DE102023116896A1 - Method for improving the imaging properties of an optical module, control, optical module and projection exposure system - Google Patents

Abstract

The invention relates to a method for improving the imaging properties of an optical module (30, 40) with an optical element (M3, 60) and at least one actuator (33.1, 33.2, 43.1, 43.2, 61) for positioning the optical element (M3, 60) relative to a reference, and at least one sensor (35.1, 35.2, 45.1, 45.2, 62) for detecting the position of the optical element (M3, 60) relative to a reference, wherein a control (50) regulates the position of the optical element (M3, 60) on the basis of a signal detected by the at least one sensor (35.1, 35.2, 45.1, 45.2, 62) and wherein the optical module (30, 40) has at least one deformation actuator (46.1, 46.2, 46.3, 46.4) for deforming an optical active surface (31,41) of the optical element (M3, 60) and the deformation actuator (46.1,46.2,46.3,46.4,68,68.1) can be controlled by the control (50), comprising the following method steps:- determination of at least one load (FΔg, FgH, FgA, FΔp, Fq) causing a deformation and/or deviation from a target position of the optical active surface (31,41),- determination of an actuator signal ILA for the deformation actuator (46.1,46.2,46.3,46.4,68,68.1) compensating for the deformation and/or deviation,- method of the deformation actuator (46.1,46.2,46.3,46.4,68,68.1).The invention further relates to a control (50) for an optical module (30,40) with an optical element (M3, 60) and at least one actuator (33.1,33.2,43.1,43.2,61) for positioning the optical element (M3, 60) relative to a reference and at least one sensor (35.1,35.2,45.1,45.2,62) for detecting the position of the optical element (M3, 60) relative to a reference, wherein the control (50) regulates the position of the optical element (M3, 60) on the basis of a signal detected by the sensor (35.1,35.2,45.1,45.2,62) and wherein the optical module (30,40) has at least one deformation actuator (46.1,46.2,46.3,46.4,68,68.1) for deforming an optical active surface (31, 41) of the optical element (M3, 60) and the Deformation actuator (46.1,46.2,46.3,46.4,68,68.1) can be controlled by the control (50). The control is characterized in that it has a module (52) for compensating a deviation from a target position and/or the deformation of the optical effective surface (31,41) on the basis of at least one load (FΔg, FgH, FgA, FΔp, Fq). The invention further relates to an optical module (30,40) and a projection exposure system (1,101).

Description

The invention relates to a method for improving the imaging properties of an optical module, a control for carrying out the method, an optical module with such a control and a projection exposure system with an optical module.

In such projection exposure systems, microscopically small structures are imaged using photolithographic processes, starting from a mask as a template, in a greatly reduced size onto a wafer coated with photoresist. In subsequent development and further processing steps, the desired structures, such as memory or logic elements, are created on the wafer, which is then divided into individual chips for use in electronic devices.

Due to the extremely small structures to be created, down to the nanometer range, extreme demands are placed on the optics of the projection exposure systems and thus on the optical elements used, such as lenses or mirrors. In addition, imaging errors regularly occur during operation of such a system, which can often be caused by changing environmental conditions such as pressure changes, temperature changes in the optics or even by changing the position and/or alignment of individual optical elements themselves.

On the one hand, these disturbances can cause a deviation of the surface used for imaging, i.e. the so-called optical effective surface, from a desired position, whereby the deviation can be a translation and/or rotation of the optical effective surface from its desired position.

On the other hand, the disturbances can develop as deformations on the optical effective surface of an optical element, whereby the deformation of the optical effective surface of a mirror in particular represents a critical design feature due to the higher sensitivity. Due to the lack of transmission in lenses, mirrors are used in particular in so-called EUV lithography with an emission wavelength of 1 nm to 120 nm, especially at 13.5 nm.

Typically, this problem is addressed by making the optical elements used movable or deformable in order to be able to correct the imaging errors mentioned during operation of the system. This deformation can be carried out from the back of a base body of the corresponding optical element.

The requirements for maintaining the shape of the optical effective surface are becoming higher from generation to generation, which means that these requirements can no longer be adequately met due to deformations of the optical effective surface caused by static and dynamic forces. The mirrors are known to be highly sensitive to deviations of the optical effective surface from their target geometry, whereby the effect can be increased by up to a factor of 100 by using mirrors with a smaller aspect ratio between thickness and diameter. A deviation from the required target geometry can therefore be caused by different physical influencing parameters or parameters, such as local variations in the acceleration due to gravity g. Other physical parameters can be, for example, parasitic forces and/or moments caused by actuators for positioning the mirror. In addition, pressure differences between the space above and below the mirror and the inclination of the mirror in its installation position to the direction of the acceleration due to gravity g can cause a significant deformation of the optical effective surface. These deformations can only be corrected partially and/or only after measuring the optical effective area using the methods known in the state of the art, which can have a negative impact on the imaging quality of the projection exposure systems.

The object of the present invention is to provide a method which eliminates the disadvantages of the prior art described above.

A further task is to provide a control for implementing the method, an optical module and a projection exposure system for semiconductor lithography, which improves the imaging properties of the projection exposure system.

This object is achieved by the method and the devices having the features of the independent claims. The subclaims relate to advantageous developments and variants of the invention.

• - Bestimmung mindestens einer eine Deformation und/oder Abweichung von einer Sollposition der optischen Wirkfläche verursachenden Last,
• - Bestimmung eines die Deformation und/oder Abweichung kompensierenden Aktuatorsignals für den Deformationsaktuator,
• - Verfahren des Deformationsaktuators.

A method according to the invention for improving the imaging properties of an optical module with an optical element and at least one actuator for positioning the optical element relative to a reference, and at least one sensor for detecting the position of the optical element relative to a Reference, wherein a control regulates the position of the optical element on the basis of a signal detected by the sensor and wherein the optical module has at least one deformation actuator for deforming an optical effective surface of the optical element and the deformation actuator can be controlled by the control, according to the invention comprises the following method steps:

• - Determination of at least one load causing a deformation and/or deviation from a target position of the optical effective surface,
• - Determination of an actuator signal for the deformation actuator compensating for the deformation and/or deviation,
• - Deformation actuator method.

