Measuring arrangement for determining position and projection exposure apparatus

Abstract

An optical measuring arrangement (100) for measuring the position and / or distance of a component relative to a reference, comprising an optical resonator (101) comprising at least one input coupling mirror (102) and an end mirror (104), which enclose a resonator cavity. The resonator cavity comprises a length adjustment range, wherein the measurement beam traverses the resonator cavity more than once. The optical resonator comprises at least one optical element or is assigned an optical element, said optical element being configured to control the beam radius of the measurement beam at the input coupling mirror and / or a Gouy phase of the measurement beam propagating in the resonator cavity, at least within the length adjustment range in the resonator cavity.

Description

[0001] Measuring arrangement for determining position and projection exposure apparatus

[0002] The present application claims the priority of German patent application 102024 210 149.4 of 21 October 2024. The entire disclosure of that patent application is incorporated by reference in the present application.

[0003] The invention relates to an optical measuring arrangement for measuring the position and / or distance of a component relative to a reference along at least one measurement axis, comprising an optical resonator that comprises at least one input coupling mirror for input coupling a measurement beam and an end mirror, which enclose a resonator cavity, wherein the resonator cavity comprises a length adjustment range and wherein the measurement beam traverses the resonator cavity more than once. The invention also relates to a projection exposure apparatus, a lithography apparatus, an inspection apparatus and a coordinate measuring machine.

[0004] Projection exposure apparatuses are used for producing extremely fine structures, in particular on semiconductor components or other microstructured component parts. The operating principle of said apparatuses is based on the production of extremely fine structures down to the order of nanometres by way of generally reducing imaging of structures on a mask, a so-called reticle, on an element to be structured, a so-called wafer, that is provided with photosensitive material. The minimum dimensions of the structures produced are directly dependent on the wavelength of the light used. Said light is shaped for the optimum illumination of the reticle in an illumination optics unit. Recently, light sources having an emission wavelength in the order of a few nanometres, for example between 1 nm and 120 nm, in particular in the order of 13.5 nm, have increasingly been used. The described wavelength range is also referred to as the EUV range.

[0005] Apart from with the use of systems which operate in the EUV range, the microstructured component parts are also produced using commercially established DUV systems, which have a wavelength of between 100 nm and 400 nm, in particular 193 nm. With the requirement to be able to produce smaller and smaller structures, the requirements in respect of optical correction in the systems have likewise increased further. Throughput is increased to increase efficiency with each new generation of projection exposure apparatuses in the EUV range or DUV range.

[0006] During operation of microlithographic projection exposure apparatuses, in which mask and wafer are usually moved relative to each other in a scanning process, the positions of the mirrors, some of which are movable in all six degrees of freedom, have to be set and maintained with high accuracy in order to avoid or at least reduce aberrations and accompanying impairments of the imaging result or else displacements of the image.

[0007] Various approaches for measuring the position of the individual mirrors and also of the wafer or the wafer stage and the reticle or the reticle stage are known in the prior art. In addition to interferometric measuring arrangements or measuring arrangements that are based on encoders, frequency-based position and / or distance measurement using an optical resonator in which a standing wave is formed is also known in this context.

[0008] For example, this is described in DE 102012212663 A1. The latter discloses an optical resonator with two resonator mirrors, of which a first resonator mirror is secured to a reference element in the form of a measurement frame fixedly connected to the housing of the projection lens of the projection exposure apparatus and a second resonator mirror (as "measurement target") is secured to a mirror to be measured with regard to the position thereof. The actual distance measuring apparatus comprises a radiation source, which is tuneable with respect to its optical frequency and which generates input coupling radiation that passes through a beam splitter and is input coupled into the optical resonator. In that case, the radiation source is controlled by a coupling device in such a way that the optical frequency of the radiation source is tuned to the resonant frequency of the optical resonator and is thus coupled to said resonant frequency. Input coupling radiation output coupled via a beam splitter is analysed by means of an optical frequency measuring device which can comprise e.g. a frequency comb generator for highly accurate determination of the absolute frequency. If the position of the EUV mirror changes in the x-direction, then together with the distance between the resonator mirrors the resonant frequency of the optical resonator also changes and hence - owing to the coupling of the frequency of the tuneable radiation source to the resonant frequency of the resonator - the optical frequency of the input coupling radiation changes as well, which is in turn recorded directly by the frequency measuring device.

[0009] Instead of a tuneable radiation source, a frequency-based position and / or distance measurement may alternatively also comprise a highly stable radiation source, the frequency of which is adjusted by means of a frequency shifter (for example by means of an IQ modulator) and using the Pound-Drever-Hall technique to follow the resonant frequency of the optical resonator and stabilized at or locked to the latter.

[0010] US 11 ,274,914 B2 discloses a measuring arrangement for frequency-based distance and / or position measurement, having an optical resonator that additionally comprises a folding mirror which is connected or connectable to the component to be measured and which is configured to steer the measurement beam back and forth between the resonator mirrors.

[0011] What is essential for the functionality of an optical resonator during the distance measurement is, firstly, that the measurement beam within the optical resonator is able to accomplish the highest possible number of circulations within the resonator (without said measurement beam leaving the cavity formed by the resonator), in order that eigenmodes may form in the resonator. What is also essential, moreover, is the capability of coupling the external radiation field present at the input of the resonator path (= "input coupling field") to the mode field of the optical resonator (= "resonator field"). In this case, the coupling efficiency that is characteristic of said coupling is defined by the overlap integral between input coupling field and resonator field, such that in order to achieve a high coupling efficiency, input coupling field and resonator field must correspond as well as possible in all relevant parameters.

[0012] WO 2019 / 223968 A1 discloses various resonators for the frequency-based position measurement of a movable component. Furthermore, DE 102023209 192 A1 discloses a resonator with a parallel beam path and a retroreflector formed from multi- pie parts. The German patent application DE 102023208513 A1 discloses a resonator cavity that is insensitive to tilts and comprises two curved resonator mirrors, and a measurement target that is arranged between the curved resonator mirrors and is configured to steer the beam back and forth between the two mirrors.

[0013] To expand the options for applying a frequency-based position and / or distance measurement, higher demands are placed on the measurement of ever larger distances. A technical challenge in this context is that of enabling a change in length over relatively large ranges with a resolving power that is as high as possible since the stability of the cavity with an increasing length adjustment range of the cavity becomes a limiting factor.

[0014] Thus, the problem addressed by the present invention is that of providing a measuring arrangement, a projection exposure apparatus, a lithography apparatus, an inspection apparatus and a coordinate measuring machine, which measure the position and / or distance of a component over a large measurement range with a high accuracy.

