Abstract
A mirror arrangement, for example for a lithography system, comprises: a plurality of mirror elements, for example in the form of MEMS mirror modules, for reflecting radiation; a plurality of carrier elements, each having a head region for accommodating one of the mirror elements; and a mount arrangement comprising insert openings, which are designed to accommodate a respective seat portion of the carrier elements. The plurality of carrier elements are accommodated with the seat portions in the insert openings in the mount arrangement. Each carrier element comprises a channel device for guiding a coolant, which comprises an inlet for the coolant and an outlet for the coolant.
Claims
1. A mirror arrangement, comprising: a plurality of MEMS mirror modules, each MEMs mirror module comprising a plurality of mirror elements configured to reflect radiation; a plurality of carrier elements, each carrier element comprising a head region and a seat portion, each head region accommodating a corresponding one of the plurality of mirror elements; a mount arrangement comprising insert openings, each insert opening accommodating a corresponding seat portion of one of the carrier elements, wherein: each carrier element comprises a channel configured to guide a coolant between an inlet of the channel and an outlet of the channel; and one of the following holds: the mount arrangement comprises a plurality of feed openings and a plurality of second openings, and for each channel: a corresponding feed opening in the mount arrangement is configured to provide the coolant to the inlet of the channel; and a corresponding discharge opening in the mount arrangement is configured to discharge the coolant from the outlet of the channel; or for each channel, each of the inlet and the outlet is separated from the corresponding mount arrangement in a fluid-tight manner.
2. The mirror arrangement of 1, wherein, for each carrier element, its channel is configured to provide the coolant into its head region and to discharge the coolant from the head region.
3. The mirror arrangement of claim 2, wherein, within the head region of each carrier, the channel is meander-shaped.
4. The mirror arrangement of claim 2, wherein, for each carrier, its channel extends over more than 50% of a surface on an end face of its head region.
5. The mirror arrangement of claim 2, wherein, within the head region of each channel, the channel comprises a plurality of channels configured to guide the coolant in parallel.
6. The mirror arrangement of claim 2, wherein, for each carrier, the plurality of channels extend over more than 50% of a surface on an end face of its head region.
7. The mirror arrangement of claim 1, wherein: the mount arrangement comprises a plurality of feed openings and a plurality of discharge openings; and for each channel: a corresponding feed opening in the mount arrangement is configured to provide the coolant to the inlet of the channel; and a corresponding discharge opening in the mount arrangement is configured to discharge the coolant from the outlet of the channel.
8. The mirror arrangement of claim 7, wherein, for each channel: the inlet and the outlet are at the seat portion; and the seat portion is sealed in the corresponding insert opening in a region of the inlet and the outlet.
9. The mirror arrangement of claim 8, wherein, for each channel, the inlet opens into an intermediate space, and the outlet opens into the intermediate space.
10. The mirror arrangement of claim 8, wherein, for each channel, the inlet opens into a ring space, the outlet opens into the ring space, and the ring space is sealed by seals extending between the seat portion of the corresponding carrier element and the corresponding insert opening.
11. The mirror arrangement of claim 8, wherein, for each channel: the corresponding feed opening opens into a first intermediate space into which the inlet of the channel opens; and the corresponding discharge opening opens into a second intermediate space into which the outlet of the channel opens.
12. The mirror arrangement of claim 8, wherein, for each channel: the corresponding feed opening opens into a first ring space into which the inlet of the channel opens; and the corresponding discharge opening opens into a second ring space into which the outlet of the channel opens.
13. The mirror arrangement of claim 12, further comprising seals that seal the first and second ring spaces are sealed from each other.
14. The mirror arrangement of claim 7, wherein, for each channel, the inlet and the outlet are disposed, with a lateral offset relative to the insert opening, on a side of the head region of the corresponding carrier element facing an end face of the mount arrangement.
