DE102022206832A1 - METHOD FOR CONTROLLING A POSITION OF AN OPTICAL COMPONENT OF A LITHOGRAPHY SYSTEM - Google Patents

Abstract

Method for controlling a position of an optical component (102) of a lithography system (1), with the steps: a) determining (S3) a first manipulated variable (ur) based on a deviation (e) of an actual value (y) from a setpoint value (r ) the position of the optical component (102), b) determining (S6) a second manipulated variable (us) for the disturbance variable based on a detected disturbance variable (d) and a predicted change in the position of the optical component (102) due to the detected disturbance variable (d ), andc) controlling (S8) an actuator device (114) for positioning the optical component (102) based on the first and second manipulated variables (ur, us).

Description

The present invention relates to a method for controlling a position of an optical component of a lithography system and a corresponding control device, a positioning system and a lithography system.

Microlithography is used to produce microstructured components, such as integrated circuits. The microlithography process is carried out using a lithography system which has an illumination system and a projection system. The image of a mask (reticle) illuminated by the illumination system is projected by means of the projection system onto a substrate, for example a silicon wafer, which is coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system, in order to project the mask structure onto the light-sensitive coating of the substrate transferred to.

Driven by the pursuit of ever smaller structures in the production of integrated circuits, EUV lithography systems are currently being developed which use light with a wavelength in the range from 0.1 nm to 30 nm, in particular 13.5 nm. Since most materials absorb light of this wavelength, reflective optics, i.e. mirrors, must be used in such EUV lithography systems instead of - as before - refracting optics, i.e. lenses.

The demands on the accuracy and precision of the imaging properties of lithography systems are constantly increasing. From a dynamic perspective, it is important to minimize the influence of interference on the movement of various components of the lithography system. For example, very precise positioning of optical components, in particular mirrors, of the lithography system is required. Dynamic interference from optical components can be generated, for example, by the movement of other components of the lithography system or by acoustic interference. Acoustic disturbances are transmitted, for example, as longitudinal waves through cooling liquids in cooling lines of a cooling device of the optical component.

As the complexity of lithography systems continues to increase, further dynamic interference excitations inside and outside the system are to be expected, so that additional mechanisms for their suppression or compensation are desirable and necessary.

Against this background, an object of the present invention is to provide an improved method for controlling a position of an optical component of a lithography system and a corresponding control device, a positioning system and a lithography system.

1. a) Ermitteln einer ersten Stellgröße basierend auf einer Abweichung eines Istwerts von einem Sollwert der Position der optischen Komponente,
2. b) Ermitteln einer zweiten Stellgröße zur Störgrößenaufschaltung basierend auf einer erfassten Störgröße und einer vorhergesagten Änderung der Position der optischen Komponente aufgrund der erfassten Störgröße, und
3. c) Ansteuern einer Aktoreinrichtung zum Positionieren der optischen Komponente basierend auf der ersten und zweiten Stellgröße.

According to a first aspect, a method for regulating a position of an optical component of a lithography system is proposed. The procedure includes the steps:

1. a) determining a first manipulated variable based on a deviation of an actual value from a target value of the position of the optical component,
2. b) determining a second manipulated variable for switching on the disturbance variable based on a detected disturbance variable and a predicted change in the position of the optical component due to the detected disturbance variable, and
3. c) controlling an actuator device for positioning the optical component based on the first and second manipulated variables.

The proposed method enables position control of the optical component based on control with disturbance variable input.

In particular, the proposed position control is based on a feedback control by feeding back the actual value of the position of the optical component to a controller to determine the first manipulated variable. Furthermore, the proposed position control provides for the influence of a disturbance variable to be taken into account in a pilot control by feeding a second manipulated variable into the disturbance variable. With the help of the disturbance variable, the effect of the disturbance on the position of the optical component can be compensated for before a control deviation due to the disturbance becomes noticeable.

The proposed method can therefore be used to better regulate the position of the optical component, even in the event of dynamic disturbance excitation. In particular, the effects of interference excitations, such as mechanical vibration excitations, acoustic excitations and electromagnetic excitations, on the optical component can be better suppressed. This leads to greater precession of the optical properties of the optical component and thus to better imaging properties of the lithography system. In addition, interference excitation can be better compensated for in increasingly complex lithography systems with an increasing number of interference sources.

The method is used for rule-based positioning of an optical component of a lithography system, such as a mirror.

The lithography system is, for example, an EUV or a DUV lithography system. EUV stands for “extreme ultraviolet” (EUV) and refers to a wavelength of work light in the range from 0.1 nm to 30 nm, in particular 13.5 nm. Furthermore, DUV stands for “deep ultraviolet” (Engl .: deep ultraviolet, DUV) and refers to a wavelength of work light between 30 nm and 250 nm.

