Determining a piece of imaging error information relating to an optical imaging device

Abstract

The present invention relates to an apparatus for determining at least one piece of imaging error information relating to a microlithographic optical imaging device (101), in particular for the use of light in the extreme ultraviolet (EUV) range, wherein the imaging device is configured to generate an optical image representation of an object in a used region (105.1) in an image plane (105.2) of the imaging device (101) by means of imaging light, having a capture device (108) configured to capture, in each case, a first piece of local imaging error information at a first number M1 of first image points (IP1) from a first image point group in the used region (105.1) in the image plane (105.2) in a temporally coherent first capture step, and a determination device (106.1 ) configured to determine a profile of the at least one piece of imaging error information over the used region (105.1) using the first number M1 of the first pieces of local imaging error information from the first capture step. The at least one piece of imaging error information is representative of at least one imaging error of the optical imaging device (101). The capture device (108) is configured to capture, in each case, a second piece of local imaging error information at a second number M2 of second image points (IP2) from a second image point group in the used region (105.1) in the image plane (105.2) in a temporally coherent second capture step, with the second capture step following the first capture step. The first image points (IP1) from the first image point group differ from the second image points (IP2) from the second image point group by at least one image point, and the determination device (106.1) is configured to determine the profile of the at least one piece of imaging error information over the used region (105.1) in a determination step that follows the second capture step and using the first number M1 of the first pieces of local imaging error information from the first capture step and the second number M2 of the second pieces of local imaging error information from the second capture step.

Description

[0001] January 20, 2026

[0002] DETERMINING A PIECE OF IMAGING ERROR INFORMATION RELATING TO AN OPTICAL IMAGING DEVICE

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims benefit pursuant to 35 U.S.C. § 119 of German patent application No.

[0005] 102025102335.2, filed on January 23, 2025, the entire disclosure of which is hereby incorporated herein by reference.

[0006] BACKGROUND OF THE INVENTION

[0007] The present invention relates to an apparatus and a method for determining at least one piece of imaging error information relating to a microlithographic optical imaging device suitable for the use of used UV light, in particular light in the extreme ultraviolet (EUV) range. Furthermore, the invention relates to an optical imaging device having such an apparatus. The invention can be used in conjunction with any desired optical imaging methods. It can be used particularly advantageously in the production or the inspection of microelectronic circuits and the optical components used for them (for example optical masks).

[0008] The optical systems used in connection with the production of such microelectronic circuits typically comprise a multiplicity of optical element modules comprising optical elements such as lens elements, mirrors, gratings, etc. arranged in the path of the light. These optical elements normally interact in an exposure process in order to illuminate a pattern formed on a mask, a reticle or the like and in order to transfer an image of this pattern onto a substrate such as a wafer. The optical elements are usually combined in one or more functionally different optical element groups, which may be mounted within different optical element units.

[0009] The ever-advancing miniaturization of semiconductor components results in a continually increasing need for increased resolution of the optical systems that are used for the production of these semiconductor components. This need for increased resolution necessitates the need for an increased numerical aperture (NA) and an increased imaging accuracy of the optical systems.

[0010] 2022P00116 WO 220908WO KA / el January 20, 2026One approach for obtaining an increased optical resolution consists in reducing the wavelength of the light used in the imaging process. The trend in recent years has increasingly fostered the development of systems in which light in the so-called extreme ultraviolet (EUV) range is used, typically at wavelengths of 5 nm to 20 nm, in most cases at a wavelength of approximately 13 nm. In this EUV range, it is no longer possible to use conventional refractive optical systems. This is owing to the fact that in this EUV range the materials used for refractive optical systems have an absorptance that is too high to achieve acceptable imaging results with the available light power. Consequently, this EUV range requires the use reflective optical systems for imaging.

[0011] This transition to purely reflective optical systems having a high numerical aperture (e.g. NA > 0.4 to 0.5) in the EUV range results in considerable challenges with regard to the design of the imaging device.

[0012] The factors mentioned above result in very stringent requirements with regard to the position and / or orientation relative to one another of the optical elements involved in the imaging and also with regard to the deformation of the individual optical elements in order to achieve a desired imaging accuracy. Moreover, it is necessary to maintain this high imaging accuracy over operation in its entirety, ultimately over the service life of the system.

[0013] As a consequence, the components of the optical imaging device (i.e. for example the optical elements of the illumination device, the mask, the optical elements of the projection device and the substrate) which cooperate during imaging must be supported in a well-defined manner in order to maintain a given well-defined spatial relationship between these components and obtain a minimal undesired deformation of these components, in order ultimately to achieve the highest possible imaging quality. Typically, the spatial pose and / or the deformation of one or more of these components is actively influenced in order to keep the imaging errors relevant to the imaging process or to the result thereof as low as possible.

[0014] A challenge frequently encountered in this context consists in determining the current value of these relevant imaging errors with good precision in order to allow appropriate active influencing that results in the most comprehensive compensation possible of the imaging error in question. One option for determining the current imaging error prevalent during the imaging onto the substrate at least to a good approximation consists in intermittently determining, for example between the exposure of different substrates, the profile of the wavefront in the image plane of the imaging device on the basis of current measurements of the wavefront in the image plane. A problem in this respect is that such a measurement is

[0015] 2022P00116 WO 220908WO KA / el January 20, 2026generally only possible at comparatively few points in the image plane so as not to significantly reduce the substrate throughput of the imaging device over time. This is due not least to the fact that the corresponding measuring devices (i.e. corresponding image sensors, for example) typically cannot be arranged with a correspondingly high resolution in the region of the image plane. Rather, corresponding measurements are frequently taken sequentially using a sensor that is positioned incrementally in the region of the corresponding image points in the image plane. Taking into account the substrate throughput and hence the time available for the measurements (between two substrates), it is possible to approach only comparatively few image points. This achieves only a comparatively low spatial resolution of the measurement, and of course this has a disadvantageous effect on the precision of the determination of the respective relevant imaging error.

[0016] BRIEF SUMMARY OF THE INVENTION

[0017] The problem addressed by the invention is therefore that of providing an apparatus and a method for determining at least one piece of imaging error information relating to a microlithographic optical imaging device, a corresponding optical imaging device and an optical imaging method that do not have the aforementioned disadvantages, or at least exhibit these to a lesser extent, and in particular allow an improved determination and optional subsequent compensation of imaging errors in a simple manner.

[0018] The invention solves this problem using the features of the independent claims.

[0019] The invention is based on the technical teaching that improved determination and optional subsequent compensation of imaging errors is easily rendered possible by determining the profile of the relevant piece of imaging error information over the used region in the image plane on the basis of the pieces of local imaging error information from at least two temporally spaced-apart, in itself temporally coherent capture steps in each of which the pieces of local imaging error information were captured temporally coherently for different image point groups in the image plane. By using the pieces of local imaging error information for different image point groups, it is possible, in particular in a simple manner, to obtain an increased spatial resolution with respect to the image points, on the basis of which the profile of the piece of imaging error information is determined over the used region in the image plane, without reducing the throughput of the imaging device on account of a longer duration of the respective capture step. Instead, the duration of the respective capture step may remain the same whilst having an increased spatial resolution of the capture. Likewise, the

[0020] 2022P00116 WO 220908WO KA / el January 20, 2026duration of the respective capture step might optionally even be reduced (i.e. the throughput of the imaging device can be increased) by virtue of an improved spatial resolution of the capture being achieved in the sum of the capture steps (vis-a-vis the single capture step) but the number of image points being reduced in at least one of the capture steps.

[0021] What was found in this case is, in particular, that the interval between the capture steps considered when determining the profile of the relevant piece of imaging error information either has no noticeable influence on the quality of determination (for instance because the relevant imaging error only has a negligible temporal drift between the capture steps) or can easily be taken into account (for instance by virtue of the temporal drift being determined, for example on the basis of the ascertained pieces of imaging error information from the capture steps, and then being taken into account accordingly).

[0022] According to one aspect, the invention therefore relates to an apparatus for determining at least one piece of imaging error information relating to a microlithographic optical imaging device, in particular for the use of light in the extreme ultraviolet (ELIV) range, wherein the imaging device is configured to generate an optical image representation of an object in a used region in an image plane of the imaging device by means of imaging light, having a capture device configured to capture, in each case, a first piece of local imaging error information at a first number M1 of first image points, in particular a first plurality M1 of mutually spaced-apart first image points (i.e. spaced apart from one another in each case), from a first image point group in the used region in the image plane in a temporally coherent first capture step, and a determination device configured to determine a profile of the at least one piece of imaging error information over the used region using the first number M1 of the first pieces of local imaging error information from the first capture step. In this case, the at least one piece of imaging error information is representative of at least one imaging error of the optical imaging device. The capture device is configured to capture, in each case, a second piece of local imaging error information at a second number M2 of second image points, in particular a second plurality M2 of mutually spaced-apart second image points, from a second image point group in the used region in the image plane in a temporally coherent second capture step, with the second capture step following the first capture step. The first image points from the first image point group differ from the second image points from the second image point group by at least one image point. The determination device is configured to determine the profile of the at least one piece of imaging error information over the used region in a determination step that follows the second capture step and using the first number M1 of the first pieces of local imaging error information from the first capture

[0023] 2022P00116 WO 220908WO KA / el January 20, 2026step and the second number M2 of the second pieces of local imaging error information from the second capture step.

[0024] It is understood that it may optionally be sufficient for the first image points from the first image point group to differ from the second image points from the second image point group only by one image point. A correspondingly more expedient, higher spatial resolution may naturally be obtained if the first image points from the first image point group differ from the second image points from the second image point group by 2 to 15 image points and preferably by 3 to 7 image points.

[0025] It is understood that the image point groups need not have any overlap whatsoever in terms of the image points. In this way, a particularly high spatial resolution may then be achieved. In certain variants, provision may be made for the first image point group and the second image point group to comprise at least one common image point, preferably 2 to 9 common image points and further preferably 3 to 5 common image points. By preference, at least one common image point lies in the region of the field centre of the field to be captured. By way of the pieces of local imaging error information relating to such common image points from the image point groups, it is for example easily and advantageously possible to draw conclusions about the temporal drift of the respective imaging error and to then take this drift into account accordingly when determining the profile of the piece of imaging error information.

[0026] In certain advantageous variants, the first image point group and the second image point group comprise at least one common image point. In this case, the determination device is configured to determine a change DT in the piece of imaging error information over time in the determination step on the basis of the first pieces of local imaging error information and the second piece of local imaging error information for the at least one common image point and to determine the profile of the at least one piece of imaging error information on the basis of the change in the imaging error information over time. In this way, a potential drift of the relevant imaging error may be taken into account particularly easily.

[0027] In principle, any desired plurality of capture steps may be used when determining the profile of the at least one piece of imaging error information over the used region in the respective determination step. In certain variants, the capture device is configured to sequentially carry out a plurality N of capture steps, with the plurality N of capture steps comprising at least the first capture step and the second capture step. In this case, the determination device is configured to determine the profile of the at least one piece of imaging error information over

[0028] 2022P00116 WO 220908WO KA / el January 20, 2026the used region in the determination step using the pieces of local imaging error information from at least two capture steps from the plurality N of capture steps. In the case of certain advantageous variants, the plurality N of capture steps total 2 to 10, preferably 2 to 5 and further preferably 2 to 3. Particularly expedient increased resolutions may be obtained therewith.

