Mirror seat, optical system and projection exposure equipment

Abstract

A mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) for an optical element (102, 102 '), comprising a central axis (126); a first spatial direction (x) oriented perpendicular to the central axis (126); and a second spatial direction (y) oriented perpendicular to the central axis (126) and perpendicular to the first spatial direction (x) wherein the mirror seat (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) has a first stiffness as viewed in the first spatial direction (x) and a second stiffness as viewed in the second spatial direction (y), and wherein the first stiffness and the second stiffness have different magnitudes.

Description

Field of the Invention

[0001] The present invention relates to a mirror mount for an optical element, an optical system having such a mirror mount, and a projection exposure apparatus having such a mirror mount and / or such an optical system.

[0002] The contents of priority applications DE 10 2023 100 393.3 and GR 20220101024 are incorporated herein by reference in their entirety for reference. Background Art

[0003] Microlithography is used for the production of microstructured components, such as integrated circuits. A lithography apparatus having an illumination system and a projection system is used to perform the microlithography process. An image of a mask (mask blank) illuminated by the illumination system is projected onto a substrate (e.g., a silicon wafer) by means of the projection system. The substrate is coated with a photosensitive layer (photoresist) and is arranged in the image plane of the projection system in order to transfer the mask structure onto the photosensitive coating of the substrate.

[0004] Driven by the demand for smaller structures in integrated circuit production, EUV lithography apparatuses using light in the wavelength range from 0.1 nm to 30 nm, in particular 13.5 nm, are currently being developed. In the case of such an EUV lithography apparatus, due to the high absorption of light of this wavelength by most materials, reflective optical elements (i.e., mirrors) must be used to replace refractive optical elements (i.e., lens elements) as described above.

[0005] By means of a mirror mount, a mirror of a projection system as described above can be coupled to a support structure in the form of, for example, a force frame, or to an actuator for aligning the mirror. For this purpose, the mirror mount is adhesively bonded to the mirror. A mirror has six degrees of freedom, specifically, three translational degrees of freedom along a first spatial direction, a second spatial direction, and a third spatial direction, and three rotational degrees of freedom about each of the aforementioned spatial directions.

[0006] It is preferably provided that exactly three mirror mounts are provided, and exactly two degrees of freedom are assigned to each mirror mount. However, this is not mandatory. For example, three degrees of freedom can also be assigned to one mirror mount, two degrees of freedom to another mirror mount, and one degree of freedom to another mirror mount. In order to introduce as little force as possible into the mirror, since this can lead to, for example, unwanted deformation of the mirror, it is desirable that the mirror mounts have different rigidities in different spatial directions. Summary of the Invention

[0007] In this context, it is an object of the present invention to provide an improved mirror mount for an optical element.

[0008] Therefore, a mirror mount for an optical element is proposed. The mirror mount includes a central axis, a first spatial direction oriented perpendicular to the central axis, and a second spatial direction oriented perpendicular to the central axis and perpendicular to the first spatial direction, wherein the mirror mount has a first rigidity when viewed in the first spatial direction and a second rigidity when viewed in the second spatial direction, and wherein the first rigidity and the second rigidity have different magnitudes.

[0009] Since the mirror mount has different magnitudes of rigidity when viewed in the first and second spatial directions, a plurality of mirror mounts for carrying an optical element can be configured without introducing unwanted forces or torques into the optical element. Thus, an undesired deformation of the optically effective surface of the optical element can be avoided. This improves the imaging quality of a projection exposure apparatus having such a mirror mount.

[0010] The optical element is a mirror module or a mirror, in particular an EUV mirror, or can be referred to as a mirror module or a mirror. However, the optical element can also be a lens element. Preferably, a plurality of mirror mounts (for example, exactly three) are assigned to the optical element. Only one mirror mount is discussed in more detail below. The optical element has an optically effective surface, in particular a reflective surface. The optical element (especially the optically effective surface) is adapted to reflect illumination radiation, in particular EUV radiation. The optically effective surface can be a coating applied to a substrate (such as a glass block or a glass-ceramic block).

[0011] Preferably, the mirror mount is integrally bonded to the optical element, in particular to the rear side of the optical element. The integral bonding connection is a connection in which the connecting mating parts are bonded together by atomic or molecular forces. At the same time, it is a non-releasable connection and can only be separated by destroying the connecting member and / or the connecting mating parts. For example, the mirror mount is adhesively bonded to the optical element.

[0012] The mirror mount is preferably constructed in a rotationally symmetric manner with respect to the central axis. Preferably, the mirror mount is constructed in a substantially rotationally symmetric manner with respect to the central axis. In this case, "substantially" means that it is not possible to rule out that the mirror mount also has regions or parts that are not constructed in a rotationally symmetric manner with respect to the central axis. The central axis can also be referred to as the symmetry axis of the mirror mount. Specifically, at least one external part and / or internal part of the mirror mount is constructed in a rotationally symmetric manner with respect to the central axis. However, rotational symmetry is not mandatory.

[0013] Each mirror mount is preferably assigned a coordinate system having a first spatial direction (also referred to as the x-direction), a second spatial direction (also referred to as the y-direction), and a third spatial direction or z-direction. The third spatial direction can be oriented parallel to the central axis or can correspond to the central axis. The second spatial direction is oriented perpendicular to the first spatial direction. The third spatial direction is oriented perpendicular to the first spatial direction and perpendicular to the second spatial direction. In this context, "perpendicular" should be understood to mean an angle of 90° ± 10°, more preferably 90° ± 5°, more preferably 90° ± 3°, more preferably 90° ± 1°, and more preferably exactly 90°. The first and second spatial directions span a plane oriented perpendicular to the central axis.

[0014] In this context, "rigidity" should be understood very generally to denote the resistance of the body (in this case the mirror mount) to elastic deformation imposed on it by external loads, and conveys the relationship between the load on the body and its deformation. Rigidity is determined by the material in the body and its geometry. For example, it is possible to achieve a first rigidity and a second rigidity of different magnitudes by adapting the geometry of the mirror mount. Preferably, the second rigidity is greater than the first rigidity.

[0015] Specifically, the mirror mount has a third rigidity as observed along the central axis or in the third spatial direction. The third rigidity is preferably greater than the first rigidity and greater than the second rigidity. In this context, having "different" magnitudes of the first and second rigidities means, in particular, that the second rigidity is greater than the first rigidity. Alternatively, the first rigidity can also be greater than the second rigidity.

[0016] According to one embodiment, the mirror mount further comprises an outer part, an inner part disposed within the outer part, and an elastically deformable connecting member, wherein the outer part is connected to the inner part by means of the connecting member.

[0017] The outer part can be annular. Thus, the outer part can also be referred to as an outer ring. The outer part can be constructed in a rotationally symmetric manner with respect to the central axis. The inner part can be annular. Thus, the inner part can also be referred to as an inner ring. The inner part can be constructed in a rotationally symmetric manner with respect to the central axis. Preferably, the outer part is connected to an optical element, in particular adhesively bonded to the optical element. The inner part can be connected to a support structure, such as a support structure in the form of a force frame. The inner part serves as an interface with the surrounding environment. In this context, the "surrounding environment" can be understood to refer to the aforementioned support structure or one or more actuators. For example, the inner part is clamped and / or screwed to the support structure. The support structure has engagement points, such as those comprising threaded connectors, for engaging the inner part. Conversely, the outer part can also be connected to the support structure and the inner part connected to the optical element.

[0018] The connecting member acts as a so-called flexure and allows relative movement of the inner member with respect to the outer member and vice versa. In this context, a "flexure" is generally understood as a region of a member, such as a narrowed or thinned cross-section, which is capable of relative movement between two rigid body regions of the member by bending or torsion. In this case, the outer member and the inner member preferably form rigid body regions, and an elastically deformable connecting member is provided between the rigid body regions as a flexure. The connecting member itself may additionally have grooves, narrowed cross-sections or thinned cross-sections, which serve as flexures directly provided on the connecting member. Thereby, the deformation ability of the connecting member can be further improved.

[0019] In this case, in fact, the connecting member being "elastically" or "resiliently" deformable means, in particular, that the connecting member is capable of passing from a non-deformed state to a deformed state by means of a force or a moment. Once the force or moment no longer acts on the corresponding connecting member, the corresponding connecting member automatically returns from the deformed state to the non-deformed state. Specifically, the connecting member is thus resiliently deformable.

[0020] Each connecting member preferably has a cross-sectional area that can be shaped as required. For example, the cross-sectional area is rectangular, triangular, circular, cross-shaped, etc. The connecting member has a connecting member width and a connecting member height. In this context, the "aspect ratio" can be understood to mean the ratio of the connecting member height to the connecting member width. By changing the aspect ratio, the rigidity of the connecting member can be changed. It is particularly preferred to provide a first connecting member and a second connecting member. That is to say, exactly two connecting members can be provided. However, in principle, any desired number of connecting members can be present.

[0021] Viewed along the connecting member length of the connecting member, the cross-sectional area of the connecting member can be constant. In this case, the "connecting member length" should be understood to represent the length of the corresponding connecting member along its main extension direction, along which the connecting member extends from the inner member towards the outer member. Viewed along the connecting member length, the cross-sectional area can also change. For example, the cross-sectional area increases from the outer member as the starting point towards the inner member, or vice versa.

[0022] In addition to the connecting member, the inner member can also be suspended on the outer member by means of additional leaf springs. The leaf springs also reinforce the mirror mount along the central axis or the third spatial direction and only minimally reinforce the mirror mount in the other two spatial directions. The leaf springs can be folded. For example, each leaf spring has a first leaf spring part and a second leaf spring part. The leaf spring parts are preferably inclined with respect to each other. For example, the first leaf spring part and the second leaf spring part can be oriented perpendicular to each other.

[0023] The connecting member preferably extends in a spatial direction among two spatial directions, which provides greater rigidity along this spatial direction. This is preferably the second spatial direction or the y-direction. However, the connecting member may also extend in the first spatial direction or the x-direction. In the latter case, the mirror mount has greater rigidity when observed in the first spatial direction or the x-direction. The mirror mount preferably has the greatest rigidity when observed along the third spatial direction or the z-direction. That is to say, the rigidity of the mirror mount when observed in the third spatial direction or the z-direction is greater than that of the mirror mount in the other two spatial directions.

