Device for holding a lens; optical system comprising a lens and lithography system

Abstract

The invention relates to a device (1) for holding a lens (2), in particular a lens of a lithography system, comprising a socket (3) with an outer ring (4) and an inner ring (5) designed to receive the lens (2), wherein the outer ring (4) and the inner ring (5) are connected to each other via a plurality of joints (6), and wherein the inner ring (4) has a plurality of lever arms (7) by the deflection of which perpendicular to the plane of the socket (3) a deformation can be imposed on the lens (2), and comprising a plurality of pairs of actuators (8), wherein each pair of actuators (8) is assigned to one of the lever arms (7), and comprising a first actuator (9) and a second actuator (10) which are arranged coaxially to each other, wherein the lever arm (7) is arranged between the two actuators (9, 10) and the actuators (9, 10) of the actuator pair (8) are suitable for exerting an opposing force on the lever arm (7) to have an effect.The first actuator (9) is designed as a fluidic actuator and the second actuator (10) as a spring device.

Description

[0001] The invention relates to a device for holding a lens, in particular a lens of a lithography system.

[0002] The invention further relates to an optical system comprising a lens, in particular a lens of a lithography system.

[0003] The invention further relates to a lithography system, in particular a projection exposure system for semiconductor lithography, with an illumination system comprising a radiation source and optics comprising at least one lens.

[0004] Lenses require a suitable holder to fix, hold, or store them in an optical system and, if necessary, to be able to position and / or align them in a targeted manner, especially to tilt them.

[0005] Even during installation, but also during positioning and / or alignment, uneven mounting or contact surfaces, manufacturing tolerances, angular or positional errors, or differences in thermal expansion between the lens and its surroundings can affect the mount or the lens. Differences in thermal expansion between the lens and its surroundings can be caused by light absorption, especially during operation.

[0006] For the aforementioned reasons, undesirable deformations can occur in the lens. These deformations can impair the functionality of the lens, especially when high precision in the beam path and / or beam profile is required, such as for the best possible image quality and the lowest possible aberrations in semiconductor lithography.

[0007] Particularly in the field of microlithography, in addition to using components manufactured with the highest possible precision, it is essential to maintain the precise alignment of the imaging system's components, especially optical elements such as lenses, mirrors, or gratings, during operation to achieve high image quality. The stringent accuracy requirements, particularly for projection exposure systems on the order of a few nanometers or less, are a consequence of the need to increase the resolution of the optical systems used in the fabrication of microelectronic circuits, thereby advancing the miniaturization of these circuits.

[0008] In connection with minimizing aberrations, it is known to actively deform the optical elements used in order to change their optical characteristics in such a way as to counteract one or more specific aberrations of the optical system, preferably to the point of complete correction of the aberration. To achieve the desired deformation of the optical element, appropriate forces are exerted on the lens in question via various actuators, in particular pairs of actuators.

[0009] Optical elements, particularly lenses used in projection exposure systems for semiconductor lithography, often employ so-called N-wave deformations (where N is an integer and N > 1) to correct imaging aberrations. This is achieved by applying corresponding actuator forces (generally parallel to the optical axis of the optical system) to the lens at N positions (usually evenly distributed) around the outer circumference of the optical element. Between each pair of adjacent actuator force points, the lens is supported by a support element (usually positioned centrally between the force points in the circumferential direction) or by another actuator. This results in a wave-like deformation of the optical element that radiates around its circumference.

[0010] Such an arrangement is known, for example, from the generic document DE 198 27 603 A1, the entire disclosure of which is included in this document by reference.

[0011] Wave-like deformation can be used to correct or compensate for aberrations, such as those caused by the heating of optical elements in the optical system, particularly wavefront aberrations caused by lens heating. This typically requires superimposing deformations of different orders N to achieve the desired correction effect. It is possible to generate lower-order deformations using an arrangement designed for a specific maximum order N. For example, an arrangement designed for a 4-wave deformation can also produce a 2-wave deformation.

[0012] Fluidic actuators, or hydraulic actuators according to DE 198 27 603 A1, are frequently used in this context. These actuators generate a corresponding actuator force by adjusting the pressure in an actuator chamber. An advantage of such fluidic actuators lies in the precisely defined relationship between the pressure in the actuator chamber and the actuator force generated by the actuator, allowing the actuator force to be controlled by regulating the pressure in the actuator chamber.

