MONOLITHIC SEALING PLUG AND PROJECTION LIGHTING SYSTEM

Abstract

A monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) for sealing a bore (130), wherein the monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) within the bore is deformed by means of elastic and / or plastic deformation from an initial state (Z1), in which the monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) can be inserted into the bore (130), to a sealing state (Z2), in which the monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) is fluid-tight against an inner surface (136) is adjacent to the borehole (130), can be moved.

Description

[0001] The present invention relates to a monolithic sealing plug and a projection exposure system with such a monolithic sealing plug.

[0002] Microlithography is used to manufacture microstructured components, such as integrated circuits. The microlithography process is carried out using a lithography system equipped with an illumination system and a projection system. The image of a mask (reticle) illuminated by the illumination system is projected by the projection system onto a substrate coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system, for example, a silicon wafer, in order to transfer the mask structure to the light-sensitive coating of the substrate.

[0003] Driven by the pursuit of ever smaller structures in the production of integrated circuits, EUV lithography systems are currently being developed that use light with a wavelength in the range of 0.1 nm to 30 nm, particularly 13.5 nm. Due to the high absorption of light at this wavelength by most materials, such EUV lithography systems require the use of reflective optics, i.e., mirrors, instead of the previously used refractive optics, i.e., lenses.

[0004] A projection system as previously explained may comprise components, for example, support structures for the aforementioned optics, which must be cooled during operation of the projection system. A cooling system may be used for this purpose. To dissipate heat from a component as previously mentioned, cooling channels in the form of holes are introduced into the component. These holes can be machined into the component from different directions. To enable a change in direction of such a cooling channel within the component, two holes can, for example, intersect, whereby some of the holes can be sealed with sealing plugs.

[0005] Against this background, it is an object of the present invention to provide an improved sealing plug.

[0006] Accordingly, a monolithic sealing plug for sealing a bore is proposed. The monolithic sealing plug can be moved within the bore by means of elastic and / or plastic deformation from an initial state in which the monolithic sealing plug can be inserted into the bore to a sealed state in which the monolithic sealing plug rests fluid-tight against an inner surface of the bore.

[0007] The monolithic design of the sealing plug results in a cleanable, one-piece construction. No particles are generated during installation. Furthermore, the monolithic construction prevents the formation of virtual leaks.

[0008] In this context, the term "monolithic" sealing plug means, in particular, that the monolithic sealing plug is not composed of different sub-components, but rather that the monolithic sealing plug forms a continuous component. In particular, the monolithic sealing plug is made entirely of the same material. Preferably, the monolithic sealing plug is made entirely of a metallic material, such as a ductile stainless steel alloy or an aluminum alloy. The monolithic sealing plug can be manufactured, for example, using a generative or additive manufacturing process, in particular using a 3D printing process. The monolithic sealing plug can also be referred to as a single-piece sealing plug, since the monolithic sealing plug is made entirely of the same material.Accordingly, the terms “monolithic” and “single-piece” can be freely interchanged in this case.

[0009] The hole is provided, in particular, within a component. The component is preferably part of a projection optics or an illumination system of a projection exposure system. The hole can be part of a cooling channel running through the component. The component can have any number of holes. Only one hole will be discussed below.

[0010] The bore can be a stepped bore. This means, in particular, that the bore can have multiple bore sections with different diameters. For example, the bore has a first bore section and a second bore section, with the second bore section, for example, having a larger diameter than the first bore section. In this case, a shoulder or step is provided between the first bore section and the second bore section, against which the monolithic sealing plug can be supported.

[0011] In this context, "elastic deformation" refers to deformation that is reversible. For example, a force can be applied to the monolithic sealing plug, causing it to deform. Once this force is removed, the monolithic sealing plug will automatically return to its original shape. In contrast, "plastic deformation" refers to a non-reversible deformation of the monolithic sealing plug.

[0012] To transform the monolithic sealing plug from its initial state to its sealed state, it can be deformed purely elastically, purely plastically, or both elastically and plastically. The monolithic sealing plug can also be returned from the sealed state to its initial state. This, in turn, requires elastic and / or plastic deformation of the monolithic sealing plug. This can be achieved using a suitable tool.

