portion of the cooling channel. The surface component facing the lighting system forms a cooling surface as defined in this disclosure. The surface components can be formed, in particular, from sheet metal parts. The course of one or more cooling channels can be embossed into at least one of the surface components by a forming process, thereby creating the aforementioned embossed feature. It is possible that the surface components are welded together along at least a portion of the cooling channel(s).

[0020] Alternatively, the active cooling element can also be manufactured using an additive manufacturing process. Within an additive manufacturing process, cooling channels can be flexibly integrated into the component.

[0021] When a quantity of thermofluid at a lower temperature than the active cooling element is passed through a cooling channel of the active cooling element, it successively absorbs heat. This means that its ability to absorb further heat tends to decrease with the distance traveled within the cooling channel. In principle, this can create an undesirable temperature gradient along the cooling channel. However, this can be counteracted by a suitable choice of the coolant channel's path. In particular, the path of at least one cooling channel can be designed in such a way as to prevent the formation of a temperature gradient. For example, this can be achieved by providing two or more independently fed cooling channels, each running along different sections of the cooling surface.Furthermore, it may be provided that two or more independently fed cooling channels are included, which are designed to distribute the coolant symmetrically within the active cooling element. Finally, it may be provided that at least two independently fed cooling channels with spatially adjacent channel sections are included, through which coolant flows in opposite directions.

[0022] The invention further relates to a projection exposure system comprising an arrangement according to the invention and a lighting system configured to illuminate the object field. The projection exposure system can be further developed by additional features described above in connection with the arrangement according to the invention.

[0023] The invention further relates to the use of an active cooling element within a projection exposure unit. Projection exposure system for microlithography. The projection exposure system comprises an illumination system, a projection system, and a wall element for thermally shielding the projection system from the illumination system. The illumination system is designed to illuminate an object field of the projection system, and the projection system is designed to image the object field onto an image plane. The wall element comprises a passive shielding surface element arranged in a transition region between a final beam section of the illumination system and a first beam section of the projection system. According to the invention, the active cooling element is positioned in the transition region such that a cooling surface of the active cooling element extends at least partially along a surface area of ​​the passive shielding surface element.The use can be further developed by additional features described above in connection with the arrangement according to the invention.

[0024] The invention is described below by way of example with reference to the accompanying drawings and advantageous embodiments. The drawings show: Fig. 1 : an embodiment of a projection exposure system according to the invention; Fig. 2: an enlarged section of figure 1; Fig. 3 : a side view of the side of the wall element facing the projection system in the embodiment of Figure 1 ; Fig. 4: a transparent three-dimensional view of the active cooling element of the embodiment of Figure 1; Fig. 5: a cross-sectional view along the lines AA drawn in Figures 3 and 4; Fig. 6: a side view of the side facing the projection system of an alternative active cooling element; Fig. 7: a cross-sectional view along the line shown in the figure 6 drawn lines BB; Fig. 8: a graphical representation of the results of theoretical calculations to illustrate the advantages of the invention.

[0025] Figure 1 schematically illustrates a microlithographic EUV projection exposure system according to the invention. The projection exposure system comprises an exposure beam source 14, an illumination system 10, and a projection system 22, which are operated together in a vacuum chamber 23.

[0026] The exposure source 14 generates electromagnetic radiation in the EUV range, specifically with a wavelength between 5 nm and 30 nm. The exposure radiation emitted by the exposure source 14 is focused by a collector 15 into an intermediate focal plane 16. Exposure radiation passing from the intermediate focal plane 16 is directed by the illumination system 10 into an object plane 12, so that an object field in the object plane 12 is illuminated with uniform radiation intensity.

[0027] The lighting system 10 comprises a deflecting mirror 17, which deflects the illumination radiation onto a first faceted mirror 18. A second faceted mirror 19 is arranged downstream of the first faceted mirror 18. The faceted mirror 19 is the last faceted mirror of the lighting system 10 with respect to the illumination beam path. The facets of the first facet mirror 18 are imaged onto the object plane 12 by the second facet mirror 19. The part of the beam path located between the facet mirror 19 and the object field is also referred to here as the last beam section of the illumination system 10.

[0028] In the object plane 12, a photomask 13 is arranged, which is imaged onto an image plane 21 via a plurality of mirrors M1-M6 of the projection system 22. The part of the beam path located between the object field and the first mirror M1 of the projection system 22 is also referred to here as the first beam section of the projection system 22.

