DE102017207433A1 - Support of an optical element - Google Patents

Abstract

The present invention relates to an optical arrangement, in particular for microlithography, with an optical element (108), a support structure (109), a connection device (110) and an actuator device (111). The connecting device (110) connects the optical element (108) at least substantially statically determined with the support structure (109) and is designed to at least substantially absorb the weight force acting on the optical element (108). The actuator device (111) mechanically connects the optical element (108) to the support structure (109) and is configured to set a position and / or orientation of the optical element (108) in at least one degree of freedom. The connecting device (110) has a connecting part and a decoupling part, wherein the decoupling part is arranged kinematically in series with the connecting part between the connecting part and the optical element (108). The actuator device (111) acts kinematically parallel to the connection part of the connection device (110) between the optical element (108) and the support structure (109). The decoupling part of the connection device (110) is designed such that it provides mechanical decoupling between the optical element (108) and the support structure (109) in the at least one degree of freedom.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an optical arrangement. Furthermore, the invention relates to an optical imaging device with such an optical arrangement, a corresponding method for supporting an optical element and a corresponding optical imaging method. The invention can be used in conjunction with any optical imaging method. It can be used particularly advantageously in the manufacture or inspection of microelectronic circuits and of the optical components (for example optical masks) used therefor.

The optical devices used in connection with the fabrication of microelectronic circuits typically comprise a plurality of optical element units comprising one or more optical elements, such as lenses, mirrors or optical gratings, arranged in the imaging light path. These optical elements typically cooperate in an imaging process to transfer an image of an object (e.g., a pattern formed on a mask) to a substrate (eg, a so-called wafer). The optical elements are typically grouped into one or more functional groups, which are optionally held in separate imaging units. Particularly in the case of mainly refractive systems operating at a wavelength in the so-called vacuum ultraviolet range (VUV, for example at a wavelength of 193 nm), such imaging units are often formed from a stack of optical modules which hold one or more optical elements. These optical modules typically include a support structure having a substantially annular outer support unit supporting one or more optical element holders, which in turn support the optical element.

The ever-advancing miniaturization of semiconductor devices leads to a constant need for increased resolution of the optical systems used in their manufacture. This need for increased resolution requires the need for increased numerical aperture (NA) and increased imaging accuracy of the optical systems.

One approach to obtaining increased optical resolution is to reduce the wavelength of the light used in the imaging process. In recent years, approaches have been increasingly followed in which light in the so-called extreme ultraviolet (EUV) was used, typically at wavelengths of 5 nm to 20 nm, in most cases at a wavelength of about 13 nm. In this EUV range it is no longer possible to use conventional refractive optical systems. This is due to the fact that the materials used for refractive optical systems in this EUV range have an absorptivity that is too high to achieve acceptable imaging results with the available light output. Consequently, in this EUV field, reflective optical systems must be used for imaging.

This transition to high numerical aperture (eg NA> 0.4 to 0.5) reflective optical systems in the EUV range poses significant challenges in terms of imager design.

The above factors lead to very stringent requirements as to the position and / or orientation of the optical elements participating in the imaging relative to one another as well as with respect to the deformation of the individual optical elements to achieve a desired imaging accuracy. In addition, it is necessary to maintain this high level of imaging accuracy throughout the operation, ultimately over the life of the system.

As a consequence, the components of the optical imaging device (eg, the mask, the optical elements, and the substrate) that interact in imaging must be supported in a well-defined manner to maintain a given well-defined spatial relationship between these components and minimal undesirable deformation to achieve these components in order ultimately to achieve the highest possible image quality.

In order to maintain this predetermined spatial relationship between the components throughout the imaging process, it is common in such optical imaging devices to at least intermittently capture this spatial relationship and at least some of the components in at least one degree of freedom (up to all six degrees of freedom in FIG Room). The same often applies to the deformation and deformation of individual components. It is also Typically, it is necessary to move the mask and substrate from time to time to image different areas of the pattern of the mask onto different areas of the substrate.

In particular, in the case of the above-described reflective optical systems in the EUV range with their actively adjustable and / or deformable mirrors, there is often the problem that each adjusting movement of the mirror at its bearings (ie at the points where the mirror via a corresponding connection means with its support structure is connected) generates a corresponding displacement. This shift at the bearing points in the relevant degree of freedom is usually against a corresponding (typically elastic) restoring force of the connecting device. These restoring forces of the bearing are introduced into the mirror and generate there parasitic voltages, which in the worst case progress to the area of the optically used surface of the mirror and there lead to an undesirable deformation of the mirror surface.

In order to avoid such parasitic voltages as much as possible, it is therefore typically provided in conventional systems that the points of application of the actuators and of the connection device to the support structure are as close as possible to one another. This is the one problem that such a design (not least because of confined space conditions) is difficult or can be realized with great effort. Often, therefore, an approach is followed, in which the actuators are integrated into the connecting device, as for example from the WO 2010/007036 A2 (Kugler et al.), The entire disclosure of which is incorporated herein by reference.

In particular, in such a compact or integrated design, however, there is the problem that the connection of the actuators must be designed as stiff as possible under dynamic aspects in order to achieve the highest possible control bandwidth. However, this rigid connection typically also has an effect on the rigidity in the region of the respective storage location, so that only a comparatively small deformation decoupling in this area can be achieved.

It is expected that the mirrors used in commercial EUV systems will become larger and more sensitive to parasitic forces and moments in the future, while at the same time the permissible deformations of the mirror surfaces will become smaller and smaller.

Another problem with these active systems is that they typically require a variety of actuators and sensors, etc., that introduce a non-negligible amount of heat into the system. The resulting thermal expansion of the system components leads to an undesirable deviation from the desired state and thus to a deterioration of the image quality.

BRIEF SUMMARY OF THE INVENTION

Against this background, the object of the invention is to make available an optical arrangement, an optical imaging device, a method for supporting an optical element and an imaging method which do not or at least to a lesser extent have the disadvantages mentioned above and in particular realized in a simple way, a reduction of the parasitic voltages in the optical element with good dynamic properties.

The invention is based on the technical teaching that in an optical arrangement of the type mentioned in a simple way, a reduction of unwanted parasitic voltages in the optical element can be realized with good dynamic properties, when the connecting device in kinematical serial sequence a connecting part and a decoupling and the actuator device kinematically acts parallel to the connection part of the connection device between the optical element and the support structure, while the decoupling part of the connection device is designed such that it interposes a mechanical decoupling in the at least one degree of freedom in which the adjustment of the optical element takes place the optical element and the support structure provides.

In a variant in which the actuator device acts on the decoupling part, ie is arranged kinematically parallel only to the connecting part, it is advantageously possible to achieve a mechanical decoupling between the optical element and the support structure via a high rigidity of the decoupling part , Thanks to the high rigidity of the decoupling part, only a comparatively small deformation of the decoupling part results even with high rigidity of the connecting part. This leads only to low parasitic forces, which then even with large restoring forces (from the Connecting part) are introduced via the decoupling in the optical element. Especially the high rigidity of the decoupling part, which is acted on by the actuator device, is thereby of great advantage from a dynamic point of view.

With a connection of the actuator device to the optical element, that is to say a completely kinematically parallel arrangement of the actuator device to the connection device, the connection of the actuator device to the optical element can be designed largely independently of the connection of the connection device to the optical element.

The connecting device is then typically designed so that it receives at least a large part, preferably all static loads during operation (usually the weight of the optical element), while the actuator means at least predominantly, preferably exclusively serves the required for the positioning movements to apply dynamic forces.

This functional separation has the advantage that the connection of the actuator device in the at least one degree of freedom, in which an active adjustment of the optical element is to take place, can be made rigid. As a result, particularly favorable dynamic properties of the system can be achieved.