[0013] In this case, the term "insertable" for the monolithic sealing plug in its initial state into the bore means, in particular, that the monolithic sealing plug can be inserted into the bore in its initial state and removed from it again. In other words, the monolithic sealing plug is received in the bore with a certain amount of play in its initial state. As soon as the monolithic sealing plug is moved from its initial state into the sealed state, it rests against the inner surface of the bore, so that the monolithic sealing plug can no longer be removed from the bore in the sealed state.

[0014] In this context, "fluid-tight" can be understood as both gas-tight and liquid-tight. The inner surface of the bore is preferably cylindrical. Accordingly, the monolithic sealing plug also has a substantially cylindrical geometry. The monolithic sealing plug is preferably assigned a central or symmetry axis, to which the monolithic sealing plug is rotationally symmetrical.

[0015] According to one embodiment, the monolithic sealing plug has a front sealing wall and a tubular outer wall, wherein the outer wall expands radially when the monolithic sealing plug is moved from the initial state into the sealing state.

[0016] In other words, the monolithic sealing plug is caulked into the bore by radially expanding the outer wall. This is achieved by moving the monolithic sealing plug from its initial state into the sealed state. "Radial" in this case means that the outer wall expands in a radial direction of the monolithic sealing plug, which is oriented perpendicular to and away from the axis of symmetry. The front sealing wall of the monolithic sealing plug can rest against the aforementioned shoulder of the bore. The sealing wall and the outer wall are integrally connected to one another, in particular by a single material component. "Integral" or "one-piece" in this case means that the sealing wall and the outer wall are not separate components, but rather form a single component, namely the monolithic sealing plug.

[0017] According to a further embodiment, an annular actuating section extends out of the outer wall, which can be subjected to a compressive force in order to move the monolithic sealing plug from the initial state into the sealing state.

[0018] The outer wall preferably encloses an interior space of the monolithic sealing plug. The actuating section projects radially into this interior space. The actuating section can be annular or disc-shaped. Any number of actuating sections can also be provided, which are pin-shaped or rod-shaped. To move the monolithic sealing plug from its initial state to the sealed state, a compressive force is applied to the actuating section using a tool, for example, a punch and a hammer. The actuating section is thereby deformed toward the sealing wall or folded over in its direction. In this process, the actuating section is elastically and / or plastically deformed.An area of ​​the outer wall, to which the actuating section is connected to the outer wall, is thinner-walled than the rest of the outer wall, so that the outer wall can be deformed with the aid of the actuating section.

[0019] According to a further embodiment, a rod-shaped tensile section extends out of the sealing wall, which can be subjected to a tensile force in order to move the monolithic sealing plug from the initial state into the sealed state.

[0020] In this case, the compressive force is applied to the actuating section and the tensile force to the tensile section. The compressive force and tensile force are oriented in opposite directions. This makes it possible for the monolithic sealing plug to be installed in a smooth bore without a shoulder as mentioned above. Supporting the sealing wall on a shoulder of the bore as mentioned above is therefore not necessary. In this case, the aforementioned tool can apply both the compressive force to the actuating section and the tensile force to the tensile section.

[0021] According to a further embodiment, a rod-shaped actuating section extends out of the sealing wall, which can be subjected to a compressive force in order to move the monolithic sealing plug from the initial state into the sealing state.

[0022] In this case, too, the compressive force is applied to the actuating section using a tool. Applying the compressive force to the actuating section deforms the sealing wall, causing the outer wall to expand radially, transforming the monolithic sealing plug from its initial state into the sealed state.

[0023] According to a further embodiment, the sealing wall has a conical geometry.

[0024] With the help of the tool, the compressive force is applied specifically to a tip of the conical geometry. The sealing wall is then deformed from its conical shape into a nearly disc-shaped form. In other words, the sealing wall folds from its initial state into the sealed state, with the outer wall also being deformed.

[0025] According to a further embodiment, the outer wall has at least one support section for supporting the monolithic sealing plug on a component through which the bore extends.

[0026] The support section can be annular. However, the support section can also be rod-shaped. In this case, any number of support sections can be provided, distributed evenly around the axis of symmetry. The outer wall can rest on an end face of the component with the support section. In this case, the bore of the component can be smooth, so it does not need to have a shoulder. Alternatively, the monolithic sealing plug can rest on a shoulder of the bore, as mentioned above, with its support section.