[0013] From DE 198 27 603 A1, it is known that two fluidic actuators form an actuator pair. The actuators of an actuator pair are arranged coaxially to each other and each generates opposing forces. Four such actuator pairs are provided for deforming a lens. The lens is usually held in a mounting ring. The connection between the mounting ring and a surrounding frame is made by four joints, which are arranged symmetrically around the circumference between each actuator pair. The mounting ring has, as can be seen from the Fig. 5 and Fig. As shown in DE 198 27 603 A1, four lever arms are used, each of which is actuated by one of the actuator pairs. To imprint the desired deformation, the four lever arms are deflected by the two opposing actuators of an actuator pair. The lever arms can be deflected in either orientation by the differential pressure of the hydraulic actuators of an actuator pair.

[0014] For a bidirectional 2-wave deformation, two pressure circles are required; for a bidirectional 4-wave deformation, four pressure circles are required.

[0015] From DE 10 2008 041 287 A1, an actuator arrangement, in particular for deforming an optical element, is known, comprising a first fluidic actuator device and a second fluidic actuator device, which apply a first actuator force and a second actuator force, respectively, which are parallel to each other, in particular collinear to each other. The maximum force value of the second actuator force is said to be smaller than the maximum force value of the first actuator force.

[0016] Actuator pairs known from the prior art for correcting wavefront aberrations make it possible to impose the desired deformations on optical elements, especially lenses. However, they have the disadvantage that eight actuators are required for each lens. These actuators must be selected from a large pool of available actuators and must be compatible with each other. The actuators should exhibit properties that are as similar as possible, particularly in accordance with the teachings of DE 198 27 603 A1, but also taking into account the different maximum force values ​​as described in DE 10 2008 041 287 A1. It has been shown that even identical actuators can differ in their properties to such an extent that this can affect the correction of the wavefront aberration. Therefore, selecting eight actuators with the most similar properties possible for each lens represents a considerable effort and incurs corresponding costs.

[0017] The present invention is based on the objective of creating a device for holding a lens that enables the most precise positioning and / or alignment of the lens possible and can be manufactured as cost-effectively as possible.

[0018] According to the invention, this problem is solved by a device having the features mentioned in claim 1.

[0019] The present invention further aims to create an optical system with a lens that enables the most precise possible deformation of the lens and can be manufactured as cost-effectively as possible.

[0020] According to the invention, this problem is solved by an optical system with the features mentioned in claim 12.

[0021] The present invention further aims to create a lithography system which has lenses that are positioned and / or aligned as precisely as possible in a cost-effective manner.

[0022] According to the invention, this problem is solved by a lithography system with the features mentioned in claim 15.

[0023] The device according to the invention for holding a lens, in particular a lens of a lithography system, comprises a mount with an outer ring and an inner ring designed to receive the lens. The outer ring and the inner ring are connected to each other by a plurality of joints. The inner ring further comprises a plurality of lever arms by whose deflection perpendicular to the plane of the mount a deformation can be imprinted on the lens. The device according to the invention comprises a plurality of actuator pairs, with each actuator pair being assigned to one of the lever arms. The actuator pairs each comprise a first actuator and a second actuator, which are arranged coaxially to each other, with the lever arm being arranged between the two actuators and the actuators of the actuator pair being capable of acting on the lever arm with an opposing force.According to the invention, the first actuator of each pair of actuators is designed as a fluidic actuator and the second actuator as a spring device.

[0024] It has been shown that it is particularly suitable for correcting wavefront aberrations, which are caused in particular by heating of the lens (the so-called "lens heating"), if the actuator pairs acting on the lever arms to impose the desired deformation of the lens are not formed by two fluidic actuators that apply opposing forces, contrary to the teaching of the prior art, but one of the fluidic actuators of the actuator pair is replaced by a spring device.

[0025] It has been shown that a spring mechanism can be used to apply a relatively constant force that counteracts the force of the fluidic actuator in such a way that the desired deformations can be imprinted on the lens, as in the prior art. The deflection of the lever arms by the respective pair of actuators is thus not restricted, yet costs can be significantly reduced, as half of the previously required fluidic actuators can be eliminated. This also reduces the previously necessary selection process of choosing eight actuators with as similar properties as possible from a comparatively large pool of fluidic actuators for each lens. The costs incurred are further reduced because the elimination of actuators also eliminates the need for attachments, especially those required to control the actuators.Spring devices are significantly cheaper to manufacture and install than fluidic actuators and also do not require any additional parts for control.