For the purposes of the invention, a load is anything that can directly or indirectly cause a deformation of the optical effective surface and/or a deviation from the desired position when the load acts on the optical element, in particular on a mirror.

In particular, the load can include a foreseeable load. A foreseeable load is a load that is known in advance due to other factors, i.e. before or when the optical element is positioned at its target position. The load can be determined on the basis of physical parameters, such as the position and/or alignment of the optical element or the installation position of the optical module in relation to the acceleration due to gravity. Based on the foreseeable load, a deviation from the target position and/or a deformation of the optical effective surface can be determined using models. The load can have different causes, which are at least partially described below.

In a first embodiment of the invention, the load can include a local acceleration due to gravity. The high sensitivity mentioned above, in particular of mirrors with a smaller aspect ratio between thickness and diameter, is so high that the difference in the acceleration due to gravity at the place of manufacture, for example of a projection exposure system, and the place of installation, i.e. the place where the projection exposure system is put into operation at a customer's site, can already lead to a significant deformation of the optical effective surface. The difference between the highest and lowest acceleration due to gravity worldwide is approximately 50 mm/s ² and is thus in the order of magnitude of the acceleration that can cause a significant deviation from the target position and/or a deformation of the optical effective surface.

In a further embodiment, the load can include a pressure fluctuation. The pressure difference between the area above the optical element and below the optical element, which is designed as a mirror, for example, is particularly relevant for the deformation. These areas are specifically flushed due to the high cleanliness requirements in the area of the optical elements, whereby changes in the pressure differences can always occur. The pressure difference can be recorded using existing pressure sensors or determined using a modeled pressure and is thus available for determining a compensating actuator signal for the deformation actuator.

The load can also include the installation position of the optical module. The installation position of the optical module in relation to the acceleration due to gravity can sometimes differ significantly from the installation position during manufacture and/or qualification of the optical module. Furthermore, due to the often modular structure of the projection exposure system, the installation position of an optical module during qualification at the place of manufacture can differ from that at the installation site. Due to the size of the projection exposure systems, they are delivered to the customer in individual modules and reassembled on site, so the installation position can also differ within the tolerances.

In addition, the load can include a change in position of the optical element, which is designed in particular as a mirror, wherein the change in position can include a translation and/or a rotation of the mirror. Depending on the deflection of the actuators for positioning the optical element, the parasitic forces of the actuator on the optical element change. This change is taken into account when determining the actuator signal to compensate for the deviation and/or the deformation.

In a further embodiment of the invention, the load can include a temperature change of the optical module. The temperature change can be detected, for example, via temperature sensors and a deviation from the target position and/or the deformation of the optical effective surface can be determined in the control via models. On this basis, an actuator signal can in turn be determined to compensate for the deviation and/or deformation.

In particular, the load can include a deviation of the optical effective surface and/or deformation of the optical effective surface. This has the advantage that all loads explained so far are already included in the deviation and/or deformation are taken into account and the compensating actuator signal can be determined directly via a model. This advantage requires an accurate measurement of the position, alignment and deformation of the optical effective surface, whereby the deformation in particular can be determined directly or indirectly.

In a further embodiment of the invention, the control can determine a compensation force for the deformation actuator for at least one load.

In particular, the force can be determined on the basis of a force profile. A force profile includes, for example in the form of a table or a matrix, an individual force for each deformation actuator to generate a predetermined deformation of the optical effective surface.

The force profile can be optimized based on a minimization of the residual deformation of the optical effective area.

Furthermore, the forces determined for at least one load can be summed up. This means that only one summed force is transmitted to a module arranged in the control system to determine the actuator signal to compensate for the deviation from the target position and/or the deformation of the optical effective surface. This has the advantage that subsequent process steps relating to the forces only have to be applied to one force.

In a further embodiment of the invention, a deformation caused by a crosstalk of the summed force in at least one non-actuated degree of freedom can be determined.

Furthermore, a compensation force based on the deformation caused by crosstalk can be determined for at least one other deformation actuator using a further force profile. This means that not only are the compensation forces for compensating the loads determined, but also the parasitic deformations caused by crosstalk, i.e. by the parasitic forces of the previously determined compensation forces that deviate from the force direction of the actuator, are determined and a compensating force is determined on the basis of these. The parasitic deviations and/or deformations caused by further crosstalk that remain after the deformations caused by crosstalk have been compensated can be neglected.

In particular, the deformation caused by the crosstalk and the compensation forces determined on the basis of this can be determined for at least one further deformation actuator.

In a further embodiment, the force for compensating the crosstalk and the force for compensating the at least one load can be added together. This means that only one actuator signal per actuator is transmitted to a subsequent control module.

Furthermore, on the basis of the summed force, a current for controlling the at least one deformation actuator designed as a Lorentz actuator can be determined using an inverse Lorentz characteristic map. The inverse Lorentz characteristic map takes into account the non-linear relationship between force and current and the relationship between force and current for controlling the actuator, which depends on the deflection of the deformation actuator. The inverse Lorentz characteristic map can be determined either by modeling and/or by measuring.

As described above, the actuators for positioning the mirror have an influence on the deformation actuators when the mirror is moved. It is clear to the person skilled in the art that, where necessary, a force correction value can also be determined for the force of the actuators for positioning by the control and can be added to the force setpoint for positioning, whereby the position actuators also contribute to compensating for the load or crosstalk between the deformation actuators and the position actuators.

A control according to the invention for an optical module with an optical element and at least one actuator for positioning the optical element relative to a reference and at least one sensor for detecting the position of the optical element relative to a reference, wherein the control regulates the position of the optical element on the basis of a signal detected by the sensor and wherein the optical module has at least one deformation actuator for deforming an optical effective surface of the optical element and the deformation actuator can be controlled by the control. According to the invention, the control has a module for compensating a deviation from a target position and/or the deformation of the optical effective surface on the basis of at least one load.

An optical module according to the invention comprises an optical element and at least one actuator for positioning the optical element relative to a reference and at least one sensor for detecting the position of the optical Element relative to a reference, wherein a control based on a signal detected by the sensor regulates the position of the optical element. Furthermore, the optical module has at least one deformation actuator for deforming an optical effective surface of the optical element, wherein the deformation actuator can be controlled by the control. According to the invention, the control has a module for compensating a deviation from a target position and/or a deformation of the optical effective surface based on loads.