[0024] According to another embodiment, the connecting member extends along a spatial direction, and along this spatial direction, the mirror mount has greater rigidity.

[0025] As mentioned above, this is preferably the second spatial direction or the y-direction. In this case, the connecting member may extend linearly along this spatial direction. However, the connecting member may also be curved, especially arc-shaped. Preferably, the connecting member extends in the second spatial direction or the y-direction. Therefore, when observed perpendicular to the connecting member, the rigidity of the mirror mount is lower than that along the connecting member.

[0026] According to another embodiment, the internal member is arranged between the first connecting member and the second connecting member.

[0027] In principle, there can be any desired number of connecting members. However, it is particularly preferred to provide exactly two connecting members, and the internal member is arranged between these two connecting members. The connecting member can be connected to the internal member by means of a joint point acting as a flexure part. For example, the connecting member can be cut and separated from the external member by means of a groove. For example, the groove can be manufactured by means of a wire erosion method.

[0028] According to another embodiment, the external member, the internal member and the connecting member are connected to each other in a one-piece manner, especially in a materially one-piece manner.

[0029] Here, "one-piece" or "one-piece forming" especially means that the external member, the internal member and the connecting member form a common member, specifically the mirror mount, and are not assembled together from different sub-components. In this case, "materially one-piece forming" means that the external member, the internal member and the connecting member are all made of the same material. The one-piece forming embodiment is optional. In principle, embodiments using different materials are also possible. Preferably, the mirror mount is made of a metal material. For example, an iron-nickel alloy, especially Invar, can be used. For example, the mirror mount can be manufactured by means of a milling method and / or a wire erosion method. However, the mirror mount can also be manufactured by means of an additive manufacturing method or a generative manufacturing method, especially by means of a 3D printing method.

[0030] According to another embodiment, the connecting members extend parallel to each other and spaced apart.

[0031] As described above, the connecting members preferably extend in the second spatial direction or y-direction. When viewed along the first spatial direction or x-direction, the connecting members are preferably arranged spaced apart from each other such that the internal member can be arranged between the connecting members. For example, the connecting members are connected to the external member at both end sides and to the internal member at the center.

[0032] According to another embodiment, the connecting member has an arcuate, in particular circular arc-shaped, curvature.

[0033] Thus, the connecting member can extend at least partially around the internal member. Thus, the connecting member can surround or enclose the internal member. Due to the arcuate geometry of the connecting member, compared with the straight configuration of the connecting member, the length of the connecting member as a connecting member can be increased.

[0034] According to another embodiment, each connecting member has a first connecting member portion and a second connecting member portion, wherein the first connecting member portion and the second connecting member portion are connected to each other by means of a deflection portion such that the connecting member has a circumferentially closed geometry.

[0035] In this case, the connecting member portions can extend along a straight line and be parallel to each other. Alternatively, the connecting member portions can also have an arcuate, in particular circular arc-shaped, curvature. In this case, the connecting member portions can also extend parallel to each other. The connecting member portions and the deflection portion together form a circumferentially closed geometry, in particular an annular geometry. For example, the connecting member is O-shaped. Thus, the term "annular" also includes non-circular closed geometries. Alternatively, the connecting member portions and the deflection portion can also be configured such that the connecting member has a circumferentially open geometry. In this case, the connecting member can be, for example, Z-shaped or have a zigzag curvature.

[0036] According to another embodiment, the connecting members together form an annular connecting member that extends at least partially around the internal member.

[0037] The internal part is arranged within an annular connecting part. The annular connecting part can be circumferentially closed. In this case, the annular connecting part extends completely around the internal part. The annular connecting part can be connected to the internal part by means of a joining point and to the external part by means of a further joining point. The joining points of the internal part and the external part are preferably arranged offset from each other by 90°. Alternatively, the annular connecting part can also be circumferentially open. For example, in this case, the annular connecting part is connected to the internal part by means of exactly one joining point and to the external part by means of two joining points. The annular connecting part can have a circular or oval shape, the oval shape having major axes of different lengths. Thus, "annular" does not necessarily mean circular in this case. Thus, not only the length of the connecting part can be used, but also the curved shape of the connecting part can be used to adapt the rigidity in the x - direction and the y - direction. Preferably, greater rigidity is obtained in the direction of the longer major axis. Preferably, less rigidity is obtained across the long major axis, i.e., along the short major axis.

[0038] According to another embodiment, the connecting part has a connecting part height when viewed along the central axis, wherein, starting from the external part, the connecting part height varies in the direction of the internal part.

[0039] In this case, "varies" specifically means that the connecting part height changes, for example, becomes higher or lower. For example, this can be achieved by milling, bevelling, etc. Thus, the rigidity of the connecting part can be adjusted. Thus, the volume of the limited installation space can be utilized effectively.

[0040] According to another embodiment, the mirror mount contains drill holes through which cutting lines can be guided for manufacturing the mirror mount.

[0041] This is advantageous for the manufacturability of the mirror mount.

[0042] According to another embodiment, the mirror mount is made of a non - magnetic material, in particular molybdenum.

[0043] This enables the mirror mount to also be used in a magnetic field. The magnetostrictive effect plays a decisive role here, because in the case of a changing magnetic field, the magnetostrictive effect can cause the material of the mirror mount to deform. Specifically, molybdenum - containing alloys can be used. The term "amagnetic" can be replaced by the term "nonmagnetic". Alternatively, the mirror mount can also be made of, for example, an iron - nickel alloy, in particular invar.

[0044] An optical system for a projection exposure apparatus is also proposed. The optical system comprises optical elements, a support structure for carrying the optical elements, and at least one such mirror mount, wherein the optical elements are connected to the support structure by means of at least one mirror mount.

[0045] The optical system may comprise any desired number of optical elements and / or mirror mounts. The optical system may be a projection optical unit or a part of this projection optical unit. Thus, this optical system may also be referred to as a projection optical unit. However, the optical system may also be an illumination system or a part of this illumination system. Thus, this optical system may also be referred to as an illumination system. However, it is assumed hereinafter that the optical system is a projection optical unit or a part of this projection optical unit. This optical system is suitable for EUV lithography. However, this optical system is also suitable for DUV lithography.

[0046] As described above, the optical element is a mirror, in particular an EUV mirror. The support structure may be a force frame as described above. In this case, the support structure that "carries" the optical element particularly means that the support structure is capable of absorbing the weight of the optical element. Thus, for example, the weight of the optical element may be transferred to the support structure via the mirror mount. The mirror mount preferably has the purpose of mechanically separating the optical element from the support structure, so that parasitic forces that may cause unwanted deformation of the optical element are not introduced into the optical element at the mirror mount.

[0047] Preferably, a plurality of mirror mounts are assigned to the optical element. The mirror mounts couple the optical element to the support structure. The optical element has six degrees of freedom, specifically, in each case three translational degrees of freedom along a first spatial direction or x-direction, a second spatial direction or y-direction, and a third spatial direction or z-direction, and in each case also three rotational degrees of freedom about the three spatial directions. That is, the position and orientation of the optical element can be determined or described by means of six degrees of freedom.

[0048] The "position" of the optical element should be understood to refer in particular to its coordinates relative to the x-direction, y-direction, and z-direction. The "orientation" of the optical element should be understood to refer in particular to its inclination relative to the three spatial directions. That is, the optical element can be tilted about the x-direction, y-direction, and / or z-direction. This provides six degrees of freedom for the position and orientation of the optical element.

[0049] The "pose" of the optical system includes both its position and orientation. Thus, the term "pose" replaces the term "position and orientation", and vice versa. In this case, the "adjustment" or "alignment" of the optical element is understood to refer in particular to a change in the pose of the optical element. Adjusting or aligning the optical element can preferably be achieved with several or all of the above six degrees of freedom. For example, a gasket element in the form of a washer can be placed under the mirror mount to adjust the pose of the optical element.

[0050] According to an embodiment, the optical system further comprises three mirror mounts, wherein the optical element has six degrees of freedom, and wherein each mirror mount is assigned exactly two degrees of freedom.

[0051] Specifically, each mirror mount has high rigidity in two degrees of freedom assigned to the respective mirror mount, and has less rigidity in the remaining four degrees of freedom. However, this is not mandatory. For example, three degrees of freedom may also be assigned to one mirror mount, two degrees of freedom to another mirror mount, and one degree of freedom to another mirror mount. The three mirror mounts are preferably arranged at the corners of an imaginary triangle formed by the three mirror mounts.

[0052] According to another embodiment, each of the three mirror mounts has a plane spanned by a central axis and a spatial direction, and when viewed along this spatial direction, the mirror mount has less rigidity, where the three mirror mounts are configured such that the planes intersect each other at a common intersection line.

[0053] Specifically, the plane is spanned by the central axis or a third spatial direction or the z - direction and a first spatial direction or the x - direction. Thus, the mirror mount has the maximum rigidity perpendicular to this plane, that is, when viewed in the second spatial direction or the y - direction. Preferably, the three mirror mounts are configured such that their lateral flexibility directions each radially point in the direction of the center of the optical element in each case, and their lateral rigidity directions are oriented perpendicular to said direction. Specifically, the intersection line is located at the center of the optical element.

[0054] Furthermore, a projection exposure apparatus having such a mirror mount and / or such an optical system is proposed.

[0055] The optical system is preferably the projection optical unit of a projection exposure apparatus. However, the optical system may also be an illumination system. The projection exposure apparatus may be an EUV lithography apparatus. EUV stands for "extreme ultraviolet light", and the wavelength of the working light is between 0.1 nm and 30 nm. The projection exposure apparatus may also be a DUV lithography apparatus. DUV stands for "deep ultraviolet light", and the wavelength of the working light is between 30 nm and 250 nm.