The EUV or DUV lithography system includes an illumination system and a projection system. In particular, with the EUV or DUV lithography system, the image of a mask (reticle) illuminated by the lighting system is projected by means of the projection system onto a substrate, for example a silicon wafer, which is coated with a light-sensitive layer (photoresist) and arranged in the image plane of the projection system to transfer the mask structure to the photosensitive coating of the substrate.

The position of the optical component is, for example, a position with respect to six degrees of freedom of the optical component. The six degrees of freedom include in particular three translational degrees of freedom (in three mutually perpendicular spatial directions) and three rotational degrees of freedom (with respect to a rotation around the three mutually perpendicular spatial directions).

The first manipulated variable is determined based on the actual value-setpoint deviation of the position of the optical component, which makes position control possible based on feedback of the measured current value (actual value) of the position of the optical component. In the proposed control, the first manipulated variable can therefore be determined depending on the actual values of the position of the optical component - and not only depending on the behavior of the controlled system predicted with a model.

The actual value of the position of the optical component is measured, for example, and fed back to an input of a position controller device.

The setpoint of the position of the optical component is, for example, a static value, so that the position of the optical component is regulated to a rest position corresponding to the static value. However, the setpoint of the position of the optical component can also change depending on time, so that the aim of the control is that the position of the optical component follows a predetermined time-dependent path (trajectory).

The deviation of the actual value of the position of the optical components from the target value (i.e. the control deviation of the proposed control loop) is determined in particular by negatively adding (subtracting) the actual value to the target value.

The first manipulated variable is determined in such a way that the current position of the optical component (controlled variable) is adapted to the setpoint (command variable). The first manipulated variable is determined, for example, by a position controller device and is an output variable of the position controller device. The first manipulated variable is in particular a measure of a change in position to be applied to the optical component.

By determining the second manipulated variable - in addition to the feedback control using the first manipulated variable - a disturbance variable can be taken into account in the sense of a feedforward control. The disturbance variable is in particular a disturbance variable that causes a change in position of the optical component. In addition, the disturbance variable is in particular a disturbance variable whose effect on the position of the optical component can be predicted. A prediction can be made, for example, through a model calculation, a simulation and/or a calculation in which the detected disturbance variable is included as an input variable. The disturbance variable is also in particular a disturbance variable that detects, e.g. B. can be measured. For example, the disturbance variable is a disturbance variable whose progression over time can be recorded. For example, the disturbance variable is detected using a sensor device and/or by a disturbance variable observer.

The second manipulated variable is determined, for example, by a disturbance variable switching device and is an output variable of the disturbance variable switching device.

The predicted change in the position of the optical component due to the detected disturbance is in particular a predicted disturbance transfer of the disturbance to the optical component.

The optical component is movably attached (for example to a support frame) using the actuator device in order to be able to adjust the position of the optical component. The actuator device represents an actuator system of the control loop. The actuator device includes in particular one or more actuators (actuators). Changing the position of the optical component. For example, the actuator device serves to change the position of the optical component in the six degrees of freedom. The actuator device is controlled in particular by transmitting a control signal to the actuator device.

The first manipulated variable, the second manipulated variable, the actual value, the setpoint, the deviation of the actual value from the setpoint and/or the disturbance variable is/are, for example, time-dependent variables.

According to one embodiment, the first manipulated variable is an output variable of a position controller device. Furthermore, the second manipulated variable between the position controller device and the actuator device is applied to the first manipulated variable.

The controlling interventions based on the second manipulated variable only take effect after the actual value-setpoint deviation or the first manipulated variable has been determined by the position controller device. This ensures that the controlling interventions based on the second manipulated variable are not compensated for by regulating the position controller device. As a result, the stability of the control of the position controller device is not impaired and/or endangered.

You can also say that the second manipulated variable is connected to the first manipulated variable.

According to a further embodiment, a total manipulated variable is determined based on the first and second manipulated variables, and the actuator device of the optical component is controlled based on the overall manipulated variable.

For example, the method before step c) includes a step of determining the overall manipulated variable. The total manipulated variable is determined, for example, by subtracting the second manipulated variable from the first manipulated variable. You can also say that the total manipulated variable is determined by summation, with the second manipulated variable being supplied negatively.

The overall manipulated variable is therefore composed, in particular, of a portion of the precontrol (feedback) and a portion of the control (first manipulated variable, which is based on the deviation of the actual value from the setpoint).

According to a further embodiment, the optical component comprises a carrier element with at least one liquid line, in particular a cooling line. Furthermore, the detected disturbance variable has a change in a pressure of a liquid in the at least one liquid line.