The connection of the connecting device, however, can advantageously have a design which, at least in the at least one degree of freedom, in which an active adjustment of the optical element by the actuator device, has the lowest possible rigidity or can follow the movements of the optical element. By means of this mechanical decoupling in the relevant degree of freedom (up to all six degrees of freedom in space), particularly favorable designs can be realized, in which only comparatively small parasitic voltages from the connecting device are introduced into the optical element.

In one aspect, the invention therefore relates to an optical arrangement, in particular for microlithography, with an optical element, a support structure, a connection device and an actuator device. The connecting device connects the optical element at least substantially statically determined with the support structure and is further adapted to at least substantially absorb the weight force acting on the optical element. The actuator device mechanically connects the optical element to the support structure and is further configured to adjust a position and / or orientation of the optical element in at least one degree of freedom. The connection device has a connection part and a decoupling part, wherein the decoupling part is arranged kinematically in series with the connection part between the connection part and the optical element. The actuator device kinematically acts parallel to the connection part of the connection device between the optical element and the support structure. In this case, the decoupling part of the connection device is designed such that it provides mechanical decoupling between the optical element and the support structure in the at least one degree of freedom.

The mechanical decoupling achieved in the region of the connection device between the support structure and the optical element in the at least one actuated degree of freedom can in principle be effected in any suitable manner.

In the variants described above with a connection of the actuator device to the decoupling part, the mechanical decoupling between the support structure and the optical element is achieved, for example, simply by a high rigidity of a component of the decoupling part which is connected between the support structure and the optical element. Thanks to the high rigidity of this component of the decoupling part, even with high rigidity of the connecting part or large loads introduced into this highly rigid component, only a comparatively small deformation of this highly rigid component of the decoupling part results. This only leads to small deformations or parasitic forces on the side of the highly rigid component facing the optical element, which are then introduced into the optical element via the remainder of the decoupling part.

In certain variants, the decoupling part of the connecting device therefore has a carrier section and a decoupling section, wherein the decoupling section is arranged kinematically in series with the carrier section between the carrier section and the optical element. The connecting part of the connecting device has, in the at least one degree of freedom, a connecting part stiffness CVT, while the carrier section has at least one degree of freedom in the carrier section stiffness CTA and the decoupling section has at least one degree of freedom Decoupling section stiffness CEA. The actuator device engages the carrier section to produce a deflection of the carrier section in the at least one degree of freedom. The connecting part exerts a restoring force in the at least one degree of freedom on the carrier section in the at least one degree of freedom during the deflection of the carrier section due to the connecting part stiffness CVT, while the restoring force causes a deformation of the carrier section in the at least one degree of freedom resulting from the decoupling section on the basis of FIG Decoupling section stiffness CEA acts a parasitic force in the at least one degree of freedom on the optical element. The support portion stiffness CTA is set so large that the parasitic force is at most 5% to 10%, preferably at most 1% to 5%, more preferably at most 0.5% to 1%, of the restoring force.

In certain other variants, the decoupling is achieved simply via a correspondingly low rigidity of the decoupling part in the relevant actuated degree of freedom.

In this case, the rigidity of the decoupling part can be in particular only a fraction, preferably only a small fraction of the rigidity of the connecting part in the actuated degree of freedom.

In certain variants, the actuator device also acts kinematically parallel to the decoupling part between the optical element and the support structure, wherein the connection part of the connection device has a connection part stiffness CVT in the at least one degree of freedom. The decoupling part of the connection device has at least one decoupling section, which provides the mechanical decoupling in the at least one degree of freedom and in which at least one degree of freedom has a decoupling part stiffness CET. In this case, the Entkopplungsteilsteifigkeit CET is at most 5% to 10%, preferably at most 1% to 5%, more preferably at most 0.5% to 1%, the connecting part stiffness CVT. Hereby, particularly favorable systems can be achieved both with regard to the dynamics and to the deformation decoupling.

The respective absolute stiffness of the decoupling part or of the connecting part of the connecting device can basically be adapted to the particular application, in particular the dynamic requirements or the requirements for the deformation decoupling. Preferably, the respective stiffness is selected such that at least 90%, preferably at least 95%, more preferably at least 99%, of the deflection imparted to the optical element by the actuator means in the at least one degree of freedom, by the decoupling part (more precisely its elastic Deformation). This can also be particularly favorable systems.

It goes without saying that, where appropriate, a plurality of decoupling sections can also be provided, which are arranged kinematically serially between the optical element and the support structure. In this way, if appropriate, particularly favorable configurations can be achieved, in which the decoupling movement is divided between the decoupling sections, so that, if appropriate, corresponding geometric boundary conditions can be maintained more easily. Furthermore, the individual decoupling sections can directly adjoin one another or follow one another. Likewise, however, one or more intermediate sections (in comparison to one or more of the decoupling sections) may also be provided between two such decoupling sections. In certain variants, one of the decoupling sections may adjoin or be connected directly to the optical element, while the other decoupling section directly adjoins or is connected to the support structure.

The connecting device can in principle be designed in any suitable manner, in particular to fulfill the function of introducing the static loads from the optical element into the supporting structure. For this purpose, the connecting device may optionally consist exclusively of the decoupling section. In particularly favorable variants, the connecting device comprises a support section. This may be arranged kinematically in series with the decoupling section and, for example, constitute an intermediate section as described above. In particular, the carrier portion (in all variants) in the actuated degree of freedom have a higher rigidity than the decoupling portion. The stiffness CTA of the support section can be in particular within the limits as mentioned above for the stiffness CTA.

The respective carrier section and / or the respective decoupling section may, if appropriate, consist of a plurality of mutually separated segments along a circumferential direction of the optical element. In particularly favorable variants, in particular the support portion is annular, wherein it extends along an outer periphery of the optical element. This can be particularly compact Be achieved designs, which are particularly favorable in terms of the defined support of the optical element. The support portion may be formed in particular in the manner of a mounting ring to achieve these advantages.

In certain variants, the decoupling section is arranged kinematically in series with the carrier section, wherein the decoupling section is preferably arranged between the carrier section and the optical element. In this way, particularly favorable configurations can be achieved in which, in particular, the support section forms a favorable, possibly sufficiently rigid interface for the defined connection to the support structure.

In principle, the mechanical decoupling in the actuated degree of freedom can be effected by the decoupling section in any suitable manner. As will be explained in more detail below, it can be provided, in particular, that an active decoupling takes place in that the decoupling section carries out an adjustment movement which follows the deflection of the optical element.

In certain variants, however, a passive mechanical decoupling is provided alone or in combination with such an active component. For this purpose, the at least one decoupling section for providing the mechanical decoupling may comprise a plurality of elastic decoupling units. These elastic decoupling units then ensure by a correspondingly low rigidity in the at least one (actuated) degree of freedom that the connecting device can follow the movement of the optical element, without generating larger elastic restoring forces and thus parasitic stresses in the optical element.

The mechanical decoupling via the elasticity or low rigidity of the decoupling units can basically be realized in any suitable manner by the material and / or the design of the decoupling units. In certain variants, the at least one decoupling unit comprises at least one spring element which provides the mechanical decoupling.

In this case, the spring element and / or its orientation in the room can basically be chosen arbitrarily suitable. In particular, the spring element and / or its orientation can be adapted to the movement to be achieved (following the optical element) or the respective degree of freedom (translational or rotational) in which the decoupling is to take place. Here, any desired spring elements can be used. Because of the particularly simple design, the spring element is preferably designed in the manner of a leaf spring element.

Preferably, the spring element has at least one spring section, which extends transversely to the at least one (actuated) degree of freedom. As a result, a favorable bending load of the spring element is realized. The spring element can basically be designed arbitrarily in its course. Preferably, the at least one spring element at least in sections has a substantially L-shaped or U-shaped configuration, since in this way particularly favorable configurations with good mechanical decoupling transversely to the legs of these L or U-shaped cross sections can be achieved.

