WO2024017836A1

WO2024017836A1 - Optical system and projection exposure apparatus

Info

Publication number: WO2024017836A1
Application number: PCT/EP2023/069802
Authority: WO
Inventors: Eduard Schweigert
Original assignee: Carl Zeiss Smt Gmbh
Priority date: 2022-07-18
Filing date: 2023-07-17
Publication date: 2024-01-25
Also published as: DE102022207312A1

Abstract

The invention relates to an optical system (100) for a projection exposure apparatus (1), the optical system comprising a first component (102), a second component (104) and a compensation device (200, 300) which is arranged between the first component (102) and the second component (104), the compensation device (200, 300) comprising connecting portions (212, 214, 216, 218, 230, 232, 234, 236, 312, 314, 318, 320) which function as solid-body articulations and are elastically deformable in order to adapt the compensation device (200, 300) to a tilting of the second component (104) relative to the first component (102) about a first spatial direction (x) and/or about a second spatial direction (y) which differs from the first spatial direction (x), the compensation device (200, 300) comprising a fastening ring (202, 302) and an inner ring (204, 304) which surrounds the fastening ring (202, 302), the inner ring (204, 304) being connected to the fastening ring (202, 302) by means of inner connecting portions (212, 214, 216, 218, 312, 314), and the inner ring (204, 304) being tiltable relative to the fastening ring (202, 302) about a first tilting axis (228, 316) by means of an elastic deformation of the inner connecting portions (212, 214, 216, 218, 312, 314).

Description

OPTICAL SYSTEM AND PROJECTION EXPOSURE SYSTEM

The present invention relates to an optical system for a projection exposure system and a projection exposure system with such an optical system.

The content of the priority application DE 10 2022 207 312.6 is fully incorporated by reference (incorporation by reference).

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

Driven by the pursuit of ever smaller structures in the production of integrated circuits, EUV lithography systems are currently being developed which use light with a wavelength in the range from 0.1 nm to 30 nm, in particular 13.5 nm. In such EUV lithography systems, because of the high absorption of light of this wavelength by most materials, reflecting optics, i.e. mirrors, must be used instead of - as before - refracting optics, i.e. lenses.

When mounting such mirrors on another component, such as a sensor frame, it may be necessary to position the mirror in relation to this component or generally in space adjust or align. The mirror can be adjusted with the help of spacers or so-called spacers, which are placed at connection points provided between the mirror and the component. The mirror and the component are then firmly connected to one another, in particular screwed together.

Since spacers of different thicknesses can be used to adjust the mirror at the different connection points, this can lead to undesirable stresses being introduced into the mirror. In order to prevent stresses from being introduced into the mirror, spherical cap-shaped compensating elements can be used between the mirror and the component, which can compensate for an angular error between the mirror and the component. However, since such compensating elements are subject to friction, undesirable stresses can still be introduced into the mirror when the mirror and the component are firmly connected. This needs to be improved.

Against this background, an object of the present invention is to provide an improved optical system for a projection exposure system.

Accordingly, an optical system for a projection exposure system is proposed. The optical system comprises a first component, a second component and a compensating device which is arranged between the first component and the second component, the compensating device having webs which act as solid-state joints and which are elastically deformable in order to adapt the compensating device to a tilting of the second Component relative to the first component to adapt to a first spatial direction and / or to a second spatial direction that differs from the first spatial direction. The compensation device has a fastening ring and a inner ring encircling the fastening ring, wherein the inner ring is connected to the fastening ring with the aid of inner webs, and wherein the inner ring can be tilted about a first tilting axis relative to the fastening ring with the aid of an elastic deformation of the inner webs.

Because the compensating device is arranged between the first component and the second component, it is possible to use the compensating device to compensate for the tilting of the second component relative to the first component, so that when the first component and the second component are firmly connected, no or at least reduced stresses are introduced into the first component and/or the second component.

The optical system can be a projection optics or part of a projection optics of the projection exposure system. However, the optical system can also be an illumination optics of the projection exposure system. The optical system can have a variety of such compensation devices. The optical system may further include any number of components as previously mentioned. The first component can also be referred to as the first component. The second component can therefore also be referred to as the second component. The terms “component” and “component” can therefore be used interchangeably in this case.

The first component can be, for example, a so-called support frame (EnglJ Force Frame) or a sensor frame (EnglJ Sensor Frame) or the like. The second component can be an optical element, for example a mirror or a lens. Preferably the second component is a mirror. The second component has an optically effective surface that is suitable for reflecting illumination radiation, in particular EUV radiation. The optically effective surface is a mirror surface. The optically effective surface can be realized, for example, with the help of a coating.

The second component has a back side facing away from the optically effective surface. The back faces a front side of the first component. The compensation device is arranged between the front of the first component and the back of the second component. The compensation device contacts both the front of the first component and the back of the second component.

Preferably, the first component is firmly connected to the second component. For example, the first component is screwed to the second component. In the event that the second component is a mirror, it can have several connection points, in particular so-called mirror sockets, at which the second component is connected to the first component. For example, three such connection points are provided. These connection points can be arranged in a triangular shape.

The optical system is assigned a coordinate system with a first spatial direction or x-direction, a second spatial direction or y-direction and a third spatial direction or z-direction. The directions are oriented perpendicular to each other. The second component or the optically effective surface of the second component has six degrees of freedom, namely three translational degrees of freedom each along the first spatial direction, the second spatial direction and the third spatial direction and three rotational degrees of freedom each about the first spatial direction, the second spatial direction and the third spatial direction . This means that a position and an orientation of the second component or the optically effective surface can be determined or described using the six degrees of freedom. The “position” of the second component or the optically effective surface is to be understood in particular as meaning its coordinates or the coordinates of a measuring point provided on the second component with respect to the first spatial direction, the second spatial direction and the third spatial direction. The “orientation” of the second component or the optically effective surface is to be understood in particular as meaning its tilting with respect to the three spatial directions. This means that the second component or the optically effective surface can be tilted about the first spatial direction, the second spatial direction and/or the third spatial direction. In the present case, “tilting” is understood to mean, in particular, a rotational movement about the respective spatial direction.

This results in the six degrees of freedom for the position and orientation of the second component or the optically effective surface. A “position” of the second component or the optically effective surface includes both its position and its orientation. The term “location” can therefore be replaced by the phrase “position and orientation” and vice versa.

For example, when mounting the second component on the first component, it may be necessary to adjust or align the second component with respect to the first component or generally in space. In the present case, “adjustment” or “alignment” is understood to mean, in particular, changing the position of the second component with respect to the first component. For example, the second component can be moved from an actual position to a target position or vice versa during adjustment.

When adjusting the second component, it is tilted relative to the first component by at least the first spatial direction or by at least the second spatial direction. In particular, the second component can also be both can be tilted around the first spatial direction as well as around the second spatial direction. Due to the webs acting as solid-state joints, the compensating device can adapt to this tilting of the second component relative to the first component in such a way that, even when the second component is tilted with respect to the first component, the compensating device is always both flat on the first component and on the second component is present.

The compensation device is adjusted purely by deforming the webs. These undergo, for example, a bend or a torsion in order to adapt or adjust the compensating device to the tilting of the second component. With the help of the compensation device, a tilt angle or an angular error of the second component relative to the first component in the first spatial direction and/or in the second spatial direction can be compensated for. The compensation device is therefore suitable for compensating for the angular error between the second component and the first component.