The optical component is, for example, a mirror with a substrate (mirror substrate) and an optically active surface. In this case, the carrier element is, for example, the substrate. However, in addition to a substrate, the optical component can also comprise a further support structure, which forms the support element.

The at least one liquid line serves to pass a liquid through.

The at least one liquid line is, for example, a cooling line for passing a cooling liquid, such as water. The at least one cooling line is, for example, part of a cooling device for cooling the optical component.

The cooling device serves in particular to avoid high temperatures and temperature fluctuations of the optical component. In particular, mirrors of an EUV lithography system (as an example of an optical component) heat up as a result of absorption of the high-energy EUV radiation. The resulting high temperatures and temperature fluctuations in the mirror and the associated thermal deformations of the mirror can lead to wavefront aberrations and thus impair the imaging properties of the mirror. To avoid thermally induced deformations, optical components of the lithography system are actively cooled.

A certain coolant flow rate is required for cooling, which is achieved via a pump system. This leads to dynamic disturbance excitation because each pump generates local pressure fluctuations. These are transmitted through the entire cooling circuit via coolant sound (water sound, longitudinal water sound wave). Furthermore, every change in cross-section and every deflection of the liquid line as well as every installed valve in the cooling circuit can represent a source of interference that causes local pressure fluctuations in the liquid. This type of dynamic disturbance excitation is also called flow-induced vibrations (FIV). The interference excitation is passed on to the cooled optical component through water sound. This causes the position of the optical component to deviate from the target position.

Because the detected disturbance variable has a change in the pressure of the liquid in the at least one liquid line of the optical component, the influence of a pressure fluctuation can be compensated for by the proposed disturbance variable connection.

According to a further embodiment, the change in the pressure of the liquid comprises a pressure wave transported in the liquid, a periodic pressure fluctuation of the liquid and/or a pressure fluctuation of the liquid with a frequency in the range of 1 Hz and 2 kHz.

For example, a frequency of the pressure fluctuation of the liquid is in the range of 1 Hz and 1 kHz, 1 Hz and 500 Hz, 1 Hz and 200 Hz, and/or 50 and 150 Hz.

According to a further embodiment, the change in pressure of the liquid causes a flow-induced vibration of the optical component.

In particular, the prediction of the change in position of the optical components due to the detected change in the pressure of the liquid includes a prediction of a flow-induced vibration of the optical component.

According to a further embodiment, the disturbance variable has a change in a magnetic field and/or an electromagnetic field in an environment of the optical component.

A change in a magnetic field and/or an electromagnetic field in the vicinity of the optical component can be caused, for example, by electric motors. The lithography system can have a variety of electric motors or electromagnetic drives. For example, a wafer stage of the lithography system is driven using a wafer displacement drive. For example, a mask holder/reticle stage of the lithography system is driven using a reticle displacement drive. All of these drives can be implemented, for example, by electric motors that generate alternating electromagnetic fields. The alternating electromagnetic fields act on magnetically active components, such as components that contain iron, copper and/or nickel, and are converted there into disruptive forces. Since the optical component can also have magnetic materials, magnetic fields and/or electromagnetic fields in the vicinity of the optical component can lead to a change in position of the optical component.

By detecting the electromagnetic interference, for example by measuring a field strength of a magnetic and/or electromagnetic field and/or measuring a time course of the corresponding field strength, the attacking interference forces and thus the expected change in position of the optical component can be determined using measurement data, simulation data and/or or models can be predicted.

According to a further embodiment, the disturbance variable has a movement of further components and/or elements of the lithography system that are different from the optical component.

The further components and/or elements of the lithography system include, for example, one or more movable holders, such as a wafer holder and/or a reticle holder. The other components and/or elements of the lithography system can also include, for example, one or more movable mirrors whose position follows a trajectory in space (for example a “stepping mirror” and/or a “scanning mirror”).

For example, a movement, e.g. B. acceleration, the wafer holder and / or the reticle holder of the lithography system leads to interference excitation of the optical component. For these disruptive forces, information about the disruption is usually already available, since the acceleration profiles of the wafer holder and the reticle holder are normally recorded during operation of the lithography system or are already known by regulating the position of the wafer holder and the reticle holder. In particular, the acceleration profiles of the wafer holder and the reticle holder may be predetermined parameters used in controlling the position of the wafer holder and the reticle holder. Precise models are also known that describe how these disruptive forces affect the optical component. A change in position of the optical component can therefore be predicted due to disruptive forces introduced by the wafer holder and/or the reticle holder. This means that they can be compensated for through the addition of disturbance variables using the proposed method.