15. The mirror arrangement of claim 14, wherein, for each channel: the inlet and the outlet each open into an intermediate space between the side of the head region facing the end face of the mount arrangement and the end face of the mount arrangement; and the intermediate space is sealed from the environment by a sealing arrangement.
16. The mirror arrangement of claim 15, wherein for each channel: the corresponding feed opening opens into a first intermediate space into which the inlet opens; and the corresponding discharge opening opens into a second intermediate space into which the outlet opens.
17. The mirror arrangement of claim 1, wherein, for each channel, each of the inlet and the outlet is separated from the corresponding mount arrangement in a fluid-tight manner.
18. The mirror arrangement of claim 17, wherein, for each channel, the inlet and the outlet are disposed at a fixing portion of the corresponding carrier element.
19. The mirror arrangement of claim 1, wherein, for each carrier element, the carrier element comprises a fixing portion fixing the carrier element in the corresponding insert opening of the mount arrangement.
20. The mirror arrangement of claim 1, wherein, for each carrier element, the head region comprises a material having a coefficient of thermal expansion which deviates by less than 100% from a coefficient of thermal expansion of a material of the mirror element which adjoins an end face of the head region.
21. A apparatus, comprising: an illumination system configured to illuminate an object, wherein the illumination system comprises a mirror arrangement according to claim 1, and the apparatus if a lithography apparatus.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Exemplary embodiments are illustrated in the schematic drawing and will be explained in the description below. In the figures:
[0044] FIG. 1 schematically shows in the meridional section a projection exposure apparatus for EUV projection lithography, having an illumination system having two facet mirrors;
[0045] FIG. 2 shows a perspective illustration of a mirror arrangement in the form of the first facet mirror of the illumination system of FIG. 1 having a plurality of mirror elements;
[0046] FIG. 3A shows a schematic sectional illustration of three mirror elements of the mirror arrangement of FIG. 2, which are mounted on carrier elements which have been inserted with a seat portion into the insert openings in a mount arrangement;
[0047] FIG. 3B shows a schematic illustration of a carrier element having, introduced therein, a channel device which has an inlet and an outlet for a coolant, which are formed on a seat portion of the carrier element;
[0048] FIG. 4 shows a schematic illustration of a head region of a carrier element having a plurality of channels through which a coolant can flow in parallel;
[0049] FIG. 5A shows a schematic illustration similar to FIG. 3A, in which the seat portion of the respective carrier element does not extend to a side of the mount arrangement facing away from the mirror elements;
[0050] FIG. 5B shows a schematic illustration similar to FIG. 3B, in which the inlet and the outlet for the coolant are formed at a head portion of the carrier element; and
[0051] FIGS. 6A-6B show schematic illustrations of a carrier element having, introduced therein, a channel device which has an inlet and an outlet for a coolant, which are not connected to the mount arrangement.
DETAILED DESCRIPTION
[0052] In the following description of the drawings, the same or functionally identical structural parts are denoted by identical reference signs.
[0053] With reference to FIG. 1, the following text describes by way of example certain constituent parts of an optical arrangement for EUV lithography in the form of a microlithographic projection exposure apparatus 1 (EUV lithography apparatus). The description of the basic setup of the projection exposure apparatus 1 and of its constituent parts should not be understood to have a limiting effect.
[0054] One embodiment of an illumination system 2 of the projection exposure apparatus 1 has, in addition to a light or radiation source 3, an illumination optical unit 4 for illuminating an object field 5 in an object plane 6. In an alternative embodiment, the light source 3 may also be provided in the form of a module separate from the rest of the illumination system. In this case, the illumination system does not comprise the light source 3.
[0055] 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 is displaceable for example in a scanning direction using a reticle displacement drive 9.
[0056] FIG. 1 shows for illustration purposes a Cartesian xyz-coordinates system. The x-direction runs perpendicularly into the drawing plane. The y-direction runs horizontally, and the z-direction runs vertically. The scanning direction in FIG. 1 runs along the y-direction. The z-direction runs perpendicularly to the object plane 6.