The fact that the compensating device “adapts” to the tilting of the second component relative to the first component about the first spatial direction and/or about the second spatial direction is therefore to be understood in particular as meaning that the compensating device applied to the two components deforms in accordance with the tilting in order to compensate for the angular error without introducing stresses into the first component and/or into the second component. The compensating device thus “follows” the tilting of the first component by deforming the compensating device.

In the present case, a “solid body joint” is generally understood to mean an area, for example a cross-sectional narrowing or thinning, of a component, in this case the compensating device, which enables a relative movement between two rigid body areas of the component by bending or torsion. By adjusting the stiffness of the webs, the compensation device can be adapted to any application. In this case, “stiffness” is generally understood to mean the resistance of a body, in this case the webs, against an elastic deformation imposed by external load and conveys the connection between the load on the body and its deformation. The stiffness is determined by the material of the body and its geometry. For example, the stiffness of the webs can be adjusted as desired using different cross-sectional geometries.

When the second component is tilted relative to the first component, the webs are deformed elastically, in particular resiliently. “Elastic” means that the deformation of the webs is reversible. The webs are deformed from an initial state into a deformation state in particular by applying a force or a moment. If this force or moment no longer acts on the respective web, it deforms independently or automatically from the deformation state back to the initial state. The webs thus function as spring elements, in particular as leaf spring elements, and can therefore also be referred to as such. In the present case, a “web” is to be understood as meaning a thin-walled region of the compensating device, which has a smaller wall thickness compared to other areas of the compensating device and is therefore elastically deformable in the manner of a solid-state joint.

The compensating device has a fastening ring and an inner ring running around the fastening ring, the inner ring being connected to the fastening ring with the aid of inner webs, and the inner ring being tiltable about a first tilting axis relative to the fastening ring with the aid of an elastic deformation of the inner webs. The balancing device is preferably assigned a radial direction. The radial direction is oriented perpendicular to a central or symmetry axis, with respect to which the compensation device is constructed essentially rotationally symmetrical. The radial direction is perpendicular to the axis of symmetry and oriented away from it. Viewed along the radial direction, the fastening ring rests within the inner ring. The inner webs are part of the previously mentioned webs. The first tilt axis coincides with the first spatial direction or with the second spatial direction.

According to a further embodiment, the compensating device has an outer ring running around the inner ring, the outer ring being connected to the inner ring with the aid of outer webs, and the outer ring being tiltable about a second tilting axis relative to the inner ring with the aid of an elastic deformation of the outer webs .

Viewed along the radial direction, the inner ring is placed inside the outer ring. The outer webs are part of the previously mentioned webs. The second tilt axis can coincide with the first spatial direction or with the second spatial direction. In the event that the first tilt axis coincides with the first spatial direction, the second tilt axis coincides with the second spatial direction. The fastening ring, the inner ring, the outer ring and the webs together form the compensation device. In particular, the compensation device is a gimbal solid joint and can therefore also be referred to as such.

According to a further embodiment, the second tilt axis is oriented perpendicular to the first tilt axis.

In the present case, “vertical” means in particular an angle of 90° ± 10°, preferably of 90° ± 5°, more preferably of 90° ± 3°, more preferably of 90° ± 1°, more preferably exactly 90°. The first tilt axis and the second tilt axis are arranged perpendicular to the axis of symmetry and intersect it.

According to a further embodiment, the outer webs are positioned perpendicular to the inner webs.

Viewed along the radial direction, the outer webs are positioned further away from the axis of symmetry than the inner webs. The outer webs are arranged offset relative to the inner webs. In particular, the outer webs are positioned 90° offset from the inner webs.

According to a further embodiment, the compensating device only rests on one of the two components with the aid of the fastening ring, with the compensating device only resting on the other of the two components with the aid of the outer ring.

For example, the fastening ring can rest on the back of the second component. However, the mounting ring does not rest on the front of the first component. The outer ring, on the other hand, rests on the front of the first component, but not on the back of the second component. The inner ring preferably lies neither on the front of the first component nor on the back of the second component. A height of the compensation device along the axis of symmetry or along the third spatial direction can be controlled by the rigidity of the webs. The webs are designed in particular in such a way that, for example, at a maximum predetermined contact pressure of the second component on the compensating device, they do not deform in such a way that the fastening ring and/or the inner ring come into contact with the front of the first component. According to a further embodiment, a first gap is provided between the inner ring and the fastening ring, with a second gap being provided between the outer ring and the inner ring.

The spaces are in particular air gaps and can therefore also be referred to as such. The first gap provided between the inner ring and the fastening ring runs around the fastening ring and is only interrupted by the inner webs. The inner webs thus bridge the first gap provided between the inner ring and the fastening ring. The same applies to the second gap provided between the inner ring and the outer ring. This second space runs around the inner ring and is only interrupted by the outer webs. The outer webs thus bridge the second gap provided between the outer ring and the inner ring.

According to a further embodiment, the fastening ring has a spherical cap-shaped contact surface, wherein the inner ring has a spherical cap-shaped counter-contact surface corresponding to the contact surface of the fastening ring, and wherein the contact surface of the fastening ring rests on the counter-contact surface of the inner ring.

Preferably, the contact surface of the fastening ring only touches the counter-contact surface of the inner ring when the second component is firmly connected to the first component. Before a predetermined force is applied to the compensating device, a gap, in particular an air gap, is provided between the contact surface of the fastening ring and the counter-contact surface of the inner ring, which disappears when the force is applied to the compensating device, so that the contact surface of the fastening ring is on the counter-contact surface of the inner ring lies flat. A “spherical cap” is primarily understood to mean a section of a sphere. According to a further embodiment, the inner ring has a spherical cap-shaped contact surface, wherein the outer ring has a spherical cap-shaped counter-contact surface corresponding to the contact surface of the inner ring, and wherein the contact surface of the inner ring rests on the counter-contact surface of the outer ring.

Here too, the contact surface of the inner ring only comes into contact with the counter-contact surface of the outer ring when a sufficiently large force is applied to the compensating device along the third spatial direction or along the axis of symmetry. As soon as this force is applied, the contact surface of the inner ring is pressed against the mating contact surface of the outer ring.

According to a further embodiment, the webs each have a cross-shaped cross-sectional geometry.

The cross-sectional geometry of the webs can basically be chosen arbitrarily. For example, different webs can also have different cross-sectional geometries. For example, the cross-section of the webs has a rectangular geometry, a circular geometry, a tubular geometry, a T-shaped geometry or any other geometry. By choosing a suitable cross-sectional geometry, the stiffness of the webs can be influenced over a wide range.

According to a further embodiment, the second component has a plurality of attachment points at which the second component is connected to the first component, with each attachment point being assigned a compensating device. Preferably exactly three attachment points are provided. The attachment points can be mirror sockets provided on the rear of the second component. A compensating device is assigned to each of these attachment points. The attachment points can also be referred to as mirror sockets. The attachment points can be on corners of an imaginary triangle.

According to a further embodiment, two webs together form a pair of webs, with a gap being provided between the webs of a pair of webs.