Furthermore, disruptive forces can act on the optical component through movable mirrors, in which the mirror position in particular follows a predetermined trajectory in space. There are also models and/or measurement data for these disruptive forces that describe how these disruptive forces affect the optical component. A change in position of the optical component due to movements of movable mirrors can therefore be predicted. This means that they can be compensated for through the addition of disturbance variables using the proposed method.

According to a further embodiment, the setpoint follows the position of the optical component of a trajectory.

In this embodiment, the setpoint of the position of the optical component changes as a function of time, so that the reference variable of the proposed control method is a time-dependent path, i.e. H. is a trajectory (e.g. in three-dimensional space).

In other embodiments, the setpoint of the position of the optical component can also be a static value, for example, so that the position of the optical component is regulated to a rest position corresponding to the static value.

According to a further embodiment, the first manipulated variable is determined based on the deviation of the actual value of the position of the optical component from the setpoint and additionally based on a precontrol that takes into account a change in the setpoint over time.

In this embodiment, an additional precontrol is provided to take a known (predetermined) setpoint change into account. In other words, a planned change in the setpoint is taken into account in a forward direction before it leads to a control deviation.

In this embodiment, two different feedforward controls are combined with the feedback control from step a). On the one hand, the disturbance variable feed-in is a pre-control to take the influence of the disturbance variable into account. On the other hand, the additional feedforward control is a feedforward control to take into account a planned change in the setpoint.

The additional precontrol to take a planned change in the setpoint into account allows the actual value of the position of the optical component to be adapted more quickly to the setpoint.

• Erfassen der Störgröße, und
• Vorhersagen der Änderung der Position der optischen Komponente aufgrund der erfassten Störgröße.

According to a further embodiment, the method has the steps:

• Detecting the disturbance, and
• Predicting the change in position of the optical component due to the detected disturbance.

The disturbance variable is detected, for example, by measuring and/or using one or more sensors (e.g. a sensor device). The disturbance variable can also be recorded using a disturbance variable observer, for example.

The method can also have a step of detecting the actual value of the position of the optical component. The position of the optical element is detected, for example, by a sensor device. A positioning system of the lithography system includes, for example, a sensor frame with a sensor device for measuring a current position of the optical component relative to the sensor frame. The sensor frame is, for example, mounted in a vibration-decoupled manner with respect to a support frame of the optical component. The sensor device includes e.g. B. one or more sensors, such as interferometers and / or other measuring devices for detecting a position, e.g. in the six degrees of freedom, of the optical component. The optical component can, for example, have reflector elements for reflecting light emitted by the sensors (e.g. laser light).

According to a further embodiment, predicting the change in the position of the optical component due to the detected disturbance includes predicting using a predetermined model, a simulation and/or a calculation based on the detected disturbance.

The change in the position of the optical component due to the detected disturbance can, for example, also be predicted using previously known measurement data, a model calculation and/or a simulation method.

• eine erste Ermittlungseinrichtung zum Ermitteln einer ersten Stellgröße basierend auf einer Abweichung eines Istwerts von einem Sollwert der Position der optischen Komponente,
• eine zweite Ermittlungseinrichtung zum Ermitteln einer zweiten Stellgröße zur Störgrößenaufschaltung basierend auf einer erfassten Störgröße und einer vorhergesagten Änderung der Position der optischen Komponente aufgrund der erfassten Störgröße, und
• eine Ansteuereinrichtung zum Ansteuern einer Aktoreinrichtung der optischen Komponente basierend auf der ersten und zweiten Stellgröße.

According to a second aspect, a control device for controlling a position of an optical component of a lithography system is proposed. The control device has:

• a first determination device for determining a first manipulated variable based on a deviation of an actual value from a target value of the position of the optical component,
• a second determination device for determining a second manipulated variable for the disturbance variable based on a detected disturbance variable and a predicted change in the position of the optical component due to the detected disturbance variable, and
• a control device for controlling an actuator device of the optical component based on the first and second manipulated variables.

The first determination device is, for example, a position controller device. The second determination device is, for example, a disturbance variable switching device.

The respective device described above or below, such as the first and second determination devices and the control device, can be implemented in hardware and/or software. In the case of a hardware implementation, the respective device can be designed, for example, as a computer or as a microprocessor. In the case of a software implementation, the respective device can be designed as a computer program product, as a function, as a routine, as an algorithm, as part of a program code or as an executable object. Furthermore, the corresponding device can also be designed as part of a higher-level control system of the lithography system.

• eine optische Komponente,
• eine Aktoreinrichtung zum Bewegen der optischen Komponente, und
• eine wie vorstehend beschriebene Regelungsvorrichtung.

According to a third aspect, a positioning system for rule-based positioning of an optical component of a lithography system is proposed. The positioning system has:

• an optical component,
• an actuator device for moving the optical component, and
• a control device as described above.

In embodiments, the positioning system further has a sensor device for detecting the disturbance variable.