[0026] A further advantage of the device according to the invention is that one pressure circuit is sufficient for a bidirectional two-wave deformation of the lens. For a bidirectional four-wave deformation, two pressure circuits are sufficient. Previously, two pressure circuits were necessary for a two-wave deformation and four for a four-wave deformation. The two-wave and four-wave deformations mentioned in the present invention are each bidirectional, meaning the deformation can be applied with either a positive or negative sign.

[0027] The spring devices of the actuator pairs are preferably designed such that the lever arm experiences its maximum deflection through the spring device in the direction in which the force of the spring device acts, i.e., the maximum intended deflection to generate the desired deformation on the lens is generated in this direction when the fluidic actuator of the respective actuator pair is not pressurized.

[0028] It is advantageous if the fluidic actuators are designed as pneumatic actuators.

[0029] It has proven particularly suitable, especially for the use of the device according to the invention for holding a lens of a lithography system or for imprinting a wave-like deformation on a lens of a lithography system to correct imaging errors, if the fluidic actuators are designed as pneumatic actuators, since the use of compressed air is more advantageous than a hydraulic system in lithography systems. Nevertheless, hydraulic actuators can also be used instead of pneumatically driven actuators, particularly if the lens is not a lens of a lithography system.

[0030] According to the invention, it can further be provided that the lever arms and the joints are preferably arranged uniformly around the circumference of the inner ring, between the inner ring and the outer ring, with one of the joints being arranged between each pair of lever arms.

[0031] Such an arrangement, especially when the lever arms and joints are arranged uniformly around the circumference of the inner ring, i.e. at a uniform distance from each other, has proven to be particularly suitable for imprinting a wave-like deformation onto the lens via the inner ring, especially for correcting aberrations.

[0032] According to the invention, it can further be provided that four lever arms, each of which is acted upon by a pair of actuators, and that four joints are provided.

[0033] Such an arrangement has proven particularly suitable for correcting imaging errors in the lenses of a lithography system.

[0034] It is advantageous if the joints are designed as solid-body joints.

[0035] The joints can be designed in particular as bridges that connect the inner ring to the outer ring at preferably four points, so that the outer ring holds the inner ring and thus also the lens, while the lever arms allow for the imprinting of a deformation onto the lens, in particular for the correction of aberrations, especially in lenses of a lithography system, wherein in particular a wave-shaped deformation is imprinted to compensate for aberrations such as those caused by the heating of the lenses of a lithography system.

[0036] Instead of forming joints to connect the inner ring to the outer ring, actuators can also be provided.

[0037] According to the invention, it can further be provided that, in the case of adjacent pairs of actuators, the first and second actuators are arranged in an alternating sequence with respect to the lever arms, such that the first actuator of one of the pairs of actuators is arranged on a first side of the lever arm and the first actuator of the adjacent pair of actuators is arranged on an oppositely oriented second side of the associated lever arm.

[0038] It has proven particularly advantageous if, in adjacent pairs of actuators, the first actuator is alternately positioned on the first side of the associated lever arm and on the second side of the associated lever arm. When the device according to the invention is used such that the first side of the lever arms is oriented upwards, the first actuator is thus located at the top and at the bottom of adjacent pairs of actuators in different configurations. The second actuators of the actuator pairs are then arranged accordingly. Adjacent pairs of actuators are thus arranged rotated by 180°, so that the actuator located at the top of one pair of actuators, for example the fluidic actuator, is located at the bottom of the adjacent pair of actuators.

[0039] It has been shown that such an arrangement makes it particularly advantageous and easy to impose a wave-like deformation on the lens. In particular, this is possible with a very simple control system.

[0040] It is advantageous if exactly one pressure circuit is provided for controlling the fluidic actuators for a 2-wave deformation of the lens.

[0041] It is also advantageous if exactly two pressure circuits are provided for controlling the fluidic actuators in a 4-shaft deformation.

[0042] In the prior art, generating a positive or negative 2w deformation (e.g., Z5 / Z6) required two pressure circuits to set a differential pressure. With the pre-tensioned actuators or the spring assembly, the need for two pressure circuits is eliminated, particularly when arranged as described above. To achieve the desired functionality, also known as BALE functionality, i.e., bidirectional 2w deformation, the device according to the invention requires only one pressure circuit.