For example, two pairs of webs offset by 180° are provided between the fastening ring and the inner ring. Accordingly, two pairs of webs offset by 180° are also provided between the inner ring and the outer ring. The bar pairs are not absolutely necessary. Exactly two webs offset by 180° can also be provided between the fastening ring and the inner ring. Accordingly, exactly two webs offset by 180° can also be provided between the inner ring and the outer ring.

According to a further embodiment, the optical system further has a fastening element for connecting the second component to the first component, the fastening element being passed through the compensation device.

The fastening element can be a screw. In particular, the fastening element is guided through the fastening ring. For this purpose, the fastening ring has a central opening through which the fastening element is passed. According to a further embodiment, the compensation device is a one-piece component, in particular a one-piece material component.

“One-piece” or “one-piece” means in particular that the compensating device is not composed of different sub-components, but rather that the fastening ring, the inner ring, the outer ring and the webs form a common component, namely the compensating device. “In one piece of material” in this case means in particular that the compensating device is made entirely of the same material. For example, the compensation device can be made of copper, aluminum, steel or the like. The compensation device can be manufactured using an additive or generative manufacturing process, in particular using a 3D printing process. Furthermore, the compensation device can also be produced using an erosion process.

Furthermore, a projection exposure system with such an optical system is proposed.

The projection exposure system can have several such optical systems. The optical system is preferably a projection optics of the projection exposure system. However, the optical system can also be a lighting system. The projection exposure system can be an EUV lithography system. EUV stands for “Extreme Ultraviolet” and describes a wavelength of the working light between 0.1 nm and 30 nm. The projection exposure system can also be a DUV lithography system. DUV stands for “Deep Ultraviolet” and describes a wavelength of work light between 30 nm and 250 nm.

In the present case, “on” is not necessarily to be understood as limiting it to exactly one element. Rather, several elements, such as two, three or more, can also be provided. Every other counting word used here is also should not be understood to mean that there is a limitation to exactly the number of elements mentioned. Rather, numerical deviations upwards and downwards are possible, unless otherwise stated.

The embodiments and features described for the optical system apply accordingly to the proposed projection exposure system and vice versa.

Further possible implementations of the invention also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

Further advantageous refinements and aspects of the invention are the subject of the subclaims and the exemplary embodiments of the invention described below. The invention is further explained in more detail using preferred embodiments with reference to the accompanying figures.

Fig. 1 shows a schematic meridional section of a projection exposure system for EUV projection lithography!

FIG. 2 shows a schematic view of an embodiment of an optical system for the projection exposure system according to FIG. 1;

Fig. 3 shows a schematic top view of the optical system according to Fig. 2;

Fig. 4 shows a schematic perspective view of an embodiment of a compensating device for the optical system according to Fig. 2; Fig. 5 shows a schematic top view of the compensation device according to Fig. 4;

6 shows schematic sectional views of different embodiments of a web for the compensation device according to FIG. 4;

Fig. 7 shows the detailed view VII according to Fig. 2;

8 shows a schematic top view of a further embodiment of a compensating device for the optical system according to FIG. 2;

Fig. 9 shows a schematic sectional view of the compensation device according to section line IX-IX of Fig. 8; and

Fig. 10 shows a further schematic sectional view of the compensation device according to the section line XX of Fig. 8.

In the figures, identical or functionally identical elements have been given the same reference numerals, unless otherwise stated. Furthermore, it should be noted that the representations in the figures are not necessarily to scale.

1 shows an embodiment of a projection exposure system 1 (lithography system), in particular an EUV lithography system. One embodiment of a lighting system 2 of the projection exposure system 1 has, in addition to a light or radiation source 3, lighting optics 4 for illuminating an object field 5 in an object plane 6. In an alternative embodiment, the light source 3 can also be provided as a module separate from the other lighting system 2. In this case, the lighting system 2 does not include the light source 3. A reticle 7 arranged in the object field 5 is exposed. The reticle 7 is held by a reticle holder 8. The reticle holder 8 can be displaced via a reticle displacement drive 9, in particular in a scanning direction.

A Cartesian coordinate system with an x-direction x, a y-direction y and a z-direction z is shown in FIG. 1 for explanation purposes. The x-direction x runs perpendicularly into the drawing plane. The y-direction y is horizontal and the z-direction z is vertical. The scanning direction in FIG. 1 runs along the y-direction y. The z direction z runs perpendicular to the object plane 6.

The projection exposure system 1 includes projection optics 10. The projection optics 10 is used to image the object field 5 into an image field 11 in an image plane 12. The image plane 12 runs parallel to the object plane 6. Alternatively, an angle other than 0 ° is also between the object plane 6 and the Image level 12 possible.

A structure on the reticle 7 is imaged on a light-sensitive layer of a wafer 13 arranged in the area of the image field 11 in the image plane 12. The wafer 13 is held by a wafer holder 14. The wafer holder 14 can be displaced in particular along the y-direction y via a wafer displacement drive 15. The displacement, on the one hand, of the reticle 7 via the reticle displacement drive 9 and, on the other hand, of the wafer 13 via the wafer displacement drive 15 can be carried out synchronously with one another.

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

The illumination radiation 16, which emanates from the light source 3, is focused by a collector 17. The collector 17 can be a collector with one or more ellipsoidal and/or hyperboloid reflection surfaces. The at least one reflection surface of the collector 17 can be in grazing incidence (EnglJ Grazing Incidence, Gl), i.e. with angles of incidence greater than 45°, or in normal incidence (EnglJ Normal Incidence, NI), i.e. with angles of incidence smaller than 45°, with the illumination radiation 16 are applied. The collector 17 can be structured and/or coated on the one hand to optimize its reflectivity for the useful radiation and on the other hand to suppress false light.

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

The lighting optics 4 comprises a deflection mirror 19 and, downstream of it in the beam path, a first facet mirror 20. The deflection mirror 19 can be a flat deflection mirror or alternatively a mirror with an effect that influences the bundle beyond the pure deflection effect. Alternatively or additionally, the deflection mirror 19 can be designed as a spectral filter which has a useful light wavelength Illuminating radiation 16 separates from false light of a different wavelength. If the first facet mirror 20 is arranged in a plane of the illumination optics 4, which is optically conjugate to the object plane 6 as a field plane, it is also referred to as a field facet mirror. The first facet mirror 20 includes a large number of individual first facets 21, which can also be referred to as field facets. Some of these first facets 21 are shown in FIG. 1 as just examples.

The first facets 21 can be designed as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or part-circular edge contour. The first facets 21 can be designed as flat facets or alternatively as convex or concave curved facets.

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

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

A second facet mirror 22 is located downstream of the first facet mirror 20 in the beam path of the illumination optics 4. If the second facet mirror 22 is arranged in a pupil plane of the illumination optics 4, it is also referred to as a pupil facet mirror. The second facet mirror 22 can also be arranged at a distance from a pupil plane of the lighting optics 4. In this case, the combination of the first facet mirror 20 and the second facet mirror 22 is also referred to as a specular reflector. Specular reflectors are known from US 2006/0132747 Al, EP 1 614

008 Bl and US 6,573,978.

The second facet mirror 22 comprises a plurality of second facets 23. In the case of a pupil facet mirror, the second facets 23 are also referred to as pupil facets.