In embodiments, the positioning system further has a further sensor device for detecting the actual value of the position of the optical component.

According to a fourth aspect, a lithography system, in particular an EUV lithography system, is proposed with a control device as described above or a positioning system as described above.

The optical component is preferably an optical component of a projection optics of the lithography system (projection exposure system). However, the optical component can also be an optical component of a lighting system of the lithography system.

In the present case, “on” is not necessarily to be understood as limiting it to exactly one element. Rather, several elements, such as two, three or more, can also be provided. Any other counting word used here should not be understood to mean that there is a limitation to exactly the number of elements mentioned. Rather, numerical deviations upwards and downwards are possible, unless otherwise stated.

The embodiments and features described for the method according to the first aspect apply accordingly to the other aspects (control device, positioning system, lithography system) and vice versa.

Further possible implementations of the invention also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

• 1 zeigt einen schematischen Meridionalschnitt einer Projektionsbelichtungsanlage für die EUV-Projektionslithographie gemäß einer Ausführungsform;
• 2 zeigt eine optische Komponente der Projektionsbelichtungsanlage aus 1 gemäß einer Ausführungsform;
• 3 zeigt einen Kühlkreislauf zum Kühlen der optischen Komponente aus 2 gemäß einer Ausführungsform;
• 4 zeigt ein Blockschaltbild einer Positionsregelung der optischen Komponente aus 2 gemäß einer Ausführungsform;
• 5 zeigt schematisch funktionelle Komponenten eines Positioniersystems zum Positionieren der optischen Komponente aus 2 gemäß einer Ausführungsform;
• 6 zeigt ein Modell zum Vorhersagen einer Änderung der Position der optischen Komponente aufgrund einer Störgröße gemäß einer Ausführungsform; und
• 7 zeigt ein Flussablaufdiagramm eines Verfahrens zum Regeln einer Position einer optischen Komponente einer Projektionsbelichtungsanlage gemäß einer Ausführungsform.

Further advantageous refinements and aspects of the invention are the subject of the subclaims and the exemplary embodiments of the invention described below. The invention is further explained in more detail using preferred embodiments with reference to the accompanying figures.

• 1 shows a schematic meridional section of a projection exposure system for EUV projection lithography according to one embodiment;
• 2 shows an optical component of the projection exposure system 1 according to one embodiment;
• 3 shows a cooling circuit for cooling the optical component 2 according to one embodiment;
• 4 shows a block diagram of a position control of the optical component 2 according to one embodiment;
• 5 schematically shows functional components of a positioning system for positioning the optical component 2 according to one embodiment;
• 6 shows a model for predicting a change in the position of the optical component due to a disturbance according to an embodiment; and
• 7 shows a flowchart of a method for controlling a position of an optical component of a projection exposure system according to an embodiment.

In the figures, identical or functionally identical elements have been given the same reference numerals, unless otherwise stated. Furthermore, it should be noted that the representations in the figures are not necessarily to scale.

1 shows an embodiment of a projection exposure system 1 (lithography system), in particular an EUV lithography system. One embodiment of a lighting system 2 of the projection exposure system 1 has, in addition to a light or radiation source 3, lighting 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 other lighting system 2. In this case, the lighting system 2 does not include the light source 3.

A reticle 7 arranged in the object field 5 is exposed. 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 purposes, a Cartesian coordinate system with an x-direction x, a y-direction y and a z-direction z is shown. The x-direction x runs perpendicularly into the drawing plane. The y-direction y is horizontal and the z-direction z is vertical. The scanning direction is in the 1 along the y-direction y. The z direction z runs perpendicular to the object plane 6.

The projection exposure system 1 includes projection optics 10. The projection optics 10 is used 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 ° is also between the object plane 6 and the Image level 12 possible.

A structure on the reticle 7 is imaged on 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 in particular along the y-direction y via a wafer displacement drive 15. The displacement, on the one hand, of the reticle 7 via the reticle displacement drive 9 and, on the other hand, of the wafer 13 via the wafer displacement drive 15 can take place synchronized with one another.

The light source 3 is an EUV radiation source. The light 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 16 in particular has a wavelength in the range between 5 nm and 30 nm. The light source 3 can be a plasma source, for example an LPP source (Laser Produced Plasma, plasma generated with the help of a laser) or a DPP source (Gas Discharged Produced Plasma). It can also be a synchrotron-based radiation source. The light source 3 can be a free electron laser (FEL).

The illumination radiation 16, which emanates from the light source 3, is focused by a collector 17. The collector 17 can be a collector with one or more ellipsoidal and/or hyperboloid 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 °, or in normal incidence (English: Normal Incidence, NI), i.e. with angles of incidence smaller than 45 ° , with the lighting radiation 16 are applied. 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 false light.