[0029] In certain variants, the capture device is configured to cyclically repeat the plurality N of capture steps. In other words, this gives rise to a capture pattern with cyclically alternating image point groups. However, it is understood that other variants may also provide for the plurality N of capture steps to be randomly strung together at least intermittently. In this case, it may be advantageous to ensure that two successive capture steps differ from each other in each case.

[0030] In certain variants, the capture device is configured to randomly select the image points for at least one of the capture steps from the plurality N of capture steps, in particular randomly select the image points of multiple capture steps from the plurality N of capture steps and in particular randomly select the image points of the respective capture step from the plurality N of capture steps. In this way, averaged over time, the profile of the piece of imaging error information can be determined particularly precisely. In this case, it is preferably possible to ensure that the image point groups in the capture steps taken into account in the determination step, in particular in immediately successive capture steps, have a predefinable degree of overlap (i.e. common image points) and / or a predefinable degree of differentiation (i.e. different image points).

[0031] In principle, any desired number of preceding capture steps can be taken into account in the determination step. In certain simple variants, the determination device is configured to determine the profile of the at least one piece of imaging error information using the pieces of local imaging error information at least from the two capture steps immediately preceding the determination step. This easily ensures that the determination takes the current state of the imaging device into account.

[0032] In certain advantageous variants with a particularly good spatial resolution, the determination device is configured to determine the profile of the at least one piece of imaging error information using the pieces of local imaging error information from 2 to 10, preferably 2 to 5 and further preferably 2 to 3 of the capture steps from the plurality N of capture steps.

[0033] 2022P00116 WO 220908WO KA / el January 20, 2026In certain advantageous variants, provision may be made for the determination device to be configured to determine the profile of the at least one piece of imaging error information using a numerical model of the imaging device determined in advance. In this case, any desired variables that have a correspondingly relevant influence on the imaging error in question may be used as input variables of the numerical model. In this respect, these may be for example (alone or in any desired combination) an imaging light power of the illumination device in the imaging device, one or more state variables, for example temperature values, of one or more components, in particular optical elements, in the imaging device.

[0034] In principle, the relevant imaging error may be captured by way of any desired suitable variables that allow sufficiently precise conclusions to be drawn about the imaging error in question. In certain advantageous variants, the capture device is configured to capture at least one local capture value, which is representative of at least one current local property of a wavefront of the imaging light at the respective image point, as a respective piece of local imaging error information. In certain variants, the determination device is configured in this case to determine the profile of the at least one piece of imaging error information over the used region in the determination step using the local capture values from the first capture step and the second capture step. For example, this may be implemented by way of appropriate interpolation using the local capture values.

[0035] In principle, the profile of the piece of imaging error information over the used region may be described in any suitable manner which allows corresponding conclusions to be drawn about the current relevant imaging error. In preferred variants which are easy to implement, the determination device is configured to describe a current profile of the at least one local property of the wavefront of the imaging light over the used region in the image plane on the basis of at least one wavefront property function, in particular on the basis of at least one Zernike polynomial, wherein the wavefront property function is determined from the local capture values from at least the first capture step and the second capture step, in particular interpolated using the local capture values from the first capture step and the second capture step.

[0036] The capture of the respective piece of local imaging error information may be implemented in any suitable manner as a matter of principle. In this case, provision may be made for the respective piece of local imaging error information for multiple image points to be implemented at least substantially simultaneously. In certain variants, the capture device is configured to capture the first piece of local imaging error information for at least two of the

[0037] 2022P00116 WO 220908WO KA / el January 20, 2026first image points sequentially with respect to each other. In addition to that or in an alternative, the capture device may likewise be configured to capture the second piece of local imaging error information for at least two of the second image points sequentially with respect to each other. It is possible in both cases to provide only one corresponding capture unit (for example an image sensor) which is sequentially displaced to the corresponding image points. As a result, the equipment outlay for the capture device can advantageously be kept comparatively low.

[0038] In certain variants, the capture device is configured to capture the first piece of local imaging error information for at least two of the first image points at least substantially simultaneously. This advantageously allows the duration of the capture step to be kept short and hence optionally allows the throughput of the imaging device to be increased. In certain variants, the capture device may likewise be configured to capture the second piece of local imaging error information for at least two of the second image points at least substantially simultaneously.

[0039] In principle, the capture device may be designed in any suitable manner in order to capture the respective piece of local imaging error information in a suitable manner. In certain variants which are preferred owing to their simple construction, the capture device comprises at least one capture unit, in particular an image sensor unit. In this case, the capture device is configured to arrange the at least one capture unit in the region of the associated image point in the image plane in order to capture one of the pieces of local imaging error information.

[0040] In variants of particularly simple design, the capture device is configured to displace the at least one capture unit between at least two image points from the image points in the image plane in order to capture the respective pieces of local imaging error information. In certain variants of simple design, the capture device is configured to position a reference point of the capture unit, in particular a centre of a surface of an image sensor unit, in the region of one of the image points in the image plane in order to capture the piece of local imaging error information in question.

[0041] In principle, the capture device may be an independent component of the imaging device. In particularly expedient variants with high functional integration, the imaging device comprises a displaceable substrate device, by means of which a substrate, in particular a wafer, is arranged in the region of the image plane during a normal operation in order to optically

[0042] 2022P00116 WO 220908WO KA / el January 20, 2026image at least a portion of an object onto the substrate, wherein the at least one capture unit is arranged on the substrate device in that case.

[0043] In principle, the respective capture step may be implemented at any desired suitable and predefinable times during the normal operation of the imaging device. In certain advantageous variants, the at least one capture unit is arranged on a displaceable substrate device of the imaging device, wherein a substrate, in particular a wafer, is arranged in the region of the image plane by way of the substrate device during an imaging step during a normal operation in order to optically image at least a portion of an object onto the substrate, and wherein the at least one capture unit is displaced into the region of the image plane in a substrate interchange step during the normal operation in order to capture the pieces of local imaging error information while the substrate is exchanged for another substrate in the substrate interchange step. In this case, use is advantageously made of an interval during the normal operation of the imaging device in which there is no imaging onto a substrate anyway. In particular, what may be achieved in the process is that the throughput of the imaging device, if at all, is adversely affected only as little as possible by the determination of the profile of the piece of imaging error information over the used region.

[0044] It is understood that, as a matter of principle, any desired suitable number of image points may be provided for the respective capture step, wherein a trade-off can be made as regards the duration of the respective capture step (and the influence thereof on the throughput of the imaging device) vis-a-vis the obtainable accuracy when determining the profile of the piece of imaging error information. In principle, only a single image point might also be sufficient for the respective capture step but a plurality of image points (i.e. at least two image points) are preferably provided for at least one capture step (further preferably for a plurality of capture steps). The fewer image points are provided per capture step, the more capture steps can typically be taken into account without a loss of speed.

[0045] In expedient variants, the first number M1 totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7. In addition to that or in an alternative, the second number M2 may total 1 to 15, preferably 3 to 9 and further preferably 5 to 7. The first and second numbers M1 , M2 may differ. The first number M1 might likewise correspond to the second number M2.

[0046] The spatial resolution of the image points over the used region in the image plane may be chosen in any suitable manner as a matter of principle for as long as a sufficiently high accuracy may be obtained for the determination of the profile of the piece of imaging error information from the pieces of local imaging error information obtained in the process. In this

[0047] 2022P00116 WO 220908WO KA / el January 20, 2026case, any desired, optionally different one-dimensional or two-dimensional image point patterns may be used for the respective capture step. In certain advantageous variants, the first image points are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region. In addition to that or in an alternative, the second image points are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region. In addition to that or in an alternative, at least some of the first image points are spaced apart from adjacent second image points by 2% to 30%, preferably 5% to 25% and further preferably 10% to 20% of a maximum dimension of the used region. With each of these variants (preferably with their combination), it is possible to obtain an advantageous spatial resolution of the image points over the used region.

[0048] It is understood that, as a matter of principle, it may be sufficient to only take a first and a second capture step into account in the determination step. In certain variants, one or more further capture steps (i.e. consequently their pieces of local imaging error information) may be taken into account in the determination step in order to achieve a further increase in the spatial resolution and the according increase in the accuracy of the result of the determination step. In this case, the respective further capture step may as a matter of principle be designed like the first or second capture step described herein, and so, in this respect, reference can be explicitly made to the statements given herein in relation to the first and second capture steps provided that no other statements in this respect are given below.

[0049] In certain advantageous variants, the capture device is consequently configured to capture, in each case, a further piece of local imaging error information at a further number Mw of further image points, in particular a further plurality Mw of mutually spaced-apart further image points, from a further image point group in the used region in the image plane in at least one temporally coherent further capture step. The further number Mw may total 1 to 15, preferably 3 to 9 and further preferably 5 to 7. Furthermore, the further number Mw may correspond to the first number M1 or the second number M2. In respect of the distance of the further image points from the further image point group from one another and from the image points from other image point groups, in particular from the first and / or second image point groups, reference is also made to the corresponding explanations given above in relation to the first and second image point groups.

[0050] Here, too, provision may be made (analogously to the first and second image point groups) for the further image points from the further image point group to differ from the image points from the first image point group or the second image point group by at least one image point,

[0051] 2022P00116 WO 220908WO KA / el January 20, 2026preferably by 2 to 15 image points and further preferably by 3 to 7 image points. Likewise (analogously in this respect), the further image point group and the first image point group and / or the second image point group comprise at least one common image point, preferably 2 to 9 common image points and further preferably 3 to 5 common image points. Likewise, provision may be made for the further image point group and the first image point group and / or the second image point group to comprise at least one common image point, and the determination device may be configured to determine a change DT in the piece of imaging error information over time in the determination step on the basis of the further pieces of local imaging error information and the first pieces of local imaging error information and / or the second piece of local imaging error information for the at least one common image point and to determine the profile of the at least one piece of imaging error information on the basis of the change in the imaging error information over time.

[0052] The temporal sequence of the first and second capture steps may in principle be implemented in any desired suitable manner that enables a reliable and sufficiently precise determination of the profile of the at least one piece of imaging error information over the used region. In certain variants, the determination device is configured to carry out the second capture step at a predefinable capture step interval TD in relation to the first capture step. In this case, provision may be made for the capture step interval TD to be 50% to 500%, preferably 100% to 300% and further preferably 100% to 200% of the duration between the start of the exposure of two successive substrates during the normal operation (for example two wafers that are exposed immediately in succession by the imaging device during the normal operation). In particular, one of the capture steps may be performed at certain predefined times independently of the state of the imaging process performed by the imaging device.

[0053] In certain variants, provision may be made for the first capture step to have a first capture step duration CD1 , and the capture step interval TD is 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the first capture step duration CD1.

[0054] Likewise, the second capture step may have a second capture step duration CD2, and the capture step interval TD may be 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the second capture step duration CD2.