The second facets 23 can also be macroscopic facets, which can have, for example, round, rectangular or even hexagonal edges, or alternatively they can be facets composed of micromirrors. In this regard, reference is also made to DE 10 2008 009 600 Al.

The second facets 23 can have flat or alternatively convex or concave curved reflection surfaces.

The lighting optics 4 thus forms a double faceted system. This basic principle is also known as the honeycomb condenser (EnglJ Fly's Eye Integrator).

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

With the help of the second facet mirror 22, the individual first facets 21 are imaged into the object field 5. The second facet mirror 22 is the last beam-forming mirror or actually the last mirror for the illumination radiation 16 in the beam path in front of the object field 5. In a further embodiment of the illumination optics 4, not shown, transmission optics can be arranged in the beam path between the second facet mirror 22 and the object field 5, which contributes in particular to the imaging of the first facets 21 into the object field 5. The transmission optics can have exactly one mirror, but alternatively also two or more mirrors, which are arranged one behind the other in the beam path of the lighting optics 4. The transmission optics can in particular comprise one or two mirrors for perpendicular incidence (Ni mirror, normal incidence mirror) and/or one or two mirrors for grazing incidence (Gl mirror, grazing incidence mirror).

1, the lighting optics 4 has exactly three mirrors after the collector 17, namely the deflection mirror 19, the first facet mirror 20 and the second facet mirror 22.

In a further embodiment of the lighting optics 4, the deflection mirror 19 can also be omitted, so that the lighting optics 4 can then have exactly two mirrors after the collector 17, namely the first facet mirror 20 and the second facet mirror 22.

The imaging of the first facets 21 into the object plane 6 by means of the second facets 23 or with the second facets 23 and a transmission optics is generally only an approximate image.

The projection optics 10 comprises a plurality of mirrors Mi, which are numbered consecutively according to their arrangement in the beam path of the projection exposure system 1.

In the example shown in FIG. 1, the projection optics 10 comprises six

Mirror Ml to M6. Alternatives with four, eight, ten, twelve or another

Number of mirrors Mi are also possible. The projection optics 10 is it is a doubly obscure optic. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 has an image-side numerical aperture that is larger than 0.5 and which can also be larger than 0.6 and, for example, 0.7 or can be 0.75.

Reflection surfaces of the mirrors Mi can be designed as free-form surfaces without an axis of rotational symmetry. Alternatively, the reflection surfaces of the mirrors Mi can be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflection surface shape. The mirrors Mi, like the mirrors of the lighting optics 4, can have highly reflective coatings for the lighting radiation 16. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

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

The projection optics 10 can in particular be anamorphic. In particular, it has different imaging scales ßx, ßy in the x and y directions x, y. The two imaging scales ßx, ßy of the projection optics 10 are preferably (ßx, ßy) = (+/- 0.25, +/- 0.125). A positive magnification ß means an image without image reversal. A negative sign for the image scale ß means an image with image reversal.

The projection optics 10 thus leads to a reduction in the ratio 4 in the x direction x, that is to say in the direction perpendicular to the scanning direction. The projection optics 10 leads to a reduction of 8D in the y direction y, that is to say in the scanning direction.

Other image scales are also possible. Image scales of the same sign and absolutely the same in the x and y directions x, y, for example with absolute values of 0.125 or 0.25, are also possible.

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

In each case one of the second facets 23 is assigned to exactly one of the first facets 21 to form an illumination channel for illuminating the object field 5. This can in particular result in lighting based on Köhler's principle. The far field is broken down into a large number of object fields 5 using the first facets 21. The first facets 21 generate a plurality of images of the intermediate focus on the second facets 23 assigned to them.

The first facets 21 are each imaged onto the reticle 7 by an assigned second facet 23, superimposed on one another, in order to illuminate the object field 5. The illumination of the object field 5 is in particular as homogeneous as possible. It preferably has a uniformity error of less than 2%. Field uniformity can be achieved by overlaying different lighting channels. By arranging the second facets 23, the illumination of the entrance pupil of the projection optics 10 can be geometrically defined. By selecting the illumination channels, in particular the subset of the second facets 23 that guide light, the intensity distribution in the entrance pupil of the projection optics 10 can be adjusted. This intensity distribution is also referred to as the lighting setting or lighting pupil filling.

A likewise preferred pupil uniformity in the area of defined illuminated sections of an illumination pupil of the illumination optics 4 can be achieved by redistributing the illumination channels.

Further aspects and details of the illumination of the object field 5 and in particular the entrance pupil of the projection optics 10 are described below.

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

The entrance pupil of the projection optics 10 cannot regularly be illuminated precisely with the second facet mirror 22. When imaging the projection optics 10, which images the center of the second facet mirror 22 telecentrically onto the wafer 13, the aperture rays often do not intersect at a single point. However, an area can be found in which the pairwise distance of the aperture beams becomes minimal. This surface represents the entrance pupil or a surface conjugate to it in local space. In particular, this surface shows a finite curvature.

It may be that the projection optics have 10 different positions of the entrance pupil for the tangential and sagittal beam paths. In this case, an imaging element, especially an optical one, should be used Component of the transmission optics, between the second facet mirror 22 and the reticle 7 are provided. With the help of this optical element, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

In the arrangement of the components of the illumination optics 4 shown in FIG. 1, the second facet mirror 22 is arranged in a surface conjugate to the entrance pupil of the projection optics 10. The first facet mirror 20 is tilted relative to the object plane 6. The first facet mirror 20 is arranged tilted to an arrangement plane that is defined by the deflection mirror 19. The first facet mirror 20 is arranged tilted to an arrangement plane that is defined by the second facet mirror 22.

2 shows a schematic view of an embodiment of an optical system 100 for the projection exposure system 1. FIG. 3 shows a schematic top view of the optical system 100. Reference will be made to FIGS. 2 and 3 simultaneously.

The optical system 100 can be a projection optics 10 as explained above or part of such a projection optics 10. Therefore, the optical system 100 can also be referred to as projection optics. However, the optical system 100 can also be a lighting system 2 as explained above or part of such a lighting system 2. Therefore, the optical system 100 can alternatively be referred to as a lighting system. However, it is assumed below that the optical system 100 is a projection optics 10 or part of such a projection optics 10. The optical system 100 is suitable for EUV lithography. However, the optical system 100 may also be suitable for DUV lithography. The optical system 100 includes a first component or a first component 102 and a second component or a second component 104 that differs from the first component 102. The first component 102 can be a sensor frame of the projection optics 10. The second component 104 can be an optical element, in particular a mirror or a mirror module. For example, the second component 104 is the mirror M5. However, the second component 104 can also be any other component of the projection optics 10. It is assumed below that the second component 104 is an optical element.

The first component 102 has a front side 106 that faces the second component 104. The second component 104 has an optically effective surface 108 which faces away from the front 106. The optically effective surface 108 is suitable for reflecting illumination radiation 16, in particular EUV radiation, during operation of the optical system 100. The optically effective surface 108 is a mirror surface. The optically effective surface 108 can be realized with the help of a coating.

Facing away from the optically effective surface 108, the second component 104 has a back side 110. The back 110 faces the front 106. The back 110 does not have any defined surface properties. This means in particular that the back 110 is not a mirror surface and therefore does not have any reflective properties.