[0029] A structure formed on the photomask 13 is transferred to a radiation-sensitive layer of a wafer 20 arranged in the image plane 21 by means of mirrors M1-M6. The photomask 13 is suspended from a first scanning device 24, and the wafer 20 rests on a second scanning device 25, so that the wafer 20 can be exposed in a single scanning operation in which the photomask 13 and the wafer 20 are moved synchronously. The photomask 13 can have an aspect ratio between 1:1 and 1:3, preferably between 1:1 and 1:2, and particularly preferably 1:1 or 1:2. The photomask 13 can be substantially rectangular. The photomask 13 can preferably be 5 to 7 inches long and wide, and particularly preferably 6 inches long and wide. Alternatively, the photomask can be 5 to 7 inches long and 10 to 14 inches wide, preferably 6 inches long and 12 inches wide.

[0030] In the example shown in Figure 1, the projection system 22 comprises six mirrors M1-M6. Alternatives with four, eight, ten, twelve, or any other number of mirrors are also possible. The penultimate mirror M5 and the last mirror M6 each have a through-opening for the Be- Illumination radiation, meaning that the projection system 22 shown is a doubly obscured optic. The projection system 22 has an image-side numerical aperture that is greater than 0.3, and which can also be greater than 0.6, for example 0.7 or 0.75.

[0031] The projection system 22 can in particular be anamorphic, i.e. it has in particular different image scales β. x , ß y in the x and y directions. The two image scales ß x , ß y of the projection system 20 are preferably located at (ß x , ß y) = ( + 0.25, / + - 0.125) . A magnification β of 0.25 corresponds to a reduction in the ratio of 4:1, while a magnification β of 0.125 results in a reduction in the ratio of 8:1. A positive sign for the magnification β indicates a magnification without image inversion, a negative sign indicates a magnification with image inversion.

[0032] The reflective surfaces of mirrors M1-M6 can be designed as freeform surfaces without an axis of rotational symmetry. Mirrors M1-M6, like the mirrors of the lighting system 10, can have reflective coatings for the illumination radiation. These reflective coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon. Despite the highly reflective coatings of the mirrors, a considerable proportion (e.g., 30%) of the illumination radiation is absorbed by the mirrors and converted into heat. This leads, in particular, to a high heat input into the mirrors 17, 18, and 19 of the lighting system. To prevent this heat from passing unhindered into the projection system 22, a wall element 28, indicated only schematically by a dashed line in Figure 1, is provided between the lighting system 10 and the projection system 22, which serves as thermal shielding.

[0033] Figure 2 shows an enlarged section of Figure 1, with the wall element 28 depicted in a schematic cross-section and in greater detail. In this view, it can be seen that the wall element 28 has a lower wall section 29 and a passive shielding element 30 attached to it. The shielding element 30 is arranged between the last beam section 41 of the illumination system 10 and the first beam section 42 of the projection system and has a recess 40 through which the beam path can pass. In the area between the beam sections 41 and 42, the installation space is limited because the beam path strikes the photomask 13 at an acute angle and is reflected. A minimum distance between the mirror M1 and an edge of the last beam section 41 (measured perpendicular to the shielding element 30) is approximately 60 mm.Since the beam sections 41, 42 taper towards the object plane 12, this distance decreases towards the object plane 12. The passive shielding surface element 30 is designed with a small material thickness of 3 mm and is made of aluminum.

[0034] On the side of the passive shielding element 30 facing the projection system 22, there is an active cooling element 31, which is attached to the shielding element 30. The active cooling element 31 is made of stainless steel and has a thermal conductivity of 20 W / (mK). A cooling surface of the active cooling element 31 is in contact with a corresponding counter surface of the passive shielding element 30. The active cooling element 31 is permeated by cooling channels (not shown in Figure 2) that extend along the cooling surface. The cooling surface has an area of ​​approximately 74 cm². 2The thickness of the active cooling element 31, measured perpendicular to the cooling surface, is approximately 7.5 mm.

[0035] Figure 3 shows a side view of the side of the wall element 28 of the embodiment of Figure 1 facing the projection system 22. In this view, it can be seen that the active cooling element 31 is attached to the passive shielding element 30 by means of fastening elements 34.