[0055] In certain advantageous variants which, in particular, enable an advantageously high throughput of the imaging device, the imaging device comprises a normal operation in which at least a portion of an object is optically imaged onto multiple substrates, in particular wafers, arranged successively in the region of the image plane, with the imaging of the object

[0056] 2022P00116 WO 220908WO KA / el January 20, 2026onto the respective substrate being implemented in a respective imaging step during the normal operation. In these cases, the capture device may be configured to carry out the first capture step before an imaging step and to carry out the second capture step after the imaging step. Consequently, it is thus possible to use the time interval required in any case for the replacement of the substrate. The capture device may be configured to carry out the first capture step immediately before an imaging step and to carry out the second capture step immediately after the imaging step in order to keep the time expenditure therefor during the normal operation as low as possible. Thus, for example, the first capture step may be carried out immediately before an imaging step, i.e. for example before the exposure of a wafer, while the second capture step in that case is carried out immediately after this imaging step, thus for example immediately after the exposure of this wafer.

[0057] In certain variants, a capture step may be performed after each imaging step, at least for a certain portion of the normal operation (for example a run-in time of the imaging device). In certain variants, the capture device may be configured in such a way that a number of imaging steps are carried out between the first capture step and the second capture step. This may be provided in particular for a period of the normal operation following a run-in time of the imaging device, during which, if at all, only a comparatively small temporal drift of the imaging error in question is to be expected.

[0058] The present invention furthermore relates to an optical imaging device, in particular microlithographic optical imaging device, having an illumination device having a first optical element group, an object device for receiving an object, a projection device having a second optical element group, an image device and a control device, wherein the illumination device is configured to illuminate the object, the projection device is configured to project an image representation of the object onto the image device, and the control device is configured to control the illumination device and the projection device and preferably at least one of the object device and the image device in an imaging control step in order to generate the image representation of the object. In this case, the control device comprises an apparatus according to the invention for determining at least one piece of imaging error information relating to the optical imaging device. In this case, the control device may be configured to undertake the imaging control step using the profile of the at least one piece of imaging error information. This makes it possible to realize the variants and advantages described above to the same extent, and so reference is made to the explanations given above in this respect.

[0059] The present invention furthermore relates to a method for determining at least one piece of imaging error information relating to a microlithographic optical imaging device, in particular

[0060] 2022P00116 WO 220908WO KA / el January 20, 2026for the use of light in the extreme ultraviolet (ELIV) range, wherein the imaging device is configured to generate an optical image representation of an object in a used region in an image plane of the imaging device by means of imaging light, wherein in each case a first piece of local imaging error information is captured at a first number M1 of first image points, in particular a first plurality M1 of mutually spaced-apart first image points, from a first image point group in the used region in the image plane in a temporally coherent first capture step, and a profile of the at least one piece of imaging error information over the used region is determined using the first number M1 of the first pieces of local imaging error information from the first capture step. The at least one piece of imaging error information is representative of at least one imaging error of the optical imaging device. Furthermore, in each case a second piece of local imaging error information is captured at a second number M2 of second image points, in particular a second number M2 of mutually spaced-apart second image points, from a second image point group in the used region in the image plane in a temporally coherent second capture step, with the second capture step following the first capture step. The first image points from the first image point group differ from the second image points from the second image point group by at least one image point. The profile of the at least one piece of imaging error information over the used region is determined in a determination step that follows the second capture step and using the first number M1 of the first pieces of local imaging error information from the first capture step and the second number M2 of the second pieces of local imaging error information from the second capture step. This also makes it possible to realize the variants and advantages described above to the same extent, and so reference is made to the explanations given above in this respect.

[0061] The present invention finally relates to an optical imaging method, in particular a microlithographic optical imaging method, wherein an illumination device which comprises a first optical element group illuminates an object and a projection device which comprises a second optical element group projects an image representation of the object onto an image device. In order to generate the image representation of the object, the illumination device and the projection device and preferably at least one of the object device and the image device are controlled in an imaging control step using a method according to the invention for determining at least one piece of imaging error information, in order to correct at least one imaging error of the imaging device using the profile of the at least one piece of imaging error information. This also makes it possible to realize the variants and advantages described above to the same extent, and so reference is made to the explanations given above in this respect.

[0062] 2022P00116 WO 220908WO KA / el January 20, 2026Further aspects and exemplary embodiments of the invention are evident from the dependent claims and the following description of preferred exemplary embodiments, which refers to the accompanying figures. All combinations of the disclosed features, irrespective of whether or not they are the subject of a claim, lie within the scope of protection of the invention.

[0063] BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 is a schematic illustration of a preferred embodiment of a projection exposure apparatus according to the invention, in which a preferred embodiment of the apparatus according to the invention is used.

[0065] Figure 2 is a schematic plan view of the image plane in the projection exposure apparatus from Figure 1.

[0066] Figure 3 is a simplified illustration of the profile of a piece of imaging error information relating to the projection exposure apparatus from Figure 1 , determined in a first state of the projection exposure apparatus using a preferred implementation of the method according to the invention over the used region in the image plane from Figure 3.

[0067] Figure 4 is a simplified illustration of the profile of a piece of imaging error information relating to the projection exposure apparatus from Figure 1 , determined in a second state of the projection exposure apparatus using a preferred implementation of the method according to the invention over the used region in the image plane from Figure 3.

[0068] DETAILED DESCRIPTION OF THE INVENTION

[0069] A preferred exemplary embodiment of a microlithographic projection exposure apparatus 101 according to the invention, which comprises a preferred exemplary embodiment of an apparatus according to the invention for determining at least one piece of imaging error information relating to the projection exposure apparatus 101 , is described below with reference to Figures 1 to 4. To simplify the following explanations, an xyz-coordinate system is indicated in the drawings, the z-direction running parallel to the direction of gravitational force. Accordingly, the x-direction and the y-direction run horizontally, with the x-direction

[0070] 2022P00116 WO 220908WO KA / el January 20, 2026running perpendicularly into the plane of the drawing in the illustration in Figure 1. It is self-evident that any other desired orientation of an xyz-coordinate system may be chosen in further configurations.

[0071] The essential constituent parts of a projection exposure apparatus 101 are described in exemplary fashion below, initially with reference to Figure 1. The description of the basic setup of the projection exposure apparatus 101 and its components should not be construed as limiting here.

[0072] An illumination device or an illumination system 102 of the projection exposure apparatus 101 comprises, in addition to a radiation source 102.1 , an optical element group in the form of an illumination optics unit 102.2 for illuminating a (schematically depicted) object field 103.1. The object field 103.1 lies in an object plane 103.2 of an object device 103. A reticle 103.3 (also referred to as a mask) arranged in the object field 103.1 is illuminated in this case. The reticle 103.3 is held by a reticle holder 103.4. The reticle holder 103.4 is displaceable by way of a reticle displacement drive 103.5, in particular in one or more scanning directions. In the present example, such a scanning direction runs parallel to the y-axis.

[0073] The projection exposure apparatus 101 furthermore comprises a projection device 104 with a further optical element group in the form of a projection optics unit 104.1. The projection optics unit 104.1 serves for imaging the object field 103.1 into a (schematically depicted) image field 105.1 , which is located in an image plane 105.2 of an image device 105. The image plane 105.2 extends parallel to the object plane 103.2. Alternatively, an angle between the object plane 103.2 and the image plane 105.2 that differs from 0° is also possible.

[0074] During exposure, a structure of the reticle 103.3 is imaged onto a light-sensitive layer of a substrate in the form of a wafer 105.3, the light-sensitive layer being arranged in the image plane 105.2 in the region of the image field 105.1. The wafer 105.3 is held by a substrate holder or wafer holder 105.4. The wafer holder 105.4 is displaceable by way of a wafer displacement drive 105.5 in particular in the y-direction. The displacement, firstly, of the reticle 103.3 by way of the reticle displacement drive 103.5 and, secondly, of the wafer 105.3 by way of the wafer displacement drive 105.5 can be synchronized with one another. This synchronization can be implemented, for example, by way of a common control device 106 (shown only very schematically in Figure 1 and without control paths).

[0075] 2022P00116 WO 220908WO KA / el January 20, 2026The radiation source 102.1 is an EUV radiation (extreme ultraviolet radiation) source. The radiation source 102.1 emits EUV radiation 107 in particular, which is also referred to below as used radiation or illumination radiation. In particular, the used radiation has a wavelength in the range between 5 nm and 30 nm, in particular a wavelength of approximately 13 nm. The radiation source 102.1 may be a plasma source, for example an LPP (laser produced plasma) source or a GDPP (gas discharge produced plasma) source. It may also be a synchrotron-based radiation source. However, the radiation source 102.1 may also be a free electron laser (FEL).

[0076] Since the projection exposure apparatus 101 operates with imaging light in the EUV range, the optical elements used are exclusively reflective optical elements. In further configurations of the invention, it is also possible (in particular depending on the wavelength of the illumination light), of course, to use any type of optical elements (refractive, reflective, diffractive) on an individual basis or in any desired combination for the optical elements.

[0077] The illumination radiation 107 emanating from the radiation source 102.1 is focused by a collector 102.3. The collector 102.3 may be a collector with one or more ellipsoidal and / or hyperboloidal reflection surfaces. The illumination radiation 107 may be incident on the at least one reflection surface of the collector 102.3 with grazing incidence (Gl), i.e. at angles of incidence of greater than 45°, or with normal incidence (Nl), i.e. at angles of incidence of less than 45°. The collector 11 may be structured and / or coated firstly to optimize its reflectivity for the used radiation and secondly to suppress extraneous light.

[0078] Downstream of the collector 102.3, the illumination radiation 107 propagates through an intermediate focus in an intermediate focal plane 107.1. In certain variants, the intermediate focal plane 107.1 may represent a separation between the illumination optics unit 102.2 and a radiation source module 102.4, which comprises the radiation source 102.1 and the collector 102.3.

[0079] Along the beam path, the illumination optics unit 102.2 comprises a deflection mirror 102.5 and a downstream first facet mirror 102.6. The deflection mirror 102.5 may be a planar deflection mirror or, alternatively, a mirror with a beam-influencing effect going beyond the pure deflection effect. In an alternative to that or in addition, the deflection mirror 102.5 may be designed as a spectral filter which at least partially separates what is known as extraneous light from the illumination radiation 107, the wavelength of said extraneous light differing from the imaging light wavelength. Should the optically effective surfaces of the first facet mirror 102.6 be arranged in the region of a plane of the illumination optics unit 102.2

[0080] 2022P00116 WO 220908WO KA / el January 20, 2026that is optically conjugate to the object plane 103.2 as a field plane, the first facet mirror 102.6 is also referred to as a field facet mirror. The first facet mirror 102.6 comprises a multiplicity of individual first facets 102.7, which are also referred to below as field facets. These first facets and their optical surfaces are indicated only very schematically in Figure 1 by the dashed contour 102.7.

[0081] The first facets 102.7 may be configured as macroscopic facets, in particular as rectangular facets or as facets with an arcuate or partly circular edge contour. The first facets 102.7 may be configured as facets with a plane optical surface or alternatively with a convexly or concavely curved optical surface.