[0027] According to a further embodiment, the outer wall has engagement ribs which are designed to deform the inner surface in the sealed state.

[0028] Any number of engagement ribs can be provided. The engagement ribs run in a ring around the axis of symmetry. With the help of the engagement ribs, the monolithic sealing plug can dig or press into the inner surface of the bore. The inner surface of the bore is plastically and / or elastically deformed in the process.

[0029] According to a further embodiment, the monolithic sealing plug is disc-shaped.

[0030] This results in a particularly simple design for the monolithic sealing plug. In this case, however, the monolithic sealing plug preferably has a conical curvature.

[0031] Furthermore, a projection exposure system with such a monolithic sealing plug is proposed.

[0032] The projection exposure system also includes the component in or on which the monolithic sealing plug can be mounted. The component can be part of a projection optics system of the projection exposure system. However, the component can also be part of an illumination system of the projection exposure system. The projection exposure system can be an EUV lithography system. EUV stands for "Extreme Ultraviolet" and refers to a wavelength of the working light between 0.1 nm and 30 nm. The projection exposure system can also be a DUV lithography system. DUV stands for "Deep Ultraviolet" and refers to a wavelength of the working light between 30 nm and 250 nm.

[0033] "One" in this case is not necessarily limited to a single element. Rather, multiple elements, such as two, three, or more, may also be included. Any other counting term used here should not be understood as implying a limitation to the exact number of elements stated. Rather, numerical deviations upwards and downwards are possible, unless otherwise stated.

[0034] The embodiments and features described for the monolithic sealing plug apply accordingly to the proposed projection exposure system and vice versa.

[0035] Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0036] Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention is explained in more detail below using preferred embodiments with reference to the accompanying figures. Fig. 1 shows a schematic meridional section of a projection exposure system for EUV projection lithography; Fig. 2 shows a schematic sectional view of an embodiment of a monolithic sealing plug for the projection exposure apparatus according to Fig. 1; Fig. 3 shows a schematic sectional view of an embodiment of a component for the projection exposure apparatus according to Fig. 1; Fig. 4 shows a further schematic sectional view of the component according to Fig. 3; Fig. 5 shows a further schematic sectional view of the component according to Fig. 3; Fig. 6 shows a further schematic sectional view of the component according to Fig. 3; Fig. 7 shows a further schematic sectional view of the component according to Fig. 3; Fig. 8 shows a further schematic sectional view of the component according to Fig. 3; Fig. 9 shows a further schematic sectional view of the component according to Fig. 3; Fig. 10 shows a further schematic sectional view of the component according to Fig. 3; Fig. 11 shows a further schematic sectional view of the component according to Fig. 3; Fig. 12 shows a further schematic sectional view of the component according to Fig. 3; Fig. 13 shows a further schematic sectional view of the component according to Fig. 3; Fig. 14 shows a further schematic sectional view of the component according to Fig. 3; Fig. 15 shows a further schematic sectional view of the component according to Fig. 3; Fig. 16 shows a further schematic sectional view of the component according to Fig. 3; Fig. 17 shows a further schematic sectional view of the component according to Fig. 3; and Fig. 18 shows a further schematic sectional view of the component according to Fig. 3.

[0037] In the figures, identical or functionally equivalent elements are provided with the same reference numerals unless otherwise indicated. Furthermore, it should be noted that the representations in the figures are not necessarily to scale.

[0038] Fig. 1 shows an embodiment of a projection exposure system 1 (lithography system), in particular an EUV lithography system. One embodiment of an illumination system 2 of the projection exposure system 1 has, in addition to a light or radiation source 3, 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 remaining illumination system 2. In this case, the illumination system 2 does not include the light source 3.

[0039] A reticle 7 arranged in the object field 5 is exposed. The reticle 7 is held by a reticle holder 8. The reticle holder 8 can be displaced via a reticle displacement drive 9, in particular in a scanning direction.

[0040] In the Fig. For illustrative purposes, Figure 1 shows a Cartesian coordinate system with an x-direction x, a y-direction y, and a z-direction z. The x-direction x runs perpendicular to the plane of the drawing. The y-direction y runs horizontally, and the z-direction z runs vertically. The scanning direction runs in the Fig. 1 along the y-direction y. The z-direction z runs perpendicular to the object plane 6.