[0043] In the prior art, four pressure circuits were required to introduce positive or negative 4w deformations (e.g., Z17 / Z18), also known as MF-BALE functionality. With the device according to the invention, two pressure circuits are now sufficient for a 4w deformation, thus significantly reducing effort and costs.

[0044] According to the invention, it can further be provided that the spring device has a spring which is preferably designed as a compression spring.

[0045] In principle, the spring force of the spring device can be generated arbitrarily, however, it has proven particularly suitable if a compression spring is used for this purpose.

[0046] According to the invention, it can further be provided that the spring device has an adjusting screw, the screw-in depth of which allows the spring preload to be adjusted.

[0047] The use of an adjusting screw makes it particularly easy and reliable to adjust the spring preload.

[0048] According to the invention, it can further be provided that the spring device has a threaded sleeve which at least partially receives the spring and into which the adjusting screw for compression and thus for adjusting the preload force of the spring can be screwed.

[0049] The aforementioned arrangement has proven particularly suitable, especially when the spring is designed as a compression spring, for setting an appropriate preload or spring force. The threaded sleeve can be directly or indirectly, and immovably or rigidly, connected to the outer ring of the socket and can serve to accommodate both the adjusting screw and the compression spring. The spring can be compressed by adjusting the screw-in depth of the adjusting screw, thus allowing for variable preload adjustment. The spring is preferably selected such that it exerts a relatively constant force on the respective lever arm within its intended range of motion.

[0050] In principle, the formation of a threaded sleeve can also be omitted if the outer ring is designed accordingly.

[0051] Instead of an adjusting screw, another actuating element, e.g. a lock screw, or another adjustment concept can be used to adjust the spring preload; however, an adjusting screw is particularly suitable for this purpose.

[0052] The device according to the invention is particularly intended to hold the lens of a projection lens of a lithography system for semiconductor lithography and to deform it in a targeted manner or to imprint wave-shaped deformations onto this lens.

[0053] The present invention also relates to an optical system comprising a device according to one of claims 1 to 11 and a lens, wherein the lens is received by the inner ring of the device and is deformable by means of the actuator pairs of the device.

[0054] For the advantages of such an optical system, reference is made to the preceding and following explanations.

[0055] It is advantageous if the lens is a lens of a lithography system.

[0056] It is particularly advantageous if the inner ring of the device, which receives the lens, has four lever arms and four joints that are evenly spaced around the circumference of the inner ring, between the inner ring and the outer ring, with one of the joints being arranged between each pair of lever arms, the joints being designed as solid-state joints, and in the case of adjacent pairs of actuators, the first and second actuators being arranged in an alternating sequence with respect to the lever arms, such that the first actuator of one of the pairs of actuators is arranged on a first side of the associated lever arm and the first actuator of the adjacent pair of actuators is arranged on an oppositely oriented second side of the associated lever arm.

[0057] Such a design of the optical system has proven particularly suitable for correcting imaging errors, especially in lenses of a projection lens of a lithography system for semiconductor lithography, which result from the heating of the lenses, whereby wave-shaped deformations are generated for this purpose.

[0058] The present invention also relates to a lithography system, in particular a projection exposure system for semiconductor lithography, comprising an illumination system with a radiation source and a projection optic comprising at least one lens. According to the invention, the lens is held by at least one device according to any one of claims 1 to 11 and / or the lens is part of an optical system according to any one of claims 12 to 14.

[0059] Advantages of such a lithography system will become apparent from the preceding and following descriptions of the device according to the invention and the optical system analogously.

[0060] Features described in connection with one of the subject matter of the invention, in particular the device according to the invention, the optical system and the lithography system, can also be advantageously implemented for the other subject matter of the invention. Likewise, advantages mentioned in connection with one of the subject matter of the invention can also be understood to relate to the other subject matter of the invention.

[0061] Exemplary embodiments of the invention are described in more detail below with reference to the drawing.

[0062] The figures each show preferred embodiments in which individual features of the present invention are combined with one another. Features of an embodiment can also be implemented independently of the other features of the same embodiment and can therefore be readily combined by a person skilled in the art to form further meaningful combinations and subcombinations with features of other embodiments.

[0063] In the figures, functionally identical elements are provided with the same reference symbols.

[0064] They show: Fig. 1 a DUV projection exposure system; Fig. 2 a top view of a lens with actuator pairs according to the invention; Fig. 3 a cut along line III - III of the Fig. 2; Fig. 4 a section through an exemplary assembly of an actuator pair according to the invention; and Fig. 5 a schematic representation of a 2w-deformation of a lens with four pairs of actuators according to the invention.