[0082] As known for example from DE 102008009600 A1 (the entire disclosure of which is incorporated herein by reference), the first facets 102.7 themselves may also be composed in each case of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 102.6 may in particular take the form of a microelectromechanical system (MEMS system), as is described in detail in DE 102008009600 A1 , for example.

[0083] In the present example, the illumination radiation 107 travels horizontally, i.e. in the y-direction, between the collector 102.3 and the deflection mirror 102.5. However, it is understood that different alignments may also be chosen in other variants.

[0084] A second facet mirror 102.8 is arranged downstream of the first facet mirror 102.6 in the beam path of the illumination optics unit 102.2. Should the optically effective surfaces of the second facet mirror 102.8 be arranged in the region of a pupil plane of the illumination optics unit 102.2, the second facet mirror 102.8 is also referred to as a pupil facet mirror. The second facet mirror 102.8 may also be arranged at a distance from a pupil plane of the illumination optics unit 102.2. In this case, the combination of the first facet mirror 102.6 and the second facet mirror 102.8 is also referred to as a specular reflector. Such specular reflectors are known, for example, from US 2006 / 0132747 A1, EP 1 614008 B1 or US 6,573,978 (the respective entire disclosures of which are incorporated herein by reference).

[0085] The second facet mirror 102.8 in turn comprises a plurality of second facets, which are indicated only very schematically in Figure 1 by the dashed contour 102.9. In the case of a pupil facet mirror, the second facets 102.9 are also referred to as pupil facets. In principle, the second facets 102.9 may have the same design as the first facets 102.7. In particular, the second facets 102.9 may likewise be macroscopic facets, which for example may have a round, rectangular or hexagonal edge. Alternatively, the second facets 102.9 may be facets

[0086] 2022P00116 WO 220908WO KA / el January 20, 2026composed of micromirrors. The second facets 102.9 in turn may have plane reflection surfaces or alternatively reflection surfaces with convex or concave curvature. In this regard, reference is made anew to DE 102008009600 A1.

[0087] In the present example, the illumination optics unit 102.2 consequently forms a doubly faceted system. This basic principle is also referred to as fly's eye integrator. In certain variants, it may furthermore be advantageous to arrange the optical surfaces of the second facet mirror 102.8 not exactly in a plane which is optically conjugate to a pupil plane of the projection optics unit 104.1.

[0088] In a further embodiment, not shown, of the illumination optics unit 102.2, a transfer optics unit 102.10 (depicted only highly schematically) contributing in particular to the imaging of the first facets 102.7 into the object field 103.1 may be arranged in the beam path between the second facet mirror 102.8 and the object field 103.1. The transfer optics unit 102.10 may have exactly one mirror, or alternatively have two or more mirrors, which are arranged one behind the other in the beam path of the illumination optics unit 102.2. The transfer optics unit 102.10 may in particular comprise one or two normal-incidence mirrors (Nl mirrors) and / or one or two grazing-incidence mirrors (Gl mirrors).

[0089] In the embodiment as shown in Figure 1, the illumination optics unit 102.2 has exactly three mirrors downstream of the collector 102.3, specifically the deflection mirror 102.5, the first facet mirror 102.6 (e.g. a field facet mirror) and the second facet mirror 102.8 (e.g. a pupil facet mirror). The deflection mirror 102.5 may also be omitted in a further embodiment of the illumination optics unit 102.2, and so the illumination optics unit 102.2 may then have exactly two mirrors downstream of the collector 102.3, specifically the first facet mirror 102.6 and the second facet mirror 102.8.

[0090] The second facet mirror 102.8 is used to image the individual first facets 102.7 into the object field 103.1. The second facet mirror 102.8 is the last beam-shaping mirror or else actually the last mirror for the illumination radiation 107 in the beam path upstream of the object field 103.1. The imaging of the first facets 102.7 into the object plane 103.2 by means of the second facets 102.9 or using the second facets 102.9 and a transfer optics unit 102.10 is often only approximate imaging.

[0091] The projection optics unit 104.1 comprises a plurality of mirrors Mi, which are numbered in accordance with their arrangement along the beam path of the projection exposure apparatus 101. In the example illustrated in Figure 1, the projection optics unit 104.1

[0092] 2022P00116 WO 220908WO KA / el January 20, 2026comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or any other number of mirrors Mi are likewise possible. The penultimate mirror M5 and the last mirror M6 may each have a passage opening (not depicted in any more detail) for the illumination radiation 107. In the present example, the projection optics unit 104.1 is a doubly obscured optics unit. The projection optics unit 104.1 has an image-side numerical aperture NA which is greater than 0.5. In particular, the image-side numerical aperture NA may also be greater than 0.6. For example, the image-side numerical aperture NA may be 0.7 or 0.75.

[0093] The reflection surfaces of the mirrors Mi may be configured as freeform surfaces without an axis of rotational symmetry. Alternatively, the reflection surfaces of the mirrors Mi may be designed as aspherical surfaces with exactly one axis of rotational symmetry of the reflection surface shape. Just like the mirrors of the illumination optics unit 102.2, the mirrors Mi may have highly reflective coatings for the illumination radiation 107. These coatings can be constructed from a plurality of coatings (multilayer coatings); in particular, they may be designed with alternating layers of molybdenum and silicon.

[0094] In the present example, the projection optics unit 104.1 has a large object-image shift in the y-direction between a y-coordinate of a centre of the object field 103.1 and a y-coordinate of the centre of the image field 105.1. This object-image shift in the y-direction may be of approximately the same order as a distance between the object plane 103.2 and the image plane 105.2 in the z-direction.

[0095] The projection optics unit 104.1 may be configured in particular in anamorphic fashion. In particular, it has different imaging scales px, y in the x- and y-directions. The two imaging scales px, Py of the projection optics unit 104.1 are preferably (Px; Py) = (+ / -0.25; + / -0.125). A positive imaging scale p means imaging without image inversion. A negative sign for the imaging scale p means imaging with image inversion. In the present example, the projection optics unit 104.1 consequently leads to a reduction in size with a ratio of 4:1 in the x-direction, i.e. in a direction perpendicular to the scanning direction. By contrast, the projection optics unit 104.1 leads to a reduction in size in the ratio of 8:1 in the y-direction, i.e. in the scanning direction. Other imaging scales are also possible. Imaging scales with the same sign and the same absolute value in the x-direction and y-direction are also possible, for example with absolute values of 0.125 or of 0.25.

[0096] The beam path between the object field 103.1 and the image field 105.1 may contain the same number of intermediate image planes in the x- and y-directions. Likewise, the number of intermediate image planes may differ, depending on the design of the projection optics unit

[0097] 2022P00116 WO 220908WO KA / el January 20, 2026104.1. Examples of projection optics units with differing numbers of such intermediate images in the x- and y-directions are known, for example, from US 2018 / 0074303 A1 (the entire disclosure of which is incorporated herein by reference).

[0098] Each pupil facet 102.9 in the present example is assigned to exactly one of the field facets 102.7 in order to form a respective illumination channel serving to illuminate the object field 103.1. In particular, this may result in illumination according to the Kohler principle. The far field is decomposed into a plurality of object fields 103.1 with the aid of the field facets 102.7. The field facets 102.7 generate a plurality of images of the intermediate focus on the pupil facets 102.9 respectively assigned thereto.

[0099] The field facets 102.7 are each imaged onto the reticle 103.3 by an assigned pupil facet 102.9, with the image representations being overlaid such that there is thus an overlaid illumination of the object field 103.1. The illumination of the object field 103.1 is preferably as homogeneous as possible. It preferably has a uniformity error of less than 2%. The field uniformity can be achieved by way of the overlay of different illumination channels.

[0100] The illumination of the entrance pupil of the projection optics unit 104.1 may be defined geometrically by way of an arrangement of the pupil facets 102.9. The intensity distribution in the entrance pupil of the projection optics unit 104.1 may be set by selecting the illumination channels, in particular the subset of the pupil facets 102.9 which guide light. This intensity distribution is also referred to as illumination setting of the illumination system 102. A likewise preferred pupil uniformity in the region of portions of an illumination pupil of the illumination optics unit 102.2 which are illuminated in a defined manner may be achieved by a redistribution of the illumination channels. In the case of actively adjustable facets, the aforementioned settings can be made in each case by corresponding control by way of the control device 106.

[0101] Further aspects and details of the illumination of the object field 103.1 and in particular of the entrance pupil of the projection optics unit 104.1 are described below.

[0102] The projection optics unit 104.1 may comprise in particular a homocentric entrance pupil. The latter may be accessible or else be inaccessible. The entrance pupil of the projection optics unit 104.1 frequently cannot be illuminated exactly using the pupil facet mirror 102.8. In the case of imaging by means of the projection optics unit 104.1 which telecentrically images the centre of the pupil facet mirror 102.8 onto the wafer 105.3, the aperture rays often do not intersect at a single point. However, it is possible to find an area in which the

[0103] 2022P00116 WO 220908WO KA / el January 20, 2026spacing of the aperture rays, which is determined in pairs, becomes minimal. This area is the entrance pupil or an area conjugate thereto in real space. In particular, this area exhibits a finite curvature.

[0104] In certain variants, the projection optics unit 104.1 may have different poses of the entrance pupil for the tangential and sagittal beam paths. In this case, it is preferable for an imaging optical element, in particular an optical component part of the transfer optics unit 102.10, to be provided between the second facet mirror 102.8 and the reticle 103.3. The different poses of the tangential entrance pupil and the sagittal entrance pupil can be taken into account with the aid of this imaging optical element.

[0105] With the arrangement of the components of the illumination optics unit 102.2 as shown in Figure 1 , the optical surfaces of the pupil facet mirror 102.8 are arranged on a surface that is conjugate to the entrance pupil of the projection optics unit 104.1. The first facet mirror 102.6 (field facet mirror) defines a first main plane of extent of its optical surfaces, which is arranged tilted to the object plane 5 in the present example. In the present example, this first main plane of extent of the first facet mirror 102.6 is arranged tilted to a second main plane of extent, which is defined by the optical surface of the deflection mirror 102.5. In the present example, the first main plane of extent of the first facet mirror 102.6 is also arranged tilted to a third main plane of extent, which is defined by the optical surfaces of the second facet mirror 102.8.

[0106] As explained below on the basis of Figures 1 to 4, the exposure process is subject to certain imaging errors lEx that in the region of the image field 105.1 (i.e. the used region in the image plane 105.2) lead to a deviation of the profile of the incident wavefront of the imaging light from its respective target value in the image plane 105.2. There may be at least a corrective counteraction to these imaging errors lEx by virtue of the control device 106 suitably controlling appropriately active components of the projection exposure apparatus 101 (in a manner known sufficiently well). Naturally, one of the preconditions for a targeted correction of the imaging errors lEx (at least the imaging errors lEx relevant to the quality of the exposure process) is that the imaging error lEx in question and optionally also the development thereof over time are, to a sufficient extent, exactly known.