[0041] 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.

[0042] 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 y, 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.

[0043] The light source 3 is an EUV radiation source. The light source 3 emits, in particular, EUV radiation 16, which is also referred to below as useful radiation, illumination radiation, or illumination light. The useful radiation 16 has, in particular, a wavelength in the range between 5 nm and 30 nm. The light source 3 can be a plasma source, for example, an LPP source (Laser Produced Plasma) or a DPP source (Gas Discharged Produced Plasma). It can also be a synchrotron-based radiation source. The light source 3 can be a free-electron laser (FEL).

[0044] The illumination radiation 16 emanating from the light 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 (GI), i.e., at angles of incidence greater than 45°, or at normal incidence (NI), i.e., at angles of incidence less than 45°. The collector 17 can be structured and / or coated, on the one hand, to optimize its reflectivity for the useful radiation and, on the other hand, to suppress stray light.

[0045] After the collector 17, the illumination radiation 16 propagates through an intermediate focus in an intermediate focal plane 18. The intermediate focal plane 18 can represent a separation between a radiation source module, comprising the light source 3 and the collector 17, and the illumination optics 4.

[0046] 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 can also be referred to as field facets. Of these first facets 21, Fig. 1 only some examples are shown.

[0047] 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.

[0048] 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.

[0049] Between the collector 17 and the deflecting mirror 19, the illumination radiation 16 runs horizontally, i.e. along the y-direction y.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The second facets 23 can have planar or alternatively convex or concave curved reflection surfaces.

[0054] The illumination optics 4 thus form a double-faceted system. This basic principle is also known as a fly's-eye integrator.

[0055] It may be advantageous to arrange the second facet mirror 22 not exactly in a plane that is optically conjugate to a pupil plane of the projection optics 10. In particular, the second facet mirror 22 can be arranged tilted relative to a pupil plane of the projection optics 10, as described, for example, in DE 10 2017 220 586 A1.

[0056] 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.

[0057] 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).

[0058] 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 first facet mirror 20 and the second facet mirror 22.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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 projection optics 10 is a doubly obscured optic. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 has an image-side numerical aperture that is greater than 0.5 and can also be greater than 0.6, for example, 0.7 or 0.75.

[0063] 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.

[0064] The projection optics 10 has a large object-image offset in the y-direction y between a y-coordinate of a center of the object field 5 and a y-coordinate of the center of the image field 11. This object-image offset in the y-direction y can be approximately as large as a z-distance between the object plane 6 and the image plane 12.

[0065] The projection optics 10 can, in particular, be anamorphic. It has, in particular, different magnifications Bx, By in the x and y directions x, y. The two magnifications Bx, By 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.

[0066] The projection optics 10 thus leads to a reduction in the ratio 4:1 in the x-direction x, i.e. in the direction perpendicular to the scanning direction.

[0067] The projection optics 10 leads to a reduction of 8:1 in the y-direction y, i.e. in the scanning direction.

[0068] Other magnifications are also possible. Magnifications with the same sign and absolutely identical in the x and y directions (x, y), for example, with absolute values ​​of 0.125 or 0.25, are also possible.

[0069] The number of intermediate image planes in the x- and y-directions x, y in the beam path between the object field 5 and the image field 11 can be the same or can be different, depending on the design of the projection optics 10. Examples of projection optics with different numbers of such intermediate images in the x- and y-directions x, y are known from US 2018 / 0074303 A1.

[0070] Each of the second facets 23 is assigned to exactly one of the first facets 21 to form a respective illumination channel for illuminating the object field 5. This can, in particular, result in illumination according to the Köhler principle. The far field is divided into a plurality of object fields 5 using the first facets 21. The first facets 21 generate a plurality of images of the intermediate focus on the second facets 23 assigned to them.

[0071] The first facets 21 are each imaged onto the reticle 7 by an associated second facet 23, superimposed on one another, to illuminate the object field 5. The illumination of the object field 5 is, in particular, as homogeneous as possible. It preferably has a uniformity error of less than 2%. Field uniformity can be achieved by superimposing different illumination channels.