[0057] The projection exposure apparatus 1 comprises a projection system 10. The projection system 10 is used to image the object field 5 into an image field 11 in an image plane 12. A structure on the reticle 7 is imaged on 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 is displaceable for example in the y-direction using a wafer displacement drive 15. The displacement of the reticle 7 on the one hand using the reticle displacement drive 9 and of the wafer 13 on the other hand using the wafer displacement drive 15 may be synchronized.
[0058] The radiation source 3 is an EUV radiation source. The radiation source 3 emits for example EUV radiation 16, which is also referred to below as used radiation, illumination radiation or illumination light. The used radiation has for example a wavelength in the range of between 5 nm and 30 nm. The radiation source 3 can be a plasma source, for example an LPP (Laser Produced Plasma) source or a GDPP (Gas Discharge Produced Plasma) source. It can also be a synchrotron-based radiation source. The radiation source 3 can be a free electron laser (FEL).
[0059] The illumination radiation 16 emanating from the radiation source 3 is focused by a collector mirror 17. The collector mirror 17 can be a collector mirror with one or more ellipsoidal and/or hyperboloidal reflection surfaces. The illumination radiation 16 can be incident on the at least one reflection surface of the collector mirror 17 with grazing incidence (GI), i.e. at angles of incidence of greater than 45, or with normal incidence (NI), i.e. at angles of incidence of less than 45. The collector mirror 17 can be structured and/or coated, firstly, for optimizing its reflectivity for the used radiation and, secondly, for suppressing extraneous light.
[0060] Downstream of the collector mirror 17, the illumination radiation 16 propagates through an intermediate focus in an intermediate focal plane 18. The intermediate focal plane 18 can constitute a separation between a radiation source module, comprising the radiation source 3 and the collector mirror 17, and the illumination optical unit 4.
[0061] The exposure optical unit 4 comprises a deflection mirror 19 and, downstream thereof in the beam path, a first facet mirror 20. The deflection mirror 19 may be a plane deflection mirror or, alternatively, a mirror with a beam-influencing effect that goes beyond the pure deflection effect. Alternatively or additionally, the deflection mirror 19 may be in the form of a spectral filter, which separates a used light wavelength of the illumination radiation 16 from extraneous light of a different wavelength. The first facet mirror 20 comprises a multiplicity of individual first facets 21, which are also referred to below as field facets. FIG. 1 illustrates only some of these facets 21 by way of example. In the beam path of the illumination optical unit 4, a second facet mirror 22 is disposed downstream of the first facet mirror 20. The second facet mirror 22 comprises a plurality of second facets 23.
[0062] The illumination optical unit 4 thus forms a double-faceted system. This basic principle is also referred to as a fly's eye condenser (fly's eye integrator). The individual first facets 21 are imaged into the object field 5 using the second facet mirror 22. The second facet mirror 22 is the last beam-shaping mirror or actually the last mirror for the illumination radiation 16 in the beam path upstream of the object field 5. Alternatively, the illumination system 2 can be based on the principle of the specular reflector as is described, for example, in DE 10317667 A1, which is incorporated in its entirety in this application by reference.
[0063] The projection system 10 comprises a plurality of mirrors Mi, which are consecutively numbered in accordance with their arrangement in the beam path of the projection exposure apparatus 1.
[0064] In the example illustrated in FIG. 1, the projection system 10 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or any other number of mirrors Mi are likewise possible. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection system 10 is a doubly obscured optical unit. The projection optical unit 10 has an image-side numerical aperture which is greater than 0.4 or 0.5 and which can also be greater than 0.6 and which can be for example 0.7 or 0.75.
[0065] Just like the mirrors of the illumination optical unit 4, the mirrors Mi can have a highly reflective coating for the illumination radiation 16.