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

The lighting optics 4 comprises a deflection mirror 19 and, downstream of it in the beam path, a first facet mirror 20. The deflection mirror 19 can be a flat deflection mirror or alternatively a mirror with an effect that influences the bundle 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 wavelength that deviates from this.

If the first facet mirror 20 is arranged in a plane of the illumination optics 4, which is optically conjugate to the object plane 6 as a field plane, it is also referred to as a field facet mirror. The first facet mirror 20 includes a large number of individual first facets 21, which can also be referred to as field facets. Of these first facets 21 are in the 1 just a few are shown as examples.

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

Like, for example, from the DE 10 2008 009 600 A1 is known, the first facets 21 themselves can also each be composed of a large number of individual mirrors, in particular a large number of micromirrors. The first facet mirror 20 can in particular be designed as a microelectromechanical system (MEMS system). For details see the DE 10 2008 009 600 A1 referred.

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

A second facet mirror 22 is located downstream of the first facet mirror 20 in the beam path of the illumination optics 4. 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 lighting 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 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 have, for example, round, rectangular or even hexagonal edges, or alternatively they can be facets composed of micromirrors. In this regard, reference is also made to the DE 10 2008 009 600 A1 referred.

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

The lighting optics 4 thus forms a double faceted system. This basic principle is also known as the 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 conjugate to a pupil plane of the projection optics 10. In particular, the second facet mirror 22 can be arranged tilted relative to a pupil plane of the projection optics 10, as is the case, for example, in FIG DE 10 2017 220 586 A1 is described.

With the help of the second facet mirror 22, the individual first facets 21 are imaged into the object field 5. The second facet mirror 22 is the last beam-forming mirror 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, 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 into 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 lighting optics 4. The transmission optics can in particular include one or two mirrors for perpendicular incidence (NI mirror, normal incidence mirror) and/or one or two mirrors for grazing incidence (GI mirror, grazing incidence mirror).

The lighting optics 4 has the version in the 1 is shown, after the collector 17 exactly three mirrors, namely the deflection mirror 19, the first facet mirror 20 and the second facet mirror 22.

In a further embodiment of the lighting optics 4, the deflection mirror 19 can also be omitted, so that the lighting 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 into the object plane 6 by means of the second facets 23 or with the second facets 23 and a transmission optics is generally only an approximate image.

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

At the one in the 1 In the example shown, the projection optics 10 includes six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or another number of mirrors Mi are also possible. The projection optics 10 is a double obscured optics. The penultimate mirror M5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 has an image-side numerical aperture that is, for example, larger than 0.3 and/or 0.5 and which can also be greater than 0.6 and which can be, for example, 0.7 or 0.75.

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

The projection optics 10 has a large object image offset in the y direction y 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 y can be in 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 imaging scales βx, βy in the x and y directions x, y. The two imaging scales Bx, By of the projection optics 10 are preferably (6x, By) = (+/- 0.25, +/- 0.125). A positive magnification 6 means an image without image reversal. A negative sign for the image scale 6 means an image with image reversal.

The projection optics 10 thus leads to a reduction in size in the x direction x, that is to say in the direction perpendicular to the scanning direction, in a ratio of 4:1.

The projection optics 10 leads to a reduction of 8:1 in the y direction y, that is to say in the scanning direction.

Other image scales are also possible. Image scales of the same sign and absolutely the same in the x and y directions x, y, 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 directions x, y in the beam path between the object field 5 and the image field 11 can be the same or, depending on the design of the projection optics 10, can be different. Examples of projection optics with different numbers of such intermediate images in the x and y directions x, y are known from US 2018/0074303 A1 .

One of the second facets 23 is assigned to exactly one of the first facets 21 to form an illumination channel for illuminating the object field 5. This can in particular result in lighting based on Köhler's principle. The far field is broken down into a large number of object fields 5 using the first facets 21. The first facets 21 generate a plurality of images of the intermediate focus on the second facets 23 assigned to them.

The first facets 21 are each imaged onto the reticle 7 by an assigned second facet 23, superimposed on one another, in order 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%. Field uniformity can be achieved by overlaying different lighting channels.

By arranging the second facets 23, the illumination of the entrance pupil of the projection optics 10 can be geometrically defined. By selecting the illumination channels, in particular the subset of the second facets 23 that guide light, the intensity distribution in the entrance pupil of the projection optics 10 can be adjusted. This intensity distribution is also referred to as the lighting setting or lighting pupil filling.

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 redistributing the illumination channels.

Further aspects and details of the illumination of the object field 5 and in particular the entrance pupil of the projection optics 10 are described below.