[0015] The problem concerning the optical measuring arrangement is solved by means of an optical measuring arrangement having the features of Claim 1. The problem concerning the projection exposure apparatus is solved by means of a projection exposure apparatus having the features of Claim 19. The problem concerning the lithography apparatus is solved by means of a lithography apparatus having the features of Claim 20, the problem concerning the inspection apparatus is solved by means of an inspection apparatus having the features of Claim 21 , and the problem concerning the coordinate measuring machine is solved by means of a coordinate measuring machine according to the features of Claim 22. Advantageous embodiments with expedient developments are specified in the dependent claims.

[0016] In particular, the optical measuring arrangement is distinguished in that the optical resonator comprises at least one optical element or is assigned thereto, said optical element being configured to control the beam radius of the measurement beam at the input coupling mirror and / or a Gouy phase of the measurement beam propagating in the optical resonator, within the length adjustment range in the resonator cavity and preferably on the basis of the change in length of the resonator cavity. In this context, the optical element of the optical resonator may be one of the mirrors that enclose the resonator cavity, i.e. for example the input coupling mirror or the end mirror, and / or at least one additional optical element assigned to the optical resonator, i.e. arranged in the resonator cavity in addition to the input coupling mirror and the end mirror. The additional optical element may also be disposed upstream of the input coupling mirror, for example be embodied as a lens element and in particular be embodied as a collimator lens element, wherein the collimator may also comprise multiple optical elements. Using the optical element, the beam radius at the input coupling mirror and / or the Gouy phase can be controlled in such a way that the input coupling efficiency of the measurement beam into the resonator cavity is high. This leads to a higher measurement accuracy, especially in the case of large differences in the length of the resonator cavity. The length adjustment range, i.e. the range within which the cavity can change its length starting from an initial length Io, is at least ±5 cm, preferably at least ±10 cm and very particularly preferably at least ±30 cm or ±50 cm. The length adjustment range consequently specifies the changes in distance and / or changes in position of the component to be measured that can be measured by means of the optical measuring arrangement. In order to be able to record an accurate measurement of the position and / or distance of the component relative to a reference, it is preferable for the resonator cavity to be stable, at least within this length adjustment range, and / or for the input coupling efficiency at the input coupling mirror to be high. The term "stable" is understood to mean that it is mainly the fundamental mode in the resonator that is excited, and that the excitation of higher mode orders is sufficiently suppressed. In particular, an optical resonator is stable within the meaning of the application if the beam radius at the input coupling mirror of the measurement beam corresponds to, or deviates by no more than 10%, preferably by no more than 5% and particularly preferably no more than 3% from, the beam radius on the input coupling mirror of the resonant beam in the resonator cavity incident on the input coupling mirror, and / or the Gouy phase is constant or approximately constant, and the quality is at least 5, preferably at least 10 and particularly preferably at least 50. Inter alia, this may be achieved by virtue of the overlap between the measurement beam to be input coupled into the resonator cavity by means of the input coupling mirror and the resonant measurement beam incident on the input coupling mirror within the resonator cavity (i.e. the measurement beam already reflected in the resonator cavity) being as large as possible. The beam radius and / or the Guoy phase can now be controlled by means of the optical element such that the overlap with the resonant measurement beam on the input coupling mirror is as large as possible, i.e. the positions and the beam radii of the input coupled and resonant measurement beams at the input coupling mirror are approximately the same. The quality of a resonator for a resonator mode is defined as the quotient of energy stored in the resonator and the energy loss occurring per oscillation period (i.e. circulation). Under the assumption of an exponential decrease in the energy of the resonator mode over time, the quality of the resonator is the quotient of the resonant frequency and the resonance width (bandwidth of the resonant frequency). If the optical resonator is formed from exactly two resonator mirrors, then one of the resonator mirrors is connected or connectable to the reference and the other one of the resonator mirrors, as measurement target, is connected or connectable to the component.

[0017] In order to provide a measuring arrangement that additionally is less sensitive to a tilt of the component and hence less sensitive to a tilt of the measurement target, it is advantageous if a mirror element is present, the latter being adjustably arranged in the resonator cavity and being configured to steer the measurement beam back and forth between the end mirror and the input coupling mirror. The mirror element may be formed as a plane folding mirror or else as a retroreflector. The mirror element may also be formed from multiple parts, in particular as a retroreflector formed from multiple parts, wherein a first partial retroreflector is connected or connectable to the component (i.e. capable of being moved with the component) and the second partial retroreflector is stationary. By preference, the two partial retroreflectors are aligned relative to each other in such a way that after passing through the input coupling mirror, the measurement beam is reflected off the partial retroreflectors to the end mirror and, from the latter, reflected back along itself to the input coupling mirror off the partial retroreflectors. By preference, the input coupling mirror and / or the end mirror are curved.

[0018] Further, it is advantageous for a frequency shifter to be present, the latter being configured to adjust the frequency of a light emitted by a light source to follow a resonant frequency of the optical resonator. By preference, the light source is formed as a frequency-stabilized light source, in particular as a highly stable light source. The Pound-Drever-Hall technique is preferably used to adjust the frequency of the light emitted by the light source to follow a resonant frequency of the optical resonator. The position and / or distance of the component relative to the reference is determined by detecting the or a resonance frequency of the optical resonator.

[0019] In this context, it is particularly advantageous if the at least one optical element is configured to keep the beam radius of the measurement beam at the input coupling mirror and / or a Gouy phase of the measurement beam propagating in the resonator cavity constant or approximately constant, at least within a length adjustment range of the resonator cavity. The longer the length adjustment range, the greater the change in the Gouy phase and the beam radius difference at the input coupling mirror between the input coupled measurement beam and the resonant measurement beam reflected in the resonator cavity. Therefore, it is particularly preferable for the at least one optical element to be configured to control the beam radius of the measurement beam at the input coupling mirror and / or a Gouy phase of the measurement beam propagating in the resonator cavity, at least within the length adjustment range of the resonator cavity, such that the measurement error is less than a predetermined or predeterminable limit value or minimal. Accordingly, it may also be advantageous to not keep the Gouy phase and / or the beam radius constant but to set them to values that generate a small or the smallest measurement error.