[0056] The "a", "an", and "one" in this case are not necessarily to be understood as being limited to exactly one element. On the contrary, a plurality of elements may also be provided, for example two, three, or more. Any other numbers used here should also not be understood as limiting the exact number of elements stated. On the contrary, unless otherwise stated, the numerical values may have upward and downward deviations.

[0057] The embodiments and features described for the mirror mount correspondingly apply to the proposed optical system and / or the proposed projection exposure apparatus, and vice versa.

[0058] Further possible implementations of the present invention also include combinations of features or embodiments not explicitly mentioned above or below with respect to the exemplary embodiments. In this case, those skilled in the art will also incorporate individual aspects as improvements or supplements into the corresponding basic forms of the present invention.

[0059] Other advantageous improvements and aspects of the present invention are the subject of the dependent claims and of the exemplary embodiments of the present invention described below. In addition, the present invention will be described in detail below with reference to the accompanying drawings based on the preferred embodiments. Description of the Drawings

[0060] Figure 1 Shows a schematic meridional section of a projection exposure apparatus for EUV projection lithography;

[0061] Figure 2 Shows for Figure 1 A schematic diagram of an embodiment of the optical system of a projection exposure apparatus according to

[0062] Figure 3 Shows according to Figure 2 A schematic top view of the optical system according to

[0063] Figure 4 Shows for Figure 2 A schematic top view of an embodiment of the mirror mount of the optical system according to

[0064] Figure 5 Shows according to Figure 4 The V-V sectional view according to

[0065] Figure 6 Shows for Figure 2 A schematic perspective view of another embodiment of the mirror mount of the optical system according to

[0066] Figure 7 Shows according to Figure 6 A schematic rear view of the mirror mount according to

[0067] Figure 8 Shows for Figure 2 A schematic perspective view of another embodiment of the mirror mount of the optical system according to

[0068] Figure 9 Shows according to Figure 6 A schematic rear view of the mirror mount according to

[0069] Figure 10 Shows for Figure 2 A schematic perspective view of another embodiment of the mirror mount of the optical system according to

[0070] Figure 11 Shows according to Figure 10 A schematic rear view of the mirror mount according to

[0071] Figure 12 Shows for Figure 2Schematic perspective view of another embodiment of the mirror mount of the optical system;

[0072] Figure 13 Shows according to Figure 12 Schematic rear view of the mirror mount;

[0073] Figure 14 Shows for the optical system according to Figure 2 Schematic perspective view of another embodiment of the mirror mount;

[0074] Figure 15 Shows according to Figure 14 Schematic rear view of the mirror mount;

[0075] Figure 16 Shows for the optical system according to Figure 2 Schematic perspective view of another embodiment of the mirror mount;

[0076] Figure 17 Shows according to Figure 16 Schematic rear view of the mirror mount;

[0077] Figure 18 Shows for the optical system according to Figure 2 Schematic perspective view of another embodiment of the mirror mount;

[0078] Figure 19 Shows according to Figure 18 Schematic rear view of the mirror mount;

[0079] Figure 20 Shows for the optical system according to Figure 2 Schematic perspective view of another embodiment of the mirror mount;

[0080] Figure 21 Shows according to Figure 20 Schematic rear view of the mirror mount;

[0081] Figure 22 Shows for the optical system according to Figure 2 Schematic perspective view of another embodiment of the mirror mount;

[0082] Figure 23 Shows according to Figure 22 Schematic rear view of the mirror mount;

[0083] Figure 24 Shows for the optical system according to Figure 2 Schematic perspective view of another embodiment of the mirror mount;

[0084] Figure 25 Shows according to Figure 24Schematic rear view of a mirror mount;

[0085] Figure 26 Shows a mirror mount for an optical system according to Figure 2 Another embodiment of a mirror mount, in a schematic perspective view;

[0086] Figure 27 Shows a mirror mount according to Figure 26 Schematic rear view of a mirror mount;

[0087] Figure 28 Shows a mirror mount for an optical system according to Figure 2 Another embodiment of a mirror mount, in a schematic perspective view;

[0088] Figure 29 Shows a mirror mount according to Figure 28 Schematic rear view of a mirror mount;

[0089] Figure 30 Shows a mirror mount for an optical system according to Figure 2 Another embodiment of a mirror mount, in a schematic perspective view;

[0090] Figure 31 Shows a mirror mount according to Figure 30 Schematic rear view of a mirror mount;

[0091] Figure 32 Shows a mirror mount for an optical system according to Figure 2 Another embodiment of a mirror mount, in a schematic perspective view; and

[0092] Figure 33 Shows a mirror mount according to Figure 32 Schematic rear view of a mirror mount. Detailed Description

[0093] Unless otherwise specified, identical or functionally identical elements are provided with the same reference numerals in the figures. It should also be noted that the illustrations in the figures are not necessarily drawn to scale.

[0094] Figure 1 Shows an embodiment of a projection exposure apparatus 1 (lithographic apparatus), in particular an EUV lithographic apparatus. An embodiment of the illumination system 2 of the projection exposure apparatus 1 has a light or radiation source 3 and also has an illumination optical unit 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 module separate from the other parts of the illumination system 2. In this case, the illumination system 2 does not include the light source 3.

[0095] A mask blank 7 disposed in the object field 5 is exposed. The mask blank 7 is held by a mask blank holder 8. The mask blank holder 8 is displaced by a mask blank displacement driver 9, in particular in a scanning direction.

[0096] For purposes of explanation, Figure 1 a Cartesian coordinate system with an x-direction x, a y-direction y, and a z-direction z is shown. The x-direction x enters the plane of the illustration perpendicularly. The y-direction y extends horizontally, and the z-direction y extends vertically. Figure 1 The scanning direction in extends along the y-direction y. The z-direction z extends perpendicular to the object plane 6.

[0097] The projection exposure apparatus 1 includes a projection optical unit 10. The projection optical unit 10 is configured to image the object field 5 onto an image field 11 in the image plane 12. The image plane 12 extends parallel to the object plane 6. Alternatively, the angle between the object plane 6 and the image plane 12 may also not be equal to 0°.

[0098] The structure on the mask blank 7 is imaged onto the photosensitive layer of the wafer 13. The wafer 13 is 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 displaced by a wafer displacement driver 15, in particular along the y-direction y. The displacement of the mask blank 7 by means of the mask blank displacement driver 9 and the displacement of the wafer 13 by means of the wafer displacement driver 15 can be synchronized with each other.

[0099] The light source 3 is an EUV radiation source. The light source 3 emits in particular EUV radiation 16, which is also referred to hereinafter as the used radiation, illumination radiation, or illumination light. In particular, the wavelength range of the used radiation 16 is between 5 nm and 30 nm. The radiation source 3 can be a plasma source, such as a laser produced plasma (LPP) source or a gas discharge produced plasma (GDPP) source. It can also be a synchrotron-based radiation source. The light source 3 can be a free electron laser (FEL).

[0100] The illumination radiation 16 emitted from the light source 3 is focused by a condenser 17. The condenser 17 can be a condenser having more than one elliptical and / or hyperbolic reflecting surface. The illumination radiation 16 can be incident on at least one reflecting surface of the condenser 17 at a grazing incidence (GI), i.e., at an incident angle greater than 45°, or at a normal incidence (NI), i.e., at an incident angle less than 45°. The condenser 17 can be structured and / or coated, mainly for optimizing its reflectivity for the used radiation and secondly for suppressing extraneous light.

[0101] Downstream of the condenser 17, the illumination radiation 16 propagates through an intermediate focus in an intermediate focal plane 18. The intermediate focal plane 18 may represent a separation between the radiation source module with the light source 3 and the condenser 17 and the illumination optical unit 4.

[0102] The illumination optical unit 4 comprises a deflection mirror 19 and a first facet mirror 20 arranged downstream thereof in the beam path. The deflection mirror 19 can be a plane deflection mirror or, alternatively, a mirror with a beam influencing effect that goes beyond a pure deflection effect. Alternatively or additionally, the deflection mirror 19 can be in the form of a spectral filter which separates the used light wavelength of the illumination radiation 16 from extraneous light whose wavelength deviates therefrom. If the first facet mirror 20 is arranged in a plane of the illumination optical unit 4 which is optically conjugate to the object plane 6 (as a field plane), the first facet mirror 20 is also referred to as a field facet mirror. The first facet mirror 20 comprises a plurality of individual first facets 21, which can also be referred to as field facets. Only some of the first facets 21 are shown exemplarily in Figure 1 middle.

[0103] The first facets 21 can be implemented as macro facets, in particular rectangular facets or facets with an arcuate edge profile or a partially circular edge profile. The first facets 21 can be in the form of planar facets or, alternatively, facets with a convex or concave curvature.

[0104] For example, it is known from DE 10 2008 009 600 A1 that the first facets 21 themselves can also each consist of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirrors 20 can in particular be in the form of a microelectromechanical system (MEMS system). For more details, please refer to DE 10 2008 009 600 A1.

[0105] Between the condenser 17 and the deflection mirror 19 the illumination radiation 16 travels horizontally, ie in the y-direction y.

[0106] In the beam path of the illumination optical unit 4, the second facet reflector 22 is arranged downstream of the first facet reflector 20. If the second facet reflector 22 is arranged in the pupil plane of the illumination optical unit 4, the second facet reflector 22 is also called a pupil facet reflector. The second facet reflector 22 can also be arranged at a distance from the pupil plane of the illumination optical unit 4. In this case, the combination of the first facet reflector 20 and the second facet reflector 22 is also called a specular reflector. Specular reflectors are known from US 2006 / 0132747 A1, EP 1 614 008 B1 and US 6,573,978.

[0107] 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 called pupil facets.

[0108] The second facet 23 can likewise be a macro facet, which can have, for example, a circular, rectangular or hexagonal boundary, or alternatively be a facet composed of micromirrors. In this regard, reference is also made to DE 10 2008 009 600 A1.

[0109] The second facet 23 can have a planar surface, or alternatively, a convex or concave curved reflective surface.

[0110] The illumination optical unit 4 thus forms a two-facet system. This basic principle is also known as a fly's eye integrator.