A projection exposure system according to the invention has such an optical module.

• 1 schematisch im Meridionalschnitt eine Projektionsbelichtungsanlage für die EUV-Projektionslithografie,
• 2 schematisch im Meridionalschnitt eine Projektionsbelichtungsanlage für die DUV-Projektionslithografie,
• 3a,b ein aus dem Stand der Technik bekanntes Spiegelmodul,
• 4 ein aus den Stand der Technik bekanntes Spiegelmodul mit einem deformierbaren Spiegel,
• 5 eine schematische Darstellung einer erfindungsgemäßen Ansteuerung zur Erläuterung des erfindungsgemäßen Verfahrens, und
• 6 ein Detail der Ansteuerung.

In the following, embodiments and variants of the invention are explained in more detail with reference to the drawing.

• 1 schematic meridional section of a projection exposure system for EUV projection lithography,
• 2 schematic meridional section of a projection exposure system for DUV projection lithography,
• 3a ,b a mirror module known from the state of the art,
• 4 a mirror module known from the state of the art with a deformable mirror,
• 5 a schematic representation of a control according to the invention to explain the method according to the invention, and
• 6 a detail of the control.

In the following, first with reference to the 1 The essential components of a projection exposure system 1 for microlithography are described by way of example. The description of the basic structure of the projection exposure system 1 and its components are not to be understood as restrictive.

One embodiment of an illumination system 2 of the projection exposure system 1 has, in addition to a radiation source 3, an illumination optics 4 for illuminating an object field 5 in an object plane 6. In an alternative embodiment, the light source 3 can also be provided as a module separate from the rest of the illumination system. In this case, the illumination system does not include the light source 3.

A reticle 7 arranged in the object field 5 is illuminated. The reticle 7 is held by a reticle holder 8. The reticle holder 8 can be displaced via a reticle displacement drive 9, in particular in a scanning direction.

In the 1 For explanation, a Cartesian xyz coordinate system is shown. The x-direction runs perpendicular to the drawing plane. The y-direction runs horizontally and the z-direction runs vertically. The scanning direction runs in the 1 along the y-direction. The z-direction is perpendicular to the object plane 6.

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

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

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

The illumination radiation 16, which emanates from the radiation source 3, is bundled by a collector 17. The collector 17 can be a collector with one or more ellipsoidal and/or hyperboloidal reflection surfaces. The at least one reflection surface of the collector 17 can be in grazing incidence (GI), i.e. with angles of incidence greater than 45° with respect to the normal direction of the mirror surface, or in normal incidence (NI), i.e. with angles of incidence less than 45°. be exposed to the illumination radiation 16. The collector 17 can be structured and/or coated on the one hand to optimize its reflectivity for the useful radiation and on the other hand to suppress stray light.

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

The illumination optics 4 comprise a deflection mirror 19 and a first facet mirror 20 arranged downstream of this in the beam path. The deflection mirror 19 can be a flat deflection mirror or alternatively a mirror with a beam-influencing effect beyond the pure deflection effect. Alternatively or additionally, the deflection mirror 19 can be designed as a spectral filter which separates a useful light wavelength of the illumination radiation 16 from false light of a different wavelength. If the first facet mirror 20 is arranged in a plane of the illumination optics 4 which is optically conjugated to the object plane 6 as a field plane, it is also referred to as a field facet mirror. The first facet mirror 20 comprises a plurality of individual first facets 21, which are also referred to below as field facets. Of these facets 21, only one is shown in the 1 only a few examples are shown.

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

As for example from the EN 10 2008 009 600 A1 As is known, the first facets 21 themselves can also be composed of a plurality of individual mirrors, in particular a plurality of micromirrors. The first facet mirror 20 can in particular be designed as a microelectromechanical system (MEMS system). For details, please refer to the EN 10 2008 009 600 A1 referred to.

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

In the beam path of the illumination optics 4, a second facet mirror 22 is arranged downstream of the first facet mirror 20. If the second facet mirror 22 is arranged in a pupil plane of the illumination optics 4, it is also referred to as a pupil facet mirror. The second facet mirror 22 can also be arranged at a distance from a pupil plane of the illumination optics 4. In this case, the combination of the first facet mirror 20 and the second facet mirror 22 is also referred to as a specular reflector. Specular reflectors are known from the US 2006/0132747 A1 , the EP 1 614 008 B1 and the US$6,573,978 .

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

The second facets 23 can also be macroscopic facets, which can be round, rectangular or hexagonal, for example, or alternatively facets composed of micromirrors. In this regard, reference is also made to the EN 10 2008 009 600 A1 referred to.

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

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

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

With the help of the second facet mirror 22, the individual first facets 21 are imaged in the object field 5. The second facet mirror 22 is the last bundle-forming or actually the last mirror for the illumination radiation 16 in the beam path in front of the object field 5.

In a further embodiment of the illumination optics 4 (not shown), a transmission optics can be arranged in the beam path between the second facet mirror 22 and the object field 5, which contributes in particular to the imaging of the first facets 21 in the object field 5. The transmission optics can have exactly one mirror, but alternatively also two or more mirrors, which are arranged one behind the other in the beam path of the illumination optics 4. The transmission optics may in particular comprise one or two mirrors for normal incidence (NI mirrors, Normal Incidence mirrors) and/or one or two mirrors for grazing incidence (GI mirrors, Gracing Incidence mirrors).

The illumination optics 4 has in the version shown in the 1 As shown, after the collector 17 there are exactly three mirrors, namely the deflection mirror 19, the field facet mirror 20 and the pupil facet mirror 22.

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

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

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

In the 1 In the example shown, the projection optics 10 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or another number of mirrors Mi are also possible. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 are doubly obscured optics. The projection optics 10 have a numerical aperture on the image side that is greater than 0.5 and can also be greater than 0.6 and can be, for example, 0.7 or 0.75.

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

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

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

The projection optics 10 thus leads to a reduction in the ratio 4:1 in the x-direction, i.e. in the direction perpendicular to the scanning direction.

The projection optics 10 leads to a reduction of 8:1 in the y-direction, i.e. in the scanning direction.