[0020] In particular, it is preferable for the resonator cavity to be configured to measure the position and / or distance of the component relative to the reference along two mutually linearly independent measurement axes. An optical resonator configured to determine the position and / or the distance of a component along two linearly independent measurement axes is disclosed in DE 102023209 192 A1 , the content of which is incorporated in full into the present application (incorporated by reference). In this context, the optical resonator comprises a retroreflector formed from multiple parts, wherein a first partial retroreflector is formed as the measurement target and arranged so as to be movable with the component within the optical cavity, and a second partial retroreflector is stationary. The two parts are aligned relative to each other in such a way that after passing through the input coupling mirror, the measurement beam is reflected off both parts of the retroreflector to the end mirror and, from the latter, reflected back to the input coupling mirror off the two parts of the retroreflector. The two parts may be formed as 2-D retroreflectors and, in particular, as 90° corner reflectors or as 90° prisms. By preference, the two parts are aligned perpendicular to each other. However, the optical measuring arrangement may also be used to measure the position and / or distance along one measurement axis only. The optical resonators may have any desired embodiment but must be embodied to form a standing wave within the optical resonator cavity. Further examples of suitable optical resonators are disclosed in WO 2019 / 223968 A1 or in the German patent application with the file reference 102023208513.5, which are likewise incorporated in full into the present disclosure (incorporated by reference).

[0021] Furthermore, it is preferable for the optical resonator to be formed in such a way that the beam radius of the measurement beam steered from the end mirror to the input coupling mirror grows and grows monotonically in particular.

[0022] Further, it is advantageous if a property of the optical element, in particular a position, deformation and / or refractive power of the optical element, is chosen or adaptable on the basis of a change in length of the resonator cavity, in such a way that a measurement error when measuring the position and / or distance is smaller than a predetermined or predeterminable limit value. The property may be the position and / or deformation of a surface and / or the refractive index of the optical element. Consequently, it is advantageous if the position of the optical element within the resonator cavity is adjustable such that the measurement error is less than the predetermined or predeterminable limit value or minimal. In an alternative to that or in addition, a surface of the optical element arranged in the resonator cavity or of an additional optical element arranged in the resonator cavity is deformable, at least in regions, such that the measurement error is less than the predetermined or predeterminable limit value. In an alternative to that or in addition, it is preferable for the refractive power of the optical element or of an additional optical element to be chosen such that the measurement error when measuring the position and / or distance is less than the predetermined or predeterminable limit value or minimal. The properties such as the position, deformation and / or refractive power of the optical element are preferably adaptable to the change in length of the resonator cavity, in such a way that the measurement error is less than the predetermined or predeterminable limit value. Furthermore, a plurality of optical elements may be provided, the latter controlling the Gouy phase and / or the beam radius of the measurement beam at the input coupling mirror. These may be embodied differently, i.e. as lens elements and / or mirrors. The optical elements may likewise be formed as deformable lens elements such that the refractive power and deformation are adjustable to a change in length of the resonator cavity. Furthermore, the deformable lens element may also be adjustably arranged within the resonator cavity such that its position, deformation and refractive power can be adjusted to a change in length of the resonator cavity. In this context, it is particularly preferable for the optical element to be a deformable optical element. To this end, the deformable optical element comprises at least one actuator, the latter being configured to deform the surface of the optical element at least in regions. Away from the optically active surface, the deformable optical element preferably comprises actuators, in particular solid-state actuators, such as pie-zostrictive or electrostrictive or magnetostrictive actuators. Alternatively, the actuator may however also be formed as a heat-induced actuator or as an electrostatic, electromagnetic or mechanical actuator. By preference, the deformable optical element is formed as a mirror, but it may also be formed as a lens element.

[0023] In this context, it is advantageous for the radius of curvature of the deformable optical element to be adapted or adaptable to a change in length of the resonator cavity. In this context, the radius of curvature of the deformable optical element is preferably chosen in such a way that the beam radius at the input coupling mirror of the measurement beam corresponds to, or deviates by no more than 10%, preferably by no more than 5% and particularly preferably no more than 3% from, the beam radius on the input coupling mirror of the resonant beam in the resonator cavity incident on the input coupling mirror, and / or the Gouy phase is constant or approximately constant. In particular, the radius of curvature of the deformable optical element is chosen such that the measurement error when measuring the position and / or distance is less than the predetermined or predeterminable limit value or minimal.

[0024] By preference, the deformable optical element comprises a deformable region and a region without actuators. In particular, the deformable optical element comprises an edge region that encloses the optically active surface at least in regions. The optically active surface is the surface on which the measurement beam is incident. By preference, at least one actuator is arranged, in particular extensively arranged, on or at the edge region. The region without actuators is preferably formed away from the edge region. In an alternative to that or in addition, the deformable region comprising at least one actuator may also be a lateral surface of the optical element, i.e. the at least one actuator is arranged on the lateral surface of the at least one optical element.

[0025] Within the scope of the invention, it is particularly preferable for the input coupling element to be formed as the optical element and in particular as the deformable optical element.

[0026] In an alternative to that or in addition, it is also advantageous for the at least one optical element to be formed as an optical element disposed upstream of the input coupling mirror. For example, the at least one optical element may be formed as at least one lens element, in particular as a collimator lens element. By preference, the at least one optical element is formed to be deformable, in particular deformable by means of at least one actuator. Moreover, it is advantageous for the optical element to be formed to be both deformable and adjustable, i.e. translatable and / or tiltable in particular. This ensures that the wavefront incident on the surface of the input coupling mirror is incident thereon in parallel. In an alternative and likewise preferably, the collimator comprises a plurality of optical elements. In an embodiment, one of the optical elements may be formed as a deformable optical element, and another one of the optical elements may be formed as an adjustable optical element, in particular as a translatable and / or tiltable optical element.

[0027] In an alternative to that or in addition, it is advantageous for the optical element to be formed as a refractive optical element. The refractive optical element is preferably formed as a lens element.

[0028] In this context, it is particularly preferable for the refractive optical element to be adjustable by means of an actuator in the resonator cavity, in such a way that the beam radius at the input coupling mirror of the measurement beam corresponds to, or deviates by no more than 10%, preferably no more than 5% and particularly preferably no more than 3% from, the beam radius on the input coupling mirror of the resonant beam in the optical cavity incident on the input coupling mirror, and / or the Gouy phase of the measurement beam propagating in the resonator cavity is constant or approximately constant. The position of the optical element in the form of the refractive optical element is preferably adaptable or adapted to a change in length of the resonator cavity. In particular, the position of the refractive optical element may be adjustable in such a way that the measurement error when measuring the position and / or distance of the component is less than a predetermined or predeterminable measurement error or minimal.

[0029] It is also advantageous for the at least one optical element, i.e. the refractive and / or deformable optical element, to be arranged or adjustably arranged in a region of the resonator cavity in which a radius of the measurement beam increases monotonically. The optical element may also be arranged non-adjustably, i.e. in fixed fashion, in the resonator cavity.

[0030] It is also preferable for the refractive optical element to be connected or connectable to the input coupling mirror by means of an actuator or for the input coupling mirror and the refractive element to be mounted on a joint load-bearing structure.