[0065] In Fig. Figure 1 shows an exemplary DUV projection exposure system 200. The DUV projection exposure system 200 comprises an illumination system 201, a device called a reticule stage 202 for receiving and precisely positioning a reticule 203, by which the subsequent structures on a wafer 204 are determined, a wafer holder 205 for holding, moving and precisely positioning the wafer 204 and an imaging device, namely a projection optic 206, with several optical elements, in particular lenses 207, which are held in a lens housing 209 of the projection optic 206 via mounts 208.

[0066] Alternatively or in addition to the lenses 207 shown, various refractive, diffractive and / or reflective lenses, including mirrors, prisms, end plates and the like, may be provided.

[0067] The basic operating principle of the DUV projection exposure system 200 provides that the structures introduced into the reticulum 203 are imaged onto the wafer 204.

[0068] The illumination system 201 provides a projection beam 210 in the form of electromagnetic radiation, which is required for imaging the reticulum 203 onto the wafer 204. A laser, a plasma source, or the like can be used as the source of this radiation. In the illumination system 201, the radiation is shaped by lenses so that the projection beam 210, upon striking the reticulum 203, exhibits the desired properties with regard to diameter, polarization, wavefront shape, and the like.

[0069] Using the projection beam 210, an image of the reticulum 203 is generated and transferred, appropriately reduced in size, to the wafer 204 by the projection optics 206. The reticulum 203 and the wafer 204 can be moved synchronously, so that areas of the reticulum 203 are mapped onto corresponding areas of the wafer 204 practically continuously during a so-called scan process.

[0070] Optionally, the air gap between the last lens 207 and the wafer 204 can be replaced by a liquid medium with a refractive index greater than 1.0. This liquid medium could, for example, be highly purified water. Such a setup is also known as immersion lithography and offers increased photolithographic resolution.

[0071] The use of the invention is not limited to applications in projection exposure systems 200, particularly not with the described setup. The invention is suitable for any lithography or microlithography system, but especially for projection exposure systems with the described setup.

[0072] The following figures represent the invention only as an example and in a highly schematic form.

[0073] The Fig. Figures 2 to 5 show an exemplary embodiment of the device 1 according to the invention for holding a lens 2, in particular a lens of a lithography system. This can be, in particular, a lens of a lithography system, especially a projection exposure system for semiconductor lithography, such as the one described in the Fig. 1 was shown. The lens 2 can in particular be a lens 207 of a projection optic 206, as shown by the Fig. 1 was presented in principle.

[0074] The device 1 according to the invention is particularly suitable for any DUV (Deep Ultra Violet) projection exposure system and is not limited to the illustration shown in the Fig. 1 limited.

[0075] Within the scope of the invention, DUV projection exposure systems are not to be understood as limited to a specific wavelength. The device according to the invention is suitable for any such system, regardless of the wavelength used, e.g., also for VUV systems and other spectral lines, in particular with a central wavelength of 365 nm (i-line). VUV radiation stands for vacuum ultraviolet radiation and denotes the spectral range of electromagnetic radiation whose long-wavelength region borders on the so-called near-UV. Depending on the definition, the short-wavelength end of the VUV spectral range borders on the EUV radiation range or on soft X-rays.

[0076] The device 1 according to the invention has, as can be seen in principle from the Fig. 2 and Fig. 3 results in a mounting 3 with an outer ring 4 and an inner ring 5 designed to receive the lens 2. The mounting 3 can in particular be a mounting 208 of a projection optic 206, such as this based on the Fig. 1 is shown or is used in the manner in which it is used for lenses of projection exposure systems.

[0077] The inner ring 5 can be designed as a lens holder for holding the lens 2, in any design.

[0078] The outer ring 4 and the inner ring 5 are connected to each other via a plurality, preferably four in the exemplary embodiment, of joints 6. The joints 6 are preferably articulated connections, in particular solid joints, preferably with the dimensions or angular dimensions as shown in the Fig. Figure 2 shows the diagram, although other, in particular smaller and larger, central angles for the joints 6 may also be provided. Actuators may also be provided instead of the joints 6 to connect the outer ring 4 to the inner ring 5.

[0079] The inner ring 5 has a plurality, in the exemplary embodiment four, of lever arms 7, by whose deflections perpendicular to the plane of the mount 3 a deformation can be applied to the lens 2. The plane of the mount 3 is parallel to the plane of the lens.