[0066] FIG. 2 shows the mirror arrangement in the form of the first facet mirror 20 of the illumination system 2 of FIG. 1 in a partial section. The mirror arrangement 20 has a plurality of mirror elements 21 which are arranged in close proximity, form a concave surface and are aligned with respect to an optical center. Each of the mirror elements 21 serves to reflect electromagnetic radiation, specifically EUV radiation 16, which is reflected from the first facet mirror 20 of the illumination system 2 to the facets 23 of the mirror arrangement 22 in the form of the second facet mirror. In the example shown, the mirror elements 21 are in the form of MEMS mirror modules. A respective MEMS mirror module has a number of micromirrors which are arranged in a grid (e.g., with 2424 micromirrors) and which can be actuated, more precisely tilted, on an individual basis. A respective mirror element 21 in the form of a MEMS mirror module has logic elements and micromechanical structures in chip format for this purpose. The mirror elements 23 or the facets of the second facet mirror 22 are likewise designed as MEMS mirror modules.
[0067] The mirror arrangement 20 shown in FIG. 2 also comprises a plurality of carrier elements 24, which each carry one of the mirror elements 21. The mirror arrangement 20 also has a mount arrangement 25 which in the example shown comprises conical insert openings 26 designed to accommodate a respective one of the conical carrier elements 24. The mount arrangement 25 has a multi-part structure and moreover has mount shells put together in layered fashion. The carrier elements 24 each have a head region 27, shown in FIGS. 3A-3B, which projects over the insert opening 26 and on which a respective mirror element 21 is mounted. The carrier elements 24 dip with a seat portion 28 into the insert opening 26. Regarding details of the structure of the mirror arrangement 20, of how the carrier elements 24 are fastened to the mount arrangement 25 and the structure of the mount arrangement 25, reference is made to DE 10 2014 219 770 A1.
[0068] FIG. 3A shows the mirror arrangement 20 of FIG. 2 in a partial section with three mirror elements 21, the reflective surfaces or end faces of which have a square geometry in the example shown. It is understood that the mirror elements 21 may also have a different geometry. As likewise evident from FIG. 3A, the mirror elements 21 are arranged in a grid arrangement having a plurality of rows and columns. In order to cool the mirror elements 21, the mount arrangement 25 has a channel system 30, which is used to guide a coolant 31, cooling water in the example shown here. Alternatively, another coolant 31 could also be used, for example a water-containing mixture, glycol, a gas or gas mixture or (liquid) CO.sub.2.
[0069] A respective carrier element 24 has a cooling device 32 shown in FIG. 3B in the form of a hollow structure, which has an inlet 33 for letting in the coolant 31 and an outlet 34 for letting out the coolant 31, which are formed in each case at the seat portion 28 of the carrier element 24. As is likewise shown in FIG. 3B, the channel device 32 is designed for feeding the coolant 31 into the head region 27 and for discharging the coolant 31 from the head region 27 of a respective carrier element 24, which is illustrated using dashes in FIG. 3B. In the example shown in FIG. 3B, the channel device 32 has exactly one continuous channel 35, which initially extends from the inlet 33 in the radial direction and then in the axial direction in order to guide the coolant 31 from the seat portion 28 into the head region 27 of the carrier element 24. In the head region 27 of the carrier element 24, the channel 35 is meander-shaped to ensure that the channel 35 extends over the largest possible proportion of a surface on an end face 27a of the head region 27 of the carrier element 24 which, in the example shown, is more than approximately 50% of the surface area of the end face 27a of the head region 27, and ideally more than 70% or more than 90%. The channel 35 then runs back in the axial direction from the head region 27 to the seat portion 28 of the carrier element 24 and then runs in the radial direction toward the outlet 34.