[0031] Moreover, it is advantageous for the adaptable property of the optical element to be controlled by means of the closed-loop control unit that adjusts a frequency of the measurement beam to follow, and locks said frequency to, the resonant frequency of the resonator cavity. Hence, it is particularly preferable for the closed-loop control unit to be configured to adapt the properties of the optical element on the basis of a resonant frequency of the resonator cavity, as ascertained by means of a Pound-Drever-Hall method, or on the basis of a variable that is derivable from the resonant frequency. Should there consequently be a change in the resonant frequency of the resonator cavity because the length within the length adjustment range is modified, the property of the optical element, i.e. a deformation (radius of curvature), refractive index (e.g. by changing the temperature) or the position within the resonator cavity, can be adapted. The closed-loop control unit may control the adaptation of the property by way of a voltage signal, for example for an actuator. To this end, a calibration method may be performed in advance, by means of which the optimal adaptation of the properties of the optical element is recorded for different resonator cavity lengths, i.e. the deformation, position and / or refractive index at which the measurement error is less than a predetermined or predeterminable limit value or minimal. Alternatively, it is also possible to determine the control variable for the actuator or for adapting the property of the optical element directly from the resonant frequency or a variable derived therefrom. Additionally, the optical element can be controlled by means of a feedforward control. The projection exposure apparatus is characterized in particular in that the latter comprises at least one optical measuring arrangement. The component to be measured of the projection exposure apparatus may preferably be at least one or more optical elements or a load-bearing structure of the projection exposure apparatus. By measuring the position of the optical elements, their position or pose or else a deformation of the optical surface may be recorded, and the position or deformation may be adjusted, preferably by means of actuators. This improves the image quality of the projection exposure apparatus. The advantages and embodiments mentioned in relation to the optical measuring arrangement are also applicable to the projection exposure apparatus comprising at least one optical measuring arrangement.

[0032] Furthermore, at least one optical measuring arrangement according to the invention may also be used in a projection lens, in particular in a projection lens of a projection exposure apparatus, for determining the position and / or distance of a movable or immovable component of the projection lens.

[0033] The optical measuring arrangement according to the invention can also be used in an illumination apparatus, in particular in an illumination apparatus for a projection exposure apparatus. The illumination apparatus preferably comprises at least one optical measuring arrangement. The latter is configured to measure the position or the distance of a movable or immovable component. To this end, the at least one optical measuring arrangement is connected or connectable indirectly or directly to the component to be measured. The component may in particular be an optical element or a load-bearing structure. To this end, the at least one optical measuring arrangement is connected or connectable indirectly or directly to the component to be measured. The illumination apparatus of a lithography apparatus comprises in particular a light source configured to generate light in an EUV or DUV wavelength range and a plurality of optical elements configured to deflect the light generated by the light source and input couple said light into the projection exposure apparatus. In this context, the advantages and embodiments mentioned in relation to the optical measuring arrangement also apply to the illumination apparatus comprising at least one optical measuring arrangement.

[0034] The lithography apparatus is characterized in particular in that it comprises at least one optical measuring arrangement. In this case, the component of the lithography apparatus may preferably be at least one or more optical elements, load-bearing structures, stages or masks of the lithography apparatus. By measuring the position of the components, formed as optical elements for example, by means of the optical measuring arrangement, their position or pose or else a deformation of the optical surface may be recorded, and the position or deformation may be adjusted, preferably by means of actuators. The advantages and embodiments mentioned in relation to the optical measuring arrangement are also applicable to the lithography apparatus comprising at least one optical measuring arrangement.

[0035] The inspection apparatus according to the invention for checking an optical element or a wafer or wafer stage or a reticle or a reticle stage comprises at least one optical measuring arrangement according to the invention. In this case, the optical measuring arrangement is configured to measure the position or the distance of a component, i.e. of for example an optical element, a wafer, a wafer stage or a reticle or a reticle stage. In this case, an evaluation unit is preferably present, the latter comparing the measured positions or distances, in particular of structures of the component, with predetermined distances or positions of the structures or components and, in the event of a deviation by a predetermined limit value, causing measures to be taken. To this end, the at least one optical measuring arrangement is connected or connectable indirectly or directly to the component to be measured. In this context, the advantages and embodiments mentioned in relation to the optical measuring arrangement also apply to the inspection apparatus comprising at least one measuring arrangement. An example of such an inspection apparatus for the inspection of masks or wafers (without the measuring arrangement according to the invention) is known from document DE 102012205181 A1, the entire content of which is incorporated into the present application by reference.

[0036] The invention may also be used in a measuring machine for measuring a position, geometry or shape of a component. In that case, the measuring machine comprises at least one optical measuring arrangement according to the invention. By preference, the at least one optical measuring arrangement is indirectly or directly connected to the component. The measuring machine may be used in particular in the context of production technology or industrial metrology in mechanical engineering, for example in the automotive industry or aeronautical engineering. To this end, the at least one optical measuring arrangement is connected or connectable indirectly or directly to the component to be measured. In this context, the advantages and embodiments mentioned in relation to the optical measuring arrangement also apply to the measuring machine comprising at least one measuring arrangement.

[0037] The coordinate measuring machine according to the invention comprises at least one optical measuring arrangement according to the invention. Coordinate measuring machines are used for inspecting or measuring components, wherein the component is usually sensed, and distances or positions are determined using the sensing results. For this purpose, an optical system as well as a movable frame structure and / or a highly accurate positioning system are present, which support the component or object to be inspected. The optical measuring arrangement is preferably connected indirectly or directly to this movable component, i.e. frame structure or positioning system. The position or distance of the movable component can be determined by means of the at least one optical measuring arrangement, whereby the scanning of the object can be controlled. Moreover, the optical measuring arrangement may also be used to measure the distance or position of the component itself and thus inspect the latter. In this context, the advantages and embodiments mentioned in relation to the optical measuring arrangement also apply to the coordinate measuring machine comprising at least one optical measuring arrangement. One example of such a coordinate measuring machine (without the measuring arrangement according to the invention) is known from document DE102019213794A1, the entire content of which is incorporated into the present application by reference.

[0038] The optical measuring arrangement according to the invention can also be used in a measuring machine. The measuring machine comprises at least one optical measuring arrangement according to the invention. In this context, the at least one optical measuring arrangement is preferably indirectly or directly connected to the component. The measuring machine may be used in particular in the context of production technology or industrial metrology in mechanical engineering, for example in the automotive industry or aeronautical engineering. To this end, the at least one optical measuring arrangement is connected or connectable indirectly or directly to the component to be measured. In this context, the advantages and embodiments mentioned in relation to the optical measuring arrangement also apply to the measuring machine comprising at least one optical measuring arrangement. Further features, properties and advantages of the present invention are described in more detail below on the basis of embodiment variants and with reference to the appended figures. In this respect, all the features described above and below are advantageous both individually and in any desired combination. The embodiment variants described below are merely examples which, however, do not limit the subject matter of the invention. In the figures:

[0039] Figure 1a shows a schematic illustration of a microlithographic projection exposure apparatus designed for operation in the EUV,

[0040] Figure 1 b shows a schematic illustration of a microlithographic projection exposure apparatus designed for operation in the DUV,

[0041] Figure 2 shows a schematic illustration of a first exemplary embodiment of an optical measuring arrangement,

[0042] Figure 3 shows a schematic illustration of a second exemplary embodiment of an optical measuring arrangement,

[0043] Figure 4 shows a schematic illustration of a third exemplary embodiment of an optical measuring arrangement, and

[0044] Figure 5 shows a schematic illustration of a further optical resonator for an optical measuring arrangement.