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 regularly be illuminated precisely with the second facet mirror 22. When imaging the projection optics 10, which images the center of the second facet mirror 22 telecentrically onto the wafer 13, the aperture rays often do not intersect at a single point. However, an area can be found in which the pairwise distance of the aperture beams becomes minimal. This surface represents the entrance pupil or a surface conjugate to it in the local space. Ins In particular, this surface shows a finite curvature.

It may be that the projection optics have 10 different positions of the entrance pupil for the tangential and sagittal beam paths.

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.

At the in the 1 As shown in the arrangement of the components of the illumination optics 4, the second facet mirror 22 is arranged in a surface conjugate to the entrance pupil of the projection optics 10. The first facet mirror 20 is tilted relative 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 that is defined by the second facet mirror 22.

2 shows positioning system 100 for positioning an optical component 102 according to an embodiment.

The optical component 102 is, for example, a mirror of the projection exposure system 1 (lithography system), in particular the projection optics 10 1 . The optical component 102 is, for example, one of the mirrors M1 - M6. The optical component 102 is described below as a mirror; however, in other examples it may also be an optical component other than a mirror.

As in 2 shown, the mirror 102 comprises a coating 104 with an optically active surface 106. The mirror 102 also comprises a substrate 108. Cooling lines 110 are arranged in the substrate 108, through which a cooling liquid 112, such as water, is passed around the mirror 102 to actively cool. Cooling the mirror 102 serves to prevent thermal deformations of the mirror 102, even when exposed to high-energy EUV radiation 16 ( 1 ), to avoid.

The mirror 102 is movably attached to a support frame 116 by means of an actuator device 114. The actuator device 114 has, for example, several actuators 118 and a drive unit (not shown). The actuator device 114 serves, for example, to position the mirror 102 with respect to six degrees of freedom (translation in the X, Y and Z directions and rotation about the X, Y and Z directions).

The positioning system 100 also has a sensor device 120 to determine a current position P (actual value y(t) of the position P, 4 ) of the mirror 102 to capture. The sensor device 120 is in 2 only indicated schematically. The sensor device 120 has one or more sensors, such as interferometers. The sensors of the sensor device 120 are attached, for example, to a sensor frame (not shown). The sensor frame is, for example, attached to the support frame 116 in a vibration-decoupled manner. For example, a current position y(t) of the mirror 102 is detected using laser beams 122.

In 3 a cooling circuit 200 of a cooling device 202 for cooling the mirror 102 is shown. The cooling device 202 includes a cooling unit 204 for cooling a cooling liquid 112 ( 2 ) and lines 206, 110 for transporting the cooling liquid 112. The cooling device 202 also includes one or more pumps 208 for generating a required coolant flow rate of the cooling liquid 112. The cooling device 202 further includes one or more valves 210 for controlling the cooling flow. The cooling device 202 can be used to cool several components of the lithography system 1. An example is in 3 the mirror 102 2 shown as a cooled component. The cooling lines 110 ( 2 ), which are arranged in the mirror substrate 108, are shown schematically in 3 drawn.

Pumps of the cooling device 202, such as the pump 208, cause local pressure fluctuations in the liquid 112, thereby creating a dynamic disturbance excitation. These pressure fluctuations are transmitted through the entire cooling circuit 200 via longitudinal water sound waves. Furthermore, cross-sectional changes (not shown) of the liquid line 206, 110, deflections 212 of the liquid line 206, 110 and valves 210 of the cooling circuit 200 can also represent a source of interference that causes local pressure fluctuations in the liquid 112. Such acoustic disturbance excitation is passed on to the cooled optical component 102 (the mirror 102) by means of water sound. This can lead to a change in the position of the mirror 102, so that the actual position y(t) of the mirror 102 deviates from a target position r(t) ( 4 ).

The following is with reference to the 4 until 7 a method for regulating a position y(t) of the optical component 102 (e.g. the mirror 102) of a lithography system 1 (projection beam lighting system 1, 1 ) described according to one embodiment.

4 shows a block diagram of a control loop 300 for controlling the position y (t) of the mirror 102 ( 2 ). The control circuit 300 is based on a feedback control and a disturbance variable feed-in, which represents a feedforward control to take a disturbance variable d(t) into account. The feedback control is implemented by a position controller device 302 and a controlled system 304. The disturbance variable connection is implemented by a disturbance variable connection device 306.

The controlled system 304 includes an actuator 308 for manipulating the position y(t) of the mirror 102. The actuator 308 is in particular through the actuator device 114 ( 2 ) realized. The controlled system 304 also includes a sensor system 310 for measuring the position y(t) of the mirror 102. The sensor system 310 is in particular through the sensor device 120 ( 2 ) realized. Furthermore, the controlled system 304 includes the optical component 102, for example the mirror 102.