[0107] One option for determining the current value of the imaging error lEx in question, at least to a good approximation, consists in intermittently determining the profile of the wavefront in the image plane 105.2, more precisely in the relevant image field 105.1 , in a determination device 106.1 of the control device 106, for example between the exposure of different wafers

[0108] 2022P00116 WO 220908WO KA / el January 20, 2026105.3: To this end, current state values of the wavefront are captured at specific image points in the image plane 105.2 by way of a suitable capture device 108. Then, the profile of the wavefront in the relevant image field 105.1 is determined in the determination device 106.1 on the basis of these current state values.

[0109] A problem in this respect is that such a capture is generally only possible at comparatively few points in the image plane 105.3 so that the throughput of wafers 105.3 over time is not reduced significantly in any case. This is due not least to the fact that the corresponding measuring devices 108.1 (i.e. corresponding image sensors 108.1 , for example) of the associated ones typically cannot be arranged with a correspondingly high resolution in the region of the image plane 105.2. Rather, corresponding measurements are frequently taken sequentially using an image sensor 108 (indicated schematically in Figure 2) that is positioned incrementally in the region of the corresponding image points IP1 , IP2, IP3 in the image plane 105.2. Taking into account the wafer throughput and hence the time available for the measurements (between two wafers 105.3), it is therefore possible to approach only comparatively few image points. This achieves only a comparatively low spatial resolution of the measurement, and of course this has a disadvantageous effect on the precision of the determination of the respective relevant imaging error lEx in conventional projection exposure apparatuses.

[0110] In the projection exposure apparatus 101 of the present example, an improved determination and subsequent compensation of imaging errors lEx is achieved by virtue of the fact that the profile of the relevant piece of imaging error information lEIx over the image field 105.1 is determined on the basis of the pieces of local imaging error information LIE lx from at least two temporally spaced-apart, temporally coherent capture steps CS1 and CS2, optionally also from multiple capture steps CSn, in which the pieces of local imaging error information LI Elx were captured, in each case temporally coherently, at different image point groups IPGn in the image plane 105.2 (for example see IPG1 , IPG2, IPG3 in Figure 2). Here, the piece of imaging error information LIEIx, lEIx in question is representative of at least one (correspondingly relevant) imaging error lEx of the projection exposure apparatus 101.

[0111] By using the pieces of local imaging error information LIEIx for different image point groups IPGn, it is easily possible to obtain an increased spatial resolution with respect to the image points, on the basis of which the profile of the piece of imaging error information I E lx in question is determined over the image field 105.1 , without reducing the wafer throughput on account of a longer duration of the respective capture step CSn. Instead, the duration of the respective capture step CSn may remain the same whilst having an increased spatial

[0112] 2022P00116 WO 220908WO KA / el January 20, 2026resolution of the capture. Likewise, the duration of the respective capture step CSn might optionally even be reduced (i.e. the wafer throughput can be increased) by virtue of an improved spatial resolution of the capture being achieved in the sum of the capture steps CSn (vis-a-vis the single capture step CSn) but the number of image points being reduced in at least one of the capture steps CSn.

[0113] What was found in this case in particular is that the interval DT between the capture steps CSn considered when determining the profile of the relevant piece of imaging error information I Elx either may have no noticeable influence on the quality of determination of the imaging error lEx (for instance because the relevant imaging error lEx only has a negligible temporal drift between the capture steps CSn) or can easily be taken into account (for instance by virtue of the temporal drift being determined, for example on the basis of the ascertained pieces of imaging error information IE lx from the capture steps CSn, and then being taken into account accordingly).

[0114] In the present example, the capture device 108 in each case captures a first piece of local imaging error information LIEU at a first plurality M1 of mutually spaced-apart first image points IP1 from a first image point group IPG1 in the image field 105.1 during a temporally coherent first capture step CS1. In Figure 2, the first image points IP1 from the first image point group IPG1 are represented by squares. Furthermore, the capture device 108 in each case captures a second piece of local imaging error information LIEI2 at a second plurality M2 of mutually spaced-apart second image points IP2 from a second image point group IPG2 in the image field 105.1 during a temporally coherent second capture step CS2 which follows the first capture step CS1. In Figure 2, the second image points IP2 from the second image point group IPG2 are represented by circles. As may be gathered from Figure 2, the first image points IP1 from the first image point group IPG1 and the second image points IP2 from the second image point group IPG2 differ by at least one image point.

[0115] In certain variants, the capture device 108 can be used to in each case capture a further piece of local imaging error information LIEIw (e.g. a third piece of local imaging error information LIEI3) at a further plurality Mw (e.g. a third plurality M3) of mutually spaced-apart further image points IPw (e.g. third image points IP3) from a second image point group IPGw (e.g. a third image point group IPG3) in the image field 105.1 during at least one further temporally coherent capture step CSw (e.g. a third capture step CS3) which follows the first and second capture steps CS1 , CS2. In Figure 2, the third image points IP3 from such a third image point group IPG3 are represented by triangles.

[0116] 2022P00116 WO 220908WO KA / el January 20, 2026In that case, the determination device 106.1 determines a profile of at least one piece of relevant imaging error information lEIx over the image field 105.2 using the first plurality M1 of the first pieces of local imaging error information LIEU from the first capture step CS1 and the second plurality M2 of the second pieces of local imaging error information LIEI2 from the second capture step CS2. The results of such a determination for different states of the projection exposure apparatus 101 are depicted in simplified fashion in Figures 3 and 4 on the basis of the pieces of local imaging error information LIEU , LIEI2 (described here by a Zernike polynomial Z2) for in each case only three of the first image points IP1 and the second image points IP2, which are spaced apart along the x-axis. The values of the pieces of local imaging error information LIEU , LIEI2 are once again represented by squares for the first image points IP1 and by circles for the second image points IP2.

[0117] It is understood that it may optionally be sufficient for the first image points IP1 from the first image point group IPG1 to differ from the second image points IP2 from the second image point group IPG2 only by one image point. A correspondingly more expedient, higher spatial resolution may naturally be obtained if the first image points IP1 from the first image point group IPG1 differ from the second image points IP2 from the second image point group IPG2 by 2 to 15 image points and preferably by 3 to 7 image points. In the example of Figure 2, there are four image points at which the first image point group IPG1 and the second image point group IPG2 differ from each other.

[0118] It is understood that the image point groups IPGn need not have any overlap whatsoever in terms of the image points. In this way, a particularly high spatial resolution may then be achieved. In certain variants, like in the present example of Figure 2, provision may be made for the first image point group IPG1 and the second image point group IPG2 to comprise at least one common image point, preferably 2 to 9 common image points and further preferably 3 to 5 common image points. By way of the pieces of local imaging error information LIEI relating to such common image points from the image point groups IPGn, it is for example easily and advantageously possible to draw conclusions about the temporal drift of the respective imaging error lEx and to then take this drift into account accordingly when determining the profile of the piece of imaging error information I E lx, as indicated in Figure 4.

[0119] In certain advantageous variants, the first image point group IPG1 and the second image point group IPG2 therefore comprise at least one common image point IPC (like in the present example of Figure 2). In that case, the determination device 106.1 determines a change DT of the imaging error information I E lx over time in the determination step DS on

[0120] 2022P00116 WO 220908WO KA / el January 20, 2026the basis of the first piece of local imaging error information LIEU and the second piece of local imaging error information LIEI2 for the at least one common image point. Subsequently, the determination device 106.1 then determines the profile FIEIx of the at least one piece of imaging error information I Elx on the basis of the change DT in the piece of imaging error information I Elx over time, as indicated in Figure 4. In this way, a potential drift of the relevant imaging error may be taken into account particularly easily.

[0121] As may be gathered from Figures 3 and 4, the profile FIEIx of the piece of imaging error information I Elx in Figure 3 is determined in a steady state of the projection exposure apparatus 101 , in which the imaging error lEx in question is not subject to any (significant) temporal drift, and so the first piece of local imaging error information LIEU and the second piece of local imaging error information LIEI2 are the same at the common image point IPC (the central image point along the x-axis) despite the interval DT between the respective captures.

[0122] By contrast, Figure 4 depicts a non-steady state (for example a run-in state at the start of the normal operation of the projection exposure apparatus 101), in which the imaging error lEx in question is subject to a significant temporal drift such that the first piece of local imaging error information LIEU and the second piece of local imaging error information LIEI2 are different at the common image point IPC on account of the interval DT between the respective captures. In the state shown in Figure 4, this is taken into account by virtue of the first piece of local imaging error information LIEU being corrected in accordance with the determined temporal drift DT before the profile FIEIx of the piece of imaging error information I Elx is determined, as indicated by the dashed squares in Figure 4.

[0123] In principle, any desired plurality of capture steps CSn may be used when determining the profile FIEIx of the at least one piece of imaging error information I E lx over the image field 105.1 in the respective determination step DS. In certain variants, a plurality N of capture steps CSn are carried out sequentially, with the plurality N of capture steps CSn comprising at least the first capture step CS1 and the second capture step CS2. The determination device 106 then determines the profile of the at least one piece of imaging error information lEIx over the image field 105.1 in the determination step DS using the pieces of local imaging error information LI Elx from at least two capture steps from the plurality N of capture steps CSn. In the case of certain advantageous variants, the plurality N of capture steps total 2 to 10, preferably 2 to 5 and further preferably 2 to 3. Particularly expedient increased resolutions may be obtained therewith.

[0124] 2022P00116 WO 220908WO KA / el January 20, 2026In certain variants, the capture device 108 repeats the plurality N of capture steps CSn cyclically. In other words, this gives rise to a capture pattern with cyclically alternating image point groups. However, it is understood that other variants may also provide for the plurality N of capture steps CSn to be randomly strung together at least intermittently. In this case, it may be advantageous for the control device 106 to ensure that two successive capture steps differ from each other in each case.

[0125] In certain variants, the capture device 108, more precisely a control module of the capture device 108, randomly selects the image points for at least one of the capture steps of the plurality N of capture steps CSn. In this case, the image points IPx of multiple capture steps of the plurality N of capture steps CSn can be selected randomly. In particular, the image points of the respective capture step CSn of the plurality N of capture steps CSn can be selected randomly. In this way, averaged over time, the profile Fl Elx of the piece of imaging error information I E lx can be determined particularly precisely. In this case, the control module of the capture device 108 can preferably ensure that the image point groups in the capture steps taken into account in the determination step DS, in particular in immediately successive capture steps, have a predefinable degree of overlap (i.e. common image points IPC) and / or a predefinable degree of differentiation (i.e. different image points IPx).

[0126] In principle, any desired number of preceding capture steps can be taken into account in the determination step DS. In certain simple variants, the determination device 106.1 determines the profile Fl Elx of the at least one piece of imaging error information I E lx using the pieces of local imaging error information LI E lx from at least the two capture steps that immediately precede the determination step DS, i.e. from the two capture steps CS1 and CS2 that immediately precede the determination step DS in the example of Figures 2 to 4. This easily ensures that the determination of the pieces of local imaging error information LI Elx takes the current state of the projection exposure apparatus 101 into account.

[0127] In certain advantageous variants with a particularly good spatial resolution, the determination device 106.1 determines the profile FIEIx of the at least one piece of imaging error information lEIx using the pieces of local imaging error information LIEIx from 2 to 10, preferably 2 to 5 and further preferably 2 to 3 of the capture steps from the plurality N of capture steps CSn.