[0070] For feeding the coolant 31 to the inlet 33 of the carrier element 24, the channel system 30 of the mount arrangement 25 has a feed opening 36 shown in FIG. 3A. The feed opening 36 opens into a first ring space 37a, which is formed between a cutout in an inner wall 26a of the conical insert opening 26 and the carrier element 24. The inlet 33 of the channel device 32 of the carrier element 24 also opens into the first ring space 37a. Accordingly, a discharge opening 38 of the channel system 30 of the mount arrangement 25 opens into a second ring space 37b, which is formed between a further cutout in the inner wall 26a of the insert opening 26 and the carrier element 24. The two ring spaces 37a, 37b are sealed off from one another and from the environment using radial seals in the form of O-rings 39. The seals 39 extend for this purpose between the seat portion 28 of the carrier element 24 and the insert opening 26 for the carrier element 24. To accommodate the seals 30, ring-shaped grooves are disposed in the seat portion 28 of the carrier element 24.
[0071] The channel system 30 of the mount arrangement 25 has a number of feed openings 36 and discharge openings 38 that corresponds to the number of mirror elements 21. The channel system 30 of the mount arrangement 25 is designed to allow parallel flows through the channel devices 32 of the carrier elements 24 and for this purpose has a meander-shaped distribution channel 40a, to which the feed openings 36 are connected, and a meander-shaped collector channel 40b, to which the discharge openings 38 are connected. The distribution channel 40a and the collector channel 40b are indicated in FIG. 3A in the form of circles.
[0072] As can be seen in FIG. 3A, a respective carrier element 24 has a through channel 41 for passing connecting and control lines through the carrier element 24. The connecting and control lines in the example shown are mounted on a rod-shaped printed circuit board 42, which is plugged into a plug connector 43 of the MEMS mirror module 21, which is mounted on the carrier element 24, in order to control the actuators which are integrated there. The actuators in the example shown are piezo actuators, which should not exceed a threshold temperature of approximately 70 C., because they will otherwise lose their piezoelectric properties and the micromirrors of the MEMS mirror module 21 can no longer be actuated. Rather than piezo actuators, it is also possible to use other types of actuators, for example electrostatic drives. In addition to the temperature of the piezo actuators, the electronic components and the reflective coating of the micromirrors should not exceed a threshold temperature either.
[0073] As can be seen in FIG. 3B, a respective mirror element 21 in the form of a MEMS mirror module comprises a ceramic substrate 21a and, applied on the ceramic substrate 23a, a micromirror array 21b with a number of, for example, 2424 micromirrors. The substrate 21a is made from a ceramic material in the form of aluminum nitride, which has a very high thermal conductivity and a low coefficient of thermal expansion CTE1 of approximately 5 ppm/K at 20 C. The carrier element 24 is likewise produced from a ceramic material in the form of aluminum oxide, which has a comparable coefficient of thermal expansion CTE2 of approximately 3 ppm/K. For the coefficient of thermal expansion CTE1 of the material of the carrier element 24 and the coefficient of thermal expansion CTE2 of the material of the substrate 21a, which adjoins an end face 27a of the head region 27 of the carrier element 24, the following applies: CTE1/CTE2=5/3=1.66. The coefficient of thermal expansion CTE2 of the material of the carrier element 24 therefore deviates by less than 70% from the coefficient of thermal expansion CTE2 of the substrate 21a of the mirror element 21.
[0074] The carrier element 24 can be connected to the mirror element 21 in different ways, for example by welding, soldering, adhesive bonding or by mechanical connection structures, by wedging or by a different joining method. The connection should enable surface-type contact between the end face 27a of the head region 27 of the carrier element 24 and the respective mirror element 21. For the case that the material of the carrier element 24 has a coefficient of thermal expansion CTE2 which differs greatly from the coefficient of thermal expansion CTE1 of the mirror element 21 or the substrate 21a, it may be desirable to realize mechanical decoupling of the carrier element 24 from the mirror element 21, for example by providing a joint or the like. In this way, thermal stresses and associated deformations and damage can be avoided.
[0075] As can likewise be seen in FIG. 3A, the carrier elements 24 have on the sides facing away from the mirror elements 21 a respective fixing portion 44, which is provided with a threaded portion. For example, a nut, which in the tightened state (fixed position) generates a holding force for the carrier element 24, can be located on the fixing portion. The holding force generated by the nut can be transferred into the mount arrangement 25 for example with the use of a spring.