In further variants, at least one decoupling unit is designed in the manner of a bipod. This makes it possible to achieve a particularly well-defined support of the optical element despite the mechanical decoupling. Preferably, the decoupling portion is formed in the manner of a Hexapods by comprising three designed in the manner of a bipod decoupling units, since hereby a particularly favorable support can be achieved. In principle, the decoupling units can be distributed arbitrarily along the circumference of the optical element.

In particular, the decoupling units can be arranged distributed substantially uniformly on a circumference of the optical element.

The connection of the optical element via the connecting device to the support structure can basically take place in any suitable manner via one or more suitable connecting elements. In certain variants, the connecting device comprises at least one kinematic serially arranged between the optical element and the support structure connecting element. This connecting element has a first end hinged at a first connection point, which is associated with the optical element, and a hinged at a second connection point second end, which is associated with the support structure. In this case, the connecting element is designed such that the first connection point of a deflection of the optical element in the at least one degree of freedom from a Resting at least partially follows. Such a connection has the advantage that a particularly simple, precisely defined connection of the optical element to the support structure can be achieved.

In certain variants, the connecting device may comprise a compensating device which is designed to at least partially reduce a relative deflection between the first connection point and the second connection point in the at least one degree of freedom caused by the deflection of the optical element. Of course, a complete compensation of the relative deflection takes place, of course. The compensation device can be designed passive, semi-active or active to realize the readjustment movement. For example, it can be provided that the readjustment movement takes place at least partially by hand via a corresponding actuating element. Likewise, additionally or alternatively, however, a correspondingly controlled actuator can also be provided.

In certain variants, however, a mechanical decoupling can also be realized in that the compensation device exerts a counterforce, in particular a magnetic counterforce, on the optical element, which counteracts an elastic restoring force resulting from the relative deflection. This force compensation preferably takes place in the region of the connection of the connecting device to the optical element, that is to say in the region of the point at which the parasitic restoring forces would otherwise be introduced into the optical element and thus generate corresponding parasitic voltages in the optical element.

In certain variants, the first attachment point undergoes a deflection by a deflection amount in the case of a predefinable deflection of the optical element in the at least one degree of freedom. The compensation device is then preferably designed to reduce the relative deflection between the first attachment point and the second attachment point in the at least one degree of freedom to less than 20% to 50%, preferably less than 10% to 20%, more preferably less than 1% to 5%. , to reduce the amount of deflection of the first attachment point. Of course, it is particularly preferable if this relative deflection is reduced to substantially 0% of the deflection amount of the first connection point. This makes it possible to achieve a particularly favorable mechanical decoupling in the relevant degree of freedom and thus a reduction of the parasitic voltages in the optical element.

The connecting elements can in principle be designed in any suitable manner. Preferably, the first connection point and / or the second connection point is designed in the manner of a solid-state joint, since in this way particularly favorable configurations with small tolerances can be realized.

The connection points can in principle be designed arbitrarily, in particular be adapted to the movement to be achieved or decoupling in the respective degree of freedom. Particularly favorable configurations with a defined decoupling in at least one degree of freedom can be achieved if the first connection point and / or the second connection point is designed in the manner of a hinge joint. A defined decoupling in several degrees of freedom can be achieved, in particular, if the first connection point and / or the second connection point is designed in the manner of a universal joint or a ball joint.

The remaining design of the connecting element, in particular the design between the two connection points, can in principle be chosen arbitrarily and optionally adapted to the geometric boundary conditions in the environment of the connecting element. Particularly simple designs result if the connecting element is designed at least between the first connection point and the second connection point in the manner of a rod.

In certain variants, the compensation device is designed to track the second connection point for reducing the relative deflection of the first connection point. In this case, the compensation device can be designed, in particular, as an active unit with a compensation actuator which acts between the support structure and the second connection point in order to shift the second connection point in the at least one degree of freedom in the direction of the first connection point. With this, it is possible, if appropriate, to achieve almost 100% mechanical decoupling or parasitic stresses can be at least almost completely avoided by elastic restoring forces.

In certain active variants, a control device is provided, which controls the actuator device and the compensation device. In this case, the control device may in particular comprise a sensor device which detects at least one deflection value representative of the deflection of the optical element and / or the first connection point in the at least one degree of freedom. The control device then controls the compensation device as a function of the detection value in order to generate the desired or required tracking of the second connection point.

In certain variants, the control device may comprise at least one temperature sensor device which detects at least one temperature value representative of a temperature of the optical arrangement. The control device can then control the compensation device as a function of the temperature value. This can be done in particular to compensate for different thermal expansions. Furthermore, the drive can be effected using a thermal model of the optical arrangement which was previously determined (theoretically and / or empirically) for the optical arrangement.

In certain variants, the compensation device comprises an intermediate unit which is arranged in the at least one degree of freedom movable between the support structure and the second attachment point. The compensation device is then designed to move the intermediate unit in the at least one degree of freedom in the direction of the first connection point in order to track the second connection point to the first connection point. This makes it possible to realize a particularly simple design with a reliable guidance of the second connection point.

In turn, the intermediate unit can in principle be connected to the support structure in any suitable manner. Preferably, the intermediate unit is connected to the support structure via a parallel guide which acts in the at least one degree of freedom, since in this way a particularly favorable kinematics can be achieved.

The intermediate unit can basically be an arbitrarily designed component. In particular, it may be a simple passive component. Preferably, the intermediate unit has a gravity compensation device for receiving at least part of the weight of the optical element. This makes it possible to achieve particularly compact and favorable designs, in which, in particular, reliable decoupling of the gravity compensation device in the relevant degree of freedom is achieved.

In certain variants, the connection device comprises at least one active gravity compensation device, which in particular primarily initiates the static loads from the optical element into the support structure. The active gravity compensation device may comprise at least one force actuator, preferably a Lorentz actuator, for actively receiving at least part of the weight of the optical element. This results in particularly favorable configurations.

The present invention can be used in principle with any optical elements. It proves to be particularly favorable when the optical element has a reflective optical surface. Preferably, the optical element is for use with UV light, in particular at a wavelength in the vacuum UV range (VUV) or in the extreme UV range (EUV), in particular at a wavelength of 193 nm to 248 nm (in the VUV range) or 5 nm to 20 nm, in particular 13 nm (EUV range) is formed. In this area, the advantages of the invention come particularly well to fruition.

The present invention further relates to an optical imaging device, in particular for microlithography and / or wafer inspection, with a lighting device having a first optical element group, an object device for receiving an object, a projection device with a second optical element group and an image device, wherein the illumination device for Lighting of the object is formed and the projection device is designed for projecting an image of the object on the image device. The illumination device and / or the projection device comprises at least one optical arrangement according to the invention. Hereby, the variants and advantages described above can be realized to the same extent, so that in this regard reference is made to the above statements.

The present invention further relates to a method for supporting an optical element, in particular for microlithography, in which the optical element is connected via a connecting device at least substantially statically determined with a support structure, wherein the connecting means at least substantially the weight force acting on the optical element receives. The optical element is mechanically connected to the support structure via an actuator device, wherein the actuator device is designed to set a position and / or orientation of the optical element in at least one degree of freedom. The actuator device acts kinematically parallel to the connection device between the optical element and the support structure, wherein the connection device in the at least one degree of freedom a mechanical decoupling between the optical element and the support structure provides. Hereby, the variants and advantages described above can be realized to the same extent, so that in this regard reference is made to the above statements.

The present invention furthermore relates to an optical imaging method, in particular for microlithography and / or wafer inspection, in which an object is illuminated via a lighting device having a first optical element group and generates an image of the object on an image device by means of a projection device having a second optical element group becomes. In this case, an inventive method for supporting an optical element used in the illumination device and / or the projection device, in particular during the generation of the image. Hereby, the variants and advantages described above can be realized to the same extent, so that in this regard reference is made to the above statements.