[0111] It may be advantageous to arrange the second facet mirror 22 imprecisely in a plane that is optically conjugate to the pupil plane of the projection optical unit 10. In particular, the pupil facet mirror 22 can be arranged inclined with respect to the pupil plane of the projection optical unit 10, as described, for example, in DE 10 2017 220 586 A1.

[0112] With the aid of the second facet mirror 22, the individual first facet 21 is imaged into the object field 5. 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.

[0113] In another embodiment (not shown) of the illumination optical unit 4, the transfer optical unit responsible for imaging the first facet 21 into the object field 5 can be arranged in the beam path between the second facet mirror 22 and the object field 5. The transfer optical unit can exactly comprise one mirror, or alternatively, more than two mirrors, which are successively arranged in the beam path of the illumination optical unit 4. In particular, the transfer optical unit can comprise one or two normal incidence mirrors (NI mirrors) and / or one or two grazing incidence mirrors (GI mirrors).

[0114] In Figure 1 the illustrated embodiment, the illumination optical unit 4 has exactly three mirrors downstream of the condenser 17, specifically the deflection mirror 19, the first facet mirror 20 and the second facet mirror 22.

[0115] In another embodiment of the illumination optical unit 4, the deflection mirror 19 may also not be required, so that the illumination optical unit 4 can then have exactly two mirrors downstream of the condenser 17, specifically the first facet mirror 20 and the second facet mirror 22.

[0116] Imaging the first facet 21 into the object plane 6 by means of the second facet 23 or using the second facet 23 and the transfer optical unit is generally only an approximate imaging.

[0117] The projection optical unit 10 includes a plurality of mirrors Mi, which are numbered according to their arrangement order in the beam path of the projection exposure apparatus 1.

[0118] In Figure 1 In the illustrated example, the projection optical unit 10 includes six mirrors M1 to M6. Alternatively, it is also possible to have four, eight, ten, twelve or any other number of mirrors Mi. The projection optical unit 10 is a double-masking optical unit. The penultimate mirror M5 and the last mirror M6 each have a through-hole for the illumination radiation 16. The projection optical unit 10 has an image-side numerical aperture greater than 0.5, which can also be greater than 0.6 and can be, for example, 0.7 or 0.75.

[0119] The reflective surface of the mirror Mi can be designed as a free-form surface without a rotational symmetry axis. Alternatively, the reflective surface of the mirror Mi can be designed as an aspherical surface with exactly one rotational symmetry axis of the reflective surface shape. Similar to the mirrors of the illumination optical unit 4, the mirror Mi can have a highly reflective coating for the illumination radiation 16. These coatings can be designed as multilayer coatings, especially with alternating layers of molybdenum and silicon.

[0120] Between the y coordinate of the center of the object field 5 and the y coordinate of the center of the image field 11, the projection optical unit 10 has a large object-image offset in the y-direction y. The magnitude of this object-image offset in the y-direction y can be approximately the same as the z distance between the object plane 6 and the image plane 12.

[0121] The projection optical unit 10 can in particular have a deformed form. It particularly has different imaging ratios βx, βy in the x-direction x and the y-direction y. The two imaging ratios βx, βy of the projection optical unit 10 are preferably (βx, βy) = (+ / -0.25, + / -0.125). A positive imaging ratio β indicates that the imaging has no image inversion. A negative sign of the imaging ratio β indicates that the imaging has an image inversion.

[0122] Therefore, the projection optical unit 10 causes the size to be reduced by a factor of 4:1 in the x-direction x (i.e., the direction perpendicular to the scanning direction).

[0123] The projection optical unit 10 causes the size to be reduced by a factor of 8:1 in the y-direction y (i.e., the scanning direction).

[0124] Other imaging ratios are also possible. It is also possible to have imaging ratios with the same sign and the same absolute value in the x-direction x and the y-direction y, for example, with an absolute value of 0.125 or 0.25.

[0125] In the beam path between the object field 5 and the image field 11, the number of intermediate image planes in the x-direction x and the y-direction y can be the same or can differ depending on the embodiment of the projection optical unit 10. Examples of projection optical units are known from US 2018 / 0074303 A1, which have different numbers of such intermediate images in the x- and y-directions x, y.

[0126] In each case, one of the second facets 23 is assigned exactly to one of the first facets 21 to form illumination channels for illuminating the object field 5, respectively. This can in particular produce illumination according to the Köhler principle. By means of the first facet 21, the far field is decomposed into a plurality of object fields 5. The first facet 21 produces a plurality of intermediate focal images on the second facet 23 assigned to it, respectively.

[0127] By means of the assigned second facet 23, the first facet 21 is imaged onto the mask reticle 7 in each case in a way that they are superimposed on one another to illuminate the object field 5. The illumination of the object field 5 is in particular as uniform as possible. It preferably has a uniformity error of less than 2%. The field uniformity can be achieved by superimposing different illumination channels.

[0128] The illumination of the entrance pupil of the projection optical unit 10 can be geometrically defined by means of the configuration of the second facet 23. The intensity distribution in the entrance pupil of the projection optical unit 10 can be set by selecting the illumination channels guiding the light, in particular a subset of the second facets 23. This intensity distribution is also referred to as illumination setting or illumination pupil filling.

[0129] Similarly good pupil uniformity in a partial region of the illumination pupil of the illumination optical unit 4 illuminated in a defined manner can be achieved by redistributing the illumination channels.

[0130] Other aspects and details of the illumination of the object field 5, in particular other aspects and details of the entrance pupil of the projection optical unit 10, are described below.

[0131] The projection optical unit 10 can in particular have a concentric entrance pupil. The latter can be accessible. It can also be inaccessible.

[0132] The entrance pupil of the projection optical unit 10 usually cannot be accurately illuminated using the second facet mirror 22. When imaging the projection optical unit 10, it images the center telecentricity of the second facet mirror 22 onto the wafer 13, and the aperture rays usually do not intersect at a single point. However, a region can be found where the spacing of the pairwise determined aperture rays becomes minimal. This region represents the entrance pupil or the region conjugate to it in real space. In particular, this region has a finite curvature.

[0133] For the tangential beam path and the sagittal beam path, the projection optical unit 10 may have entrance pupils in different postures. In this case, an imaging element, in particular an optical component of the transfer optical unit, should be provided between the second faceted mirror 22 and the mask blank 7. With the aid of this optical element, the different postures of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

[0134] In Figure 1 the configuration of the component parts of the illumination optical unit 4 shown, the second faceted mirror 22 is arranged in the region conjugate to the entrance pupil of the projection optical unit 10. The first faceted mirror 20 is arranged to be inclined with respect to the object plane 6. The first faceted mirror 20 is arranged to be inclined with respect to the configuration plane defined by the deflection mirror 19. The first faceted mirror 20 is arranged to be inclined with respect to the configuration plane defined by the second faceted mirror 22.

[0135] Figure 2 A schematic view of an embodiment of an optical system 100 for a projection exposure apparatus 1 is shown. Figure 3 A schematic top view of the optical system 100 is shown. The following is described with reference to Figure 2 and Figure 3 simultaneously.

[0136] The optical system 100 may be the projection optical unit 4 as described above or a part of this projection optical unit 4. Therefore, the optical system 100 may also be referred to as the projection optical unit. However, the optical system 100 may also be the illumination system 2 or a part of this illumination system 2. Therefore, the optical system 100 may alternatively be referred to as the illumination system. However, it is assumed below that the optical system 100 is the projection optical unit 4 or a part of this projection optical unit 4. The optical system 100 is suitable for EUV lithography. However, the optical system 100 can also be suitable for DUV lithography.

[0137] The optical system 100 may comprise a plurality of optical elements 102, however Figure 2 and Figure 3 only one of them is shown. Therefore, only one optical element 102 is discussed below. The optical element 102 may be one of the mirrors M1 to M6. In particular, the optical element 102 is the mirror M5. The optical element 102 comprises a substrate 104 and an optically effective surface 106, such as a reflecting surface. The substrate 104 may also be referred to as the mirror substrate. The substrate 104 may comprise glass, ceramic, glass ceramic or other suitable materials.

[0138] The optically effective surface 106 is provided on the front side 108 of the substrate 104. The optically effective surface 106 can be realized by means of a coating applied to the front side 108. The optically effective surface 106 is a reflecting mirror surface. The optically effective surface 106 is suitable for reflecting illumination radiation 16, in particular EUV radiation, during operation of the optical system 100. The optically effective surface 106 can have an oval or elliptical geometry in a top view according to Figure 3 . The optical element 102 or the substrate 104 can have a triangular geometry. However, generally speaking, any desired geometry can be present.

[0139] The optical element 102 has a rear side 110 facing away from the optically effective surface 106 or the front side 108. The rear side 110 does not have defined optical properties. That is to say, in particular, the rear side 110 is not a reflecting mirror surface and thus does not have reflection properties either.

[0140] A plurality of mirror mounts 112, 114, 116 are provided on the rear side 110. However, the mirror mounts 112, 114, 116 can also be positioned on or at the front side 108, in particular in the vicinity of the optically effective surface 106. The mirror mounts 112, 114, 116 can be adhesive mounts. A first mirror mount 112, a second mirror mount 114 and a third mirror mount 116 are provided. In other words, the optical element 102 includes exactly three mirror mounts 112, 114, 116. The mirror mounts 112, 114, 116 can have geometrically identical designs. The mirror mounts 112, 114, 116 extend beyond the rear side 110 on the lower side along Figure 2 . The mirror mounts 112, 114, 116 can be adhesively bonded to the substrate 104. The mirror mounts 112, 114, 116 form the corners of a virtual triangle.

[0141] The optical element 102 or the optically effective surface 106 has six degrees of freedom, namely three translational degrees of freedom along a first spatial direction or x-direction x, a second spatial direction or y-direction y and a third spatial direction or z-direction z, and three rotational degrees of freedom about the x-direction x, y-direction y and z-direction z. That is to say, the position and orientation of the optical element 102 or the optically effective surface 106 can be defined or described by means of six degrees of freedom.