[0076] FIG. 4 shows the head region 27 of the carrier element 24, which differs from the carrier element 24 shown in FIG. 3B in that the channel device 32 comprises, in place of a meander-shaped channel 35, a plurality of parallel channels 35, 35, which are used to guide the coolant 31. The coolant 31 in the example shown in FIG. 4 enters the head region 27 of the carrier element 24 at the inlet 33 and is initially distributed over six parallel first channels 35, through which the coolant 31 flows in parallel. The coolant 35 is then guided around the plug connector 43 of the mirror element 32, which dips into the through channel of the carrier element 24 (not depicted in FIG. 4). The coolant 31 is then distributed over six second channels 35 of the channel device 32, through which the coolant 31 flows in parallel, before the coolant 31 exits the carrier element 24 at the outlet 34.
[0077] In contrast to the carrier element 24 shown in FIGS. 3A-3B, the inlet 33 and the outlet 34 in the carrier element 24 shown in FIG. 4 are mounted on the head region 27, more specifically on a lower side of the head region 27 facing away from the mirror elements 21. FIGS. 5A-5B likewise show carrier elements 24, in which the inlet 33 and the outlet 34 are formed at the side 27b of the head region 27 facing away from the mirror elements 21. As can be seen in FIGS. 5a,b, the head region 27 projects not only upward over a respective insert opening 26 of the mount arrangement 25, but also extends laterally next to the insert opening 26, with the result that the inlet 33 and the outlet 34 for the coolant 31 are arranged, with a lateral offset with respect to the insert opening 26, on the side 27b of the head region 27 facing away from the mirror element 21.
[0078] In order to connect the channel system 30 of the mount arrangement 25 in a fluid-tight manner to the inlet 33 and the outlet 34 of the head region 27 of the carrier element 24, the mirror arrangement 20 comprises a sealing arrangement, which seals in the axial direction and is designed as a molded seal 45 in the example shown. The molded seal 45 is located in its installation position between an end face 25a of the mount arrangement 25 facing the mirror elements 21 and the lower side 27b of the head region 27 of the respective carrier element 24. The molded seal 45 has a first opening, which, in its installation position, forms a first intermediate space 46a into which the feed opening 36 of the channel system 30 of the mount arrangement 25 opens in order to feed the coolant 31 to the inlet 33. The molded seal 45 has a second opening, which, in its installation position, forms a second intermediate space 46b, into which the discharge opening 38 of the channel system 30 of the mount arrangement 25 opens, in order to discharge the heated coolant 31 exiting from the outlet 34.
[0079] The carrier element 24 in the example shown has four fixing portions 44, which are each provided with a threaded portion. The fixing portions 44, of which FIG. 5A shows two, are arranged in the region of the corners of the head region 27 of the carrier element 24. Unlike the case in FIGS. 3A-3B, the fixing portions 44 in the example shown in FIGS. 5A-5B are mounted on the lower side 27b of the head region 27 of the carrier element 24 facing the mount arrangement 25. The fixing portions 44 project downward over the remaining head region 27 of the carrier element 24 and exert a holding force acting in the axial direction on the carrier element 24 by way of correspondingly shaped nuts. Due to the application of the holding force, the molded seal 45 is also compressed in the axial direction in order to enhance the sealing action thereof.
[0080] As can be seen in FIGS. 5A-5B, the seat portion 28 with which the carrier element 24 dips into the mount arrangement 25 has a significantly smaller cross section than the seat portion 28 of the carrier element 24 shown in FIGS. 3A-3B. This is due to the fact that no coolant 31 is guided in the seat portion 28 of the carrier element 24 of FIGS. 5A-5B. The seat portion 28 of the carrier element 24 extends in the axial direction only over approximately half the height of the mount arrangement 25, which is sufficient for the correct alignment of the carrier element 24 relative to the mount arrangement 25. The seat portion 28 in the example shown has a cylindrical geometry with an oval, non-radially symmetric cross section. This makes it possible to align the respective carrier element 24 in a desired rotational position during the insertion into the insert opening 26.