Further aspects and embodiments of the invention will become apparent from the dependent claims and the following description of preferred embodiments, which refers to the accompanying figures. All combinations of the disclosed features, whether or not they are the subject of a claim, are within the scope of the invention.

list of figures

• 1 is a schematic representation of a preferred embodiment of a projection exposure apparatus according to the invention, which comprises a preferred embodiment of an optical arrangement according to the invention and can be carried out with the preferred embodiments of the inventive method.
• 2 is a schematic sectional view of a variant of the optical arrangement according to the invention 1 ,
• 3 is a schematic sectional view of the details of the optical arrangement 2 ,
• 4 is a schematic sectional view of a detail of a further variant of the optical arrangement according to the invention 1 ,
• 5 shows schematic sectional views of a further variant of the optical arrangement according to the invention in different states (A to C).
• 6 shows schematic sectional views of a detail of a further variant of the optical arrangement according to the invention in different states (A and B).
• 7 is a diagram of the forces involved in the optical arrangement 6 Act.

DETAILED DESCRIPTION OF THE INVENTION

First embodiment

The following is with reference to the 1 to 3 a first preferred embodiment of a projection exposure apparatus according to the invention 101 described, which comprises a preferred embodiment of an optical module according to the invention. To simplify the following explanations, an x, y, z coordinate system is indicated in the drawings, the z direction corresponding to the direction of gravitational force. Of course, it is possible in further embodiments to choose any deviating orientations of an x, y, z coordinate system.

1 is a highly schematic, not to scale representation of the projection exposure system 101 , which can be used in a microlithography process for the production of semiconductor devices. The projection exposure machine 101 includes a lighting device 102 and a projection device 103 , The projection device 103 is designed to be an image of a structure of a mask in an exposure process 104.1 in a mask unit 104 is arranged on a substrate 105.1 to transfer that in a substrate unit 105 is arranged. For this illuminates the lighting device 102 the mask 104.1 , The optical projection device 103 receives the light from the mask 104.1 and project the image of the mask structure of the mask 104.1 on the substrate 105.1 such as a wafer or the like.

The lighting device 102 comprises an optical element group 106 which is an optical module 106.1 having. The projection device 103 comprises an optical element group 107 , which is an optical arrangement according to the invention in the form of an optical module 107.1 having. The optical modules 106.1 . 107.1 the optical element groups 106 . 107 are along a folded optical axis 101.1 the projection exposure system 101 arranged. Each of the optical element groups 106 . 107 can be a variety of optical modules 106.1 . 107.1 include.

In the present embodiment, the projection exposure apparatus operates 101 with light in the EUV range (extreme UV range), with wavelengths between 5 nm to 20, in particular with a wavelength of about 13 nm. For the optical modules 106.1 . 107.1 the lighting device 102 and the projection device 103 In the present example, these are exclusively reflective optical elements. In further embodiments of the invention, it is of course also possible (in particular as a function of the wavelength of the illumination light) to use any type of optical elements (refractive, reflective, diffractive) alone or in any desired combination. In particular, the lighting device 102 and / or the projection device 103 one or more optical modules according to the invention 107.1 include. In further variants of the invention, the imaging device 101 (with appropriate adjustments to the components and their arrangement) for example, for inspection purposes, for example, for wafer inspection, are used.

2 shows a detail of an embodiment of an optical module according to the invention 107.1 , Again 2 can be seen, includes the optical module 107.1 an optical element 108 and a support structure 109 the projection device 103 , The optical element 108 comprises an inner, at least partially optically usable useful area with an optically used in operation optical surface 108.1 ,

The optical element 108 is with the support structure 109 via a connection device 110 connected. The connection device 110 supports the optical element 108 essentially static on the support structure. In this case, the connection device takes 110 the on the optical element 108 acting weight at least substantially.

To the optical element 108 in the operation of the imaging device 101 to be able to actively adjust is an actuator device 111 provided that the optical element 108 also mechanically with the support structure 109 combines. The actuator device 111 is designed to be controlled by a (not shown) control device, a position and / or orientation of the optical element 108 sets in at least one degree of freedom.

In the present example, the actuator device 111 including the position of the optical element 108 in two actuated translational degrees of freedom, namely along the x-axis and the y-axis. It is understood that the actuator device 111 in other variants, the optical element 108 in any number of the six degrees of freedom in space can move. In particular, the adjusting movement can be limited to only one aktuierten degree of freedom, but also positioning movements in all six degrees of freedom are possible.

Again 2 can be seen, the actuator device acts 111 kinematically parallel to the connection device 110 between the optical element 108 and the support structure 109 acts. In this case, the connection device 110 designed such that they in the respective actuated degree of freedom mechanical decoupling between the optical element 108 and the support structure, as described below by way of example with reference to the actuated degree of freedom DOFx along the x-axis. It is understood that a corresponding mechanical decoupling can be realized in an analogous manner for any other degrees of freedom.

Due to the kinematically parallel arrangement of the connecting device 110 and the actuator device 111 may be the connection of the actuator 111 on the optical element 108 largely independent of the connection of the connecting device 110 on the optical element 108 be designed. The connection device 110 Therefore, it can be designed to operate in the imaging device 101 absorbs all static loads (usually the weight of the optical element 108 ), while the actuator device 111 exclusively serves for the adjusting movements on the optical element 108 apply required dynamic forces.

This functional separation has the advantage that the connection of the actuator device 111 in the degree of freedom DOFx, in which the active displacement of the optical element 108 should be done, can be made rigid. As a result, particularly favorable dynamic properties of the system can be achieved.

The connection of the optical element 108 via the connection device 110 On the other hand, it advantageously has a design which has the least possible rigidity in the actuated degree of freedom DOFx or the movements of the optical element 108 can follow without significant resistance. As a result of this mechanical decoupling in the actuated degree of freedom DOFx, only comparatively low parasitic voltages resulting from elastic restoring forces of the connecting device result from the adjusting movement 110 conditional and in the optical element 108 be initiated.

The mechanical decoupling between the support structure 109 and the optical element 108 becomes in the actuated degree of freedom DOFx simply over a correspondingly low total rigidity of the connecting device 110 achieved in the actuated degree of freedom DOFx. In the present example, the overall rigidity of the connector is 110 in the actuated degree of freedom DOFx chosen so low that the connecting device 110 at the deflection of the optical element 108 in the actuated degree of freedom DOFx only a small parasitic restoring force in the optical element 108 initiates.

In order to achieve the low rigidity and thus the mechanical decoupling in the actuated degree of freedom DOFx, the connecting device comprises 110 a connection part and a decoupling part. The decoupling part comprises a decoupling section 110.1 and a support section 110.3 , The decoupling section 110.1 is from a variety of decoupling units 110.2 in the form of spring elements 110.4 formed, which provide the mechanical decoupling. The connecting part is in the present example of an intermediate unit in the form of a gravity compensation device 110.5 educated.

In the present example, the decoupling part (from decoupling section 110.1 and beam section 110.3 ) in the degree of freedom DOFx a Entkopplungsteilsteifigkeit CET, which is at most 5% to 10%, preferably at most 1% to 5%, more preferably at most 0.5% to 1%, the connecting part stiffness CVT of the connecting part 110.5 in the actuated degree of freedom DOFx is. In other variants, however, other stiffness values can also be selected.

In the present example, there is only one decoupling section 110.1 between the support structure 109 and the optical element 108 intended. However, it goes without saying that if necessary also several decoupling sections 110.1 may be provided, which are mutually kinematically serially between the optical element 108 and the support structure 109 are arranged. In this way, if appropriate, particularly favorable configurations can be achieved in which the decoupling movement is effected on the decoupling sections 110.1 is divided, so possibly corresponding geometric boundary conditions, such as the available space for movement of the optical element 108 and the moving parts of the connecting device 110 , can be complied with more easily. Furthermore, the individual decoupling sections 110.1 directly adjoin or follow one another. Likewise, between two decoupling sections 110.1 but also one or more intermediate sections may be provided which are stiffer in the actuated degree of freedom DOFx than one or both of the decoupling sections 110.1 , In certain variants, one of the decoupling sections 110.1 (as shown) directly to the optical element 108 be adjacent to this or connected thereto, while the other decoupling section 110.1 (not shown) directly to the support structure 109 adjacent to or connected to this.