The second component 104 or the optically effective surface 108 has six degrees of freedom, namely three translational degrees of freedom each along the first spatial direction or x-direction x, the second spatial direction or y-direction y and the third spatial direction or z-direction z as well as three rotational degrees of freedom each about the x-direction x, the y-direction y and the z-direction z. That is, a position and an orientation of the second Component 104 or the optically effective surface 108 can also be used

can be determined or described using the six degrees of freedom.

The “position” of the second component 104 or the optically effective surface 108 is to be understood in particular as meaning its coordinates or the coordinates of a measuring point provided on the second component 104 with respect to the x-direction x, the y-direction y and the z-direction z . The “orientation” of the second component 104 or the optically effective surface 108 is to be understood in particular as its tilting with respect to the three spatial directions x, y, z. This means that the second component 104 or the optically effective surface 108 can be tilted about the x-direction x, the y-direction y and/or the z-direction z.

This results in the six degrees of freedom for the position and orientation of the second component 104 or the optically effective surface 108. A "position" of the second component 104 or the optically effective surface 108 includes both its position and its orientation. The term “location” can therefore be replaced by the phrase “position and orientation” and vice versa.

2, the solid lines show an actual position IL of the second component 104 or the optically active surface 108, and the dashed lines and the reference number 104' or 108' show a target position SL of the second component 104 or the optically active surface 108 shown. The second component 104 can be moved from its actual position IL to the target position SL and vice versa. For example, the second component 104 in the target position SL meets certain optical specifications or requirements that the second component 104 does not meet in the actual position IL. For example, when mounting the second component 104 on the first component 102, it may be necessary to adjust or align the second component 104 with respect to the first component 102 or generally in space. In the present case, “adjustment” or “alignment” is to be understood in particular as changing the position of the second component 104. For example, the second component 104 can be moved from the actual position IL to the target position SL or vice versa during the adjustment.

The second component 104 can be connected to the first component 102 using a fastening element 112. For example, the second component 104 is connected to the first component 102 at several connection points 114, 116, 118. The connection points 114, 116, 118 are provided on the back 110 of the second component 104. For example, the second component 104 can have three mirror sockets that are provided at corners of an imaginary triangle. These mirror sockets function as connection points 114, 116, 118.

The second component 104 can be connected to the first component 102 at each connection point 114, 116, 118 or at each mirror socket. The second component 104 is then adjusted with the help of spacers or so-called spacers, which are placed under the connection points 114, 116, 118. The components 102, 104 are then firmly connected to one another, in particular screwed together. For this purpose, the fastening element 112, in particular in the form of a screw, is provided.

Since spacers of different thicknesses can be used to adjust the second component 104 at the different connection points 114, 116, 118, this can, on the one hand, lead to the second component 104 moving around the x-direction x and/or around the y-direction y tilted and to others, that when the fastening element 112 is tightened, undesirable stresses are introduced into the second component 104.

In order to prevent the introduction of stresses into the second component 104, spherical cap-shaped compensating elements (not shown) can be used between the components 102, 104, which can compensate for an angular error between the components 102, 104. However, since such spherical cap-shaped compensating elements are subject to friction, unwanted stresses can still be introduced into them when the two components 102, 104 are firmly connected. This needs to be improved.

In order to enable the aforementioned angular compensation between the second component 104 and the first component 102, the optical system 100 includes a compensating device 200. The compensating device 200 is a spacer or spacer and can also be referred to as such. The compensation device 200 allows a friction-free tilting of the second component 104 relative to the first component 102 about the x-direction x and/or about the y-direction y. Furthermore, the compensation device 200 allows a height adjustment along the z-direction z. The compensating device 200 is placed between the front 106 of the first component 102 and the back 110 of the second component 104. The compensation device 200 contacts both the front 106 and the back 110.

4 shows a schematic perspective view of the compensation device 200. FIG. 5 shows a schematic top view of the compensation device 200. Reference will be made to FIGS. 4 and 5 simultaneously.

The compensation device 200 has a circumferential fastening ring 202, an inner ring 204 and an outer ring 206. The inner ring 204 runs in a ring around the fastening ring 202. The outer ring 206 runs around in a ring shape the inner ring 204. The inner ring 204 is thus positioned between the fastening ring 202 and the outer ring 206. The fastening ring 202 has a central opening 208, for example in the form of a bore, through which the fastening element 112 is passed.

The compensation device 200 is constructed essentially rotationally symmetrical to a central or symmetry axis 210. In particular, the fastening ring 202, the inner ring 204 and the outer ring 206 are each constructed rotationally symmetrically to the axis of symmetry 210. The opening 208 is also constructed rotationally symmetrical to the axis of symmetry 210.

The compensation device 200 is assigned a radial direction R. The coordinate system with the directions x, y, z can also be assigned to the compensation device 200. The radial direction R is perpendicular to the axis of symmetry 210 and oriented away from it. Viewed along the radial direction R, the fastening ring 202 is placed within the inner ring 204 and the inner ring 204 is placed within the outer ring 206.

The inner ring 204 is connected to the fastening ring 202 with the help of webs 212, 214, 216, 218. The webs 212, 214, 216, 218 can be referred to as inner webs. The webs 212, 214 form a first pair of webs 220 and the webs 216, 218 form a second pair of webs 222. The webs 212, 214, 216, 218 do not necessarily have to be arranged in pairs. It is also possible for the inner ring 204 to be connected to the fastening ring 202 with the aid of exactly two webs 212, 214, 216, 218, which are arranged on both sides of the fastening ring 202 in the orientation of FIGS. 4 and 5. An air gap or space 224, 226 is provided between the webs 212, 214 and the webs 216, 218. The webs 212, 214, 216, 218 are solid-state joints. In the present case, a “solid body joint” is generally understood to mean a region, for example a cross-sectional narrowing or thinning, of a component which enables a relative movement between two rigid body regions of the component by bending. In the present case, the fastening ring 202 and the inner ring 204 form rigid body regions which are movably connected to one another with the aid of the webs 212, 214, 216, 218. The webs 212, 214, 216, 218 each form a cross-sectional narrowing or thinning compared to the fastening ring 202 and the inner ring 204.

The webs 212, 214, 216, 218 enable the inner ring 204 to be tilted relative to the fastening ring 202 about a first tilt axis 228. The first tilt axis 228 can correspond to the x-direction x or the y-direction y. The first tilt axis 228 is oriented perpendicular to the z direction z. When the inner ring 204 is tilted relative to the fastening ring 202 about the first tilt axis 228, the webs 212, 214, 216, 218 are twisted or twisted.

The outer ring 206 is connected to the inner ring 204 using webs 230, 232, 234, 236. The webs 230, 232, 234, 236 can be referred to as outer webs. The webs 230, 232, 234, 236 are oriented perpendicular to the webs 212, 214, 216, 218. In particular, the webs 230, 232, 234, 236 are positioned offset by 90° to the webs 212, 214, 216, 218. The webs 230, 232 form a first pair of webs 238 and the webs 234, 236 form a second pair of webs 240. The webs 230, 232, 234, 236 do not necessarily have to be arranged in pairs.