[0128] In certain advantageous variants, the determination device 106.1 may also determine the profile FIEIx of the at least one piece of imaging error information I E lx using a numerical model NM of the projection exposure apparatus 101 determined in advance. In this case, any

[0129] 2022P00116 WO 220908WO KA / el January 20, 2026desired variables that have a correspondingly relevant influence on the imaging error lEx in question may be used as input variables of the numerical model NM. In this respect, for example a imaging light power of the illumination device 102, one or more state variables, for example temperature values, of one or more components, in particular optical elements, in the projection exposure apparatus 101 may be used (alone or in any desired combination).

[0130] In principle, the relevant imaging error lEx may be captured by way of any desired suitable variables that allow a sufficiently precise conclusion to be drawn about the imaging error lEx in question. In the present example, at least one local capture value, which is representative of at least one current local property of the wavefront of the imaging light at the respective image point IPx, is captured as respective piece of local imaging error information LIEIx. The profile FIEIx of the at least one piece of imaging error information Fl E lx over the image field 105.1 is then determined in the determination step DS using the local capture values LIEIx from the first capture step CS1 and the second capture step CS2. Like in the present example, this may for example be implemented by way of appropriate interpolation using the local capture values LIEIx.

[0131] In principle, the profile FIEIx of the piece of imaging error information I E lx over the image field 105.1 may be described in any suitable manner which allows corresponding conclusions to be drawn about the current relevant imaging error lEx. In preferred variants that are easy to implement (such as the present example), the determination device 106.1 describes a current profile FIEIx of the at least one local property of the wavefront of the imaging light over the image field 105.1 on the basis of at least one wavefront property function Zx, in particular on the basis of at least one Zernike polynomial (see Z2in Figures 3 and 4).

[0132] In this case, the wavefront property function Zx is determined from the local capture values LIEIx from at least the first capture step CS1 and the second capture step CS2. In this case, the wavefront property function Zx may be interpolated in particular using the local capture values LIEIx from at least the first capture step CS1 and the second capture step CS2.

[0133] The capture of the respective piece of local imaging error information LIEIx may be implemented in any suitable manner as a matter of principle. In this case, provision may be made for the respective piece of local imaging error information LIEIx for multiple image points to be implemented at least substantially simultaneously. In certain variants, the capture device is configured like in the present example to capture the first piece of local imaging error information LIEU for at least two of the first image points IP1 sequentially with respect to each other. In addition to that or in an alternative, the capture device may likewise

[0134] 2022P00116 WO 220908WO KA / el January 20, 2026be configured to capture the second piece of local imaging error information LIEI2 for at least two of the second image points IP2 sequentially with respect to each other. It is possible in both cases to provide only one corresponding capture unit 108.1 (for example a corresponding image sensor) which is sequentially displaced to the corresponding image points. As a result, the equipment outlay for the capture device 108 can advantageously be kept comparatively low.

[0135] In certain variants, the capture device 108 may be configured to capture the first piece of local imaging error information LIEU for at least two of the first image points IP1 at least substantially simultaneously. This advantageously allows the duration of the capture step CS1 to be kept short and hence optionally allows the wafer throughput to be increased. In certain variants, the capture device may likewise be configured to capture the second piece of local imaging error information LIEI2 for at least two of the second image points IP2 at least substantially simultaneously.

[0136] In principle, the capture device 108 may be designed in any suitable manner in order to capture the respective piece of local imaging error information LI E lx in a suitable manner. In certain variants which are preferred owing to their simple construction, the capture device 108 comprises at least one capture unit 108.1 (for example an image sensor unit) like in the present example, said capture unit being arranged in the region of the associated image point IPx in the image field 105.1 in order to capture one of the pieces of local imaging error information LIEIx.

[0137] In variants of particularly simple design, the at least one capture unit 108.1 is displaced between at least two image points from the image points IPx in the image plane 105.2 in order to capture the respective pieces of local imaging error information LIEIx. In certain variants of simple design, the capture device 108 positions (like in the present example) a reference point of the capture unit, in particular a centre of a surface of an image sensor unit 108.1, in the region of one of the image points IPx in the image plane 105.2 in order to capture the piece of local imaging error information LIEIx in question.

[0138] In principle, the capture device 108 may be an independent component of the projection exposure apparatus 101. In the present example, a high functional integration is realized by virtue of the capture unit 108.1 being arranged on the substrate device, i.e. the wafer holder 105.4, and being accordingly able to be displaced (together with the wafer holder 105.4) by the wafer displacement drive 105.5.

[0139] 2022P00116 WO 220908WO KA / el January 20, 2026In principle, the respective capture step CSn may be implemented at any desired suitable and predefinable times during the normal operation of the projection exposure apparatus 101. In the present example, the (at least one) capture unit 108.1 is displaced in the region of the image plane 105.2 in a wafer interchange step (i.e. a substrate interchange step) during the normal operation in order to capture the pieces of local imaging error information LI Elx while the exposed wafer 105.3 is exchanged in the wafer interchange step for another wafer 105.3 to be exposed. In this case, the wafer interchange interval in which no wafer 105.3 is exposed in any case is advantageously exploited. In particular, what may be achieved in the process is that the wafer throughput of the projection exposure apparatus 101 , if at all, is adversely affected only as little as possible by the determination of the profile Fl E lx of the piece of imaging error information lEIx over the image field 105.1.

[0140] It is understood that, as a matter of principle, any desired suitable number of image points IPx may be provided for the respective capture step CSn, wherein a trade-off can be made as regards the duration of the respective capture step CSn (and the influence thereof on the wafer throughput) vis-a-vis the obtainable accuracy when determining the profile Fl Elx of the piece of imaging error information lEIx.

[0141] In expedient variants, the first number M1 of the first image points IP1 totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7. In addition to that or in an alternative, the second number M2 of the second image points IP2 may total 1 to 15, preferably 3 to 9 and further preferably 5 to 7. The first and second numbers M1 , M2 may differ. The first number M1 might likewise correspond to the second number M2.

[0142] The spatial resolution of the image points IPx over the image field 105.1 may be chosen in any suitable manner as a matter of principle for as long as a sufficiently high accuracy may be obtained for the determination of the profile FIE lx of the piece of imaging error information IE lx from the pieces of local imaging error information LI Elx obtained in the process. In this case, any desired, optionally different one-dimensional image point patterns (see image points IP1 and IP2 in Figure 2) or two-dimensional image point patterns (see image points IP3 in Figure 2) may be used for the respective capture step CSn. In certain advantageous variants, the first image points IP1 are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region. In addition to that or in an alternative, the second image points IP2 are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region. In addition to that or in an alternative, at least some of the first image points IP1 are spaced apart from adjacent second image points

[0143] 2022P00116 WO 220908WO KA / el January 20, 2026IP2 by 2% to 30%, preferably 5% to 25% and further preferably 10% to 20% of a maximum dimension of the used region. With each of these variants (preferably with their combination), it is possible to obtain an advantageous spatial resolution of the image points IPx over the image field 105.1.

[0144] It is understood that, as a matter of principle, it may be sufficient to only take a first and a second capture step CS1 , CS2 into account in the determination step DS. In certain variants, one or more further capture steps CSw (i.e. consequently their pieces of local imaging error information LIEIw) may be taken into account in the determination step DS in order to achieve a further increase in the spatial resolution and the attendant increase in the accuracy of the result of the determination step DS. In this case, the respective further capture step CSw may as a matter of principle be designed like the first or second capture step CS1 , CS2 described herein, and so, in this respect, reference can be explicitly made to the statements given herein in relation to the first and second capture steps CS1 , CS2 provided that no other statements in this respect are given below.

[0145] In certain advantageous variants, the capture device 108 in each case captures a further piece of local imaging error information LIEIw (e.g. a third piece of imaging error information LIEI3) at a further number Mw (e.g. a third number M3) of mutually spaced-apart further image points IPw (e.g. third image points IP3; see Figure 2) from a further image point group IPGw (e.g. a third image point group IPG3) in the image field 105.1 during at least one temporally coherent further capture step CSw (e.g. a third capture step CS3). The further number Mw may total 1 to 15, preferably 3 to 9 and further preferably 5 to 7. Furthermore, the further number Mw may correspond to the first number M1 or the second number M2. In respect of the distance of the further image points IPw from the further image point group IPGw from one another and from the image points from other image point groups, in particular from the first and / or second image point groups IPG1 , IPG2, reference is also made to the corresponding explanations given above in relation to the first and second image points groups IPG1, IPG2.

[0146] Here, too, provision may be made (analogously to the first and second image point groups IPG1 , IPG2) for the further image points IPw from the further image point group IPGw to differ from the image points IP1 , IP2 from the first image point group IPG1 or the second image point group IPG2 by at least one image point, preferably by 2 to 15 image points and further preferably by 3 to 7 image points. Likewise (analogously in this respect), the further image point group IPGw and the first image point group IPG1 and / or the second image point group IPG2 may comprise at least one common image point IPC, preferably 2 to 9 common

[0147] 2022P00116 WO 220908WO KA / el January 20, 2026image points IPC and further preferably 3 to 5 common image points IPC. Likewise, provision can be made for the further image point group IPGw and the first image point group IPG1 and / or the second image point group IPG2 to comprise at least one common image point IPC. In that case, the determination device 108 can determine a change DT in the piece of imaging error information I E lx over time in the determination step DS on the basis of the further pieces of local image error information LIEIw and the first pieces of local imaging error information LIEU and / or the second piece of local imaging error information LIEI2 for the at least one common image point IPC and determine the profile Fl E lx of the at least one piece of imaging error information I E lx on the basis of the change DT in the imaging error information lEIx overtime.

[0148] The temporal sequence of the first and second capture steps CS1 , CS2 may in principle be implemented in any desired suitable manner that enables a reliable and sufficiently precise determination of the profile Fl Elx of the at least one piece of imaging error information I Elx over the image field 105.1. In certain variants, the determination device 106.1 carries out the second capture step CS2 at a predefinable capture step interval TD in relation to the first capture step CS1. In this case, the capture step interval TD may be 50% to 500%, preferably 100% to 300% and further preferably 100% to 200% of the duration between the start of the exposure of two successive substrates during the normal operation. In particular, one of the capture steps CSn may be performed at certain predefined times independently of the state of the imaging process.

[0149] In certain variants, provision may be made for the first capture step CS1 to have a first capture step duration CD1 , and for the capture step interval TD to be 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the first capture step duration CD1. Likewise, the second capture step CS2 may have a second capture step duration CD2, and the capture step interval TD may be 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the second capture step duration CD2.

[0150] In certain advantageous variants that allow an advantageously high wafer throughput in particular, the imaging device has a normal operation like in the present example, during which multiple wafers 105.3 are successively arranged in the region of the image plane 105.2 and exposed in a respective imaging step. In these cases, the capture device 108 carries out the first capture step CS1 before an imaging step and the second capture step CS2 after the imaging step. Consequently, it is thus possible to use the time interval required in any case for the replacement of the wafer 105.3. The capture device may carry out the first capture step CS1 immediately before an imaging step and the second capture step CS2

[0151] 2022P00116 WO 220908WO KA / el January 20, 2026immediately after the imaging step in order to keep the time expenditure therefor during the normal operation as low as possible.