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

The number of intermediate image planes in the x- and y-direction in the beam path between the object field 5 and the image field 11 can be the same or can be different depending on the design of the projection optics 10. Examples of projection optics with different numbers of such intermediate images in the x- and y-direction are known from US 2018/0074303 A1 .

Each of the pupil facets 23 is assigned to exactly one of the field facets 21 to form an illumination channel for illuminating the object field 5. This can result in particular in illumination according to the Köhler principle. The far field is broken down into a plurality of object fields 5 using the field facets 21. The field facets 21 generate a plurality of images of the intermediate focus on the pupil facets 23 assigned to them.

The field facets 21 are each imaged onto the reticle 7 by an associated pupil facet 23, superimposing one another, to illuminate the object field 5. The illumination of the object field 5 is in particular as homogeneous as possible. It preferably has a uniformity error of less than 2%. The field uniformity can be achieved by superimposing different illumination channels.

By arranging the pupil facets, the illumination of the entrance pupil of the projection optics 10 can be defined geometrically. By selecting the illumination channels, in particular the subset of the pupil facets that guide light, the intensity distribution in the entrance pupil of the projection optics 10 can be set. This intensity distribution is also referred to as the illumination setting.

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

In the following, further aspects and details of the illumination of the object field 5 and in particular of the entrance pupil of the projection optics 10 are described.

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

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

It is possible that the projection optics 10 have different positions of the entrance pupil for the tangential and the sagittal beam path. In this case, an imaging element, in particular an optical component of the transmission optics, should be provided between the second facet mirror 22 and the reticle 7. With the help of this optical element, the different positions of the tangential entrance pupil and the sagittal entrance pupil can be taken into account.

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

The first facet mirror 20 is arranged tilted to an arrangement plane which is defined by the second facet mirror 22.

2 shows schematically in meridional section a further projection exposure system 101 for DUV projection lithography, in which the invention can also be used.

The structure of the projection exposure system 101 and the principle of imaging is comparable to that in 1 described structure and procedure. Identical components are provided with a 100 1 raised reference numerals, the reference numerals in 2 So start with 101.

In contrast to a 1 Due to the longer wavelength of the DUV radiation 116 used as useful light in the range from 100 nm to 300 nm, in particular from 193 nm, in the EUV projection exposure system 1 described, refractive, diffractive and/or reflective optical elements 117, such as lenses, mirrors, prisms, cover plates and the like, can be used in the DUV projection exposure system 101 for imaging or for illumination. The projection exposure system 101 essentially comprises an illumination system 102, a reticle holder 108 for receiving and precisely positioning a reticle 107 provided with a structure, by means of which the later structures on a wafer 113 are determined, a wafer holder 114 for holding, moving and precisely positioning this wafer 113 and a projection lens 110 with a plurality of optical elements 117, which are held via mounts 118 in a lens housing 119 of the projection lens 110.

The illumination system 102 provides DUV radiation 116 required for imaging the reticle 107 on the wafer 113. A laser, a plasma source or the like can be used as a source for this radiation 116. The radiation 116 is shaped in the illumination system 102 via optical elements such that the DUV radiation 116 has the desired properties with regard to diameter, polarization, shape of the wavefront and the like when it strikes the reticle 107.

The structure of the subsequent projection optics 101 with the lens housing 119 does not differ in principle from that in 1 described structure and is therefore not described further.

3a shows a schematic representation of an optical module known from the prior art and designed as a mirror module 30 with a mirror M3 in the embodiment shown, as it is in the 1 explained projection exposure system 1 is used, formed optical element.

und in der 3a als Flächenlast dargestellt ist.Based on 3a and 3b The influence of the acceleration due to gravity g _H on the mirror M3 will be explained using the example of 3a the mirror M3 is shown at its place of manufacture. The mirror M3 has an optical effective surface 31 which is in the 3a is shown as a dotted line. In the simplified two-dimensional example, the mirror M3 is connected to a module base plate 34 at two bearing points 32.1, 32.2 via actuators 33.1, 33.2. A force F _gH caused by the acceleration due to gravity g _H at the place of manufacture of the mirror module 30 and the mass m _S of the mirror M3 acts on the mirror M3, which is calculated as follows: $${\text{F}}_{\text{gH}}={\text{G}}_{\text{H}}*{\text{m}}_{\text{S}}$$

and in the 3a is represented as a surface load.

The actuators 33.1, 33.2 generate actuator forces F _AU1 , F _AU2 acting against the weight force F _gH , which in the 3 are shown as arrows.

The actuators 33.1, 33.2 are preferably designed as force actuators, in particular as Lorentz actuators, although alternatively other force actuators or displacement actuators, such as electrostrictive actuators, can also be used.

The optical effective surface 31 is machined at the manufacturing site in such a way that the deflection of the mirror M3 caused by the surface load F _gH is compensated, so that the optical effective surface 31 corresponds to its desired geometry.

In addition to applying the actuator forces F _AU1 , F _AU2 to compensate for the weight force F _gH , the actuators 33.1, 33.2 can also position the mirror M3, whereby the position of the mirror M3 is detected by sensors 35.1, 35.2. The actuator forces required to position the mirror M3 are determined by a 3a not shown control, which in the 6 will be explained in detail.

3b shows a schematic representation of the 3a explained mirror module 30 at its installation location, for example after delivery of a projection exposure system 1 to a location other than the place of manufacture. In the 3b only the mirror M3 and the forces acting on it F _gA , F _gH , F _Δg , F _AU1 , F _AU2 are shown. The force F _gA acting on the mirror M3 is calculated from the local acceleration due to gravity g _A at the installation site. In the example shown, the force F _gA is greater than the force F gH by the force F _Δg from the difference Δg of the acceleration due to gravity g _H at the place of manufacture and the acceleration due to gravity at the place of manufacture g _H times the mass m _S of the mirror _M3 and is calculated as follows. $${\text{F}}_{\text{gA}}={\text{G}}_{\text{A}}{\text{m}}_{\text{S}}={\text{F}}_{\text{gH}}+{\text{F}}_{\mathrm{\Delta }\text{G}}=\left({\text{G}}_{\text{H}}+\mathrm{\Delta }\text{G}\right)*{\text{m}}_{\text{S}}$$

The deviating from the place of manufacture in the 3b The weight force F _gA , represented as a surface load, causes the mirror M3 and thus the optical effective surface 31 to bend. The target geometry of the mirror M3 at the place of manufacture is shown in the 3b shown by dashed lines for comparison. The deformations that occur cannot be corrected by machining the optical effective surface 31, as is the case at the manufacturing site, which reduces the image quality of the projection exposure systems 1 ( 1 ) can be negatively influenced.