[0142] The "position" of the optical element 102 or the optically effective surface 106 is understood in particular to mean its coordinates or the coordinates of a measurement point provided on the optical element 102 relative to the x-direction x, y-direction y and z-direction z. The "orientation" of the optical element 102 or the optically effective surface 106 is understood to refer in particular to its inclination relative to the three directions x, y, z. That is to say, the optical element 102 or the optically effective surface 106 can be inclined about the x-direction x, y-direction y and / or z-direction z.

[0143] This results in six degrees of freedom for the position and orientation of the optical element 102 or the optically effective surface 106. The "attitude" of the optical element 102 or the optically effective surface 106 encompasses both its position and orientation. Thus, the term "attitude" can be replaced by the words "position and orientation", and vice versa.

[0144] Figure 2 The actual attitude IL of the optical element 102 or the optically effective surface 106 is shown by a solid line, and the target attitude SL of the optical element 102 or the optically effective surface 106 is shown by a dashed line, with reference numerals 102' and 106'. The optical element 102 can move from its actual attitude IL to the target attitude SL, and vice versa. For example, the optical element 102 in the target attitude SL satisfies specific optical specifications or requirements that the optical element 102 in the actual attitude IL does not satisfy.

[0145] To bring the optical element 102 from the actual attitude IL to the target attitude SL, spacers can be provided, for example, at the mirror mounts 112, 114, 116, or the optical element 102 can be variably actuated during operation. In this case, "spacer" is understood to mean a cushioning element, in particular a so-called shim, for example in the form of a washer, placed beneath the mirror mounts 112, 114, 116. This allows the adjustment or alignment of the optical element 102.

[0146] In this case, "adjustment" or "alignment" is understood to particularly refer to a change in the attitude of the optical element 102. For example, the optical element 102 can move from the actual attitude IL to the target attitude SL. Thus, the adjustment or alignment of the optical element 102 can be performed in all six of the above-mentioned degrees of freedom.

[0147] The mirror mounts 112, 114, 116 are joined to a fixed ground or support structure 124 by means of the joining points 118, 120, 122. The joining points 118, 120, 122 can comprise a screwed connection. The support structure 124 can be a force frame or any other support structure. Each mirror mount 112, 114, 116 is assigned a joining point 118, 120, 122. Specifically, this means that exactly three joining points 118, 120, 122 are provided. Each joining point 118, 120, 122 can be assigned two of the above-mentioned degrees of freedom. Thus, all six degrees of freedom of the optical element 102 are defined by means of the three joining points 118, 120, 122.

[0148] The first joint 118 is assigned to the first mirror mount 112. The second joint 120 is assigned to the second mirror mount 114. The third joint 122 is assigned to the third mirror mount 116. The mirror mounts 112, 114, 116 preferably have the same design. Accordingly, the joints 118, 120, 122 also have the same design. Therefore, only the first mirror mount 112 and the first joint 118 will be discussed hereinafter, which will be simply referred to as the mirror mount 112 and the joint 118 hereinafter. All explanations given hereinafter regarding the mirror mount 112 also apply to the mirror mounts 114, 116, and vice versa. The corresponding statements also apply to the joint 118 and the joints 120, 122.

[0149] Once all six degrees of freedom are defined, the optical element 102 is statically determined. Each further additional definition may lead to overdetermination. If the optical element 102 is overdetermined, forces and thus also deformations may be introduced into the optical element 102. The aim is to avoid this by means of a suitable design of the mirror mounts 112, 114, 116.

[0150] Figure 4 A schematic top view of an embodiment of the mirror mount 112A as described above is shown. Figure 5 A schematic sectional view of the mirror mount 112A according to the Figure 4 section line V-V is shown. The following is described with reference to Figure 4 and Figure 5 simultaneously.

[0151] The mirror mount 112A is assigned a coordinate system containing an x-direction x, a y-direction y, and a z-direction z. The mirror mount 112A has a symmetry axis or central axis 126, and the mirror mount has a structure that is substantially rotationally symmetric with respect to the symmetry axis or central axis 126. However, the mirror mount 112A may also have interfaces or cut surfaces that do not have a rotationally symmetric structure, such as drilled or milled sections. The central axis 126 corresponds to the z-direction z or is oriented parallel to the z-direction z.

[0152] The mirror mount 112A includes an outer part 128 and an inner part 130 disposed within the outer part 128. The outer part 128 is annular and may thus also be referred to as an outer ring. The inner part 130 is annular and may thus also be referred to as an inner ring. The outer part 128 is connected to the optical element 102, in particular adhesively bonded to the optical element 102. The inner part 130 is connected to the joint 118, for example, by a threaded connection and / or a clamping connection. The inner part 130 can be part of the joint 118. When viewed along the z-direction z, the rigidity of the mirror mount 112A is greater than the rigidity along the directions x, y.

[0153] The x-direction x and the z-direction z, or the x-direction x and the central axis 126 span the first plane E1. The y-direction y and the z-direction z, or the y-direction y and the central axis 126 span the second plane E2. The mirror mount 112A has a structure that is mirror-symmetric with respect to each of the first plane E1 and the second plane E2. The planes E1, E2 intersect on the central axis 126. The planes E1, E2 are perpendicularly aligned with each other.

[0154] As Figure 3 shown, the three mirror mounts 112, 114, 116 are arranged such that the three first planes E1 intersect at a common straight line intersection line or intersection line G. The intersection line G extends parallel to the z-direction z or coincides therewith. The intersection line G intersects the optically effective surface 106.

[0155] Please refer back to Figure 4 and Figure 5 , the outer part 128 is connected to the inner part 130 by means of the connecting parts 132, 134. A first connecting part 132 and a second connecting part 134 are provided. The outer part 128, the inner part 130 and the connecting parts 132, 134 can be integrally formed, in particular in a materially integrally formed manner. Here, "one-piece" or "integrally formed" particularly means that the outer part 128, the inner part 130 and the connecting parts 132, 134 form a common part, specifically the mirror mount 112A, and are not assembled from different sub-parts. In this case, "materially integrally formed" means that the outer part 128, the inner part 130 and the connecting parts 132, 134 are all made of the same material.

[0156] The connecting parts 132, 134 extend along the y-direction y. Therefore, the mirror mount 112A as observed in the y-direction y has greater rigidity than the mirror mount 112A as observed in the x-direction x. In this case, "rigidity" should be understood to mean the resistance of the body (specifically the mirror mount 112A) to elastic deformation imposed thereon by an external load, and conveys the relationship between the load on the body and its deformation. Rigidity is determined by the material in the body and its geometry. Therefore, the rigidity of the mirror mount 112A can be affected by changing the geometry of the connecting parts 132, 134.

[0157] In this case, the force flow is transmitted from the inner part 130 to the outer part 128 via the connecting parts 132, 134, or vice versa, where the deformation of the connecting parts 132, 134 determines the rigidity. In this case, the force is preferably introduced at the inner part 130, where the outer part 128 is connected to the optical element 102. Conversely, in this case, the force can also be introduced at the outer part 128, where the inner part 130 is connected to the optical element 102.

[0158] The inner part 130 has a circular perforation 136, for example in the form of a circular drill hole. The inner part 130 can have an interface with the surrounding environment, for example in the form of the perforation 136. The perforation 136 can be annular. However, a threaded drill hole, an adhesive joint, etc. can also serve as the interface. A gap 138 is provided between the outer part 128 and the inner part 130. The connecting components 132, 134 pass through the gap 138, so the connecting components 132, 134 bridge the gap 138.

[0159] As Figure 5 shown, the connecting components 132, 134 have a cross-sectional area 140 depicted by hatching, which preferably has a rectangular geometry. The cross-sectional area 140 can be rectangular and includes a connecting component height h extending in the z-direction z and a connecting component width b extending in the x-direction x. The connecting component height h is greater than the connecting component width b. The rigidity of the connecting components 132, 134 can be modified by changing the ratio of the connecting component height h to the connecting component width b. In principle, the cross-sectional area 140 can have any desired geometry. For example, the cross-sectional area 140 can also be square, trapezoidal, circular, triangular, cross-shaped, etc.

[0160] Each of the connecting components 132, 134 has a top side 142, a bottom side 144 remote from the top side 142, and two side faces 146, 148. The connecting components 132, 134 can be elastically deformed, especially elastically recoverable deformed. That is to say, the connecting components 132, 134 can be reversibly deformed. In this case, "elastic recovery" means that the connecting components 132, 134 can be deformed from a non-deformed state into a deformed state by applying a force or a moment. Once the force or moment no longer acts, the connecting components 132, 134 will automatically return from the deformed state to the non-deformed state.

[0161] The mirror mount 112A has its minimum rigidity when viewed in the x-direction x and its maximum rigidity when viewed in the z-direction z. The rigidity when viewed in the z-direction z is greater than the rigidity when viewed in the x-direction x and greater than the rigidity when viewed in the y-direction y. Since the mirror mount 112A is more flexible when viewed in the x-direction x than when viewed in the y-direction y, a better mechanical separation between the optical element 102 and the support structure 124 can be obtained.

[0162] Figure 6 A schematic perspective view of another embodiment of the mirror mount 112B is shown. Figure 7 A schematic rear view of the mirror mount 112B is shown. The following is described with joint reference Figure 6 and Figure 7 hereinafter.

[0163] In terms of its structure, the mirror mount 112B corresponds to the mirror mount 112A. The mirror mount 112B includes an outer member 128 and an inner member 130, which are constructed in a rotationally symmetric manner with respect to the central axis 126. The outer member 128 has a front side 150 facing away from the optical element 102 and a rear side 152 facing the optical element 102.

[0164] The rear side 152 is integrally joined to the optical element 102, in particular adhesively bonded thereto. The integral joining connection is a connection in which the connecting mating parts are joined together by atomic or molecular forces. At the same time, it is a non-releasable connection and can only be separated by destroying the connecting means and / or the connecting mating parts.