It is also possible for the outer ring 206 to be connected to the inner ring 204 with the aid of exactly two webs 230, 232, 234, 236, which are arranged above and below the inner ring 204 in the orientation of FIGS. 4 and 5. An air gap or space 242, 244 is provided between the webs 230, 232 and the webs 234, 236. The webs 230, 232, 234, 236 are also solid-state joints. The webs 230, 232, 234, 236 enable the outer ring 206 to be tilted relative to the inner ring 204 about a second tilt axis 246 that differs from the first tilt axis 228. The second tilt axis 246 is positioned perpendicular to the first tilt axis 228. The second tilt axis 246 can coincide with the x direction x or the y direction y. In the event that the first tilt axis 228 corresponds to the x-direction x, the second tilt axis 246 corresponds to the y-direction y and vice versa. The second tilt axis 246 is oriented perpendicular to the z direction z.

5 shows, a first air gap or first space 248 is provided between the fastening ring 202 and the inner ring 204. The first gap 248 runs in a ring shape around the fastening ring 202 and is only interrupted by the web pairs 220, 222. The web pairs 220, 222 run through the first gap 248 and connect the fastening ring 202 to the inner ring 204.

A second air gap or second space 250 is provided between the inner ring 204 and the outer ring 206. The second gap 250 runs in a ring shape around the inner ring 204 and is only interrupted by the web pairs 238, 240. The web pairs 238, 240 run through the second gap 250 and connect the inner ring 204 to the outer ring 206.

The compensation device 200 is a one-piece component, in particular a one-piece material component. “One-piece” or “one-piece” means that the compensating device 200 is not composed of different sub-components, but rather that the fastening ring 202, the inner ring 204, the outer ring 206 and the webs 212, 214, 216, 218, 230, 232, 234, 236 form a common component, namely the compensation device 200. “In one piece of material” in this case means that the compensating device 200 is made entirely of the same material. For example, the compensation device 200 can be made of copper, aluminum, steel or the like. The compensation device 200 can be produced using an additive or generative manufacturing process, in particular using a 3D printing process. Furthermore, the compensation device 200 can also be produced using an erosion process.

6 shows various sectional views of various embodiments of a cross-sectional geometry 252 of the web 212.

All statements regarding the web 212 are applicable to the webs 214, 216, 218, 230, 232, 234, 236 and vice versa. The webs 212, 214, 216, 218, 230, 232, 234, 236 can have identical or different cross-sectional geometries 252. Only the bridge 212 will be discussed below.

6 shows, the cross-sectional geometry 252 of the web 212 can be rectangular (first line, left part of FIG. 6), triangular (first line, middle part of FIG. 6), tubular and circular (first line, right part of FIG - gur of Fig. 6), tubular and oval (second line, left part of figure of Fig. 6), trapezoidal (second line, middle part of figure of Fig. 6), hexagonal (second line, right part of figure of Fig. 6), hollow profile-shaped and rectangular (third line, left part of figure of Fig. 6), double-T-shaped (third line, middle part of figure of Fig. 6), C-shaped (third line, right part of figure of Fig. 6), cruciform (fourth line , left partial figure of FIG. 6), T-shaped (fourth line, middle partial figure of FIG. 6) or circular (fourth row, right partial figure of FIG. 6). As mentioned previously, these cross-sectional geometries 252 can be combined with one another in any way. In principle, any cross-sectional geometry 252 can be used. Fig. 7 shows the detailed view VII according to Fig. 2.

In contrast to FIG. 2, the optical system 100 is shown in section in FIG. 7. As previously mentioned, the compensating device 200 is placed between the front 106 of the first component 102 and the back 110 of the second component 104. The compensation device 200 contacts both the front 106 and the back 110.

The fastening ring 202 is assigned a first end face 254 which runs annularly around the axis of symmetry 210 and a second end face 256 which faces away from the first end face 254. The compensating device 200 rests on the back 110 with the first end face 254. The second end face 256 faces the front side 106, but does not rest against it. This means that the second end face 256 does not contact the first component 102.

The inner ring 204 also includes a first end face 258, which is arranged parallel to the first end face 254 of the fastening ring 202. The first end face 258 faces the back 110, but does not contact it. A second end face 260 of the inner ring 204 is positioned facing away from the first end face 258. The second end face 260 is placed parallel to the second end face 256. The second end face 260 of the inner ring 204 faces the front side 106, but does not contact it. This means that the inner ring 204 neither contacts the first component 102 nor the second component 104.

The outer ring 206 includes a first end face 262, which is placed facing the back 110. However, the first end face 262 does not contact the back 110. The first end face 262 of the outer ring 206 is placed parallel to the first end face 254 of the inner ring 204. A second end face 264 of the Outer ring 206 faces away from the first end face 262. The second front side

264 lies on the front 106 of the first component 102.

The fastening ring 202, the inner ring 204, the outer ring 206 and the webs 212, 214, 216, 218, 230, 232, 234, 236 together form a gimbal solid-state joint. Therefore, the compensation device 200 can also be referred to as a gimbal solid joint.

The compensation device 200 thus rests on the back 110 of the second component 104 with the aid of the first end face 254 of the fastening ring 202 and on the front side 106 of the first component 102 with the aid of the second end face 264 of the outer ring 206. The fastening element 112, in this case a screw, is passed through the opening 208 of the fastening ring 202.

The compensation device 200 has a height h when viewed along the z direction z. The height h simultaneously corresponds to a distance between the front side 106 of the first component 102 and the back side 110 of the second component 104. To compensate along the z-direction z, the height h can be selected accordingly. The compensating device 200 thus functions as a spacer or spacer in the z direction.

The functionality of the compensation device 200 is explained below. As already mentioned in detail, when installing the second component 104 on the first component 102, it may be necessary to adjust the second component 104 and, for example, to move the second component 104 from the actual position IL to the target position SL. For this purpose, spacers or spacers are placed at multiple connection points or connection points 114, 116, 118, for example at three mirror sockets, between the second component 104 and the first component 102, around the second component 104 from the actual position IL to the target position SL. Several compensating devices 200 can be used as spacers. Additionally or alternatively, spacers that have a disk-shaped structure can also be used.

When adjusting the second component 104, it can tilt about the x-direction x and/or about the y-direction y by a tilt angle a (FIG. 2) relative to the first component 102. The compensating device 200 compensates for this tilt angle a when the fastening element 112 is tightened or tightened in such a way that the inner ring 204 tilts about the first tilt axis 228 relative to the fastening ring 202 and/or that the outer ring 206 tilts about the second tilt axis 246 relative to the inner ring 204.

The fastening ring 202 then rests flatly with its first end face 254 on the back 110 of the second component 104. The outer ring 206 rests flatly on the front side 106 of the first component 102 with its second end face 264. The tilt angle a is compensated via the webs 212, 214, 216, 218, 230, 232, 234, 236, which deform elastically so that the fastening element 112 can be tightened without introducing undesirable tensions into the second component 104 .

When the inner ring 204 is tilted relative to the fastening ring 202 and when the outer ring 206 is tilted relative to the inner ring 204, the webs 212, 214, 216, 218, 230, 232, 234, 236 are deformed elastically, in particular resiliently. “Elastic” means that the deformation is reversible. The webs 212, 214, 216, 218, 230, 232, 234, 236 are deformed from an initial state into a deformation state by applying a force or a moment. If this force or moment no longer acts on the respective web 212, 214, 216, 218, 230, 232, 234, 236, it automatically deforms from the deformation state back to the initial state. The footbridges 212, 214, 216, 218, 230, 232, 234, 236 thus function as spring elements, in particular as leaf spring elements, and can therefore also be referred to as such.