In this case, the forces F _AU1 , F _AU2 of the actuators 33.1, 33.2 counteracting the weight force F _gA are greater than at the place of manufacture.

4 shows a schematic representation of an optical module known from the prior art, designed as a mirror module 40, with an optical element designed as a deformable mirror M3 in the embodiment shown. Deformable mirrors M3 are already used to correct imaging errors of the projection optics 10 ( 1 ), i.e. to correct the cumulative imaging errors of the entire system. The 3b The effects of the locally deviating acceleration due to gravity Δg described above are only recorded as part of the imaging error of the system. This is determined by a time-consuming measurement of the imaging quality and, due to the negative impact of the measurement on the productivity of the projection exposure system 1, is only carried out at long intervals compared to the throughput. A solution for correcting foreseeable deformations, as described above, is therefore advantageous. The 4 serves to explain the compensation of the deformation of the optical effective surface 41 caused by the deviating acceleration due to gravity Δg by a deformable mirror M3.

The structure of the mirror module 40 is identical to that in the 3a explained mirror module 30, whereby where appropriate corresponding elements with opposite 3a are designated by reference numerals increased by 10. In the example shown, the mirror module 40 additionally comprises four Deformation actuators 46.1, 46.2, 46.3, 46.4 for deforming the mirror M3 and the optical effective surface 41 formed thereon. The mirror M3 is shown at the installation site, i.e. it is deformed at the installation site by the gravitational acceleration g _A , which differs from the place of manufacture.

The deformation actuators 46.1, 46.2, 46.3, 46.4, which in the example shown are also designed as Lorentz actuators, cause forces F _LA1 , F _LA2 , F _LA3 , F _LA4 at their connection points 47.1, 47.2, 47.3, 47.4 to the mirror M3, which in the 4 are shown as arrows. The sum of the forces F _LA1 , F _LA2 , F _LA3 , F _LA4 corresponds to the difference F _Δg of the weight force F _gH at the place of manufacture and the weight force F _gA at the place of installation. The mass m _S of the mirror M3 and the accelerations due to gravity g _A , g _H , Δg are known, so that the forces required to compensate for the deformation can be calculated using a control system according to the invention, which is shown in the 4 not shown, can be compensated locally, i.e. at the place of origin. The control is shown in the 5 and the 6 explained in detail and has the advantage that the deformation caused by the locally deviating acceleration due to gravity can be compensated without a direct or indirect measurement of the deformation of the optical effective surface 41. This also applies to the other parameters already explained.

Alternatively, the deformation actuators 46.1, 46.2, 46.3, 46.4 can also be designed as electrostrictive actuators and/or arranged parallel to the optical active surface 41, i.e., for example, connected to the back of the mirror M3 via an adhesive connection. In this case, the deformation of the optical active surface 41 is caused by a tensile stress or compressive stress on the back of the mirror M3 caused by an expansion or contraction of the deformation actuator 46.1, 46.2, 46.3, 46.4, which causes a local bending of the mirror M3 and thus a dent or elevation on the opposite optical active surface 41.

The deformation actuators 46.1, 46.2, 46.3, 46.4 predominantly cause a static compensation of the deformation of the optical effective surface 41, wherein the force F _LA1 , F _LA2 , F _LA3 , F _LA4 to be applied to each deformation actuator 46.1, 46.2, 46.3, 46.4 is determined by the control via a force profile.

Optionally, the deformation of the optical effective surface 41 can be detected by a sensor 48, which comprises, for example, an interferometer, as in the 4 shown by dashed lines. The resulting deviation of the optical effective surface 41 from its nominal shape can be used as input for controlling the deformation of the optical effective surface 41, for checking and/or calibrating the control and/or for improving models used in the control. The sensor 48 is not, however, necessary for determining the forces F _LA1 , F _LA2 , F _LA3 , F _LA4 . Due to the integration options being made more difficult by the installation space conditions and a measuring location only being formed in a non-optimal position due to the beam path of the useful radiation used for imaging, a measurement of the deformations for checking and calibration is preferably carried out using a temporary structure as part of the qualification of the mirror module 40. 5 shows a schematic representation of a control 50 for controlling the actuators 61 and deformation actuators 68 to explain the invention. Compared to a position control 51 known from the prior art, which is described in the 5 is shown surrounded by a dashed box, the control 50 has a further compensation module 52 according to the invention. This determines the forces F _LA1 , F _LA2 , F _LA3 , F _LA4 of the deformation actuators 46.1, 46.2, 46.3, 46.4 ( 4 ) to compensate for the deformation of the optical effective surface 41 ( 4 ) based on the physical parameters Δg (gravitational acceleration), Δp (pressure differences) described above and the parasitic forces and moments of the position actuators 43.1, 43.2 ( 4 ).

The position control module 51 controls the target position q specified by the setpoint generator 53 and comprises a position controller 66 and a feedforward control 67, which are in the 5 are each surrounded by a dashed box and are explained in more detail below.

In the position controller 66, the target position q for the mirror 60 (M3 in the 3 and 4 ) from the setpoint generator 53 to a difference point 54. At this point, the difference between the setpoint position q and the actual position of the mirror 60, which is measured via sensors 63 (45.1,45.2 in 4 ) and is also transmitted to the difference point 54. This position deviation q _A , referred to as the control difference, is transmitted to the position controller 55, which uses the position deviation q _A to determine the forces F _q for positioning the mirror 60 in the target position q on the basis of a coordinate system based on a reference point on the mirror 60 and transmits them to a first addition point 56.