[0072] By arranging the second facets 23, the illumination of the entrance pupil of the projection optics 10 can be geometrically defined. By selecting the illumination channels, in particular the subset of the second facets 23 that guide light, the intensity distribution in the entrance pupil of the projection optics 10 can be adjusted. This intensity distribution is also referred to as the illumination setting or illumination pupil fill.

[0073] 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.

[0074] 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.

[0075] The projection optics 10 can, in particular, have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

[0076] The entrance pupil of the projection optics 10 cannot usually be precisely illuminated with the second facet mirror 22. When imaging the projection optics 10, which images the center of the second facet mirror 22 telecentrically onto the wafer 13, the aperture rays often do not intersect at a single point. However, 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.

[0077] 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.

[0078] In the Fig. In the arrangement of the components of the illumination optics 4 shown in Figure 1, the second facet mirror 22 is arranged in a surface conjugate to the entrance pupil of the projection optics 10. The first 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. The first facet mirror 20 is arranged tilted relative to an arrangement plane defined by the second facet mirror 22.

[0079] Fig. 2 shows a schematic sectional view of an embodiment of a monolithic sealing plug 100A.

[0080] The term "monolithic" for the sealing plug 100A is understood in particular to mean that the sealing plug 100A is not constructed from multiple separate sub-components, but rather forms a continuous component. In other words, the sealing plug 100A is made entirely of the same material. Metals, such as ductile stainless steel alloys or aluminum alloys, are particularly used as materials for the sealing plug 100A. Additive or generative manufacturing processes, in particular 3D printing processes, can be used to manufacture the sealing plug 100A.

[0081] The sealing plug 100A is designed to be rotationally symmetrical to a central or symmetry axis 102. The sealing plug 100A is assigned a radial direction R that is perpendicular to and oriented away from the symmetry axis 102. The sealing plug 100A comprises a disk-shaped sealing wall 104 that is designed to be rotationally symmetrical to the symmetry axis 102. The sealing wall 104 comprises a front surface 106 and a rear surface 108 facing away from the front surface 106.

[0082] The sealing plug 100A has a hollow cylindrical or tubular outer wall 110 extending around the axis of symmetry 102. The sealing wall 104 and the outer wall 110 are formed integrally, in particular from a single material. "Integral" or "single-piece" means in particular that the sealing wall 104 and the outer wall 110 do not form separate components, but rather a common component, namely the sealing plug 100A. "Single-piece" means in this case that the sealing plug 100A is made entirely of the same material. Accordingly, the terms "monolithic" and "single-piece" are to be used interchangeably.

[0083] The outer wall 110 has a cylindrical outer surface 112. On the outer surface 112, a plurality of engagement ribs 114A (left side of the Fig. 2) formed, of which in the Fig. 2, only one is provided with a reference numeral. The engagement ribs 114A can have any desired geometry. Facing away from the outer surface 112, the outer wall 110 has an inner surface 116. Facing away from the front surface 106, the outer wall 110 has a rear surface 118.

[0084] However, engagement ribs 114B (right side of the Fig. 2) that do not extend beyond the outer surface 112. The engagement ribs 144B end flush with the outer surface 112. The engagement ribs 114B can be tooth-shaped. The engagement ribs 114B also extend completely around the axis of symmetry 102. The previously explained engagement ribs 114A can also be tooth-shaped.

[0085] The outer wall 110 encloses an interior space 120 of the sealing plug 100A. The interior space 120 is defined or delimited by the rear surface 108 and the inner surface 116. An annular actuating section 122 extends from the inner surface 116 into the interior space 120. The actuating section 122 is inclined at an angle α relative to the axis of symmetry 102. The angle α is less than 90°. The actuating section 122 has a central opening 124. The actuating section 122 can be annular. However, this is not mandatory. Alternatively, any number of rod-shaped actuating sections 122 can be provided, which are arranged evenly distributed around the axis of symmetry 102.

[0086] The outer wall 110 has a wall thickness a. However, the wall thickness a is not constant. In particular, the wall thickness a is reduced in a region 126 surrounding the axis of symmetry 102, in which the actuating section 122 is connected to the outer wall 110.