In the present example, the connection device comprises 110 a support member annularly surrounding the optical element in the form of a mounting ring 110.3 , The mounting ring 110.3 is kinematically serial to the decoupling section 110.1 arranged, wherein the decoupling section 110.1 between the mounting ring 110.3 and the optical element 108 lies.

The mounting ring 110.3 FIG. 12 illustrates an intermediate portion as described above having a stiffness CTA in the actuated degree of freedom DOFx which is significantly higher than the decoupling portion stiffness CEA of the decoupling portion 110.1 , The stiffness CTA of the mounting ring 110.3 lies within the limits, as will be specified below in connection with a further variant. The mounting ring 110.3 thus forms a cheap, rigid interface to the defined connection of the optical element 108 to the support structure 109 ,

The connection of the mounting ring 110.3 to the support structure 109 can in principle be done in any suitable manner. In particular, the mount ring 110.3 directly to the support structure 109 be connected, for example, be flanged. In the present example, however, the connection is made via the intermediate unit in the form of the gravity compensation device 110.5 which are the static ones Loads from the optical element 108 in the support structure 109 initiates, thus for receiving the weight of the optical element 108 serves.

The gravity compensation device 110.5 in the present example comprises three (preferably evenly) on the circumference of the mounting ring 110.3 distributed gravity compensation devices 110.6 , The gravity compensation devices 110.6 may be simple passive components in certain variants. In the present example, the gravity compensation device 110.5 however, designed as an active component. For this purpose, each gravity compensation device 110.6 comprises (in a well-known manner) a force actuator, for example a Lorentz actuator.

The mechanical decoupling between the optical element 108 and the support structure 109 in the actuated degree of freedom DOFx, in the present example, purely passive occurs via the spring elements 110.2 of the decoupling section 110.1 at the outer periphery of the optical element 108 or on the inner circumference of the mounting ring 110.3 (preferably evenly) are distributed. These spring elements 110.2 form elastic decoupling, which has a correspondingly low rigidity CEA of the decoupling section 110.1 in the actuated degree of freedom DOFx. Due to this low stiffness CEA ensures that the connecting device 110 the movement of the optical element 108 can follow without major elastic restoring forces FR and thus parasitic voltages in the optical element 108 to create.

The mechanical decoupling on the elasticity or low stiffness of the spring elements 110.2 can in principle in any suitable manner by the material and / or the design of the spring elements 110.2 will be realized. In this case, the spring element 110.2 and / or its orientation in space to be achieved (the optical element 108 following) movement or the respective actuated degree of freedom DOF be adapted (translational or rotary) in which the decoupling is to take place. This can be designed as desired spring elements 110.2 be used. Because of the particularly simple design is the respective spring element 110.2 formed in the present example in the manner of a leaf spring element.

How the particular 3 can be seen, has the respective spring element 110.2 in the direction perpendicular to the circumferential direction of the optical element 108 standing radial plane (here: in the xz plane) in sections a substantially L-shaped cross-section. Here is the spring element 110.2 arranged so that a spring section 110.4 (which forms one of the legs of the L-shaped cross section) extends transversely to the actuated degree of freedom DOFx. As a result, a favorable bending load of the spring element 110.2 realized, which ensures an effective decoupling in the actuated degree of freedom DOFx.

The 3 shows a deflected state in which the optical element 108 opposite to its resting state (dashed contour 113 ) in the actuated degree of freedom DOFx by the actuator device 111 is deflected by the deflection amount DA. Due to the actuator device 111 generated shift of the optical element 108 in the actuated degree of freedom DOFx results in the support of the optical element 108 on the decoupling section 110 an elastic restoring force FR, which leads to parasitic stresses in the optical element 108 leads.

wobei gilt: $$CR=\frac{CTA}{1+\frac{CTA}{CEA}}\cdot$$

With the above described stiffness values of the mounting ring 110.3 (CTA), the decoupling section 110.1 (CEA), the combined stiffness (CR) of frame ring 110.3 and decoupling section 110.1 and the stiffness values of the optical element 108 (CO) and the gravity compensation device 110.5 (CG) in the actuated degree of freedom DOFx results in the following relationship for the elastic restoring force FR in comparison to an elastic restoring force FRD, which in the case of a direct connection of the optical element 108 via the gravity compensation device 110.5 to the support structure 109 would work (as in 2 through the dashed outline 114 is indicated): $$FR=FRD\cdot \left[\frac{CG+CO}{CG+CO+\frac{CG\cdot CO}{CR}}\right].$$

where: $$CR=\frac{CTA}{1+\frac{CTA}{CeA}}\cdot$$

As can be seen from equation (2), the combined stiffness CR (of ferrule 110.3 and decoupling section 110.1 ) significantly when the stiffness CEA of the decoupling section 110.1 (which in any case is less than the stiffness CTA of the mounting ring 110.3 ) is lowered. It can be seen from equation (1) that, in comparison with the direct connection of the optical element (see contour 114 in 2 ) Also a significant reduction of the elastic restoring force FR and thus the parasitic voltages in the optical element 108 can be achieved.

It is understood that with the present example of the imaging device 101 the inventive method described above for supporting the optical element 108 or let the imaging method described above be performed.

Second embodiment

The following is with reference to the 1 . 2 and 4 a further preferred embodiment of the optical arrangement according to the invention in the form of an optical module 207.1 described, which instead of the optical module 107.1 in the imaging device 101 can be used. The optical module 207.1 corresponds in its basic design and operation of the optical module of the 2 and 3 , so that only the differences should be discussed here. In particular, identical components are provided with the same reference numerals, while similar components with the value 100 are provided with increased reference numerals. Unless otherwise stated below, with regard to the features, functions and advantages of these components, reference is made to the above statements in connection with the first exemplary embodiment.

A difference to the optical module 107.1 is that in the optical module 207.1 a connection of the (again at the support structure 109 connected) actuator device 211 on the mounting ring 210.3 the decoupling part takes place, as in 2 through the dashed outline 211 is indicated. The actuator device 111 generates the desired deflection of the mounting ring 110.3 and thus the optical element 108 in the at least one actuated degree of freedom DOFx. In this variant, the actuator device 211 thus only to the connecting part 110.5 arranged kinematically in parallel.

The connecting part 110.5 the connecting device has, in the at least one actuated degree of freedom DOFx, the above-described connecting part stiffness CVT, while the mounting ring 210.3 (That is, the support portion) in the at least one actuated degree of freedom DOFx has a support portion stiffness CTA and the decoupling portion 210.2 in which at least one actuated degree of freedom DOFx has a decoupling section stiffness CEA.

The connecting part 110.5 exercises at the deflection of the mounting ring 110.3 (As in the first embodiment) due to the connecting part stiffness CVT in the at least one actuated degree of freedom DOFx a restoring force FR in the at least one degree of freedom DOFx on the mounting ring 210.3 out. This restoring force FR, together with the force FA, causes the actuator device 211 a deformation of the mounting ring 210.3 in the at least one degree of freedom DOFx from that at the decoupling section 210.1 due to the decoupling section stiffness CEA, a parasitic force FP results in the at least one degree of freedom DOFx impinging on the optical element 108 acts.

Carrier portion rigidity CTA of the socket ring 210.3 is chosen so large in the present example that the parasitic force FP is at most 5% to 10%, preferably at most 1% to 5%, more preferably at most 0.5% to 1%, of the restoring force FR.