In parallel to the position controller 66, the setpoint generator 53 in the feedforward control 67 initially determines a movement trajectory of the mirror 60 on the basis of the current setpoint q and its subsequent setpoint q ₊₁ . The movement trajectory The trajectory therefore describes the movement of the mirror 60 from the current target position q to the subsequent target position q ₊₁ which deviates from the current target position. From the movement trajectory, consistent time courses of the path and acceleration of the mirror 60 are subsequently determined and the time course of the acceleration is used to determine the necessary force F _V for changing the position of the mirror 60 from the current target position q to the subsequent target position q ₊₁ according to F = m*a.

The force F _V determined in this way is added to the force F _q of the position controller 66 at the addition point 56, so that the positioning of the mirror 60 from the current target position q to the subsequent target position q ₊₁ is advantageously anticipated. This means that the position deviation of the mirror 60 from the subsequent target position q ₊₁ does not have to be detected by the sensors 62 (35,45 in the 3 and 4 ) of the position controller 66 must be detected and corrected, but is already approached simultaneously with the transmission of the subsequent setpoint q ₊₁ by the additional force F _V. The position controller 66 therefore only has to correct the position deviations caused by disturbances in the controlled system.

The force F _qV resulting from the forces F _q and F _V is transmitted from the addition point 56 to a coordinate transformation module 58. This transforms the forces F _qV based on a mirror coordinate system into the forces F qV generated by the position actuators 61 (33.1, 33.2, 43.1, 43.2 in the 3 and 4 ), forces F _AU to be caused and the forces generated by the deformation actuators 68 (46.1,46.2, 46.3, 46.4 in the 4 ) to cause forces F _L .

In the position controller 66, the forces F _AU are transmitted to a map module 59, in which the forces F _AL are mapped into a current I _AU , which is transmitted to the actuators 61 of the mirror module 30, 40.

The characteristic map module 59 comprises an inverse Lorentz characteristic map, which contains the non-linear dependence of the force F _AU on the current and the deflection of the actuators 61. The data points of the characteristic map are created in advance empirically or by sampling a function, so that the corresponding value can be determined by searching and interpolating to map the current values F _AU on the basis of the determined force values f _AU .

The actuators 61 of the mirror module 30, 40 then position the mirror 60 to the target position q. The sensors 62 detect the actual position of the mirror 60 and transmit this to another coordinate transformation module 63. This transforms the position of the mirror 60 detected in sensor coordinates into the position of the mirror 60 in the mirror coordinate system and transmits this to the difference point 54.

The compensation module 52 comprises various force profile modules 64.1, 64 2, 64.3, 64.4 for compensating various deformations of the optical effective surface 41 ( 4 ) causing physical parameters. The force profiles are determined based on an optimization that minimizes the residual deformation of the optical effective area.

One of these parameters is the 3a , 3b , 4 explained deviation Δg of the acceleration due to gravity between the place of manufacture g _H and the place of installation g _A of the projection exposure system 1. Other parameters are, as explained above, the deviation Δp of the air pressure between the space above and below the mirror 60 and the parasitic forces and moments caused by the actuators 61 used to position the mirror 60. The parasitic forces and moments can be caused, for example, by solid-state joints in the connection of the actuators 61 and are dependent on the position q of the mirror 60.

The parameters Δg, Δp, q are transmitted as input to the force profile modules 64.2, 64.3, 64.4. The force profile modules 64.2, 64.3, 64.4 map a force F' _Δg , P _Δp , F _qD corresponding to the value of the respective input parameter Δg, Δp, q in accordance with the stored force profiles to compensate for the deformation of the optical effective surface 41 and transmit the force values F' _Δg , P _Δp , F _qD to an addition point 65. The force F' _Δg is dependent on the force value specified in the 3b described load F _Δg . Furthermore, the force F _qD refers to the deformation actuators 68, whereby the force Fq or FqV refers to the position actuators 61. The force profile module 64.1 in the 5 is intended to illustrate that in addition to the parameters Δg, Δp, q explained in the example, further parameters may be present, such as a thermal expansion of the mirror 60 and/or the module base plate 44 ( 4 ), which can cause a compensable deformation of the optical effective surface 41.

The portion of the force F _qV determined in the position controller 55 and in the feedforward control 57 of the position control module 51, which must be applied by the deformation actuators 68, is transformed in the coordinate transformation module 58 from the mirror coordinate system into the actuator coordinate systems and transmitted as force F _L to the addition point 65 of the compensation module 52.

The sum of all forces F _LA added at the addition point 65 are sent to an extended map module 70, which is located in the 6 explained in detail, to determine the current I _LA required to generate the force F _LA by the deformation actuators 68.

The current I _LA is transmitted to the deformation actuators 68 of the mirror module 40 in a manner comparable to the position controller 66, whereby the deformation actuators 68 exert a force on the mirror 60, which causes the deformation of the optical effective surface 41 ( 4 ) of the mirror 60. The position of the mirror M3 is detected by the position sensors 62, as in the position control 66, and transmitted to the coordinate transformation module 63, thereby closing the control loop of the compensation module 52. The 4 The deformation sensor 48, which is described as optional, is not taken into account in the control 50.

6 shows a detail of the compensation control module 52, in which the extended map module 70 for the deformation actuators 68 (46.1, 46.2, 46.3, 46.4 in 4 ), hereinafter referred to as deformation actuators 68. The extended characteristic map module 70 comprises a separate control path for each of the deformation actuators 68, wherein the input and output parameters in the control paths are designated in the figure with consecutive indices (1 ... N).

In the following, the function of the control paths is explained using the control path with the index 1 (the top one in the figure), whereby what is said there applies equally to all other control paths. The deformation actuator corresponding to the control path is designated 68.1 for differentiation, whereby all other deformation actuators continue to be designated 68 for simplicity.

The control path comprises a coordinate transformation module 71.1 corresponding to the deformation actuator 68.1, which is controlled by the setpoint generator 53 ( 5 ) receives the target position q of the mirror 60 as input. The coordinate transformation module 71.1 uses this to determine the target position q _LA1 of the deformation actuator 68.1, i.e. its deflection q _LA1 corresponding to the mirror position q, which is sent as input to a map module 74.1, explained in more detail below, and to a module 72.1, explained in more detail below, for determining the crosstalk of the deformation actuator 68.1. The crosstalk is the parasitic effect of the deformation actuator 68 in one of the non-actuated degrees of freedom, which causes a deformation of the mirror 60. The map module 74.1 and the module 72.1 are modules of the extended map module 70.