[0165] A plurality of adhesive pads or adhesive areas 154 are provided on the rear side 152, but only one of them has a reference numeral in Figure 7 . The adhesive areas 154 are configured to be evenly distributed around the central axis 126. The adhesive areas 154 and the non-adhesive areas 156 are alternately arranged. That is, one area 156 is arranged between two adhesive areas 154 and vice versa. When observed in the z-direction z, the area 156 is recessed backward with respect to the adhesive areas 154. An adhesive (not shown), such as epoxy resin or cyanoacrylate, is provided on the adhesive areas 154.

[0166] The inner member 130 is connected to the outer member 128 by means of connecting members 132, 134. The connecting members 132, 134 extend along the y-direction y. When observed in the x-direction x, the inner member 130 is disposed between the two connecting members 132, 134. The inner member 130 is connected to the connecting members 132, 134 by means of ridge joints 158, 160.

[0167] Each of the connecting members 132, 134 has a plurality of flexure portions 162, and only one flexure portion has a reference numeral in Figure 6 and Figure 7 . In this case, a "flexure portion" is generally understood as an area of a component, such as a narrowed or thinned cross-section, which is capable of relative movement between two rigid body areas of the component by bending or twisting. Specifically, the flexure portions 162 are formed as notches that are rounded on both sides and attached to the connecting members 132, 134. The joints 158, 160 are disposed between the two flexure portions 162. The connecting members 132, 134 themselves also act as flexures between the outer member 128 and the inner member 130.

[0168] To align the mirror mount 112B, the latter has a groove 164 provided on the outer part 128. The inner part 130 has a front side 166 oriented parallel to the front side 150 and a rear side 168 oriented parallel to the rear side 152. A chamfer 170 facing the perforation 136 is provided on the front side 166.

[0169] Figure 8 Fig. shows a schematic perspective view of another embodiment of the mirror mount 112C. Figure 9 Fig. shows a schematic rear view of the mirror mount 112C. The following is described with common reference Figure 8 and Figure 9 hereinafter.

[0170] In terms of its structure, the mirror mount 112C corresponds to the mirror mount 112A. The mirror mount 112C includes an outer part 128 and an inner part 130, which are constructed in a rotationally symmetric manner with respect to the central axis 126. The outer part 128 has a front side 150 facing away from the optical element 102 and a rear side 152 facing the optical element 102.

[0171] The rear side 152 is integrally joined to the optical element 102, in particular adhesively bonded thereto. A plurality of adhesive pads or adhesive areas 154 are provided on the rear side 152, but Figure 9 only one of them has a reference numeral. The adhesive areas 154 are configured to be evenly distributed around the central axis 126. The adhesive areas 154 alternate with non-adhesive areas 156. That is, one area 156 is arranged between two adhesive areas 154, and vice versa. As shown in the z-direction z, the area 156 is recessed backward with respect to the adhesive area 154.

[0172] The inner part 130 is connected to the outer part 128 by means of connecting members 132, 134. The connecting members 132, 134 extend along the y-direction y. When viewed in the x-direction x, the inner part 130 is disposed between the two connecting members 132, 134. The inner part 130 is connected to the connecting members 132, 134 by means of ridge-shaped joints 158, 160.

[0173] The connecting members 132, 134 are cut and separated from the outer part 128 by means of grooves 172, 174. Drilled holes 176 are provided at the ends of the grooves 172, 174, and Figure 8 and Figure 9 only one of the drilled holes has a reference numeral. Each groove 172, 174 is assigned two drilled holes 176. The cutting lines for wire erosion of the grooves 172, 174 can be guided through the drilled holes 176.

[0174] The mirror mount 112C has a groove 164 provided on the outer member 128. In this case, the groove 164 is used to reduce the rigidity of the connecting member. The inner member 130 has a front side 166 oriented parallel to the front side 150 and a rear side 168 oriented parallel to the rear side 152. A chamfer 170 facing the perforation 136 is provided on the front side 166. When viewed along the z-direction z, the front side 166 has been placed rearward relative to the front side 150.

[0175] Figure 10 A schematic perspective view of another embodiment of the mirror mount 112D is shown. Figure 11 A schematic rear view of the mirror mount 112D is shown. The following is described with joint reference Figure 10 and Figure 11 hereinafter.

[0176] In terms of its structure, the mirror mount 112D corresponds to the mirror mount 112C. The mirror mount 112D differs from the mirror mount 112C only in that the connecting members 132, 134 do not linearly extend in the y-direction y, but have an arcuate geometry, in particular a circular arc geometry. Accordingly, the grooves 172, 174 also have an arcuate curvature, in particular a circular arc curvature.

[0177] Figure 12 A schematic perspective view of another embodiment of the mirror mount 112E is shown. Figure 13 A schematic rear view of the mirror mount 112E is shown. The following is described with joint reference Figure 12 and Figure 13 hereinafter.

[0178] In terms of its structure, the mirror mount 112E corresponds to the mirror mount 112C. The mirror mount 112E differs from the mirror mount 112C only in that the grooves 172, 174 do not have two drilled holes 176 at their ends, but each have a central drilled hole 178. In addition, a groove 180 is provided on the inner member 130.

[0179] The inner member 130 is centrally fastened to the connecting members 132, 134, and the connecting members 132, 134 merge into the outer member 128 at the ends of the connecting members. On the connection lines perpendicular to the connecting members 132, 134 at the joint points 158, 160, the inner member 130 is flexibly joined to the connecting members 132, 134 through the joint points 158, 160. The appropriate selection of the rotational orientation of the mirror mount 112E on the optical element 102 depends on the separation effect and dynamic performance to be obtained.

[0180] Figure 14 A schematic perspective view of another embodiment of the mirror mount 112F is shown. Figure 15 A schematic rear view of the mirror mount 112F is shown. The following is described with joint reference Figure 14 andFigure 15 is described.

[0181] In terms of its structure, the mirror mount 112F corresponds to the mirror mount 112A. The mirror mount 112F includes an outer part 128 and an inner part 130, which are constructed in a rotationally symmetric manner with respect to the central axis 126. The outer part 128 has a front side 150 facing away from the optical element 102 and a rear side 152 facing the optical element 102. The rear side 152 is integrally joined to the optical element 102, in particular adhesively bonded thereto.

[0182] A plurality of adhesive pads or adhesive regions 154 are provided on the rear side 152, but Figure 15 only one of them has a reference numeral. The adhesive regions 154 are configured to be evenly distributed around the central axis 126. The adhesive regions 154 alternate with non-adhesive regions 156. That is, one region 156 is arranged between two adhesive regions 154, and vice versa. As shown in the z-direction z, the region 156 is recessed backward with respect to the adhesive region 154.

[0183] The inner part 130 is connected to the outer part 128 by means of connecting parts 132, 134. The connecting parts 132, 134 extend along the y-direction y. Grooves 182 are provided on the outer part 128 on both sides of each connecting part 132, 134 in each case, but Figure 14 and Figure 15 only one of the grooves has a reference numeral. Starting from the gap 138, the grooves 182 extend radially into the outer part 128. For example, the grooves 182 have been manufactured by means of wire erosion method.

[0184] In order to align the mirror mount 112F, the latter has a groove 180 provided on the inner part 130. The inner part 130 has a front side 166 oriented parallel to the front side 150 and a rear side 168 oriented parallel to the rear side 152. A chamfer 170 facing the perforation 136 is provided on the front side 166.

[0185] The inner part 130 is suspended on the outer part 128 by means of two straight connecting parts 132, 134 extending along the y-direction y. The mirror mount 112F has a mirror-symmetric structure and is relatively flexibly joined in the x-direction x. The desired absolute rigidity level can be set by the respective connecting part lengths of the connecting parts 132, 134.

[0186] For the most flexible connection possible in the x-direction x, the connecting parts 132, 134 have been wire-eroded into the edge region of the outer part 128 by means of the grooves 182. The connecting parts 132, 134 are additionally reinforced in the inner region, in particular at the inner part 130, thereby achieving high axial rigidity in the z-direction z.

[0187] Figure 16 A schematic perspective view showing another embodiment of the mirror mount 112G. Figure 17 A schematic rear view of the mirror mount 112G is shown. The following is a combined reference Figure 16 and Figure 17 for description.

[0188] In terms of its structure, the mirror mount 112G corresponds to the mirror mount 112E. The difference between the mirror mount 112G and the mirror mount 112E is that the gap 138 between the internal member 130 and the external member 128 is not rectangular but cylindrical. This shape of the mirror mount 112G is because the gap 138 is laterally bounded by the straight connecting members 132, 134. Compared with the mirror mount 112E, longer connecting members 132, 134 incorporated into the external member 128 are provided in the mirror mount 112G. When using a non-magnetic material (such as molybdenum) with a higher Young's modulus, this can achieve a rigid behavior equivalent to that of the mirror mount 112E.

[0189] In the case of the mirror mount 112G, the internal member 130 is suspended on two connecting members 132, 134, and the two connecting members 132, 134 are fixed on both sides by means of the joining points 158, 160. The configuration of the connecting members 132, 134 is mirror-symmetrical and relatively flexible in the x-direction x. The desired absolute rigidity level can be set by the connecting member length of the connecting members 132, 134. Through the aspect ratio of the cross-sectional area 140 of the connecting members 132, 134, a high ratio of rigidity in the z-direction z to rigidity in the x-direction x is set purposefully.

[0190] Joining the internal member 130 to the connecting members 132, 134 in the x-direction x results in a small inclination of the joining points 158, 160 under the load in the x-direction x, and thus results in a small induced moment about the y-direction y. The cutting lines for manufacturing the grooves 172, 174 and thus the connecting members 132, 134 can introduce holes 178 through the central region of the connecting members 132, 134.

[0191] Figure 18 A schematic perspective view showing another embodiment of the mirror mount 112H. Figure 19 A schematic rear view of the mirror mount 112H is shown. The following is a combined reference Figure 18 and Figure 19 for description.