[0045] Figure 1a shows a schematic illustration of an exemplary projection exposure apparatus 600 which is designed for operation in the EUV and in which the present invention can be realized. However, the invention may also be used in other nanopositioning systems.

[0046] According to Fig. 1a, an illumination device in a projection exposure apparatus 600 designed for EUV comprises a field facet mirror 603 and a pupil facet mirror 604. The light from a light source unit comprising a plasma light source 601 and a collector mirror 602 is steered to the field facet mirror 603. A first telescope mirror 605 and a second telescope mirror 606 are arranged downstream of the pupil facet mirror 604 in the light path. A deflection mirror 607 is arranged downstream in the light path and steers the radiation that is incident thereon onto an object field in the object plane of a projection lens comprising six mirrors 651-656. At the location of the object field, a reflective structure-bearing mask 621 is arranged on a mask stage 620 and with the aid of the projection lens is imaged into an image plane, in which a substrate 661 coated with a light-sensitive layer (photoresist) is situated on a wafer stage 660.

[0047] The invention may likewise be used in a DUV apparatus, as illustrated in Figure 1b. A DUV apparatus is set up in principle like the above-described EUV apparatus from Figure 1a, wherein mirrors and lens elements can be used as optical elements in a DUV apparatus and the light source of a DUV apparatus emits used radiation in a wavelength range of 100 nm to 400 nm.

[0048] The DUV lithography apparatus 700 illustrated in Figure 1b comprises a DUV light source 701. For example, an ArF excimer laser that emits radiation 702 in the DUV range at for example 193 nm may be provided as the DUV light source 701. A beam shaping and illumination system 703 guides the DUV radiation 702 onto a photomask 704. The photomask 704 is embodied as a transmissive optical element and may be arranged outside the systems 703. The photomask 704 comprises a structure that is imaged onto a wafer 706 or the like in a reduced fashion by means of the projection system 705. The projection system 705 comprises multiple lens elements 707 and / or mirrors 708 for imaging the photomask 704 onto the wafer 706. In this case, individual lens elements 707 and / or mirrors 708 of the projection system 705 may be arranged symmetrically with respect to the optical axis 709 of the projection system 705. It should be noted that the number of lens elements 707 and mirrors 708 of the DUV lithography apparatus 700 is not restricted to the number illustrated. A greater or lesser number of lens elements 707 and / or mirrors 708 may also be provided. In particular, the beam shaping and illumination system 703 of the DUV lithography apparatus 700 comprises multiple lens elements 707 and / or mirrors 708. Furthermore, the mirrors are generally curved on their front side for beam shaping purposes. An air gap 710 between the last lens element 707 and the wafer 706 can be replaced by a liquid medium having a refractive index of >1. The liquid medium may be high-purity water, for example. Such a construction is also referred to as immersion lithography and has an increased photolithographic resolution.

[0049] Figure 2 shows a first exemplary embodiment of an optical measuring arrangement 100 for measuring the position and / or the distance of a component (not depicted in detail) relative to a reference (not depicted in detail) along at least one measurement axis. The optical measuring arrangement 100 comprises an optical resonator 101 that comprises at least one input coupling mirror 102 and an end mirror 104, which enclose a resonator cavity 105. The input coupling mirror 102, which is usually connected to the reference, is configured to input couple a measurement beam 103, which was emitted by a light source 116 and preferably collimated by means of a collimator 117, into the resonator cavity 105. Moreover, the optical resonator 101 comprises a mirror element that is connected or connectable to the component, formed as a measurement target 106, adjustably arranged in the resonator cavity 105 and configured to steer the measurement beam 103 back and forth between the end mirror 104 and the input coupling mirror 102. The mirrors 102, 104, 106 of the resonator cavity 105 may be curved or planar. Moreover, the mirror element may also be formed as a retroreflector, in particular as a retroreflector formed from multiple parts. The resonator cavity 105 might also merely comprise exactly two mirrors or else reflective lens elements. The resonator cavity 105 comprises a length adjustment range 107. The length adjustment range 107 specifies the change in length of the resonator cavity from an initial length Io. The length adjustment range 107 is preferably at least ±5 cm, preferably at least ±10 cm and very preferably at least ±30 cm or ±50 cm. The length adjustment range 107 consequently specifies the changes in distance and / or changes in position of the component to be measured that can be measured by means of the optical measuring arrangement 100. By preference, the resonator cavity 105 is stable within the length adjustment range 107, with the term "stable" being understood to mean that it is mainly the fundamental mode in the optical resonator 101 that is excited, and that the excitation of higher mode orders is sufficiently suppressed. Furthermore (albeit not depicted in detail here), the optical measuring arrangement comprises a frequency shifter that is con- figured to adjust the frequency of a light emitted by a light source to follow a resonant frequency of the optical resonator 101. By preference, the light source is formed as a frequency-stabilized light source, in particular as a highly stable light source. The Pound-Drever-Hall technique is preferably used to adjust the frequency of the light emitted by a light source to follow a resonant frequency of the optical resonator. The position and / or distance of the component relative to the reference is determined by detecting the or a resonance frequency of the optical resonator. To measure the distance and / or position as accurately as possible, it is advantageous for the input coupling efficiency at the input coupling mirror 102 to be high. The longer the length adjustment range 107, the greater the change in the Gouy phase and the beam radius difference at the input coupling mirror between the input coupled measurement beam and the resonant measurement beam reflected in the resonator cavity, and so these changes need to be compensated for or approximately compensated for in order to obtain a high measurement accuracy. To this end, the optical resonator 101 comprises at least one optical element 108 that is configured to control the beam radius of the measurement beam 103 at the input coupling mirror 102 and / or a Gouy phase of the measurement beam 103 propagating in the resonator cavity 105, at least within the length adjustment range 107 in the resonator cavity 105. Using the optical element 108, the beam radius at the input coupling mirror 102 and / or the Gouy phase can be controlled in such a way that the input coupling efficiency of the measurement beam 103 into the resonator cavity 105 is high. Inter alia, this may be achieved by virtue of the overlap between the measurement beam 103 to be input coupled into the resonator cavity 105 by means of the input coupling mirror 102 and the resonant measurement beam 103 incident on the input coupling mirror 102 within the resonator cavity 105 (i.e. the measurement beam 103 already reflected in the resonator cavity 105) being as large as possible. The beam radius and / or the Guoy phase can now be controlled by means of the at least one optical element 108 such that the overlap between the input coupled and resonant measurement beams 103 on the input coupling mirror 102 is as large as possible, i.e. the positions and the beam radii of the input coupled and resonant measurement beams 103 at the input coupling mirror 102 are approximately the same.