[0036] Figure 4 shows a transparent three-dimensional view of the active cooling element 31 of the embodiment shown in Figure 1. The active cooling element 31 has a curved central section and two flat side sections. Each side section has three through-holes 45 through which fastening elements for attaching the active cooling element to the passive shielding element 30 can be passed. A plurality of through-holes extend along a vertical direction of the active cooling element 31, each forming sections of cooling channels 35, 35', 35''. In the region of the upper and lower side surfaces 39 of the active cooling element 31, several of the through-holes are fluidly connected to each other by means of distribution elements 38, 38' embedded in the active cooling element 31. The active cooling element also has several fluid connections 33, 33', 33' ', 34, 34', 34' ', to which fluid lines for supply and / orA thermal fluid can be connected for drainage.

[0037] For example, a thermal fluid can be supplied via connection 33, which is guided through the two bores connected to connection 33 to the distribution element 38 and from there through two further bores to be discharged again via fluid connection 34. A first cooling channel 35, formed by the bores and the distribution element 38, extends between fluid connections 33 and 34. A second cooling channel extends similarly within the curved central section. 35' extends from connection 33' via the associated bores and distribution elements 38' to fluid connection 34'. Finally, a third cooling channel 35'' (essentially symmetrical to the first cooling channel 35) extends from fluid connection 33'' to fluid connection 34''. The three aforementioned cooling channels 35, 35', 35'' are supplied independently with a thermofluid, each running only through a partial section of the cooling element 31 and are correspondingly shorter. Furthermore, there are sections of cooling channels 35 and 35'', and 35' and 35'', in which the thermofluid flows in opposite directions. This reduces the temperature gradient that would otherwise arise along the cooling channels within the cooling element 31.

[0038] Figure 5 shows a cross-sectional view along the lines AA drawn in Figures 3 and 4. Figures 4 and 5 show that the passive shielding element 30 also has a curvature in a central section, with a contour of the active cooling element, or rather its cooling surface 32, being adapted to a contour of the passive shielding element 30. The cooling surface 32 is in full thermal contact with the passive shielding element 30.

[0039] The active cooling element 31 effectively removes heat from the passive shielding element 30. This limits the rate of change of the heat flow from the lighting system to the projection system during operation of the projection exposure system.

[0040] Figure 6 shows a side view of an alternative active cooling element 31, which can be used in an alternative embodiment of the invention. Figure 7 shows a cross-sectional view along the line shown in Figure 6. The active cooling element 31, in this embodiment, comprises two surface components 36 and 37, each formed by metal sheets. The surface component 36 has two cooling channels 35 embossed into it. Apart from the areas formed by the embossing, the two surface components 36 and 37 have corresponding contours, so that two cooling channels 35 are formed between them when they are placed on top of each other. The surface components 36 and 37 are welded together along the cooling channels. Fluid connections 33 and 34 are also provided for supplying and removing a thermofluid. The surface of the surface component 37 pointing away from the surface component 36 forms a cooling surface which can be brought into thermal contact with a counter surface of a suitable passive shielding surface element to form an arrangement according to the invention.

[0041] In this embodiment, the cooling channels 35 each extend over a section of the active cooling element 31, with the two cooling channels 35 being essentially symmetrical to each other with respect to a vertical axis of symmetry.

[0042] Within the scope of the invention, theoretical calculations were carried out using FEM simulation to simulate the effects of an active cooling element on the heat flow that transfers from the lighting system to the projection system within an exemplary projection exposure system. Figure 8 shows the results of these calculations. In particular, the normalized heat flux Q = —, which in the exemplary projection system dt transitions from the lighting system to an optical element of the projection system, is shown over time, with the time axis also being normalized. A warm-up phase, which is not relevant for the present analysis, is not shown.

[0043] Graph 52 illustrates the heat flow that results when the optical element of the projection system is shielded from the heat source solely by a passive shielding element without an active cooling element. Graph 53 shows the heat flow that results when an active cooling element is used according to the invention, positioned between the passive shielding element and the first beam section of the projection system, as shown in Figures 1 and 2. The normalization factor used corresponds to the maximum heat flow achieved when no active cooling is used (Graph 52).