[0192] In terms of its structure, the mirror mount 112H corresponds to the mirror mount 112E. Compared with the mirror mount 112E, the mirror mount 112H includes two connecting members 132, 134, and each connecting member 132, 134 includes two connecting member portions 184, 186 that extend parallel to each other. A groove 188 is provided between the connecting member portions 184, 186. A first connecting member portion 184 and a second connecting member portion 186 are provided. The connecting member portions 184, 186 are connected to each other at the deflection portions 190, 192, so that the connecting member portions 184, 186 and the deflection portions 190, 192 form a circumferentially closed geometry.

[0193] The connecting members 132, 134 are connected to the internal member 130 by means of the joint points 158, 160 and are connected to the external member 128 by means of the joint points 194, 196. Due to the closed annular shape of the connecting members 132, 134, a large connecting member length and low rigidity in the lateral direction can be achieved. However, the range of the straight connecting member shape can be defined by the external member 128.

[0194] Figure 20 A schematic perspective view of another embodiment of the mirror mount 112I is shown. Figure 21 A schematic rear view of the mirror mount 112I is shown. The following is described with common reference Figure 20 and Figure 21 as follows.

[0195] In terms of its structure, the mirror mount 112I corresponds to the mirror mount 112H. The mirror mount 112I differs from the mirror mount 112H only in that the connecting members 132, 134 do not extend linearly in the y-direction y, but have an arcuate geometry, especially a circular arc geometry. Therefore, the connecting member portions 184, 186 also have an arcuate curvature, especially a circular arc curvature.

[0196] The advantage of the arcuate connecting members 132, 134 is that a longer connecting member length can be achieved without colliding with the external member 128. However, the curvature of the connecting members 132, 134 also has an impact on the rigidity behavior. As a result, for the same connecting member length, a higher rigidity in the x-direction x is obtained than in the case of the mirror mount 112H according to Figure 18 and Figure 19

[0197] Figure 22 A schematic perspective view of another embodiment of the mirror mount 112J is shown. Figure 23 A schematic rear view of the mirror mount 112J is shown. The following is described with common reference Figure 22 and Figure 23 as follows.

[0198] In terms of its structure, the mirror mount 112J corresponds to the mirror mount 112E. In contrast to the mirror mount 112E, the mirror mount 112J has two arcuate, in particular circular-arc-shaped, curved connecting members 132, 134, and the curved connecting members 132, 134 together form a closed annular connecting member 198 that completely surrounds the inner member 130. The annular connecting member 198 is joined to the inner member 130 via two joining points 158, 160. The annular connecting member 198 is also joined to the outer member 128 via two joining points 194, 196. The joining points 158, 160 and the joining points 194, 196 are arranged offset from each other by 90°. Grooves 200, 202 are provided between the inner member 130 and the annular connecting member 198.

[0199] In Figure 23 orientation, the annular connecting member 198 is joined to the outer member 128 from the top and bottom by means of the joining points 194, 196. In Figure 23 orientation, the inner member 130 is joined to the annular connecting member 198 on the right and left. The joining is relatively rigid in the transverse direction compared to the axial z-direction z.

[0200] Figure 24 Fig. shows a schematic perspective view of another embodiment of the mirror mount 112K. Figure 25 Fig. shows a schematic rear view of the mirror mount 112K. The following will be described with reference to Figure 24 and Figure 25 together.

[0201] In terms of its structure, the mirror mount 112K corresponds to the mirror mount 112J. Compared to the mirror mount 112J, the annular connecting member 198 formed by the connecting members 132, 134 of the mirror mount 112K is not closed but open. The annular connecting member 198 is connected to the inner member 130 by means of the joining point 158 and is connected to the outer member 128 by means of two joining points 194, 196. Since the annular connecting member 198 is not closed but open, the rigidity at the joint has a high degree of flexibility.

[0202] Figure 26 Fig. shows a schematic perspective view of another embodiment of the mirror mount 112L. Figure 27 Fig. shows a schematic rear view of the mirror mount 112L. The following will be described with reference to Figure 26 and Figure 27 together.

[0203] In terms of its structure, the mirror mount 112L substantially corresponds to the structure of the mirror mount 112F. In the case of the mirror mount 112L, as shown in the x-direction x, the connecting members 132, 134 are arranged spaced apart from each other, so that the internal member 130 is asymmetrically suspended on the external member 128. The internal member 130 is connected to the external member 128 on one side by means of the connecting members 132, 134.

[0204] Figure 28 Fig. shows a schematic perspective view of another embodiment of the mirror mount 112M. Figure 29 Fig. shows a schematic rear view of the mirror mount 112M. The following is a combined reference Figure 28 and Figure 29 for description.

[0205] In terms of its structure, the mirror mount 112M corresponds to the structure of the mirror mount 112L. Compared with the mirror mount 112L, the connecting members 132, 134 of the mirror mount 112M are not straight, but arc-shapedly extend around the internal member 130, especially in a circular arc shape. The stoppers 204, 206 for the internal member 130 extend into the gap 138 in the direction of the internal member 130, and the stoppers 204, 206 are provided on the external member 128.

[0206] Therefore, the mirror mount 112M has a point-symmetric connecting member design with the connecting members 132, 134 fixed on one side. The connecting members 132, 134 are circularly guided around the internal member 130 and are realized by using a long connecting member length in the limited installation space between the internal member 130 and the external member 128. The basic rigidity can be adjusted within a wide range by changing the connecting member length.

[0207] Figure 30 Fig. shows a schematic perspective view of another embodiment of the mirror mount 112N. Figure 31 Fig. shows a schematic rear view of the mirror mount 112N. The following is a combined reference Figure 30 and Figure 31 for description.

[0208] In terms of its structure, the mirror mount 112N corresponds to the structure of the mirror mount 112M. Compared with the mirror mount 112M, additional leaf springs 208, 210 are provided in the mirror mount 112M. A first leaf spring 208 and a second leaf spring 210 are provided. The leaf springs 208, 210 extend from the stoppers 204, 206 and connect the external member 128 to the internal member 130 in addition to the bent connecting members 132, 134.

[0209] The leaf springs 208, 210 are folded. For example, each leaf spring 208, 210 has a first leaf spring portion 212 and a second leaf spring portion 214. The leaf spring portions 212, 214 are arranged perpendicular to each other. The folded leaf springs 208, 210 result in a high axial rigidity in the z-direction z, without significantly changing the lateral rigidity in the x-direction x and the y-direction y.

[0210] Figure 32 Schematic perspective view showing another embodiment of the mirror mount 112O. Figure 33 Schematic rear view showing the mirror mount 112O. The following is a common reference Figure 32 and Figure 33 for description.

[0211] In terms of its structure, the mirror mount 112O corresponds to the structure of the mirror mount 112E. Compared with the mirror mount 112E, the mirror mount 112O includes two connecting components 132, 134, and each connecting component includes a plurality of arc-shaped (especially circular arc-shaped) curved connecting component parts 216, 218, 220. By means of the grooves 222, 224, 226, 228, the connecting component parts 216, 218, 220 are cut from the outer member 128 and the inner member 130. The connecting component parts 216, 218, 220 are connected to each other by means of the deflection parts 230, 232.

[0212] The profiles of the connecting components 132, 134 from the inner member 130 to the outer member 128 are folded multiple times, thereby enabling a very long connecting component length to be obtained. The inner member 130 can be joined to the outer member 128 very flexibly. Due to the folded geometry, the connecting components 132, 134 have a zigzag or serpentine geometry.

[0213] All embodiments of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O can be made of non-magnetic or non-ferromagnetic materials or substances. Therefore, the parasitic forces and torques caused by relatively strong magnetic fields can be minimized. For example, molybdenum can be used. In the case of not using non-magnetic materials, invar, especially for example Invar, can be used.

[0214] The mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O can achieve direction-related decoupling of forces and torques. The mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O are adapted to mechanical properties, such as the high Young's modulus of the selected non-magnetic material molybdenum. This allows reducing the deformation (surface shape deformation, SFD) of the optically effective surface 106 on the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O caused by the magnetic effects of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O themselves or external influences, thus improving the imaging quality.

[0215] For example, due to the magnetostrictive effect, when using the mirror mounts 112A, 112B, 112H, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O in a relatively strong magnetic field, the redesigned mirror mounts 112A, 112B, 112H, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O made of non-magnetic material are used to reduce parasitic forces. The previously used invar material was replaced with molybdenum. As an important mechanical parameter, the Young's modulus of the new molybdenum material is approximately 2.3 times higher at E Mo = 320 GPa (E Invar = 1.37 GPa).

[0216] By adapting the geometry of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, especially the connecting parts 132, 134, the intention is to achieve the equivalent rigid behavior of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, so that the behavior regarding SFD and dynamics remains unchanged.

[0217] The mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O are implemented in a two-component construction. The outer part 128 and the inner part 130 are connected to each other by means of connecting components 132, 134. In this case, when viewed along the x-direction x, the inner part 130 is preferably flexibly joined to the outer part 128, thus achieving a decoupling effect and keeping the deformation of the optical element 102 as low as possible. For a good dynamic behavior of the optical element 102 with a high bandwidth, the joining along the axial z-direction z is as rigid as possible. The joining rigidity of the connecting components 132, 134 can be set purposefully by the shape and dimensions of the connecting components 132, 134.

[0218] The design of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O has manufacturing-related and installation-space-related boundary conditions, which need to correspond to determining the dimensions of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O. For example, the inner part 130 has an outer diameter of approximately 10 mm. The outer part 128 has an outer diameter of approximately 20 mm, for example.

[0219] The desired geometry of the connecting components 132, 134 can be manufactured by wire erosion on components machined previously by turning and milling. This results in requirements regarding the structural dimensions. Generally, a connecting component width b and a gap width of approximately 0.4 mm or larger can be manufactured. However, with suitable processes, smaller structures are also possible. The design of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O allows for features that enable simple production. One example is a drilled through-hole through which a cutting line can be inserted into the design.