The module 72.1 is assigned the deflection q _LA1 starting from the addition point 65 ( 5 ) the value of the force f _LA1 to be generated by the deformation actuator 68.1 is also transmitted. The module 72.1 determines, on the basis of this force F _LA1 and the position q _LA1 , with which parasitic force F _XLA1 the deformation actuator 68.1 acts on the mirror 60. The force F _XLA1 is transmitted to a force profile module 73.1, which maps a compensating force F _XLA12 , F _XLA1N based on the parasitic deformation caused by the force F _XLA1 for each additional deformation actuator 68 (two additional control paths are shown in the example). These forces F _XLA12 , F _XLA1N therefore compensate for the deformation of the optical active surface 41 caused by the parasitic force F _XLA1 , thereby reducing the deformation of the optical active surface 41. The forces F _XLA12 , F _XLA1N determined in this way are transmitted to addition points 75.2, 75.3 of the further control paths.

In the case of the first control path, the forces F _XLA21 , F XLAN1 are transmitted at the addition point 75.1 from the other two control paths shown in the example and are combined with the force F XLA22 , F _XLAN1 also from the compensation control module 52 ( 5 ) is added to the force F _LA1 transmitted to the addition point 75.1. The resulting force F _LAk1 is transmitted to the characteristic map module 74.1 mentioned above with an inverse Lorentz characteristic map corresponding to the control path to map the current I _LA1 required to generate the force F _LAk1 . The inverse Lorentz characteristic map contains the non-linear dependence of the force F _LAk1 on the current I and the deflection q _LA1 of the deformation actuator 68.1, which is transmitted to the characteristic map module 74.1 as explained. On the basis of the target position q _LA1 , the current I _LA1 required to control the deformation actuator 68.1 is mapped in the characteristic map module 74.1 with the force F _LAk1 determined for the deformation actuator 68.1 in the inverse Lorentz characteristic map by searching and interpolating and is transmitted to the deformation actuator 68.1.

The extended characteristic map module 70 thus reduces both the non-linear dependence of the force F on the current I and on the deflection q _LA1 in the actuation direction of the deformation actuator 68.1, which is known for Lorentz actuators, and the parasitic forces and moments caused in the five non-actuated degrees of freedom, whereby the deformation of the optical effective surface 41 ( 4 ) can be advantageously reduced or completely avoided.

The control 50 according to the invention compensates for all causes of deformation of the optical effective surface 41 ( 4 ), by adding a compensation module 51 to an existing position control 51. This has the advantage that a large proportion of deformations are compensated without the need for a complex optical measurement of the image quality and thus the image quality of the projection exposure system 1 is improved.

List of reference symbols

1

Projection exposure system

2

Lighting system

3

Radiation source

4

Lighting optics

5

Object field

6

Object level

7

Reticle

8th

Reticle holder

9

Reticle displacement drive

10

Projection optics

11

Image field

12

Image plane

13

Wafer

14

Wafer holder

15

Wafer relocation drive

16

EUV radiation

17

collector

18

Intermediate focal plane

19

Deflecting mirror

20

Faceted mirror

21

Facets

22

Faceted mirror

23

Facets

30

Mirror module

31

optical effective area

32.1-32.3

Storage locations

33.1-33.3

Actuators

34

Module base plate

35.1,35.2

sensor

40

Mirror module

41

optical effective area

42.1,42.2

Storage locations

43.1,43.2

Actuators

44

Module base plate

45.1,45.2

Position sensor

46.1-46.4

Deformation actuator

47.1-47.4

Connection points

48

Deformation sensor

50

Control

51

Position control module

52

Compensation control module

53

Setpoint generator

54

Differential module

55

Position controller

56

Addition point

57

Pre-control

58

Coordinate transformation module

59

Map module

60

Mirror

61

Position actuators

62

Sensors

63

Coordinate transformation module

64.1-64.4

Force profile modules

65

Addition point

66

Position controller

67

Pre-control

68

Deformation actuators

70

Extended map module

71.1-71.3

individual coordinate transformation

72.1-72.3

individual model for crosstalk

73.1-73.3

individual strength profile

74.1-74.3

Map module

75.1-75.3

Addition point

101

Projection exposure system

102

Lighting system

107

Reticle

108

Reticle holder

110

Projection optics

113

Wafer

114

Wafer holder

116

DUV radiation

117

optical element

118

Frames

119

Lens housing

M1-M6

Mirror

gH

Acceleration due to gravity Place of manufacture

gA

Acceleration due to gravity Installation location

Δg

Difference in acceleration due to gravity between place of manufacture and place of installation

mS

Mass mirror

m1, m2

Mass fraction of mirror on actuator

FgH

Weight Place of manufacture

FgA

Weight Installation location

FΔg

Difference in weight forces between place of manufacture and place of installation

FAU1, FAU2

Forces Position Actuators

FLA1-FLA4

Forces Deformation Actuators

Q

Target position

q+1

subsequent target position

qLA1-qLAN

Target deflections deformation actuators

A

acceleration

F'Δg

Force vector difference gravitational acceleration

FΔp

Force vector pressure difference

FqD

Force vector deformation actuators mirror target position

FV

Force vector feedforward control

FqV

Force vector mirror target position and feedforward control

FAU

Force vector position actuators

FLA

Force vector deformation actuators

FLA1-FLAN

Force vectors deformation actuators

FXLA1-FXLAN

Force vector crosstalk

FXLA12, FXLA1N

Force vector compensation crosstalk from actuator 1

FXLA21, FXLA2N

Force vector compensation crosstalk from actuator 2

FXLAN1, FXLAN2

Force vector compensation crosstalk from actuator N

IAU

Current position actuators

ILA; ILA1-ILAN

Current deformation actuators

QUOTES INCLUDED IN THE DESCRIPTION

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

Cited patent literature

• DE 102008009600 A1 [0045, 0049]
• US 20060132747 A1 [0047]
• EP 1614008 B1 [0047]
• US6573978 [0047]
• DE 102017220586 A1 [0052]
• US 20180074303 A1 [0066]

Claims (20)