[0152] In certain variants, a capture step may be performed after each imaging step, at least for a certain portion of the normal operation (for example a run-in time of the projection exposure apparatus 101). In certain variants, a plurality of imaging steps can be carried out between the first capture step CS1 and the second capture step CS2. This may be provided in particular for a period of the normal operation following a run-in time of the projection exposure apparatus 101 , during which, if at all, only a comparatively small temporal drift of the imaging error lEx in question is to be expected.

[0153] The present invention has been described above exclusively on the basis of examples from the field of microlithography. However, it is self-evident that the invention can also be used in the context of any desired other optical applications, in particular imaging methods at different wavelengths, in which similar problems arise in terms of the correction of thermal imaging aberrations.

[0154] Furthermore, the invention can be used in connection with the inspection of objects, such as for example so-called mask inspection, in which the masks used for microlithography are inspected for their integrity, etc. In Figure 1 , a sensor unit, for example, which detects the image representation of the projection pattern of the reticle 104.1 (for further processing), then takes the place of the wafer 105.1. This mask inspection may then take place substantially at the same wavelength as is used in the later microlithographic process.

[0155] However, it is similarly possible also to use any desired wavelengths deviating therefrom for the inspection.

[0156] Lastly, the present invention was described above on the basis of specific exemplary embodiments, which show specific combinations of the features defined in the following patent claims. It should expressly be pointed out at this juncture that the subject matter of the present invention is not restricted to these combinations of features, rather all other combinations of features such as are evident from the following patent claims also belong to the subject matter of the present invention.

[0157] 2022P00116 WO 220908WO KA / el January 20, 2026

Claims

1. January 20, 2026CLAIMS1. Apparatus for determining at least one piece of imaging error information relating to a microlithographic optical imaging device (101), in particular for the use of light in the extreme ultraviolet (ELIV) range, wherein the imaging device is configured to generate an optical image representation of an object in a used region (105.1) in an image plane (105.2) of the imaging device (101 ) by means of imaging light, having a capture device (108) configured to capture, in each case, a first piece of local imaging error information at a first number M1 of first image points (IP1), in particular a first plurality M1 of mutually spaced-apart first image points (IP1 ), from a first image point group in the used region (105.1) in the image plane (105.2) in a temporally coherent first capture step, anda determination device (106.1) configured to determine a profile of the at least one piece of imaging error information over the used region (105.1) using the first number M1 of the first pieces of local imaging error information from the first capture step,wherein- the at least one piece of imaging error information is representative of at least one imaging error of the optical imaging device (101),- the capture device (108) is configured to capture, in each case, a second piece of local imaging error information at a second number M2 of second image points (IP2), in particular a second plurality M2 of mutually spaced-apart second image points (IP2), from a second image point group in the used region (105.1) in the image plane (105.2) in a temporally coherent second capture step, with the second capture step following the first capture step,characterized in that- the first image points (IP1 ) from the first image point group and second image points (IP2) from the second image point group differ by at least one image point and- the determination device (106.1 ) is configured to determine the profile of the at least one piece of imaging error information over the used region (105.1) in a determination step that follows the second capture step and using the first number M1 of the first pieces of local imaging error information from the first capture step2022P00116 WO 220908WO KA / el January 20, 2026and the second number M2 of the second pieces of local imaging error information from the second capture step.

2. Apparatus according to Claim 1 , wherein at least one of the following applies:- the first image points ( I P1 ) from the first image point group differ from the second image points (IP2) from the second image point group by 2 to 15 image points, preferably by 3 to 7 image points;- the first image point group and the second image point group comprise at least one common image point, preferably 2 to 9 common image points and further preferably 3 to 5 common image points,- the first image point group and the second image point group comprise at least one common image point (IPC), and the determination device (106.1) is configured to determine a change DT in the piece of imaging error information over time in the determination step on the basis of the first pieces of local imaging error information and the second piece of local imaging error information for the at least one common image point (IPC) and to determine the profile of the at least one piece of imaging error information on the basis of the change in the imaging error information over time.

3. Apparatus according to Claim 1 or 2, wherein- the capture device (108) is configured to sequentially carry out a plurality N of capture steps, with the plurality N of capture steps comprising at least the first capture step and the second capture step, and- the determination device (106.1 ) is configured to determine the profile of the at least one piece of imaging error information over the used region (105.1) in the determination step using the pieces of local imaging error information from at least two capture steps from the plurality N of capture steps,wherein in particular at least one of the following applies:- the plurality N of capture steps total 2 to 10, preferably 2 to 5 and further preferably 2 to 3;- the capture device (108) is configured to cyclically repeat the plurality N of capture steps;2022P00116 WO 220908WO KA / el January 20, 2026- the capture device (108) is configured to randomly select the image points for at least one of the capture steps from the plurality N of capture steps, in particular randomly select the image points of multiple capture steps from the plurality N of capture steps and in particular randomly select the image points of the respective capture step from the plurality N of capture steps;- the determination device (106.1 ) is configured to determine the profile of the at least one piece of imaging error information using the pieces of local imaging error information at least from the two capture steps immediately preceding the determination step;- the determination device (106.1 ) is configured to determine the profile of the at least one piece of imaging error information using the pieces of local imaging error information from 2 to 10, preferably 2 to 5 and further preferably 2 to 3 of the capture steps from the plurality N of capture steps;- the determination device (106.1 ) is configured to determine the profile of the at least one piece of imaging error information using a numerical model of the imaging device.

4. Apparatus according to any of Claims 1 to 3, wherein- the capture device (108) is configured to capture at least one local capture value, which is representative of at least one current local property of a wavefront of the imaging light at the respective image point, as a respective piece of local imaging error information,wherein in particular at least one of the following applies:- the determination device (106.1 ) is configured to determine the profile of the at least one piece of imaging error information over the used region (105.1) in the determination step using the local capture values from the first capture step and the second capture step;- the determination device (106.1 ) is configured to describe a current profile of the at least one local property of the wavefront of the imaging light over the used region (105.1) in the image plane (105.2) on the basis of at least one wavefront property function, in particular on the basis of at least one Zernike polynomial, wherein the wavefront property function is determined from the local capture values from at least the first capture step and the second capture step, in particular interpolated2022P00116 WO 220908WO KA / el January 20, 2026using the local capture values from the first capture step and the second capture step.

5. Apparatus according to any of Claims 1 to 4, wherein at least one of the following applies:- the capture device (108) is configured to capture the first piece of local imaging error information for at least two of the first image points (IP1 ) sequentially with respect to each other;- the capture device (108) is configured to capture the second piece of local imaging error information for at least two of the second image points (IP2) sequentially with respect to each other;- the capture device (108) is configured to capture the first piece of local imaging error information for at least two of the first image points (IP1) at least substantially simultaneously;- the capture device (108) is configured to capture the second piece of local imaging error information for at least two of the second image points (IP2) at least substantially simultaneously.

6. Apparatus according to any of Claims 1 to 5, wherein:- the capture device (108) comprises at least one capture unit, in particular an image sensor unit, and- the capture device (108) is configured to arrange the at least one capture unit in the region of the associated image point in the image plane (105.2) in order to capture one of the pieces of local imaging error information;wherein in particular at least one of the following applies:- the capture device (108) is configured to displace the at least one capture unit between at least two image points from the image points in the image plane (105.2) in order to capture the respective pieces of local imaging error information; - the capture device (108) is configured to position a reference point of the capture unit, in particular a centre of a surface of an image sensor unit, in the region of one of the image points in the image plane (105.2) in order to capture the piece of local imaging error information in question;2022P00116 WO 220908WO KA / el January 20, 2026- the imaging device comprises a displaceable substrate device (105.4), by means of which a substrate (105.3), in particular a wafer, is arranged in the region of the image plane (105.2) during a normal operation in order to optically image at least a portion of an object onto the substrate (105.3), wherein the at least one capture unit is arranged on the substrate device (105.4),- the at least one capture unit is arranged on a displaceable substrate device (105.4) of the imaging device, wherein a substrate (105.3), in particular a wafer, is arranged in the region of the image plane (105.2) by way of the substrate device (105.4) during an imaging step during a normal operation in order to optically image at least a portion of an object onto the substrate (105.3), and wherein the at least one capture unit is displaced into the region of the image plane (105.2) in a substrate interchange step during the normal operation in order to capture the pieces of local imaging error information while the substrate (105.3) is exchanged for another substrate (105.3) in the substrate interchange step.

7. Apparatus according to any of Claims 1 to 6, wherein at least one of the following applies:- the first number M1 totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7; - the second number M2 totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7;the first number M1 corresponds to the second number M2;- the first image points (IP1 ) are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region;- the second image points (IP2) are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region;at least some of the first image points (IP1 ) are spaced apart from adjacent second image points (IP2) by 2% to 30%, preferably 5% to 25% and further preferably 10% to 20% of a maximum dimension of the used region.2022P00116 WO 220908WO KA / el January 20, 20268. Apparatus according to any of Claims 1 to 7, wherein at least one of the following applies:- the capture device (108) is configured to capture, in each case, a further piece of local imaging error information at a further number Mw of further image points (IP3), in particular a further plurality Mw of mutually spaced-apart further image points (IP3), from a further image point group in the used region (105.1) in the image plane (105.2) in at least one temporally coherent further capture step, wherein in particular at least one of the following applies:- the further number Mw totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7;the further number Mw corresponds to the first number M1 or the second number M2;- the further image points (IP3) from the further image point group differ from the image points (IP1) from the first image point group or the second image point group by at least one image point, preferably by 2 to 15 image points and further preferably by 3 to 7 image points;- the further image point group and the first image point group and / or the second image point group comprise at least one common image point (IPC), preferably 2 to 9 common image points and further preferably 3 to 5 common image points, - the further image point group and the first image point group and / or the second image point group comprise at least one common image point (IPC), and the determination device (106.1) is configured to determine a change DT in the piece of imaging error information over time in the determination step on the basis of the further pieces of local imaging error information and the first pieces of local imaging error information and / or the second piece of local imaging error information for the at least one common image point and to determine the profile of the at least one piece of imaging error information on the basis of the change in the imaging error information over time.

9. Apparatus according to any of Claims 1 to 8, wherein:- the determination device (106.1 ) is configured to carry out the second capture step at a predefinable capture step interval TD in relation to the first capture step, wherein at least one of the following applies:2022P00116 WO 220908WO KA / el January 20, 2026- the capture step interval TD is 50% to 500%, preferably 100% to 300% and further preferably 100% to 200% of the duration between the start of the exposure of two successive substrates during the normal operation;- the first capture step has a first capture step duration CD1 , and the capture step interval TD is 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the first capture step duration CD1 ;- the second capture step has a second capture step duration CD2, and the capture step interval TD is 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the second capture step duration CD2.