[0050] This may be achieved by virtue of the optical element 108 being configured to keep the beam radius of the measurement beam 105 at the input coupling mirror and / or a Gouy phase of the measurement beam 103 propagating in the resonator cavity 105 constant or approximately constant, at least within the length adjustment range 107 of the resonator cavity 105. Expressed in more general terms, the at least one optical element 108 is configured to control the beam radius of the measurement beam 103 at the input coupling mirror 102 and / or a Gouy phase of the measurement beam 103 propagating in the resonator cavity 105, at least within the length adjustment range 107 of the resonator cavity 105, such that the measurement error is less than a predetermined or predeterminable limit value or minimal. Accordingly, it may also be advantageous to not keep the Gouy phase and / or the beam radius of the measurement beam constant but to set them to values that generate a small or the smallest measurement error when measuring the position and / or distance of the component. The optical element 108 may be a mirror that encloses the resonator cavity 105, i.e. the input coupling mirror 102 or the end mirror 104 for example. In an alternative to that or in addition, the optical element 108 may also be at least one additional optical element that is assigned to the optical resonator 101. This additional optical element may be arranged in the resonator cavity 105, i.e. in the beam path between the end mirror 104 and the input coupling mirror 102, or else be disposed upstream of the input coupling mirror 102.

[0051] In this case, the optical resonator 101 is formed in such a way that the beam radius of the measurement beam 103 steered from the end mirror 104 to the input coupling mirror 102 grows and grows monotonically in particular. In this case, the optical element 108 is arranged in that region of the resonator cavity 105 in which the beam radius of the measurement beam 103 grows and grows monotonically in particular. The at least one optical element 108 is formed as a deformable optical element 109 in Figure 2. To this end, the deformable optical element 109 comprises at least one actuator 113, the latter being configured to deform the surface of the deformable optical element 109 at least in regions. By preference, a plurality of actuators are arranged, in particular extensively arranged, in planar fashion on a back side of the deformable optical element 109 that faces away from the resonator cavity 105. The actuators 113 may be formed as solid-state actuators, i.e. piezostrictive or electro-strictive or magnetostrictive actuators, or in an alternative they may also be in the form of a heat-induced actuator or an electrostatic, electromagnetic or mechanical actuator. By preference, the deformable optical element is formed as a mirror, but it may also be formed as a lens element. In the exemplary embodiment according to Figure 2, the deformable optical element 109 is formed as the input coupling mirror 102; however, it may self-evidently also be formed as an additional optical element within the resonator cavity 105. For example (but not shown presently), the deformable optical element 109 may be disposed upstream or downstream of the input coupling mirror 102 in the beam path of the optical measuring arrangement 100. In the present case, the radius of curvature of the deformable optical element 109 is adapted or adaptable to a change in length of the resonator cavity 105. In this case, the radius of curvature of the deformable optical element 109 is preferably chosen in such a way that the beam radius at the input coupling mirror 102 of the measurement beam 103 corresponds to, or has a maximum relative deviation of no more than 5% from, the beam radius on the input coupling mirror 102 of the resonant measurement beam in the resonator cavity incident on the input coupling mirror 109, and / or the Gouy phase of the measurement beam 103 propagating in the resonator cavity 105 is constant or approximately constant. In particular, the radius of curvature of the deformable optical element 109 is chosen such that the measurement error when measuring the position and / or distance is less than the predetermined or predeterminable limit value or minimal.

[0052] In the present case, the deformable optical element 109 comprises a deformable region 110, i.e. a region with actuators 113, and a region 111 without actuators. In particular, the deformable optical element 109 comprises an edge region that encloses the optically active surface at least in regions. The optically active surface is the surface on which the measurement beam 103 is incident. By preference, at least one actuator 113 is arranged, in particular extensively arranged, on or at the edge region. The region 111 without actuators is preferably formed away from the edge region. In an alternative to that or in addition, the deformable region 110 comprising at least one actuator 113 may also be a lateral surface of the optical element 108, i.e. the at least one actuator 113 is arranged on the lateral surface of the at least one optical element.

[0053] Figure 3 shows a further exemplary embodiment of the optical measuring arrangement 100, wherein this exemplary embodiment is distinguished in that the at least one optical element 108 is formed as a refractive optical element 112. The refractive optical element 112 is preferably formed as a lens element. In this case, the refractive optical element 112 is adjustable by means of an actuator 113 in the resonator cavity 105, in such a way that the beam radius at the input coupling mirror 102 of the measurement beam 103 corresponds to, or has a relative deviation of no more than 10%, preferably of no more than 5% and particularly preferably of no more than 3% from, the beam radius on the input coupling mirror 102 of the resonant measurement beam 103 in the resonator cavity 105 incident on the input coupling mirror 102, and / or the Gouy phase of the measurement beam 103 propagating in the resonator cavity 105 is constant or approximately constant. In this case, the position and / or refractive power of the optical element 108 in the form of the refractive optical element 112 is adaptable or adapted to a change in length of the resonator cavity 105. In particular, the position of the refractive optical element 112 may be adjustable in such a way that the measurement error when measuring the position and / or distance of the component is less than a predetermined or predeterminable measurement error or minimal.

[0054] The refractive optical element 112 may be connected or connectable to the input coupling mirror 102 by means of the at least one actuator 113, or the input coupling mirror 102 and the refractive optical element 112 are mounted on a joint load-bearing structure, wherein the at least one actuator is preferably arranged on the refractive optical element 112 and the load-bearing structure.