In comparison to a spherical cap-shaped compensation element as described in the introduction, the angle compensation of the tilt angle a in the compensation device 200 takes place purely via the deformation of the webs 212, 214, 216, 218, 230, 232, 234, 236 and thus friction-free. This means that no major stresses are caused when tightening the fastening element 112. However, the compensation device 200 allows the same degrees of freedom as a spherical cap-shaped compensation element, with the required stiffness of the webs 212, 214, 216, 218, 230, 232, 234, 236 being able to be calculated. In this way, a defined state can be achieved in comparison to spherical cap-shaped compensating elements that are subject to friction.

In this case, “stiffness” is generally understood to mean the resistance of a body, in this case the webs 212, 214, 216, 218, 230, 232, 234, 236, against an elastic deformation imposed by external load and conveys the connection between the load of the body and its deformation. The stiffness is determined by the material of the body and its geometry. For example, the different cross-sectional geometries 252 according to FIG. 6 have different stiffnesses.

The webs 212, 214, 216, 218, 230, 232, 234, 236 are designed in particular in such a way that even when the fastening element 112 is tightened, there is no contact between the fastening ring 202 and the first component 102, and there is no contact between the inner ring 204 with the first component 102 or the second component 104 and there is no contact of the outer ring 206 with the second component 104. The stiffness along the z-direction z can be influenced in particular via the height h. With the help of Compensating device 200 can also improve decoupling on glued mirror sockets of second component 104.

Fig. 8 shows a schematic top view of a further embodiment of a compensation device 300 for the optical system 100. Fig. 9 shows a schematic sectional view of the compensation device 300 according to section line IX-IX of Fig. 8. Fig. 10 shows a further schematic sectional view of the Compensating device 300 according to the section line XX of FIG. 8. Reference will be made to FIGS. 8 to 10 at the same time.

The compensating device 300 essentially corresponds in its structure and function to the structure and function of the compensating device 200. The compensating device 300 has a circumferential fastening ring 302, an inner ring 304 and an outer ring 306. The inner ring 304 runs in a ring around the fastening ring 302. The outer ring 306 runs around the inner ring 304 in a ring shape. The inner ring 304 is thus positioned between the fastening ring 302 and the outer ring 306. The fastening ring 302 has a central opening 308, for example in the form of a bore, through which the fastening element 112 is passed.

The compensation device 300 is constructed essentially rotationally symmetrical to a central or symmetry axis 310. In particular, the fastening ring 302, the inner ring 304 and the outer ring 306 are each constructed rotationally symmetrical to the axis of symmetry 310. The breakthrough 308 is also constructed rotationally symmetrical to the axis of symmetry 310.

The inner ring 304 is connected to the fastening ring 302 using webs 312, 314. The webs 312, 314 can be referred to as inner webs. The webs 312, 314 have a cross-shaped cross-sectional geometry 252, as shown in the left partial figure of the last line of FIG. 6. The inner ring 304 is connected to the fastening ring 302 with the aid of exactly two webs 312, 314, which are arranged on both sides of the fastening ring 302 in the orientation of FIG. However, the webs 312, 314 can also be arranged in pairs, as was explained with reference to the compensation device 200. The webs 312, 314 are solid joints.

The webs 312, 314 enable the inner ring 304 to be tilted relative to the fastening ring 302 about a first tilt axis 316. The first tilt axis 316 can correspond to the x-direction x or the y-direction y. The first tilt axis 316 is oriented perpendicular to the z direction z. When the inner ring 304 is tilted relative to the fastening ring 302 about the first tilt axis 316, the webs 312, 314 are twisted or twisted.

The outer ring 306 is connected to the inner ring 304 using webs 318, 320. The webs 318, 320 can be referred to as outer webs. The webs 318, 320 are oriented perpendicular to the webs 312, 314. In particular, the webs 318, 320 are positioned offset by 90° to the webs 312, 314. The webs 318, 320 can also be arranged in pairs. The webs 318, 320 are cross-shaped in cross section. In principle, the webs 312, 314, 318, 320 can have any cross-sectional geometry 252 (FIG. 6). The outer ring 306 is connected to the inner ring 304 with the aid of exactly two webs 318, 320, which are arranged above and below the inner ring 304 in the orientation of FIG.

The webs 318, 320 are also solid-state joints. The webs 318, 320 enable the outer ring 306 to be tilted relative to the inner ring 204 about a second tilt axis 322 that differs from the first tilt axis 316. The second tilt axis 322 is positioned perpendicular to the first tilt axis 316. The second tilt axis 322 can coincide with the x-direction x or the y-direction y. In the event that the first tilt axis 316 coincides with the x-direction x, the second tilt axis 322 corresponds to the y-direction y and vice versa.

The second tilt axis 322 is oriented perpendicular to the z direction z.

A first air gap or first space 324 is provided between the fastening ring 302 and the inner ring 304. The first gap 324 runs in a ring shape around the fastening ring 302 and is only interrupted by the webs 312, 314. The webs 312, 314 run through the first gap 324 and connect the fastening ring 302 to the inner ring 304.

A second air gap or second space 326 is provided between the inner ring 304 and the outer ring 306. The second gap 326 runs in a ring shape around the inner ring 304 and is only interrupted by the webs 318, 320. The webs 318, 320 run through the second space 326 and connect the inner ring 304 to the outer ring 306.

The compensation device 300 is a one-piece component, in particular a one-piece material component. For example, the compensation device 200 can be made of copper, aluminum, steel or the like. The compensation device 300 can be manufactured using an additive or generative manufacturing process, in particular using a 3D printing process. Furthermore, the compensation device 300 can also be produced using an erosion process.

The compensating device 300 is placed between the front 106 of the first component 102 and the back 110 of the second component 104. The compensating device 300 contacts both the front side 106 and the back side 110. The fastening ring 302 is assigned a first end face 328 which runs annularly around the axis of symmetry 310 and a second end face 330 which faces away from the first end face 328. Between the end faces 328, 330, a contact surface 332 is provided facing the inner ring 304. The Contact surface 332 is curved in the shape of a spherical cap. With the first front side

328 is the compensation device 300 on the back 110. The second end face 330 faces the front side 106, but does not rest against it.

The inner ring 304 also includes a first end face 334, which is arranged parallel to the first end face 328. The first end face 334 faces the back 110, but does not contact it. A second end face 336 of the inner ring 304 is positioned facing away from the first end face 334. The second end face 336 is placed parallel to the first end face 334. The second end face 336 of the inner ring 204 faces the front side 106, but does not contact it.

Between the end faces 334, 336, a counter-contact surface 338 curved in the shape of a spherical cap is provided facing the contact surface 332 of the fastening ring 302. The contact surface 332 and the counter-contact surface 338 are suitable for abutting one another. Furthermore, facing away from the counter contact surface 338, i.e. facing the outer ring 306, a further contact surface 340 is provided on the inner ring 304. The contact surface 340 is also curved in the shape of a spherical cap.