10. Apparatus according to any of Claims 1 to 9, wherein:- the imaging device comprises a normal operation in which at least a portion of an object is optically imaged onto multiple substrates, in particular wafers, arranged successively in the region of the image plane (105.2), with the imaging of the object onto the respective substrate (105.3) being implemented in a respective imaging step during the normal operation,wherein at least one of the following applies:- the capture device (108) is configured to carry out the first capture step before an imaging step and to carry out the second capture step after the imaging step; - the capture device (108) is configured to carry out the first capture step immediately before an imaging step and to carry out the second capture step immediately after the imaging step;- the capture device (108) is configured in such a way that a plurality of imaging steps are carried out between the first capture step and the second capture step.

11. Optical imaging device, in particular microlithographic optical imaging device, having an illumination device (102) having a first optical element group (102.2), an object device (103) for receiving an object (103.3),a projection device (104) having a second optical element group (104.1), an image device (105) anda control device (106),wherein2022P00116 WO 220908WO KA / el January 20, 2026- the illumination device (102) is configured to illuminate the object (103.3),- the projection device (104) is configured to project an image representation of the object (103.3) onto the image device (105),the control device (106) is configured to control the illumination device (102) and the projection device (104) and preferably at least one of the object device (103) and the image device (105) in an imaging control step in order to generate the image representation of the object (103.3),characterized in that- the control device (106) comprises an apparatus according to any of Claims 1 to 10,wherein- the control device (106) is configured in particular to undertake the imaging control step using the profile of the at least one piece of imaging error information.

12. Method for determining at least one piece of imaging error information relating to a microlithographic optical imaging device, in particular for the use of light in the extreme ultraviolet (ELIV) range, wherein the imaging device is configured to generate an optical image representation of an object in a used region (105.1) in an image plane (105.2) of the imaging device by means of imaging light, wherein in each case a first piece of local imaging error information is captured at a first number M1 of first image points (IP1 ), in particular a first plurality M1 of mutually spaced-apart first image points (IP1 ), from a first image point group in the used region (105.1) in the image plane (105.2) in a temporally coherent first capture step, anda profile of the at least one piece of imaging error information over the used region (105.1) is determined using the first number M1 of the first pieces of local imaging error information from the first capture step,wherein- the at least one piece of imaging error information is representative of at least one imaging error of the optical imaging device,in each case a second piece of local imaging error information is captured at a second number M2 of second image points (I P2), in particular a second plurality M2 of mutually spaced-apart second image points (IP2), from a second image2022P00116 WO 220908WO KA / el January 20, 2026point group in the used region (105.1) in the image plane (105.2) in a temporally coherent second capture step, with the second capture step following the first capture step,characterized in that- the first image points (IP1 ) from the first image point group and second image points (IP2) from the second image point group differ by at least one image point and- the profile of the at least one piece of imaging error information over the used region (105.1) is determined in a determination step that follows the second capture step and using the first number M1 of the first pieces of local imaging error information from the first capture step and the second number M2 of the second pieces of local imaging error information from the second capture step.

13. Method according to Claim 12, wherein at least one of the following applies:- the first image points (IP1 ) from the first image point group differ from the second image points (IP2) from the second image point group by 2 to 15 image points, preferably by 3 to 7 image points;- the first image point group and the second image point group comprise at least one common image point (IPC), preferably 2 to 9 common image points and further preferably 3 to 5 common image points,- the first image point group and the second image point group comprise at least one common image point (IPC), and a change DT in the piece of imaging error information over time is determined in the determination step on the basis of the first pieces of local imaging error information and the second piece of local imaging error information for the at least one common image point (IPC), and the profile of the at least one piece of imaging error information is determined on the basis of the change in the imaging error information over time.

14. Method according to Claim 12 or 13, whereina plurality N of capture steps are carried out sequentially, with the plurality N of capture steps comprising at least the first capture step and the second capture step, and- the profile of the at least one piece of imaging error information over the used region is determined in the determination step using the pieces of local imaging2022P00116 WO 220908WO KA / el January 20, 2026error information from at least two capture steps from the plurality N of capture steps,wherein in particular at least one of the following applies:- the plurality N of capture steps total 2 to 10, preferably 2 to 5 and further preferably 2 to 3;- the plurality N of capture steps are repeated cyclically;- the image points for at least one of the capture steps from the plurality N of capture steps are selected randomly, the image points of multiple capture steps from the plurality N of capture steps in particular are selected randomly and the image points of the respective capture step from the plurality N of capture steps in particular are selected randomly;- the profile of the at least one piece of imaging error information is determined using the pieces of local imaging error information at least from the two capture steps immediately preceding the determination step;- the profile of the at least one piece of imaging error information is determined using the pieces of local imaging error information from 2 to 10, preferably 2 to 5 and further preferably 2 to 3 of the capture steps from the plurality N of capture steps;- the profile of the at least one piece of imaging error information is determined using a numerical model of the imaging device.

15. Method according to any of Claims 12 to 14, whereinat least one local capture value, which is representative of at least one current local property of a wavefront of the imaging light at the respective image point, is captured as a respective piece of local imaging error information,wherein in particular at least one of the following applies:- the profile of the at least one piece of imaging error information over the used region (105.1) is determined in the determination step using the local capture values from the first capture step and the second capture step;a current profile of the at least one local property of the wavefront of the imaging light over the used region (105.1) in the image plane (105.2) is described on the basis of at least one wavefront property function, in particular on the basis of at least one Zernike polynomial, wherein the wavefront property function is2022P00116 WO 220908WO KA / el January 20, 2026determined from the local capture values from at least the first capture step and the second capture step, in particular interpolated using the local capture values from the first capture step and the second capture step.

16. Method according to any of Claims 12 to 15, wherein at least one of the following applies:- the first piece of local imaging error information for at least two of the first image points (IP1 ) is captured sequentially with respect to each other;- the second piece of local imaging error information for at least two of the second image points (IP2) is captured sequentially with respect to each other;- the first piece of local imaging error information for at least two of the first image points (IP1 ) is captured at least substantially simultaneously;- the second piece of local imaging error information for at least two of the second image points (IP2) is captured at least substantially simultaneously.

17. Method according to any of Claims 12 to 16, wherein:at least one capture unit, in particular an image sensor unit, is arranged in the region of the associated image point in the image plane (105.2) in order to capture one of the pieces of local imaging error information;wherein in particular at least one of the following applies:- the at least one capture unit is displaced between at least two image points from the image points in the image plane (105.2) in order to capture the respective pieces of local imaging error information;a reference point of the capture unit, in particular a centre of a surface of an image sensor unit, is positioned in the region of one of the image points in the image plane (105.2) in order to capture the piece of local imaging error information in question;- the imaging device comprises a displaceable substrate device (105.4), by means of which a substrate (105.3), in particular a wafer, is arranged in the region of the image plane (105.2) during a normal operation in order to optically image at least a portion of an object onto the substrate (105.3), wherein the at least one capture unit is arranged on the substrate device (105.4),2022P00116 WO 220908WO KA / el January 20, 2026- the at least one capture unit is arranged on a displaceable substrate device (105.4) of the imaging device, wherein a substrate (105.3), in particular a wafer, is arranged in the region of the image plane (105.2) by way of the substrate device (105.4) during an imaging step during a normal operation in order to optically image at least a portion of an object onto the substrate (105.3), and wherein the at least one capture unit is displaced into the region of the image plane (105.2) in a substrate interchange step during the normal operation in order to capture the pieces of local imaging error information while the substrate (105.3) is exchanged for another substrate (105.3) in the substrate interchange step.

18. Method according to any of Claims 12 to 17, wherein at least one of the following applies:- the first number M1 totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7; - the second number M2 totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7;the first number M1 corresponds to the second number M2;- the first image points (IP1 ) are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region;- the second image points (IP2) are spaced apart from one another by 3% to 50%, preferably 10% to 40% and further preferably 20% to 30% of a maximum dimension of the used region;at least some of the first image points (IP1 ) are spaced apart from adjacent second image points (IP2) by 2% to 30%, preferably 5% to 25% and further preferably 10% to 20% of a maximum dimension of the used region.

19. Method according to any of Claims 12 to 18, wherein at least one of the following applies:in each case a further piece of local imaging error information is captured at a further number Mw of further image points (I P3), in particular a further plurality Mw of mutually spaced-apart further image points (IP3), from a further image point group in the used region (105.1) in the image plane (105.2) in at least one temporally coherent further capture step,wherein in particular at least one of the following applies:2022P00116 WO 220908WO KA / el January 20, 2026- the further number Mw totals 1 to 15, preferably 3 to 9 and further preferably 5 to 7;the further number Mw corresponds to the first number M1 or the second number M2;- the further image points (IP3) from the further image point group differ from the image points (IP1 , IP2) from the first image point group or the second image point group by at least one image point, preferably by 2 to 15 image points and further preferably by 3 to 7 image points;- the further image point group and the first image point group and / or the second image point group comprise at least one common image point (IPC), preferably 2 to 9 common image points and further preferably 3 to 5 common image points, - the further image point group and the first image point group and / or the second image point group comprise at least one common image point (IPC), and a change DT in the piece of imaging error information over time is determined in the determination step on the basis of the further pieces of local imaging error information and the first pieces of local imaging error information and / or the second piece of local imaging error information for the at least one common image point (IPC), and the profile of the at least one piece of imaging error information is determined on the basis of the change in the imaging error information over time.

20. Method according to any of Claims 12 to 19, wherein:- the second capture step is carried out at a predefinable capture step interval TD in relation to the first capture step,wherein at least one of the following applies:- the capture step interval TD is 50% to 500%, preferably 100% to 300% and further preferably 100% to 200% of the duration between the start of the exposure of two successive substrates during the normal operation;- the first capture step has a first capture step duration CD1 , and the capture step interval TD is 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the first capture step duration CD1 ;- the second capture step has a second capture step duration CD2, and the capture step interval TD is 200% to 4000%, preferably 400% to 2000% and further preferably 500% to 1000% of the second capture step duration CD2.2022P00116 WO 220908WO KA / el January 20, 202621 . Method according to any of Claims 12 to 20, wherein:- the imaging device comprises a normal operation in which at least a portion of an object is optically imaged onto multiple substrates, in particular wafers, arranged successively in the region of the image plane (105.2), with the imaging of the object onto the respective substrate (105.3) being implemented in a respective imaging step during the normal operation,wherein at least one of the following applies:- the first capture step is carried out before an imaging step, and the second capture step is carried out after the imaging step;- the first capture step is carried out immediately before an imaging step, and the second capture step is carried out immediately after the imaging step;a plurality of imaging steps are carried out between the first capture step and the second capture step.

22. Optical imaging method, in particular microlithographic optical imaging method, whereinan illumination device (102) which comprises a first optical element group (102.2) illuminates an object (103.3) anda projection device (104) which comprises a second optical element group (104.1) projects an image representation of the object (103.3) onto an image device (105), characterized in thatin order to generate the image representation of the object (103.3), the illumination device (102) and the projection device (104) and preferably at least one of the object device (103) and the image device (105) are controlled in an imaging control step using a method according to any of Claims 12 to 21 , in order to correct at least one imaging error of the imaging device (101) using the profile of the at least one piece of imaging error information.2022P00116 WO 220908WO KA / el January 20, 2026

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