Method for improving the imaging properties of an optical module (30,40) with an optical element (M3, 60) and at least one actuator (33.1,33.2,43.1,43.2,61) for positioning the optical element (M3, 60) relative to a reference, and at least one sensor (35.1,35.2,45.1,45.2,62) for detecting the position of the optical element (M3, 60) relative to the reference, wherein a control (50) regulates the position of the optical element (M3, 60) on the basis of a signal detected by the at least one sensor (35.1,35.2,45.1,45.2,62) and wherein the optical module (30,40) has at least one deformation actuator (46.1,46.2,46.3,46.4) for deforming an optical effective surface (31,41) of the optical Element (M3, 60) and the deformation actuator (46.1,46.2,46.3,46.4,68,68.1) can be controlled by the control (50), comprising the following method steps: - determining at least one load (F _Δg , F _gH , F _gA , P _Δp , F _q ) causing a deformation and/or deviation from a desired position of the optical active surface (31,41), - determining an actuator signal I _LA for the deformation actuator (46.1, 46.2, 46.3, 46.4, 68, 68.1) compensating for the deformation and/or deviation, - method of the deformation actuator (46.1,46.2,46.3,46.4,68,68.1). Procedure according to Claim 1 , characterized in that the load (F _Δg , F _gH , F _gA , F _Δp , F _q ) comprises a foreseeable load. Method according to one of the Claims 1 or 2 , characterized in that the load (F _Δg , F _gH , F _gA , F _Δp , F _q ) includes a local acceleration due to gravity (g _A , g _H ). Method according to one of the preceding claims, characterized in that the load (F _Δg , F _gH , F _gA , F _Δp , F _q ) comprises a pressure fluctuation Δp. Method according to one of the preceding claims, characterized in that the load (F _Δg , F _gH , F _gA , F _Δp , F _q ) comprises an installation position of the optical module (30,40). Method according to one of the preceding claims, characterized in that the load (F _Δg , F _gH , F _gA , F _Δp , F _q ) comprises a change in position of the optical module (30, 40). Method according to one of the preceding claims, characterized in that the load (F _Δg , F _gH , F _gA , F _Δp , F _q ) comprises a temperature change of the optical module (30, 40). Method according to one of the preceding claims, characterized in that the load (F _Δg , F _gH , F _gA , P _Δp , F _q ) comprises a deformation of the optical active surface (31, 41). Method according to one of the preceding claims, characterized in that the control (50) determines a compensation force (F' _{Δg , F Δp , F qD ) for the deformation actuator (46.1,46.2,46.3,46.4,68,68.1) for each existing load (F Δg , F gH ,} F _gA , F _Δp , F _q ). Procedure according to Claim 9 , characterized in that the compensation force (F' _Δg , F _Δp , F _qD ) is determined on the basis of at least one force profile (64.1,64.2,64.3,64.4). Procedure according to Claim 10 , characterized in that the at least one force profile (64.1,64.2,64.3,64.4) is optimized on the basis of a minimization of the residual deformation of the optical effective surface (31,41). Method according to one of claims 10 or 11, characterized in that the forces (F' _Δg , F _Δp , F _qD ) determined for the at least one load (F _Δg , F _gH , F _gA , F _Δp , F _q ) are summed up. Procedure according to Claim 12 , characterized in that a deformation caused by a crosstalk of the summed force (F _LAx ) in at least one non-actuated degree of freedom is determined. Procedure according to Claim 13 , characterized in that a compensation force (F _XLA1N ) based on the deformation caused by crosstalk is determined for at least one further deformation actuator (46.1,46.2,46.3,46.4,68) via a further force profile (73.1,73.2,73.3). Procedure according to Claim 14 , characterized in that the deformation caused by the crosstalk and the compensation forces (F _XLANN ) determined on the basis of this are determined for at least one further deformation actuator (46.1,46.2, 46.3,46.4,68,68.1). Method according to one of the Claims 14 or 15 , characterized in that the forces (F _XLANN ) for compensating the crosstalk and the forces (F _LAx ) for compensating the at least one load (F _Δg , F _gH , F _gA , F _Δp , F _q ) are summed. Procedure according to Claim 16 , characterized in that on the basis of the summed force (F _LAkx ) with the aid of an inverse Lorentz characteristic field (59,74.x) a current (I _LAx ) for controlling (50) the at least one deformation actuator (46.1,46.2,46.3,46.4,68,68.1) designed as a Lorentz actuator is determined. Control (50) for an optical module (30,40) with an optical element (M3, 60) and at least one actuator (33.1,33.2,43.1,43.2,61) for positioning the optical element (M3, 60) relative to a reference and at least one sensor (35.1,35.2,45.1,45.2,62) for detecting the position of the optical element (M3, 60) relative to a reference, wherein the control (50) regulates the position of the optical element (M3, 60) on the basis of a signal detected by the sensor (35.1,35.2,45.1,45.2,62) and wherein the optical module (30,40) has at least one deformation actuator (46.1,46.2,46.3,46.4,68,68.1) for deforming an optical active surface (31, 41) of the optical element (M3, 60) and the deformation actuator (46.1,46.2,46.3,46.4,68,68.1) can be controlled by the control (50), characterized in that the control (50) has a module (52) for compensating a deviation from a desired position and/or the deformation of the optical active surface (31,41) on the basis of at least one load (F _Δg , F _gH , F _gA , P _Δp , F _q ). Optical module (30,40) with an optical element (M3, 60) and at least one actuator (33.1,33.2,43.1,43.2,61) for positioning the optical element (M3, 60) relative to a reference and at least one sensor (35.1,35.2,45.1,45.2, 62) for detecting the position of the optical element (M3, 60) relative to a reference, wherein a control (50) regulates the position of the optical element (M3, 60) on the basis of a signal detected by the sensor (35.1,35.2,45.1,45.2,62) and wherein the optical module (30,40) has at least one deformation actuator (46.1,46.2,46.3,46.4,68,68.1) for deforming an optical effective surface (31,41) of the optical element (M3, 60) and the deformation actuator (46.1,46.2,46.3,46.4,68,68.1) can be controlled by the control (50), characterized in that the optical module (30,40) has a control (50) according to Claim 18 includes. Projection exposure system (1,101) with an optical module (30,40) according to Claim 19 .

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