The outer ring 306 includes a first end face 342, which is placed facing the back 110. However, the first end face 342 does not contact the back 110. The first end face 342 of the outer ring 306 is placed parallel to the first end face 334 of the inner ring 304. A second end face 344 of the outer ring 306 faces away from the first end face 342. The second end face 344 rests on the front 106. Between the end faces 342, 344, a counter-contact surface 346 is provided on the outer ring 306, facing the contact surface 340. The contact surface 340 and the counter-contact surface 346 are suitable for adhering to one another. The compensating device 300 thus rests on the back 110 of the second component 104 with the aid of the first end face 328 of the fastening ring 302 and on the front side 106 of the first component 102 with the aid of the second end face 344 of the outer ring 306. The fastening element 112, in this case a screw, is passed through the opening 308 of the fastening ring 302.

The functionality of the compensation device 300 corresponds to the functionality of the compensation device 200 with the difference that when the fastening element 112 is tightened, the contact surface 332 and the counter-contact surface 338 as well as the contact surface 340 and the counter-contact surface 346 are pressed against one another. The force is then transmitted with the help of the contact surfaces 332, 340 and the counter-contact surfaces 338, 346. Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

REFERENCE SYMBOL LIST

1 projection exposure system

2 lighting system

3 light source

4 lighting optics

5 object field

6 object level

7 reticles

8 reticle holders

9 reticle displacement drive

10 projection optics

11 image field

12 image levels

13 wafers

14 wafer holders

15 wafer displacement drive

16 illumination radiation

17 collector

18 intermediate focus plane

19 deflection mirrors

20 first facet mirror

21 first facet

22 second facet mirror

23 second facet

100 optical system

102 component

104 component

106 front

108 visually effective area 110 back

112 fastener

114 Connection gsp point

116 Connection gsp point

118 connection point

200 compensation device

202 fastening ring

204 inner ring

206 outer ring

208 breakthrough

210 axis of symmetry

212 jetty

214 jetty

216 jetty

218 jetty

220 pair of bars

222 pair of bars

224 space

226 space

228 tilt axis

230 jetty

232 jetty

234 jetty

236 jetty

238 pair of bars

240 pair of bars

242 space

244 space

246 tilt axis

248 space 250 space

252 cross-sectional geometry

254 front side

256 front side

258 front side

260 front side

262 front side

264 front side

300 compensation device

302 mounting ring

304 inner ring

306 outer ring

308 breakthrough

310 axis of symmetry

312 jetty

314 jetty

316 tilt axis

318 jetty

320 jetty

322 tilt axis

324 space

326 space

328 front side

330 front side

332 investment area

334 front side

336 front side

338 counter contact area

340 investment area

342 front side 344 front side

346 counter contact surface h height Ml mirror

M2 mirror

M3 mirror

M4 mirror

M5 mirror M6 mirror

R radial direction x x- direction y y- direction z z- direction a tilt angle

Claims

PATENT CLAIMS

1. Optical system (100) for a projection exposure system (1), comprising a first component (102), a second component (104), and a compensation device (200, 300) between the first component (102) and the second component (104) is arranged, the compensating device (200, 300) having webs (212, 214, 216, 218, 230, 232, 234, 236, 312, 314, 318, 320) which act as solid-state joints and which are elastically deformable, around the compensation device (200, 300) to tilt the second component (104) relative to the first component (102) about a first spatial direction (x) and/or about a second spatial direction (y) that differs from the first spatial direction (x). ), wherein the compensating device (200, 300) has a fastening ring (202, 302) and an inner ring (204, 304) running around the fastening ring (202, 302), the inner ring (204, 304) being provided with the aid of inner webs ( 212, 214, 216, 218, 312, 314) is connected to the fastening ring (202, 302), and wherein the inner ring (204, 304) with the aid of an elastic deformation of the inner webs (212, 214, 216, 218, 312 , 314) can be tilted about a first tilt axis (228, 316) relative to the fastening ring (202, 302).

2. Optical system according to claim 1, wherein the compensation device (200, 300) has an outer ring (206, 306) running around the inner ring (204, 304), the outer ring (206, 306) being supported by means of outer webs (230, 232 , 234, 236, 318, 320) is connected to the inner ring (204, 304), and wherein the outer ring (206, 306) with the aid of an elastic deformation of the outer webs (230, 232, 234, 236, 318, 320) can be tilted relative to the inner ring (204, 304) about a second tilt axis (246, 322).

3. Optical system according to claim 2, wherein the second tilt axis (246, 322) is oriented perpendicular to the first tilt axis (228, 316).

4. Optical system according to claim 2 or 3, wherein the outer webs (230, 232, 234, 236, 318, 320) are positioned perpendicular to the inner webs (212, 214, 216, 218, 312, 314).

5. Optical system according to one of claims 2 - 4, wherein the compensating device (200, 300) only rests on one of the two components (102, 104) with the aid of the fastening ring (202, 302), and wherein the compensating device (200, 300 ) with the help of the outer ring (206, 306) only rests on the other of the two components (102, 104).

6. Optical system according to one of claims 2 - 5, wherein a first gap (248, 324) is provided between the inner ring (204, 304) and the fastening ring (202, 302), and wherein between the outer ring (206, 306) and the inner ring (204, 304) is provided with a second gap (250, 326).

7. Optical system according to one of claims 2 - 6, wherein the fastening ring (302) has a spherical cap-shaped contact surface (332), the inner ring (304) having a spherical cap-shaped counter-contact surface (338) corresponding to the contact surface (332) of the fastening ring (302). and wherein the contact surface (332) of the fastening ring (302) rests on the counter-contact surface (338) of the inner ring (304).

8. Optical system according to one of claims 2 - 7, wherein the inner ring (304) has a spherical cap-shaped contact surface (340), the outer ring (306) corresponding to the contact surface (340) of the inner ring (304). has a spherical cap-shaped counter-contact surface (346), and wherein the abutment surface (340) of the inner ring (304) rests on the counter-contact surface (346) of the outer ring (306).

9. Optical system according to one of claims 1 - 8, wherein the webs (212, 214, 216, 218, 230, 232, 234, 236, 312, 314, 318, 320) each have a cross-shaped cross-sectional geometry (252).

10. Optical system according to one of claims 1 - 9, wherein the second component (104) has a plurality of connection points (114, 116, 118) at which the second component (104) is connected to the first component (102), and wherein each connection point (114, 116, 118) is assigned a compensation device (200, 300).

11. Optical system according to one of claims 1 - 10, wherein two webs (212, 214, 216, 218, 230, 232, 234, 236) together form a pair of webs (220, 222, 238, 240), and between A gap (224, 226, 242, 244) is provided in each of the webs (212, 214, 216, 218, 230, 232, 234, 236) of a pair of webs (220, 222, 238, 240).

12. Optical system according to one of claims 1 - 11, further comprising a fastening element (112) for connecting the second component (104) to the first component (102), the fastening element (112) passing through the compensating device (200, 300). is carried out.

13. Optical system according to one of claims 1 - 12, wherein the compensation device (200, 300) is a one-piece component, in particular a one-piece material component.

14. Projection exposure system (1) with an optical system (100) according to one of claims 1 - 13.