In the present example, the mechanical decoupling between the support structure 109 and the optical element 108 thus substantially by a high rigidity CTA of a component, namely the mounting ring 210.3 of the decoupling part (from mounting ring 210.3 and decoupling section 210.1 ) achieved between the support structure 109 and the optical element 108 is switched. Thanks to the high rigidity CTA, CVT of the connecting part is obtained even with high rigidity 110.5 or large in the high-stiff rim ring 210.3 introduced loads (restoring force FR) only a relatively small deformation of the mounting ring 210.3 , This only leads to small deformations of the optical element 108 facing interface of the mounting ring 210.3 and thus to low parasitic forces FP, via the decoupling section 210.1 in the optical element 108 be initiated.

Another difference from the design of the first embodiment is that instead of the plurality of decoupling in the form of the spring elements 110.2 a decoupling section 210.1 is realized, in which three (preferably evenly) on the outer circumference of the optical element 108 distributed decoupling units 210.2 are provided.

Each of the three decoupling units 210.2 is designed in the manner of a bipod, so that the decoupling section 210.1 overall designed in the manner of a hexapod is hereby a particularly favorable, well-defined connection of the optical element 108 to the mounting ring 210.3 and thus the support structure 109 can be achieved. The individual pursuits 210.7 of the respective bipod 210.2 are designed so that they each restrict exactly one degree of freedom (namely, the degree of freedom along its longitudinal axis). For this purpose, they can be designed for example as a simple bar springs.

It is understood that also with the optical module 207.1 in the imaging device 101 the inventive method described above for supporting the optical element 108 or let the imaging method described above be performed.

Third embodiment

The following is with reference to the 1 and 5 a further preferred embodiment of the optical arrangement according to the invention in the form of an optical module 307.1 described, which instead of the optical module 107.1 in the imaging device 101 can be used. The optical module 307.1 corresponds in its basic design and operation of the optical module of the 2 and 3 , so that only the differences should be discussed here. In particular, identical components are provided with the same reference numerals, while similar components with the value 200 are provided with increased reference numerals. Unless otherwise stated below, with regard to the features, functions and advantages of these components, reference is made to the above statements in connection with the first exemplary embodiment.

A difference to the design of the first embodiment is the connection of the optical element 108 via the connection device 310 to the support structure 109 , In the present example, this connection is made via three (preferably uniformly) on the outer circumference of the optical element 108 distributed rod-shaped connecting elements 310.8 in the form of so-called pins. The connecting elements 310.8 are mutually kinematically parallel between the optical element 108 and the support structure 109 arranged, wherein the respective connecting element 310.8 in itself kinematically serially between the optical element 108 and the support structure 109 is arranged.

The respective connecting element 310.8 has a first end that at a first connection point 310.9 hinged to the optical element 108 is connected (thus therefore the optical element 108 assigned). The connecting element 310.8 also has a second end at a second attachment point 310.10 hinged to an intermediate unit 310.6 tethered, in turn, to the support structure 109 is connected. The second end of the connecting element 310.8 is thus the support structure 109 assigned.

At a deflection of the optical element 108 through the actuator 111 from a rest position (see 5 , State A) is followed by the first connection point 310.9 in the actuated degree of freedom DOFx the optical element 108 like this in 5 (see state B) is shown. From this deflection results in an elastic restoring force FR, at the first connection point 310.9 leading to parasitic voltages in the optical element 108 would lead.

In order to avoid such parasitic voltages, the connection means comprises 310 a compensation device 310.11 , one by the deflection of the optical element 108 Conditional Relativauslenkung between the first connection point 310.9 and the second connection point 310.10 in the actuated degree of freedom DOFx (here: x-direction) is at least partially reduced. The compensation device 310.11 Thus, therefore, is adapted to track the second connection point to reduce the relative displacement of the first connection point. Of course, a complete compensation of the relative deflection takes place, of course.

The compensation device 310.11 is at the support structure 109 supported and can be passive, semi-active or actively designed to realize the Nachstellbewegung. For example, it can be provided that the readjustment movement takes place at least partially by hand via a corresponding actuating element. In the present example, an active readjustment movement takes place. For this purpose, the compensation device comprises 310.11 a correspondingly controlled compensation actuator, which is located between the support structure 109 and the second connection point 310.10 acts to the second connection point 310.10 in the actuated degree of freedom DOFx in the direction of the first connection point 310.9 to move.

In the present example, the first attachment point experiences 310.9 at a predetermined deflection of the optical element 108 in the actuated degree of freedom DOFx a deflection by a deflection amount DA (see 5 , Condition B). The compensation device 310.11 then reduced, controlled by a corresponding control device (not shown), the relative displacement DAR between the first connection point 310.9 and the second connection point 310.10 by placing the intermediary 310.6 in the actuated degree of freedom DOFx shifts (see 5 , Condition C).

In the present example, the relative displacement DAR by the compensation device 310.11 reduced to the value zero. However, it goes without saying that, if necessary, a certain relative deflection DAR can also be present even after the readjusting movement. However, the relative displacement DAR is preferably reduced to less than 20% to 50%, preferably less than 10% to 20%, more preferably less than 1% to 5%, of the deflection amount DA of the first connection point 310.9 (please refer 5 , State B) from the rest position (see 5 , State A) reduced. Of course, it is particularly preferred if this relative displacement DAR amounts to essentially 0% of the deflection amount DA of the first connection point 310.9 is reduced. This allows a particularly favorable mechanical decoupling in the relevant degree of freedom DOFx and thus a reduction of the parasitic voltages in the optical element 108 achieve.

It is understood that, in principle, any desired time sequence of the actuating movements of the actuator device 111 and the compensation device 310.11 can be realized. So first, the deflection of the optical element 108 through the actuator device 111 and only after the completion of the adjustment by the compensation device 310.11 respectively. In principle, however, a reverse order of the positioning movements can be provided. Furthermore, it is possible that the actuating movements of the actuator 111 and the compensation device 310.11 at least in sections, parallel in time.

To achieve a defined adjustment movement, the intermediate unit is 310.6 in the present example via a parallel guidance acting in the actuated degree of freedom 310.12 with the support structure 109 connected, since hereby a particularly favorable kinematics can be achieved. It is understood, however, that in other variants, any other suitable guide means may be provided which provide a guide in the respective degrees of freedom available.

In this example, the first attachment point is 310.9 and the second connection point 310.10 each formed in the manner of a solid state joint, as this particularly favorable configurations can be realized with low tolerances. The connection points 310.9 . 310.10 can be adapted to the movement to be achieved or decoupling in the respective degree of freedom DOF. Particularly favorable configurations with a defined decoupling in one degree of freedom (for example DOFx) can be achieved if the first connection point 310.9 and the second connection point 310.10 is designed in the manner of a hinge joint. A defined decoupling in several degrees of freedom can be achieved in particular if the first connection point 310.9 and / or the second attachment point 310.10 is designed in the manner of a universal joint or a ball joint.

The remaining design of the connecting element 310.8 , in particular the design between the two connection points 310.9 and 310.10 , can in principle be chosen arbitrarily and optionally to the geometric boundary conditions in the vicinity of the connecting element 310.8 be adjusted. Particularly simple designs arise when the connecting element at least between the first connection point 310.9 and the second connection point 310.10 as in the present example is designed in the manner of a rod.

In the present example with the active compensation device 310.11 a control device (not shown) is provided, which controls the actuator device 111 and the compensation device 310.11 controls. In this case, the control device may in particular comprise a (not shown) sensor device which at least one for the deflection DA of the optical element 108 and / or the first access point 310.9 in the actuated degree of freedom DOFx representative deflection value EDA detected. The control device then controls the compensation device 310.11 in response to the detection value EDA to the desired or required tracking of the second connection point 310.10 to create.