[0087] Fig. 3 shows a schematic sectional view of a component 128. Fig. 4 shows another schematic sectional view of component 128. Fig. 5 shows another schematic sectional view of component 128. Fig. 6 shows another schematic sectional view of component 128. Fig. 7 shows a further schematic sectional view of component 128. The following refers to the Fig. 2 to 7 are referred to simultaneously.

[0088] Component 128 can, for example, be a support structure that supports one of the mirrors M1 to M6. In other words, component 128 can be part of a projection optics system 10 as mentioned above. However, component 128 can also be part of an illumination system 2 as mentioned above. Component 128 is preferably made of a metallic material, such as a steel alloy.

[0089] During operation of the projection exposure insert 1, heat can be introduced into the component 128, which can be dissipated from the component 128 with the aid of a cooling system. For this purpose, cooling channels can run through the component 128. For this purpose, a bore 130 can be introduced into the component 128. The component 128 can have any number of bores 130. With the aid of any number of bores 130, cooling channels can be formed in the component 128 as mentioned above. However, only one bore 130 will be discussed below.

[0090] In the present case, the bore 130 is a stepped bore and has a first bore section 132 and a second bore section 134. However, this is not absolutely necessary. The bore 130 can also be smooth. In the present case, the first bore section 132 has a smaller diameter than the second bore section 134. The bore 130, in particular the second bore section 134, has an inner surface 136. The outer surface 112 of the sealing plug 100A can bear against the inner surface 136. Because the bore sections 132, 134 have different diameters, a step or shoulder 138 is provided between the two bore sections 132, 134, against which the front surface 106 of the sealing plug 100A can bear.

[0091] The functionality of the sealing plug 100A is explained below. First, the sealing plug 100A is oriented with the front surface 106 toward the shoulder 138, inserted into the bore 130, in particular into the second bore section 134, until the front surface 106 rests against the shoulder 138, as shown in the Fig. 4 is shown.

[0092] Then, as in the Fig. 5 and Fig. 6, the actuating section 122 is displaced or deformed in the direction of the sealing wall 104 by means of a tool 140. As a result, the sealing plug is moved from one into the Fig. 2, Fig. 4 and Fig. 5 shown initial state Z1 into one shown in the Fig. 6 and Fig. 7, in which the sealing plug 100A rests fluid-tight against the inner surface 136 of the bore 130. A punch and a hammer, for example, can serve as the tool 140. With the aid of the tool 140, a compressive force is applied to the actuating section 122, as shown in FIG. Fig. 5 is indicated by an arrow 142.

[0093] The sealing plug 100A is caulked in the bore 130 when it is moved from the initial state Z1 to the sealing state Z2. In the process, the sealing plug 100A is elastically and / or plastically deformed. An outer diameter of the sealing plug 100A thereby increases. This means, in particular, that the sealing plug 100A expands in the radial direction R when it is moved from the initial state Z1 to the sealing state Z2. At the same time, the inner surface 136 of the bore can, as shown in the Fig. 6 and Fig. 7, also plastically deform. The engagement ribs 114A, 114B can dig or press into the inner surface 136.

[0094] Once the sealing plug is in the sealed state Z2, the tool 140 can be removed again. The bore 130 can now be filled with coolant 144, with the front surface 106 of the sealing plug 100A facing the coolant 144. To remove the sealing plug 100A from the bore 130, it is necessary to reshape the actuating section 122 so that the sealing plug 200A can be moved from the sealed state Z2 back to the initial state Z1. For this purpose, a suitable tool can be provided that is capable of reshaping the actuating section 122.

[0095] Fig. 8 shows a further schematic sectional view of component 128, Fig. 9 shows a further schematic sectional view of component 128. The following refers to the Fig. 8 and Fig. 9 simultaneously referred to.

[0096] In this case, the component 128 does not have a stepped bore 130, but rather a continuous smooth bore 130. A further embodiment of a sealing plug 100B as previously mentioned is accommodated in the bore 130.

[0097] The sealing plug 100B differs from the sealing plug 100A only in that a tensile section 146 extends out of the rear surface 108 of the sealing wall 104.

[0098] The pulling section 146 can be gripped by a tool 140 (not shown) as mentioned above. With the help of the tool 140, a compressive force can be exerted on the actuating section 122, as shown in the Fig. 8 by means of arrows 148, 150, and at the same time a tensile force can be applied to the tensile section 146, as indicated by an arrow 152.