[0044] The curve of graph 52 initially shows a steep increase in heat flow (see line 54) until it eventually approaches the maximum heat flow asymptotically. If an active cooling element is present (graph 53), the heat flow follows a fundamentally similar time course, although the maximum heat flow is significantly lower than in graph 52. In particular, the active cooling element can also significantly reduce the maximum rate of change of the heat flow, which is given by the slope of the dashed lines 55. Due to the limitation of the rate of change of the heat flow, potential changes in the position of the optical elements in the projection system can be sufficiently counteracted by the active temperature control or readjustment of the optical element positions available there, thus ensuring high image quality.

Claims

Claims 1. An arrangement comprising a projection system (22) for microlithography and a wall element (28) for thermal shielding the projection system (22) from an illumination system (10), wherein the projection system (22) has an object field that can be illuminated by the illumination system (10) and optical elements (M1 - M6) for imaging the object field onto an image plane (21), wherein the wall element (28) has a passive shielding surface element (30) that is arranged in a transition area between a last beam section (41) of the illumination system (10) and a first beam section (42) of the projection system (22), wherein the last beam section (41) is the part of an illumination beam path of the illumination system (10) that is located between an object plane (12) of the projection system (22) and a last faceted mirror (19) of the illumination system (10) with respect to the illumination beam path, characterized in thatthat the arrangement further comprises an active cooling element (31) positioned in the transition area with a cooling surface (32) which extends at least partially along a surface area of ​​the passive shielding surface element (30).

2. Arrangement according to claim 1, characterized in that the active cooling element (31) is positioned on the side of the passive shielding surface element (30) facing the projection system (22).

3. Arrangement according to one of claims 1 to 2, characterized in that the cooling surface (32) is oriented substantially parallel to the passive shielding surface element (30), wherein preferably a contour of the cooling surface (32) is adapted to a contour of the passive shielding surface element (30).

4. Arrangement according to one of claims 1 to 3, characterized in that the cooling surface (32) is in thermal contact with at least a partial surface of the passive shielding surface element (30).

5. Arrangement according to claim 4, characterized in that the cooling surface (32) has an area between 100 cm 2 and 5000 cm 2 lies.

6. Arrangement according to claim 4 or 5, characterized in that the active cooling element has a thickness between 2 mm and 30 mm.

7. Arrangement according to one of claims 1 to 6, characterized in that the active cooling element (31) is attached to the passive shielding surface element (30).

8. Arrangement according to one of claims 1 to 7, characterized in that the active cooling element (31) has at least one through-hole extending along the cooling surface (32), which forms at least part of a cooling channel (35).

9. Arrangement according to claim 8, characterized in that the active cooling element (31) has at least two through-holes, wherein the through-holes in the area of ​​a side surface (39) of the active cooling element (31) are fluidly connected to each other by a distribution element (38).

10. Arrangement according to one of claims 1 to 7, characterized in that the active cooling element (31) has two surface components (36, 37) which correspond to each other have contours and are connected to each other over a surface, wherein at least one of the surface components (36, 37) has an embossing, such that the embossing between the Surface components (36, 37) form at least a part of the cooling channel (35).

11. Arrangement according to one of claims 1 to 7, characterized in that the active cooling element (31) is manufactured by an additive manufacturing process.

12. Arrangement according to one of claims 1 to 11, characterized in that the active cooling element (31) has at least one cooling channel (35) extending along the cooling surface (32) of the active cooling element (31).

13. Arrangement according to claim 12, characterized in that the course of the at least one cooling channel (35) is designed in such a way as to counteract the formation of a temperature gradient within the active cooling element (31).

14. Projection exposure system comprising an arrangement according to one of claims 1 to 12 and a lighting system (10) which is configured to illuminate the object field.

15. Use of an active cooling element within a projection exposure system for microlithography comprising an illumination system (10), a projection system (22) and a wall element (28) for thermal shielding the projection system (22) from the illumination system (10), wherein the illumination system (10) is configured to illuminate an object field of the projection system (22), wherein the projection system (22) is configured to image the object field onto an image plane (21), and wherein the wall element has a passive shielding surface element (30) located in a transition area between a final beam section of the illumination system (10) and a first beam section of the projection system (22), wherein the last beam section (41) is the part of an illumination beam path of the illumination system (10) that is located between an object plane (12) of the projection system (22) and a last faceted mirror (19) of the illumination system (10) with respect to the illumination beam path, characterized in that the active cooling element (31) is positioned in the transition area such that a cooling surface (32) of the active cooling element (31) extends at least partially along a The surface area of ​​the passive shielding element (30) extends .

Images