In certain variants, the control device may comprise at least one temperature sensor device, which at least one for a temperature of the optical arrangement 107.1 representative temperature value ET recorded. The control device can then the compensation device 310.11 triggering in dependence on the temperature value ET. This can in particular for the compensation of different thermal expansions between the optical element 108 and the support structure 109 respectively. Furthermore, the drive can be controlled using a thermal model MT of the optical arrangement 107.1 take place, which previously for the optical arrangement 107.1 (theoretically and / or empirically) was determined and stored in the control device.

The intermediate unit 310.6 can basically be an arbitrarily designed component. In particular, it may be a simple passive component. However, in the present example, the intermediate unit is again an active gravity compensation device 310.6 designed to absorb the static loads from the optical element 108 serves as already above in connection with the gravity compensation device 110.6 has been described.

It is understood that also with the optical module 307.1 in the imaging device 101 the inventive method described above for supporting the optical element 108 or let the imaging method described above be performed.

Fourth embodiment

The following is with reference to the 1 . 6 and 7 a further preferred embodiment of the optical arrangement according to the invention in the form of an optical module 407.1 described, which instead of the optical module 107.1 in the imaging device 101 can be used. The optical module 407.1 corresponds in its basic design and operation of the optical module 307.1 out 5 , so that only the differences should be discussed here. In particular, identical components are provided with the same reference numerals, while similar components with the value 100 are provided with increased reference numerals. Unless otherwise stated below, with regard to the features, functions and advantages of these components, reference is made to the above statements in connection with the first exemplary embodiment.

A difference to the design of the third embodiment is the connection of the optical element 108 via the connection device 410 to the support structure 109 , In the present example, this connection again takes place via preferably three (preferably uniformly) on the outer circumference of the optical element 108 distributed rod-shaped connecting elements 410.8 in the form of so-called pins. The connecting elements 410.8 in turn are kinematically parallel between the optical element 108 and the support structure 109 arranged, wherein the respective connecting element 410.8 in turn alone kinematically serially between the optical element 108 and the support structure 109 is arranged.

In contrast to the third embodiment, the connecting elements 410.8 in the area of its second end over the second connection point 410.10 connected directly to the support structure. The compensation device 410.11 In contrast, each includes a passive magnetic compensation unit 410.13 with a cup-like first compensation element 410.14 and an annular second compensation element 410.15 ,

Again 6 can be seen, the connecting element extends 410.8 in the interior of the first compensation element 410.14 into and is connected to its bottom. The second compensation element 410.15 surrounds the first compensation element 410.14 and is rigid with the support structure 109 connected. The first compensation element 410.14 and the second compensation element 410.15 each comprise radial magnetized permanent magnets. The magnetization is such that on the outer circumference of the first compensation element 410.14 around the north pole is formed, while on the inner circumference of the second compensation element 410.15 surrounding the south pole is formed.

In the in 6 Rest position shown on the left (state A) are the two compensation elements 410.14 and 410.15 centered on each other, so that the magnetic force acting between them Attractions pick each other up. At a deflection of the optical element 108 through the actuator device 111 in the actuated degree of freedom DOFx by the amount of deflection DA (see 6 , State B) become the two compensation elements 410.14 and 410.15 shifted to each other, resulting in a change in the between the compensation elements 410.14 and 410.15 acting attractions.

7 schematically shows the course of the cutting plane in the 6 acting left-hand magnetic attraction FML (on the left side of the first compensation element 410.14 ) and the right-hand magnetic attraction FMR (on the right side of the first compensation element 410.14 ) as a function of the deflection D (from the rest position D = 0) between the compensation elements 410.14 and 410.15 , It also shows the course of the magnetic force FM resulting from the attractive forces FMR and FML at the first compensation element 410.14 , Further shows 7 the negative value -FR of the elastic restoring force FR, which from the deflection of the connecting element 410.8 results and on the optical element 108 acts.

Again 7 can be seen, the magnetic attraction forces FMR and FML are coordinated such that the resulting magnetic force FM over a working range AB substantially the negative value -FM of the elastic restoring force FR corresponds, therefore, the following applies: $$\text{FM}=\text{-FR}\text{,}$$

In other words, lift up on the first compensation element 410.14 that from the deflection of the optical element 108 resulting elastic restoring force FR and the resultant magnetic force FM on each other. About the connection of the first compensation element 410.14 on the optical element 108 Thus, despite the deflection of the optical element 108 no parasitic forces in the optical element 108 initiated, which could lead to parasitic voltages there.

Thus, in the present example, the mechanical decoupling between the optical element 108 and the support structure 109 So via a passive force compensation by the magnetic forces FM of the compensation unit 410.13 achieved, which the elastic restoring force FR of the connecting element 410.8 compensated.

It is understood that also with the optical module 407.1 in the imaging device 101 the inventive method described above for supporting the optical element 108 or let the imaging method described above be performed.

The present invention has been described above with reference to individual embodiments, which are based in part on different principles of action. However, it is understood that the variants shown can also be arbitrarily combined with one another in order to achieve a desired mechanical decoupling between the optical element 108 and the support structure 109 to achieve.

The present invention has been described above with reference to an example from the field of microlithography. It is understood, however, that the invention may also be used in connection with any other optical applications, in particular imaging processes at other wavelengths.

Furthermore, the invention can be used in connection with the inspection of objects, such as the so-called mask inspection, in which the masks used for microlithography are examined for their integrity, etc. In place of the substrate 105.1 then enters 1 For example, a sensor unit, which is the image of the projection pattern of the mask 104.1 (for further processing). This mask inspection may then be performed at substantially the same wavelength as used in the later microlithography process. Likewise, however, any deviating wavelengths may be used for the inspection.

Finally, the present invention has been described above on the basis of concrete exemplary embodiments, which show concrete combinations of the features defined in the following patent claims. It should be expressly noted at this point that the subject matter of the present invention is not limited to these combinations of features, but also all other combinations of features, as they result from the following claims, are the subject of the present invention.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2010/007036 A2 [0010]

Claims (15)