[0080] Instead of the lever arms 7, other projections may also be provided, in particular projections that extend radially beyond or project beyond the circumference of the inner ring 5.

[0081] The device 1 according to the invention further comprises a plurality of actuator pairs 8. Each of the actuator pairs 8 is assigned to one of the lever arms 7, as can be seen from the schematic sectional view according to the Fig. 3 is recognizable. Each of the actuator pairs 8 has a first actuator 9 and a second actuator 10, which are arranged coaxially to each other. The lever arm 7 is located between the two actuators 9, 10. The actuators 9, 10 of the actuator pairs 8 are capable of acting with an opposing force on their respective assigned lever arm 7.

[0082] With regard to the basic structure of the device 1 according to the invention, in particular the housing 3, the joints 6, the lever arms 7 and the arrangement of the actuator pairs 8, reference is also made to the descriptions in the generic document, DE 198 27 603 A1. It should be explicitly noted that all embodiments and variants as described in the generic document can also be used in the device 1 according to the invention, as well as in the optical system and the lithography system according to the invention.

[0083] Furthermore, reference is made to the actuator arrangement according to DE 10 2008 041 287 A1. While DE 10 2008 041 287 A1 proposes actuator arrangements in which two fluidic actuators form an actuator pair, this document also describes embodiments and variants that may also be suitable for the device, optical system, and lithography system according to the invention. Therefore, explicit reference is also made to the content of this document.

[0084] It should be noted that in other variants of the invention any other number of actuator pairs 8 and / or levers 7 and / or joints 6 may also be provided, the number of actuator pairs depending on a desired type of deformation of the lens 2, for which reference is also made to the explanations in DE 10 2008 041 287 A1.

[0085] In the present embodiment, the first actuator 9 of each pair of actuators 8 is designed as a fluidic actuator and the second actuator 10 as a spring device. This is shown in the Fig. 3 shown accordingly. Fig. Figure 4 shows a particularly advantageous embodiment of an actuator pair 8 in section in a more detailed representation, compared to the representation of the Fig. 3. In the Fig. 3 and the Fig. Figure 4 shows that the fluidic actuator 9 and the spring assembly 10 exert opposing forces on one of the lever arms 7 of the inner ring 5. By selecting a suitable preload or spring force for the spring assembly 10, or by applying a suitable pressure to the fluidic actuator 9 during operation, the lever arm 7 can be deflected perpendicular to the plane of the mount 3 in the desired manner to apply a deformation to the lens 2, particularly to correct aberrations.

[0086] In the exemplary embodiment, the fluidic actuator 9 is designed as a pneumatic actuator.

[0087] It should be noted that the first actuator 9, which opposes the spring device 10, does not necessarily have to be a fluidic actuator (as claimed); the use of an electrically actuated actuator would also be possible.

[0088] Both the first actuator 9 and the second actuator 10 can act directly on the lever arm 7, as shown in the exemplary embodiment; however, it can also be provided that the action on the lever arm 7 takes place via intermediate elements.

[0089] The Fig. Figure 4 shows an exemplary embodiment of a pneumatic actuator 9, which may be particularly suitable for realizing the device 1 according to the invention. Regarding possible configurations of the pneumatic actuator 9, reference is made to the descriptions in DE 10 2008 041 287 A1, in which advantageous fluidic actuators and their construction are described, in particular also with regard to the actuator chamber and the pressure control. In this respect, explicit reference is also made to the descriptions of the Fig. Reference is made to paragraphs 1 to 3 of DE 10 2008 041 287 A1.

[0090] As a matter of principle, especially the Fig. 2 and Fig. As can be seen from Figure 5 of the drawing of the device 1 according to the invention, the four lever arms 7 and the four joints 6 are preferably arranged evenly around the circumference of the inner ring 5, between the inner ring 5 and the outer ring 4, with one of the joints 6 being arranged between each pair of lever arms 7. The lever arms 7 or the actuator pairs 8 and the joints 6, which can also be referred to as articulated retaining elements, are thus each rotated by an angle of 45° relative to an adjacent lever arm 7 or joint 6.

[0091] The joints 6 are preferably designed as solid body joints.