[0081] As can likewise be seen in FIG. 5B, the molded seal 45 has a third opening, through which extends the seat portion 28 of the carrier element 24. In the example shown in FIGS. 5A-5B, the rod-shaped printed circuit board 42 is plugged, as it is in FIGS. 3A-3B, into the plug connector 43 of the MEMS mirror module 21 mounted on the carrier element 24. The through channel 41 of the carrier element 24 is continued in a through opening of the mount arrangement 25 following the insert opening 26 in order to insert, and be able to make contact with, the rod-shaped printed circuit board 42 from the lower side of the mount arrangement 25.
[0082] As is shown in FIG. 5B, the coolant 31 flows, in the channel device 32 starting from the inlet 33, through the head region 27 initially in an axial channel and is guided therein into the immediate vicinity of the end face 27a of the head region 27 of the carrier element 24. Here, the coolant 31 is distributed over a plurality of channels 35 carrying parallel flows, before it is combined again to laterally flow around the plug connector 43. Next, the coolant 31 is distributed again over a plurality of channels 35, which carry parallel flows, before the coolant 31 is guided via a further channel extending in the axial direction to the outlet 34 of the cooling device 32.
[0083] Both in the example shown in FIGS. 3A-3B and in the example shown in FIGS. 5A-5B, the channels 35, 35, 35 run in the immediate vicinity of the MEMS mirror module 21, more specifically of the lower side of the substrate 21a, to be precise typically at a distance of approximately 1 mm or less. In this way, the heat path from the heat source in the form of the mirror elements 32 to the coolant 31 can be minimized.
[0084] FIGS. 6A-6B each show a detail of a mirror arrangement 20, in which the mount arrangement 25 has no channel system for feeding and discharging the coolant 31 to and from the channel device 32 of the carrier element 34. The inlet 33 and the outlet 34 of the channel device 32 of the carrier element 24 (not depicted in FIGS. 6A-6B) are therefore not fluidically connected to the mount arrangement 25.
[0085] In the example shown in FIG. 6A, the coolant 31 is fed to the inlet 33, which is formed at a fixing portion 44 of the carrier element 24 projecting over the insert opening 26, via a feed line (not depicted) from an external cooling device and discharged via a discharge line (not depicted) by the outlet 34 and transported to the external cooling device. The outlet 34 is likewise formed at the fixing portion 44 of the carrier element 24 projecting over the insert opening 26.
[0086] In the example shown in FIG. 6B, arranged adjacent to the mount arrangement 25 is a heatsink 47 comprising a channel system 30, which is designed analogously to the channel system 30 of the mount arrangement 25, in order to feed the coolant 31 to the inlet 33 of the carrier element 24 and discharge it from the outlet 34 of the carrier element 24. Thermal deformations of the mount arrangement 25 can be reduced by guiding the coolant 31 in the additional heatsink 47. In this case, too, it can be desirable to seal off the inlet 33 and the outlet 34 using seals (not depicted). A radial and/or axial sealing concept can be used to this end. With a suitable design of the respective seals, for example in the manner of a suitable adapter or the like, it is possible for the carrier element 24 to be replaced, if appropriate, without the need to interrupt the transport of the coolant 31 for this purpose. For example, a fluid-tight connection between the inlet 33 and the outlet 34 and the channel system 30 of the heatsink 47 can be established when fixing the carrier element 24 in the mount arrangement 25.
[0087] It is understood that not only the first facet mirror 20, but also the second facet mirror 22 may be designed in the manner described further above. Mirror arrangements which are not part of the illumination system 2 or the lithography apparatus 1 can also be designed in the manner described further above in order to minimize the heat path to the coolant 31 as much as possible.