Optical arrangement, in particular for microlithography, with an optical element (108), a support structure (109), a connection device (110, 210, 310, 410) and an actuator device (111, 211), wherein the connecting device (110, 210, 310, 410) at least substantially statically connects the optical element (108) to the support structure (109) and is designed to at least substantially receive the weight force acting on the optical element (108), the actuator device (111; 211) mechanically connects the optical element (108) to the support structure (109) and is adapted to set a position and / or orientation of the optical element (108) in at least one degree of freedom, characterized in that the connection device (110, 210, 310, 410) has a connection part and a decoupling part, the decoupling part is arranged kinematically in series with the connection part between the connection part and the optical element (108), - the actuator device (111; 211) acts kinematically parallel to the connection part of the connection device (110; 210; 310; 410) between the optical element (108) and the support structure (109) and - The decoupling part of the connecting device (110; 210; 310; 410) is designed such that it provides in the at least one degree of freedom, a mechanical decoupling between the optical element (108) and the support structure (109). Optical arrangement according to Claim 1 in which - the decoupling part of the connecting device (110; 210; 310; 410) has a carrier section (210.3) and a decoupling section (210.1), - the decoupling section (210.1) is kinematically serial to the carrier section (110.3) between the carrier section (110.3) and the connecting element (110; 210; 310; 410) has a connecting part stiffness CVT in the at least one degree of freedom, - the carrier section (110.3) has a support section stiffness CTA in the at least one degree of freedom, the decoupling section (210.1) in which at least one degree of freedom has a decoupling section stiffness CEA, - the actuator device (211) acts on the carrier section (210.3) to produce a deflection of the carrier section (210.3) in the at least one degree of freedom, wherein - the connecting part the deflection of the carrier section (210.3) due to the verb and the restoring force causes deformation of the support portion (210.3) in the at least one degree of freedom from that at the decoupling portion (210.1) due to the decoupling portion stiffness CEA a parasitic force in which at least one degree of freedom acts on the optical element (108), the support section stiffness CTA is chosen so large that the parasitic force is at most 5% to 10%, preferably at most 1% to 5%, more preferably at most 0, 5% to 1%, the restoring force amounts. Optical arrangement according to Claim 1 in which - the actuator device (111) acts kinematically parallel to the decoupling part between the optical element (108) and the support structure (109), - the connection part of the connection device (110; 210; 310; 410) has a connection part stiffness CVT in the at least one degree of freedom and - the decoupling part of the connection device (110; 210; 310; 410) has at least one decoupling section (110.1; 210.1) which provides the mechanical decoupling in the at least one degree of freedom and in which at least one degree of freedom has a decoupling part stiffness CET, - The Entkopplungsteilsteifigkeit CET is at most 5% to 10%, preferably at most 1% to 5%, more preferably at most 0.5% to 1%, the connecting part stiffness CVT. Optical arrangement according to Claim 2 or 3 in which - the connecting device (110; 210; 310; 410) has a carrier section (110.3), wherein - the support section (110.3; 210.3) is in particular of annular design, preferably designed in the manner of a mounting ring, and extends along an outer circumference of the optical element (108) and / or - the decoupling section (110.1; 210.1) in particular kinematically serially to the support section ( 110.3; 210.3) is arranged, preferably between the support section (110.3; 210.3) and the optical element (108) is arranged. Optical arrangement according to Claim 3 or 4 in which - the at least one decoupling section (110.1; 210.1) for providing the mechanical decoupling comprises a plurality of elastic decoupling units (110.2; 210.2), wherein - at least one decoupling unit (110.2; 210.2) comprises in particular at least one spring element, wherein the at least one spring element is preferably formed in the manner of a leaf spring element, wherein the at least one spring element preferably has at least one spring portion which extends transversely to the at least one degree of freedom and / or the at least one spring element at least partially has a substantially L-shaped or U-shaped configuration, and / or - at least one decoupling unit (210.2) is designed in the manner of a bipod, and / or - the decoupling section (210.1) is designed in the manner of a hexapod by comprising three decoupling units designed in the manner of a bipod, wherein the decoupling units (210.2) , especially e substantially uniformly distributed on a circumference of the optical element (108). Optical arrangement according to one of Claims 1 to 5 in which - the connecting device (110; 210; 310; 410) has at least one connecting element (310.8) arranged kinematically in series between the optical element (108) and the supporting structure (109), - the connecting element (310.8) articulates at a first connecting point having tethered first end associated with the optical element (108) and having a second end hinged at a second attachment point associated with the support structure (109), the connection element (310.8) being formed such that the first attachment point a deflection of the optical element (108) in the at least one degree of freedom from a rest position is at least partially followed, and - the connecting device (110; 210; 310; 410) comprises compensating means (310.10; 410.10) which is adapted to move one through the Deflection of the optical element (108) conditional Relativauslenkung between the first connection point and the second connection point in the at least one degree of freedom at least partially reduce and / or a counterforce, in particular a magnetic counterforce to exert, which counteracts a resulting from the Relativauslenkung elastic restoring force, wherein - the first connection point at a predetermined deflection of the optical element (108) in the at least one degree of freedom experiences a deflection by a deflection amount, and the compensation device (310.10) is designed in particular to reduce the relative deflection between the first attachment point and the second attachment point in the at least one degree of freedom to less than 20% to 50%, preferably less than 10% to 20%, more preferably less than 1% to 5%, of the amount of deflection of the first attachment point. Optical arrangement according to Claim 6 in which - the first connection point and / or the second connection point is designed in the manner of a solid-body joint and / or - the first attachment point and / or the second attachment point are designed in the manner of a hinge joint or a cardan joint or a ball joint and / or - the connection element ( 310.8, 410.8) is formed at least between the first connection point and the second connection point in the manner of a rod. Optical arrangement according to Claim 6 or 7 in which - the compensation device (310.10) is designed to track the second connection point for reducing the relative deflection to the first connection point, wherein - the compensation device (310.10) is designed in particular as an active unit with a compensation actuator which is arranged between the support structure (109) and the second attachment point acts to shift the second attachment point in the at least one degree of freedom toward the first attachment point. Optical arrangement according to Claim 8 , in which - a control device is provided, which activates the actuator device (111) and the compensation device (310.10), wherein - the control device comprises in particular a sensor device which at least one for the deflection of the optical element (108) and / or the first connection point in the at least one Degree of freedom representative deflection detected, and the control device controls the compensation device in response to the detection value, and / or - the control device comprises at least one temperature sensor device which detects at least one representative of a temperature of the optical arrangement temperature value, and the control device, the compensation device, in particular for Compensation of different thermal expansions, depending on the temperature value, in particular using a thermal model of the optical arrangement, drives. Optical arrangement according to Claim 8 or 9 wherein - the compensation means (310.10) comprises an intermediate unit (310.6) movably disposed in the at least one degree of freedom between the support structure (109) and the second attachment point, and - the compensation means (310.10) is adapted to interconnect the intermediate unit (310.6 ) in the at least one degree of freedom in the direction of the first attachment point, in order to track the second attachment point to the first attachment point, wherein - the intermediate unit (310.6) is connected to the support structure (109) in particular via a parallel guide (310.12) acting in the at least one degree of freedom and / or - the intermediate unit (310.6) in particular has a gravity compensation device for receiving at least part of the weight of the optical element (108). Optical arrangement according to one of Claims 1 to 10 in which - the connecting device (110; 210; 310; 410) has at least one active gravity compensation device (110.6; 310.6), wherein - the active gravity compensation device (110.6; 310.6) for actively receiving at least part of the weight of the optical element (108) in particular at least one force actuator, preferably a Lorentz actuator comprises. Optical arrangement according to one of Claims 1 to 11 in which - the optical element (108) has a reflective optical surface (108.1) and / or - the optical element (108) for use with UV light, in particular at a wavelength in the vacuum UV range (VUV) or in extreme UV Range (EUV), in particular at a wavelength of 193 nm to 248 nm or from 5 nm to 20 nm. Optical imaging device, in particular for microlithography and / or wafer inspection, comprising - a lighting device (102) having a first optical element group (106), - an object device (104) for receiving an object (104.1), - a projection device (103) a second optical element group (107) and - an image device (105), wherein - the illumination device (102) is designed to illuminate the object (104.1) and - the projection device (103) to project an image of the object (104.1) onto the image device (105) is formed, characterized in that - the illumination device (102) and / or the projection device (103) at least one optical arrangement according to one of Claims 1 to 12 includes. Method for supporting an optical element, in particular for microlithography, in which - the optical element (108) is connected to a support structure (109) at least substantially statically via a connecting device (110; 210; 310; 410), wherein the connecting device (110; 210; 310; 410) at least substantially receives the weight force acting on the optical element (108), - the optical element (108) is mechanically connected to the support structure (109) via an actuator device (111), wherein the actuator device (111) is adapted to set a position and / or orientation of the optical element (108) in at least one degree of freedom, characterized in that - a decoupling part of the connection means (110; 210; 310; 410) kinematically serially to a connection part of the connection means (110; 210; 310; 410) is arranged between the connection part and the optical element (108), the actuator device (111) acts kinematically parallel to the connection part of the connection device (110; 210; 310; 410) between the optical element (108) and the support structure (109) and - the decoupling part of the connection device (110; 210; 310; 410) wherein at least one degree of freedom provides mechanical decoupling between the optical element (108) and the support structure (109). Optical imaging method, in particular for microlithography and / or wafer inspection, in which - an object (104.1) is illuminated via a lighting device (102) having a first optical element group (106) and - by means of a projection device (103) having a second optical element group (107) an image of the object (104.1) on an image device (105) is generated, characterized in that - in the illumination device (102) and / or the projection device (103), in particular during the generation of the image, a method according to Claim 14 is used.

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