[0055] The exemplary embodiments according to Figures 2 to 4 disclose resonator cavities 105 with exactly one optical element 108. Naturally, multiple optical elements 108 that control the beam radius of the measurement beam at the input coupling mirror 102 and / or the Gouy phase may also be arranged in the resonator cavity 105. They may also have different embodiments. Consequently, lens elements and / or mirrors may be arranged in the resonator cavity 105. Likewise, the optical element 108 may have multiple properties that are adaptable or adapted in such a way that the beam radius of the measurement beam 103 at the input coupling mirror and / or the Gouy phase can be controlled, in particular in such a way that a measurement error when measuring the position and / or the distance is smaller than a predetermined or predeterminable limit value and / or constant. By preference, the adaptable property is the position, refractive power and / or deformation of the optical element 108. For example, the optical element 108 may be formed as deformable lens elements such that the refractive power and deformation are adjustable to a change in length of the resonator cavity 105. Furthermore, the deformable lens element may also be adjustably arranged within the resonator cavity 105 such that its position, deformation and refractive power can be adjusted to a change in length of the resonator cavity. Likewise, the position of a deformable optical element 109 may also be additionally adjustable within the resonator cavity 105.

[0056] At least one property of the at least one optical element 108 is chosen or adaptable on the basis of a change in length of the resonator cavity 105, in such a way that a measurement error when measuring the position and / or distance is less than a predetermined or predeterminable limit value. The position of the optical element 108 within the resonator cavity 105 is adjustable such that the measurement error is less than the predetermined or predeterminable limit value or minimal. In an alternative to that or in addition, a surface of the optical element 108 arranged in the resonator cavity or of an additional (further) optical element 108, 109 arranged in the resonator cavity is deformable, at least in regions, such that the measurement error is less than the predetermined or predeterminable limit value. In an alternative to that or in addition, it is preferable for the refractive power and / or position of the optical element 108 or of an additional (further) optical element 108, 112 to be chosen such that the measurement error when measuring the position and / or distance is less than the predetermined or predeterminable limit value or minimal.

[0057] In this case, the adaptable property is preferably controlled by means of the closed-loop control unit that adjusts a frequency of the measurement beam 103 to follow, and locks said frequency to, the resonant frequency of the resonator cavity 105, or the resonant frequency or a variable derivable from the resonant frequency serves as a control variable for adapting the property. The closed-loop control unit is consequently configured to adapt the property of the optical element 108 on the basis of a resonant frequency of the resonator cavity 105, as ascertained by means of a Pound-Drever-Hall method, or on the basis of a variable that is derivable from the resonant frequency. Should there consequently be a change in the resonant frequency of the resonator cavity 105 because the length within the length adjustment range 107 is modified, the property of the optical element 108, i.e. a deformation (radius of curvature), refractive index (e.g. by changing the temperature) and / or the position within the resonator cavity 105, can be adapted. The closed-loop control unit may control the adaptation of the property by way of a voltage signal, for example for an actuator 113. To this end, a calibration method may be performed in advance, by means of which the optimal adaptation of the properties of the optical element 108 is recorded for different resonator cavity lengths, i.e. the deformation, position and / or refractive index at which the measurement error is less than a predetermined or predeterminable limit value or minimal. Alternatively, the adaptation of the property may also be ascertained directly from the resonant frequency or a variable derived therefrom.

[0058] The exemplary embodiment depicted in Figure 4 differs to the effect that the at least one optical element 108 assigned to the optical resonator is disposed upstream (i.e. disposed upstream in the beam path) of the input coupling mirror 102, i.e. the optical resonator 101. In the present case, the at least one optical element 108 is formed as the collimator 117, wherein the collimator comprises at least one optical element, for example a lens element. In the present case, the at least one optical element 108 of the collimator is formed as an optical element 109 that is deformable by means of at least one actuator 113, in particular formed as a deformable lens element. The collimator 117, and in particular the optical element thereof, is moreover arranged so as to be adjustable, in particular translatable or tiltable, relative to the optical resonator 101 for the purpose of adapting the mode to a mode of the optical resonator 101 , i.e. the collimator 117 is adjustable and deformable in the present case. The focal length of the lens is adapted by the lens deformation, and so the beam radius on the input coupling mirror is modified, whereby the wavefront incident on the input coupling mirror is changed as well. To ensure that the latter is incident on the surface of the input coupling mirror 102 in parallel, the optical element 108 may additionally be formed to be adjustable, or else the collimator comprises not only the deformable optical element 109 but also at least one additional adjustable, in particular translatable, optical element. In other words, the collimator 117 comprises multiple optical elements for mode adaptation in that case. The at least one actuator 113 is arranged on the optical element 108, in such a way that a deformable region 110 and a region 111 without actuators are formed. The exemplary embodiments depicted in Figures 2 to 4 may be combined with one another as desired, and so the optical measuring arrangement 100 may also comprise and / or be assigned a plurality of optical elements 108 (that are formed differently and / or arranged at different positions) for controlling the beam radius of the measurement beam 103 at the input coupling mirror 102 and / or a Guoy phase of the measurement beam 103 propagating in the resonator cavity 105, on the basis of a change in length of the resonator cavity 105.

[0059] Figure 5 shows a resonator cavity 105 that is configured to measure the position and / or distance of the component relative to the reference along two mutually linearly independent measurement axes. As a mirror element, the resonator cavity 105 comprises a retroreflector 118 formed from multiple parts in this case, wherein a first partial retroreflector 114 is formed as the measurement target 106 and arranged so as to be movable with the component within the resonator cavity 105, and a second partial retroreflector 115 is stationary and connected or connectable to the reference. The two partial retroreflectors 114, 115 are aligned relative to each other in such a way that after passing through the input coupling mirror 102, the measurement beam 103 is reflected off both partial retroreflectors 114, 115 to the end mirror 104 and, from the latter, reflected back to the input coupling mirror 102 off the two parts 114, 115 of the retroreflector 118. The two partial retroreflectors 114, 115 may be formed as 2-D retroreflectors and, in particular, as 90° corner reflectors or as 90° prisms, i.e. each one of the two partial retroreflectors 114, 115 comprises 2 reflective surfaces 114a,b, 115a,b that are angled to each other. By preference, the two parts 114, 115 are aligned perpendicular to each other.