[0092] In the exemplary embodiment, it is provided that in adjacent pairs of actuators 8, the first actuator 9 and the second actuator 10 are arranged in a different order with respect to the lever arm 7, such that the first actuator 9 of one of the pairs of actuators 8 is arranged on a first side 7a of the associated lever arm 7, and the first actuator 9 of the adjacent pair of actuators 8 is arranged on an oppositely oriented second side 7b of the associated lever arm 7. In an arrangement in which the first sides 7a of the lever arms are oriented upwards, as is exemplified in the Fig. As shown in Figure 3, it is provided that if a first actuator 9 of an actuator pair 8 adjoins the first side 7a of the lever arm from above, the two actuator pairs 8 adjacent to this actuator pair 8, between which the actuator pair 8 is arranged, are oriented such that their first actuator 9 adjoins the second side 7b of the respective lever arms 7 from below. Fig. Figure 3 shows two of the four actuator pairs 8. The four actuator pairs 8 are arranged such that adjacent actuator pairs 8 are rotated 180° relative to each other. The in Fig. The 3 pairs of actuators 8 shown are identically oriented with respect to the respective lever arms 7, due to the sectional view (which shows opposing pairs of actuators 8).

[0093] The Fig. Figure 5 shows a corresponding arrangement, from which it can be seen that two lever arms 7 are subjected to force from below by a spring device 10 and two lever devices 7 are subjected to force from above by the spring device 10, wherein the subjection of adjacent actuator pairs 8 is different in each case.

[0094] In the Fig. 3 and in more detail in the Fig. Figure 4 shows exemplary embodiments of the spring assembly 10. In this exemplary embodiment, the spring assembly 10 comprises a spring 11 designed as a compression spring. Furthermore, the spring assembly 10 includes an adjusting screw 12 and a threaded sleeve 13. The threaded sleeve 13 is rigidly connected to the outer ring 4. The threaded sleeve 13 at least partially accommodates the compression spring 11. The adjusting screw 12 can be screwed into the threaded sleeve 13, and the compression of the compression spring 11, and thus the preload force or spring force of the compression spring 11, can be adjusted by the screw-in depth of the adjusting screw 12 into the threaded sleeve 13.

[0095] The Fig. Figure 5 shows an exemplary 2w deformation (e.g., Z5 / Z6) using a so-called BALE functionality, in which (not shown in detail in the embodiment) a pressure circuit is provided. In principle, four joints 6 are shown, wherein in Fig. Figure 5 is intended to symbolize a connection to the "solid world," particularly to the outer ring 4. Furthermore, four pairs of actuators 8 are depicted, with the fluidic actuators 9 of each pair being symbolized only by black arrows acting on a lever arm 7 represented as a circle. The spring mechanisms 10 of the actuator pairs 8 are symbolized by a spring. Two of the lever arms 7 are depicted as black circles; for these, pressure is applied in the plane of the image from above, using the fluidic actuators 9. Two of the lever arms 7 are depicted as half-filled circles; for these, pressure is applied in the plane of the image. Fig. 5, considered, is done from below with the aid of the fluidic actuators 9. In the exemplary embodiment according to Fig. Figure 5 shows a 2w deformation. However, a 4w deformation can also be represented, in which case two pressure circuits are provided.

[0096] The exemplary embodiment also serves to disclose an optical system which, in addition to the device 1 according to the invention, has a lens 2.

[0097] The exemplary implementations according to the Fig. Sections 2 to 5 of the device 1 according to the invention, or the optical system, are particularly suitable for holding, as well as for positioning and / or aligning, a lens 2 of a lithography system. The lens can, in particular, be a lens 207 of a projection exposure system 200 for semiconductor lithography, with an illumination system 201 comprising a radiation source and a projection optic 206, according to the Fig.1. In the lithography system according to the invention, at least one of the lenses 207 is held, positioned, and / or aligned by at least one device 1 according to the invention. In the lithography system according to the invention, at least one of the lenses 207 and its mount 206 form an optical system according to the invention. Reference symbol list 1 Device 2 lenses Version 3 4 outer ring 5 inner ring 6 joint 7 Lever arm 7a first side of the lever arm 7b second side of the lever arm 8 pairs of actuators 9 first actuator, fluidic actuator, pneumatic actuator 10 second actuator, spring assembly 11 Spring, compression spring 12 Adjusting screw 13 Threaded sleeve 200 DUV projection exposure system 201 Lighting system 202 reticulation days 203 reticles 204 wafers 205 wafer holders 206 Projection optics 207 lens Version 208 209 lens bodies 210 Projection beam QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 198 27 603 A1 [0010, 0012, 0013, 0016, 0082] DE 10 2008 041 287 A1 [0015, 0016, 0083, 0084, 0089]