[0099] Thus, the sealing plug 100B can be separated from the Fig. 8 shown initial state Z1 in the Fig. 9, the actuating section 122 is moved toward the sealing wall 104, as previously explained with reference to the sealing plug 100A, and the tension section 146 simultaneously serves as an abutment. This makes it possible to mount the sealing plug 100B without a shoulder 138 provided on the bore 130.

[0100] Fig. 10 shows another schematic sectional view of component 128.

[0101] The component 128 comprises a bore 130 as previously mentioned with two bore sections 132, 134 and a shoulder 138. A sealing plug 100C is received in the bore 130, the functionality of which essentially corresponds to that of the sealing plug 100A.

[0102] The sealing plug 100C comprises a front sealing wall 154 that is conical in cross-section. The tubular or hollow-cylindrical outer wall 156 extends around the sealing wall 154. To secure the sealing plug 100C in the aforementioned sealing state Z2, a fastening element 158 ​​is provided. The fastening element 158 ​​can be a grub screw screwed into the bore 130. With the aid of the fastening element 158, a permanent preload force can be applied to the sealing plug 100C. The fastening element 158 ​​can also be used for the aforementioned embodiments of the sealing plug 100A, 100B.

[0103] Fig. 11 shows another schematic sectional view of component 128. Fig. 12 shows a further schematic sectional view of component 128. In the following, reference is made to the Fig. 11 and Fig. 12 received at the same time.

[0104] Component 128 has a smooth bore 130 without a shoulder 138 as previously mentioned. A sealing plug 100D is received in the bore, the functionality of which is essentially the same as that of sealing plug 100A.

[0105] The sealing plug 100D comprises a sealing wall 160, from which an actuating section 162 extends centrally. A tubular or hollow-cylindrical outer wall 164 extends around the sealing wall 160. The outer wall 164 is supported by support sections 166 on an end face 168 of the component 128.

[0106] To remove the sealing plug 100D from the Fig. 11 shown initial state Z1 in the Fig. 12, a compressive force is applied to the actuating section 162 with the aid of a tool 140 as mentioned above. The sealing wall 160 is elastically and / or plastically deformed, so that the outer wall 164 is pressed against the inner surface 136 of the bore 130.

[0107] Fig. 13 shows another schematic sectional view of component 128. Fig. 14 shows a further schematic sectional view of the component 128. In the following, reference is made to the Fig. 13 and Fig. 14 were received at the same time.

[0108] In this case, component 128 has a stepped bore 130 with a first bore section 132 and a second bore section 134. A shoulder 138, as previously mentioned, is provided between bore sections 132, 134. In this case, the previously explained sealing plug 100D rests with its support sections 166 not on the end face 168 of component 128, but on the shoulder 138.

[0109] Fig. 15 shows another schematic sectional view of component 128. Fig. 16 shows a further schematic sectional view of component 128. The following refers to the Fig. 15 and Fig. 16 referred to at the same time.

[0110] Component 128 includes a bore 130 with a first bore portion 132 and a second bore portion 134. A shoulder 138, as previously mentioned, is provided between bore portions 132 and 134. A sealing plug 100E is received in bore 130, the functionality of which is essentially the same as that of sealing plug 100A.

[0111] The sealing plug 100E comprises a sealing wall 170 which is conically shaped. An actuating section 172 extends from the sealing wall 170. An outer wall 174 runs around the sealing wall 170. The sealing plug 100E is inserted into the bore 130 so that the sealing wall 170 rests against the shoulder 138. A compressive force is applied to the actuating section 172 using a tool 140 as mentioned above, whereby the sealing plug 100E is released from the Fig. 15 shown initial state Z1 in the Fig. 16 shown sealing state Z2.

[0112] Fig. 17 shows another schematic sectional view of component 128. Fig. 18 shows a further schematic sectional view of component 128. The following refers to the Fig. 17 and Fig. 18 referred to at the same time.

[0113] Component 128 includes a bore 130 with a first bore portion 132 and a second bore portion 134, with a shoulder 138 provided between bore portions 132 and 134. A sealing plug 100F is received in the bore, the functionality of which is essentially the same as that of sealing plug 100A.