[0060] In the present case, the optical element 108 is formed as the input coupling mirror and embodied as a deformable optical element 109. In an alternative to that or in addition, it is self-evident that a further element formed as a refractive optical element 112, the position of which and / or the refractive index of which is adaptable, may also be adjustably arranged in the resonator cavity. Moreover, the optical element 108 may also be disposed upstream of the input coupling mirror and may be formed as a lens element, in particular as a collimator lens element. Mixed forms as described above, i.e. deformable and / or adjustably arranged refractive optical elements and adjustable deformable optical elements are self-evidently also possible. LIST OF REFERENCE SIGNS

[0061] 100 Measuring arrangement

[0062] 101 Optical resonator

[0063] 102 Input coupling mirror

[0064] 103 Measurement beam

[0065] 104 End mirror

[0066] 105 Resonator cavity

[0067] 106 Measurement target

[0068] 107 Length adjustment range

[0069] 108 Optical element

[0070] 109 Deformable optical element

[0071] 110 Deformable region

[0072] 111 Region without actuators

[0073] 112 Refractive optical element

[0074] 113 Actuator

[0075] 114 First partial retroreflector

[0076] 115 Second partial retroreflector

[0077] 116 Light source

[0078] 117 Collimator

[0079] 118 Retroreflector

[0080] 600 Projection exposure apparatus

[0081] 601 Plasma light source

[0082] 602 Collector mirror

[0083] 603 Field facet mirror

[0084] 604 Pupil facet mirror

[0085] 605 First telescopic mirror

[0086] 606 Second telescopic mirror

[0087] 607 Deflection mirror

[0088] 620 Mask stage

[0089] 621 Mask

[0090] 651 Mirror (projection lens)

[0091] 652 Mirror (projection lens)

[0092] 653 Mirror (projection lens) 654 Mirror (projection lens)

[0093] 655 Mirror (projection lens)

[0094] 656 Mirror (projection lens)

[0095] 660 Wafer stage

[0096] 661 Coated substrate

[0097] 700 DUV lithography apparatus

[0098] 701 DUV light source

[0099] 702 DUV radiation / beam path

[0100] 703 Beam shaping and illumination system (DUV) 704 Photomask

[0101] 705 Projection system

[0102] 706 Wafer

[0103] 707 Lens element

[0104] 708 Mirror

[0105] 709 Optical axis

Claims

CLAIMS1. Optical measuring arrangement (100) for measuring the position and / or distance of a component relative to a reference along at least one measurement axis, comprising an optical resonator (101) that comprises at least one input coupling mirror (102) for input coupling a measurement beam (103) and an end mirror (104), which enclose a resonator cavity (105), wherein the resonator cavity (105) comprises a length adjustment range (107) and wherein the measurement beam traverses the resonator cavity more than once, characterized in that the optical resonator (101) comprises at least one optical element (108) or is assigned thereto, said optical element being configured to control the beam radius of the measurement beam (103) at the input coupling mirror (102) and / or a Gouy phase of the measurement beam (103) propagating in the resonator cavity (105), on the basis of a change in length of the resonator cavity (105).

2. Optical measuring arrangement (100) according to Claim 1, characterized in that a mirror element is present, the latter being adjustably arranged in the resonator cavity (105) and being configured to steer the measurement beam (103) back and forth between the end mirror (104) and the input coupling mirror (102).

3. Optical measuring arrangement (100) according to Claim 1 or 2, characterized in that a frequency shifter is present, the latter being configured to adjust the frequency of a light emitted by a light source to follow a resonant frequency of the optical resonator and that the position and / or distance is .

4. Optical measuring arrangement (100) according to any of Claims 1 to 3, characterized in that the at least one optical element (108) is configured to keep the beam radius of the measurement beam (103) at the input coupling mirror (102) and / or a Gouy phase of the measurement beam (103) propagating in the resonator cavity (105) constant or approximately constant, at least within the length adjustment range (107) of the resonator cavity (105).

5. Optical measuring arrangement (100) according to any of Claims 1 to 4, characterized in that the length adjustment range is at least ±5 cm.

6. Optical measuring arrangement (100) according to any of Claims 1 to 5, characterized in that the resonator cavity (105) is configured to measure the position and / or distance of the component relative to the reference along at least two linearly independent measurement axes.

7. Optical measuring arrangement (100) according to any of Claims 1 to 6, characterized in that the beam radius of the measurement beam (103) steered from the end mirror (104) to the input coupling mirror (102) grows.

8. Optical measuring arrangement (100) according to any of Claims 1 to 7, characterized in that a position, deformation or refractive power of the optical element (108) is chosen on the basis of a change in length of the resonator cavity (105), in such a way that a measurement error when measuring the position and / or distance is smaller than a predetermined or predeterminable limit value.

9. Optical measuring arrangement (100) according to any of Claims 1 to 8, characterized in that the optical element (108) is a deformable optical element (109).

10. Optical measuring arrangement (100) according to Claim 9, characterized in that a radius of curvature of the deformable optical element (109) is adapted to a change in length of the resonator cavity (105).

11. Optical measuring arrangement (100) according to Claim 9 or 10, characterized in that the radius of curvature of the deformable optical element (109) is chosen in such a way that the beam radius at the input coupling mirror (102) of the measurement beam (103) corresponds to, or deviates by no more than 10% from, the beam radius on the input coupling mirror (102) of the resonant measurement beam (103) in the resonator cavity (105) incident on the input coupling mirror (102), and / or the Gouy phase of the measurement beam (103) propagating in the resonator cavity (105) is constant or approximately constant.

12. Optical measuring arrangement (100) according to any of Claims 9 to 11 , characterized in that the deformable optical element (109) comprises a deformable region (110) and a non-deformable region (111) that is formed without actuators.

13. Optical measuring arrangement (100) according to any of Claims 9 to 12, characterized in that the deformable optical element (109) is formed as the input coupling mirror (102).

14. Optical measuring arrangement (100) according to any of Claims 1 to 13, characterized in that the at least one optical element (109) is formed as an optical element (108) disposed upstream of the input coupling mirror (102).

15. Optical measuring arrangement (100) according to any of Claims 1 to 14, characterized in that the at least one optical element (108) is formed as a refractive optical element (112).

16. Optical measuring arrangement (100) according to Claim 15, characterized in that the refractive optical element (112) is adjustable by means of an actuator (113) in the resonator cavity (105), in such a way that the beam radius at the input coupling mirror (102) of the measurement beam corresponds to, or deviates by no more than 10% from, the beam radius on the input coupling mirror (102) of the resonant beam in the resonator cavity (105) incident on the input coupling mirror (102), and / or the Gouy phase of the measurement beam (103) propagating in the resonator cavity (105) is constant or approximately constant.

17. Optical measuring arrangement (100) according to Claim 15 or 16, characterized in that the refractive optical element (112) is adjustably arranged in a region of the resonator cavity (105) in which a radius of the measurement beam (103) increases monotonically.

18. Optical measuring arrangement (100) according to any of Claims 15 to 17, characterized in that the refractive optical element (112) is connected or connectable to the input coupling mirror (102) by means of an actuator (113) or in that the input coupling mirror (102) and the refractive optical element (112) are mounted on a load-bearing structure.

19. Projection exposure apparatus (600, 700) having at least one optical measuring arrangement (100) according to any of Claims 1 to 18.

20. Lithography apparatus having at least one optical measuring arrangement (100) according to any of Claims 1 to 18.

21. Inspection apparatus for inspecting a shape, pose or geometry of an object, having at least one optical measuring arrangement (100) according to any of Claims 1 to 18.

22. Coordinate measuring machine having at least one optical measuring arrangement (100) according to any of Claims 1 to 18.

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