[0220] The magnitude of the rigidity can be set by the respective connecting member lengths of the connecting members 132, 134 and / or the cross-sectional area 140. The aspect ratio of the connecting member height h to the connecting member width b determines the rigidity ratio c(z) / c(x). The target is a ratio c(z) / c(x) = 10 or more, and the rigidity in the axial direction is not less than c(z) = approximately 107 N / m. Therefore, it is preferable to use the cross-sectional area 140 with the maximum possible connecting member height h. The rigidity and stress can be optimized by changing the cross-sectional area 140 along the connecting member length. In this case, the configuration and shape of the connecting members 132, 134 affect the rigidity.

[0221] The purpose of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O is to provide a direction-dependent separation of the optical element 102 from the support structure 124 with a relatively rigid mount material, so that the optical element 102 is joined in an axially rigid and laterally flexible manner. This is achieved by means of the appropriate geometry of the connecting members 132, 134 between the internal member 130 and the external member 128.

[0222] Specifically, the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O differ in that the required rigidity characteristics can be achieved by adapting the geometry of the connecting members 132, 134 and also by using different materials with a high Young's modulus, molybdenum in this case. By changing the material to a non-magnetic material, the influence of magnetic forces and magnetostriction is minimized. A design with equivalent or better rigidity is obtained by adapting the geometry of the connecting members 132, 134.

[0223] Each embodiment of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O has connecting members 132, 134 located between the internal member 130 and the external member 128, and these have an aspect ratio of the connecting member height h to the connecting member width b sufficient to achieve the required rigidity ratio (lateral / axial) and the connecting member length for setting the absolute rigidity range. For example, this can be achieved by wire erosion. To reduce the magnetic effect, it is necessary to use non-magnetic materials.

[0224] Preferably, the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O have drilled holes 176, 178 or any type of perforations, etc., for supplying wires for wire erosion. In this case, the minimum clearance width or the width b of the connecting part for wire erosion needs to be considered.

[0225] By changing the cross-sectional area 140 of the connecting parts 132, 134 in the length of the connecting parts, the rigidity adjustment can be improved again. The installation space limitation can be circumvented and / or the adjustment of rigidity can be achieved through the geometric shape of the height-graded connecting parts. This results in a high ratio c(y) / c(x) of the lateral rigidity.

[0226] Any desired process (such as turning, milling, grinding, wire erosion, etc.) can be used to produce the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O. The ratio c(y) / c(x) of the lateral rigidity is not fixedly specified, but is preferably greater than 1 to obtain the decoupling of the desired SFD effect and sufficient dynamic behavior at the optical element 102.

[0227] Non-magnetic materials with different mechanical and thermal properties can be used in the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O. However, due to the optimized adjustment of the mirror mounts 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, there is no loss of system performance caused by SFD, thermal, and / or dynamic effects.

[0228] Although the present invention has been described based on exemplary embodiments, it can be modified in various ways.

[0229] List of reference numerals

[0230] 1 Projection exposure apparatus

[0231] 2 Illumination system

[0232] 3 Light source

[0233] 4 Illumination optical unit

[0234] 5 Object field

[0235] 6 Object plane

[0236] 7 Mask Master

[0237] 8 Mask Master Holder

[0238] 9 Mask Master Displacement Driver

[0239] 10 Projection Optical Unit

[0240] 11 Image Field

[0241] 12 Image Plane

[0242] 13 Wafer

[0243] 14 Wafer Holder

[0244] 15 Wafer Displacement Driver

[0245] 16 Illumination Radiation

[0246] 17 Condenser

[0247] 18 Intermediate Focal Plane

[0248] 19 Deflection Mirror

[0249] 20 First Facet Mirror

[0250] 21 First Facet

[0251] 22 Second Facet Mirror

[0252] 23 Second Facet

[0253] 100 Optical System

[0254] 102 Optical Element

[0255] 102’ Optical Element

[0256] 104 Substrate

[0257] 106 Optically Effective Surface

[0258] 106’ Optically Effective Surface

[0259] 108 Front Side

[0260] 110 Rear Side

[0261] 112 Mirror Mount

[0262] 112A Mirror Mount

[0263] 112B Mirror Mount

[0264] 112C Mirror Mount

[0265] 112D Mirror Mount

[0266] 112E Mirror Base

[0267] 112F Mirror Base

[0268] 112G Mirror Base

[0269] 112H Mirror Base

[0270] 112I Mirror Base

[0271] 112J Mirror Base

[0272] 112K Mirror Base

[0273] 112L Mirror Base

[0274] 112M Mirror Base

[0275] 112N Mirror Base

[0276] 112O Mirror Base

[0277] 114 Mirror Base

[0278] 116 Mirror Base

[0279] 118 Junction Point

[0280] 120 Junction Point

[0281] 122 Junction Point

[0282] 124 Support Structure

[0283] 126 Central Axis

[0284] 128 External Component

[0285] 130 Internal Component

[0286] 132 Connecting Component

[0287] 134 Connecting Component

[0288] 136 Opening

[0289] 138 Gap

[0290] 140 Section Area

[0291] 142 Top Side

[0292] 144 Bottom Side

[0293] 146 Side

[0294] 148 Side

[0295] 150 Front Side

[0296] 152 Rear Side

[0297] 154 bonding area

[0298] 156 area

[0299] 158 joint point

[0300] 160 joint point

[0301] 162 flexure

[0302] 164 groove

[0303] 166 front side

[0304] 168 rear side

[0305] 170 chamfer

[0306] 172 groove

[0307] 174 groove

[0308] 176 drill hole

[0309] 178 drill hole

[0310] 180 groove

[0311] 182 groove

[0312] 184 connecting part section

[0313] 186 connecting part section

[0314] 188 groove

[0315] 190 deflection part

[0316] 192 deflection part

[0317] 194 joint point

[0318] 196 joint point

[0319] 198 annular connecting part

[0320] 200 groove

[0321] 202 groove

[0322] 204 stop

[0323] 206 stop

[0324] 208 leaf spring

[0325] 210 leaf spring

[0326] 212 leaf spring section

[0327] 214 leaf spring section

[0328] 216 connecting component part

[0329] 218 connecting component part

[0330] 220 connecting component part

[0331] 222 groove

[0332] 224 groove

[0333] 226 groove

[0334] 228 groove

[0335] 230 deflection part

[0336] 232 deflection part

[0337] b connecting component width

[0338] E1 plane

[0339] E2 plane

[0340] G intersection line

[0341] h connecting component height

[0342] IL actual attitude

[0343] M1 mirror

[0344] M2 mirror

[0345] M3 mirror

[0346] M4 mirror

[0347] M5 mirror

[0348] M6 mirror

[0349] SL target attitude

[0350] xx - direction

[0351] yy - direction

[0352] zz - direction

Claims

1. A mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) for an optical element (102, 102'), comprising: a central axis (126); a first spatial direction (x) oriented perpendicular to the central axis (126); and a second spatial direction (y) oriented perpendicular to the central axis (126) and perpendicular to the first spatial direction (x), wherein the mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) has a first rigidity when observed in the first spatial direction (x) and a second rigidity when observed in the second spatial direction (y), and wherein the first rigidity and the second rigidity have different magnitudes.

2. The mirror mount according to claim 1, further comprising an outer member (128), an inner member (130) disposed within the outer member (128), and an elastically deformable connecting member (132, 134), wherein the outer member is connected to the inner member (130) by means of the connecting member (132, 134).

3. The mirror mount according to claim 2, wherein the connecting member (132, 134) extends in the spatial direction (x, y), and when observed along the spatial direction (x, y), the mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) has a greater rigidity.

4. The mirror mount according to claim 2 or 3, wherein the inner member (130) is disposed between a first connecting member (132) and a second connecting member (134).

5. The mirror mount according to any one of claims 2 to 4, wherein the outer member (128), the inner member (130), and the connecting member (132, 134) are connected to each other in an integrally formed manner, in particular in a materially integrally formed manner.

6. The mirror mount according to any one of claims 2 to 5, wherein the connecting members (132, 134) extend parallel to and spaced apart from each other and / or wherein the connecting members (132, 134) have an arcuate, in particular circular arc-shaped curvature.

7. The mirror mount according to any one of claims 2 to 6, wherein each of the connecting members (132, 134) has a first connecting member portion (184) and a second connecting member portion (186), and wherein the first connecting member portion (184) and the second connecting member portion (186) are connected to each other by means of deflection portions (190, 192) such that the connecting members (132, 134) have a circumferentially closed geometry.

8. The mirror mount according to any one of claims 2 to 6, wherein the connecting members (132, 134) together form an annular connecting member (198) that extends at least partially around the inner member (130).

9. The mirror mount according to any one of claims 2 to 8, wherein the connecting members (132, 134) have a connecting member height (h) when viewed along the central axis (126), and wherein, Starting from the outer member (128), the height (h) of the connecting member varies in the direction of the inner member (130).

10. The mirror mount according to any one of claims 1 to 9, wherein the mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) includes drill holes (176, 178) through which a cutting line can be guided for manufacturing the mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116).

11. The mirror mount according to any one of claims 1 to 10, wherein the mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) is made of a non-magnetic material, in particular molybdenum.

12. An optical system (100) for a projection exposure apparatus (1), comprising: optical elements (102, 102'); a support structure (124) for supporting the optical elements (102, 102'); and at least one mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) according to any one of claims 1 to 11, wherein the optical elements (102, 102') are connected to the support structure (124) by means of the at least one mirror mount (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116).

13. The optical system according to claim 12 further includes three mirror mounts (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116), wherein the optical element (102, 102') has six degrees of freedom, and each of the mirror mounts (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) is precisely assigned two degrees of freedom.

14. The optical system according to claim 13, wherein each of the three mirror mounts (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) has a plane (E1) spanned by the central axis (126) and the spatial directions (x, y), and when observed along the spatial directions (x, y), the mirror mounts (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) have relatively low rigidity, and the three mirror mounts (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) are configured such that the planes (E1) intersect each other on a common intersection line (G).

15. A projection exposure apparatus (1) having the mirror mounts (112, 112A, 112B, 112C, 112D, 112E, 112F, 112G, 112H, 112I, 112J, 112K, 112L, 112M, 112N, 112O, 114, 116) according to any one of claims 1 to 11 and / or the optical system (100A, 100B) according to any one of claims 12 to 14.

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