[0114] The sealing plug 100F is disc-shaped with a conical curvature. With the aid of a tool 140, the sealing plug 100F can be removed from the Fig. 17 shown initial state Z1 in the Fig. 18 shown sealing state Z2.

[0115] Although the present invention has been described using exemplary embodiments, it can be modified in many ways. LIST OF REFERENCE SYMBOLS 1 projection exposure system 2 Lighting system 3 Light 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 Illumination radiation 17 Collector 18 Intermediate focal plane 19 Deflecting mirrors 20 first facet mirror 21 first facet 22 second facet mirror 23 second facet 100A sealing plug 100B sealing plug 100C sealing plug 100D sealing plug 100E sealing plug 100F sealing plug 102 axis of symmetry 104 Sealing wall 106 front surface 108 back surface 110 exterior wall 112 exterior area 114A engagement rib 114B engagement rib 116 interior surface 118 back surface 120 interior 122 operating section 124 Breakthrough 126 Area 128 components 130 bore 132 bore section 134 borehole section 136 interior surface 138 shoulder 140 tools 142 Arrow 144 Coolant 146 train section 148 Arrow 150 arrows 152 Arrow 154 Sealing wall 156 exterior wall 158 Fastening element 160 sealing wall 162 operating section 164 exterior wall 166 support section 168 frontal area 170 Sealing wall 172 operating section 174 exterior wall a wall thickness M1 mirror M2 mirror M3 mirror M4 mirror M5 mirror M6 mirror R Radial direction x x-direction y y-direction z z-direction Z1 initial state Z2 Sealing condition α angle 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] DE 10 2008 009 600 A1 [0048, 0052] US 2006 / 0132747 A1

[0050] EP 1 614 008 B1

[0050] US 6,573,978

[0050] DE 10 2017 220 586 A1

[0055] US 2018 / 0074303 A1

[0069]

Claims

[1] Monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) for closing a bore (130), wherein the monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) within the bore by means of an elastic and / or plastic deformation from an initial state (Z1), in which the monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) can be inserted into the bore (130), into a sealing state (Z2), in which the monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) is fluid-tightly connected to a inner surface (136) of the bore (130). [2] Monolithic sealing plug according to claim 1, wherein the monolithic sealing plug (100A, 100B, 100C, 100D, 100E) has an end-side sealing wall (104, 154, 160, 170) and a tubular outer wall (110, 154, 164, 174), and wherein the outer wall (110, 154, 164, 174) expands radially when the monolithic sealing plug (100A, 100B, 100C, 100D, 100E) is moved from the initial state (Z1) into the sealing state (Z2). [3] Monolithic sealing plug according to claim 2, wherein an annular actuating portion (122) extends out of the outer wall (110) and can be subjected to a compressive force to move the monolithic sealing plug (100A, 100B) from the initial state (Z1) into the sealing state (Z2). [4] Monolithic sealing plug according to claim 2 or 3, wherein a rod-shaped tensile section (146) extends out of the sealing wall (104) and can be subjected to a tensile force to move the monolithic sealing plug (100B) from the initial state (Z1) into the sealed state (Z2). [5] Monolithic sealing plug according to claim 2, wherein a rod-shaped actuating section (162, 172) extends out of the sealing wall (160, 170) and can be subjected to a compressive force to move the monolithic sealing plug (100D, 100E) from the initial state (Z1) into the sealing state (Z2). [6] Monolithic sealing plug according to one of claims 2-5, wherein the sealing wall (154, 160, 170) has a conical geometry. [7] Monolithic sealing plug according to one of claims 2-6, wherein the outer wall (164) has at least one support portion (166) for supporting the monolithic sealing plug (100D) on a component (128) through which the bore (130) extends. [8] Monolithic sealing plug according to one of claims 2-7, wherein the outer wall (110) has engagement ribs (114A, 114B) which are adapted to deform the inner surface (136) in the sealing state (Z2). [9] Monolithic sealing plug according to claim 1, wherein the monolithic sealing plug (100E) is disc-shaped. [10] Projection exposure apparatus (1) with a monolithic sealing plug (100A, 100B, 100C, 100D, 100E, 100F) according to one of claims 1-9.

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