Claims

[1] Device (1) for holding a lens (2), in particular a lens (2) of a lithography system, comprising a mount (3) with an outer ring (4) and an inner ring (5) designed to receive the lens (2), wherein the outer ring (4) and the inner ring (5) are connected to each other via a plurality of joints (6), and wherein the inner ring (5) has a plurality of lever arms (7) by the deflection of which perpendicular to the plane of the mount (3) a deformation can be imposed on the lens (2), and comprising a plurality of pairs of actuators (8), wherein each pair of actuators (8) is assigned to one of the lever arms (7), and comprising a first actuator (9) and a second actuator (10) which are arranged coaxially to each other, wherein the lever arm (7) is arranged between the two actuators (9, 10) and the actuators (9, 10) of the actuator pair (8) are suitable for exerting an opposing force on the lever arm (7) to act, characterized by, that in each case the first actuator (9) of the actuator pairs (8) is designed as a fluidic actuator and the second actuator as a spring device (10). [2] Device (1) according to claim 1, characterized by , that the fluidic actuators are designed as pneumatic actuators (9). [3] Device (1) according to claim 1 or 2, characterized by that the lever arms (7) and the joints (6) are preferably arranged uniformly around the circumference of the inner ring (5), between the inner ring (5) and the outer ring (4), wherein one of the joints (6) is arranged between each pair of lever arms (7). [4] Device (1) according to one of claims 1, 2 or 3, characterized by , that four lever arms (7) on which a pair of actuators (8) acts and four joints (6) are provided. [5] Device (1) according to any one of claims 1 to 4, characterized by , that the joints (6) are designed as solid body joints. [6] Device (1) according to any one of claims 1 to 5, characterized by , that in adjacent pairs of actuators (8) the first and second actuators (9, 10) are arranged in an alternating order with respect to the lever arms (7), such that the first actuator (9) of one of the pairs of actuators (8) is arranged on a first side of the lever arm (7a) and the first actuator (9) of the adjacent pair of actuators (8) is arranged on an oppositely oriented second side of the associated lever arm (7b). [7] Device (1) according to any one of claims 1 to 6, characterized by , that the spring assembly (10) has a spring (11) preferably designed as a compression spring. [8] Device (1) according to claim 7, characterized by , that the spring assembly (10) has an adjusting screw (12) by whose screw-in depth a preload force of the spring (11) can be adjusted. [9] Device (1) according to claim 8, characterized by, that the spring assembly (10) has a threaded sleeve (13) which at least partially receives the spring (11) and into which the adjusting screw (12) can be screwed for compression and thus for adjusting the preload force of the spring (11). [10] Device (1) according to any one of claims 1 to 9, characterized by , that a pressure circuit is provided for controlling the fluidic actuators (9) for a 2-wave deformation of the lens. [11] Device (1) according to any one of claims 1 to 9, characterized by , that for a 4-wave deformation two pressure circuits are provided for controlling the fluidic actuators (9). [12] Optical system comprising a device (1) according to any one of claims 1 to 11 and a lens (2), wherein the lens (2) is received by the inner ring (5) of the device (1) and is deformable by means of the actuator pairs (8) of the device (1). [13] Optical system according to claim 12, characterized by, that the lens (2) is a lens of a lithography system. [14] Optical system according to claim 12 or 13, characterized by , that the inner ring (4) of the device (1), which receives the lens (2), has four lever arms (7) and four joints (6) which are arranged uniformly around the circumference of the inner ring (5), between the inner ring (5) and the outer ring (4), wherein one of the joints (6) is arranged between each pair of lever arms (7), wherein the joints (6) are designed as solid body joints and, in the case of adjacent pairs of actuators (8), the first and second actuators (9, 10) are arranged in an alternating sequence with respect to the lever arms (7), such that the first actuator (9) of one of the pairs of actuators (8) is arranged on a first side of the associated lever arm (7a) and the first actuator (9) of the adjacent pair of actuators (8) is arranged on an oppositely oriented second side of the associated lever arm (7b). [15] Lithography system, in particular projection exposure system (200) for semiconductor lithography, comprising an illumination system (201) with a radiation source and a projection optic (206) comprising at least one lens (207), characterized by that the lens (207) is held by at least one device (1) according to one of claims 1 to 11 and / or is part of an optical system according to one of claims 12 to 14.

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