The position controller device 302, together with the controlled system 304, forms the feedback control and ensures that a deviation e(t) of the actual position y(t) from a target position r(t) of the mirror 102 is as small as possible, ideally to zero , is held. This target position r(t) can be a static value (r(t) = const.) or can also be a function that depends on time t (r(t) ≠ const.). In particular, the target position r(t) of the mirror 102 can also follow any trajectory in (e.g. three-dimensional) space. The target position r(t) of the mirror 102 can follow a constant or an unsteady trajectory in space.

In a first step S1 of the method, the actual value y(t) of the position P of the mirror 102 is recorded. For example, the actual value y(t) is measured using the sensor device 120. The actual value y(t) is transmitted to the position controller device 302, ie fed back or fed back. For example, the actual value y(t) is fed back negatively to the position controller device 302 (minus sign in the control loop 300 in 4 ).

In a second step S2 of the method, the deviation e(t) of the actual value y(t) from the setpoint value r(t) of the position P of the mirror 102 is determined. The deviation e(t) is determined, for example, by the position controller device 302 or by an upstream summation unit 312. For example, the actual value y(t) is subtracted from the setpoint r(t). To determine the deviation e(t), the setpoint r(t) is stored, in particular stored, in the position controller device 302 or in the upstream summation unit 312.

In a third step S3 of the method, a first manipulated variable u _r (t) is determined based on the deviation e (t).

The position y(t) of the mirror 102 is affected by disturbances (not shown) that are generally unknown and unpredictable, such as noise or ground vibrations. It is usually not possible to predict the effect of such disturbance variables on the position y(t) of the mirror 102, so that they cannot be compensated for by a control with an open effect chain. However, they can be corrected using the feedback control described in steps S1 to S3 by determining the actual deviation e(t) of the actual value y(t) from the setpoint r(t).

The situation is different in the case of disturbance variables d(t), for which an effect on the position y(t) of the mirror 102 (disruption transmission 314 in 4 ) can be predicted using calculations, model calculations, simulations, predetermined measurement data or similar. In this case, the influence of the disturbance variable d(t) on the controlled variable, here the position y(t) of the mirror 102, can be taken into account using a disturbance variable feed-in u _s (t). An example of such a disturbance variable d(t), which can be taken into account using a disturbance variable feed-in, is the pressure fluctuations of the liquid 112 in the cooling circuit 200 ( 3 ), which are caused, for example, by a pump 208 of the cooling circuit 200. On the one hand, these pressure fluctuations can be measured. On the other hand, based on the measurement results, an effect of the disturbance variable d(t), here the pressure fluctuations, on the position y(t) of the mirror 102 can be predicted.

Other examples of disturbance variables d(t) that can be compensated for using disturbance input are magnetic and/or electromagnetic disturbances caused by a magnetic field and/or electromagnetic field (B and E in 2 ) in an environment U of the mirror 102. A further example of disturbance variables d(t) that can be compensated for using a disturbance variable connection are movements, in particular accelerations, of other components of the lithography system 1, such as a wafer holder 14 and/or a reticle holder 8 ( 1 ).

The following describes the control circuit 300 and the method for pressure fluctuations of the liquid 112 in the cooling circuit 200 as an example of a disturbance variable d(t) that acts on the position y(t) of the mirror 102. However, the method can also be used for other disturbance variables d(t), using a Disturbance input can be compensated for.

In a fourth step S4 of the method, the disturbance variable d(t) is detected.

For example, the disturbance variable d(t) is measured. To detect the disturbance variable d(t), the positioning device 100 has, for example, a further sensor device 124. The sensor device 124 includes z. B. one or more sensors and/or measuring devices. In 2 is schematically shown as an example a pressure gauge 124 for measuring a pressure D of the liquid 112. The pressure measuring device 124 is in fluid communication with the liquid line 110. The pressure measuring device 124 is, for example, a liquid pressure gauge, a piston pressure gauge, a spring pressure gauge or another pressure gauge for measuring a pressure D of the liquid 112 in the line 110.

In other examples, the disturbance d(t) can also be detected by a disturbance observer. For example, the disturbance variable d(t) is not measured directly, but is reconstructed from other (e.g. measured) process variables.

In a fifth step S5 of the method, a change in the position P of the mirror 102 is predicted based on the detected disturbance variable d(t). The change in the position P of the mirror 102 due to the detected disturbance variable d(t) is in particular the effect of the disturbance variable d(t) on the position P of the mirror 102. This effect can be predicted, for example, using a predetermined model. In 6 A simple model 400 is shown as an example, which describes pressure-reaction behavior. The model 400 describes in particular a linear relationship 402 between the pressure D of the liquid 112 and a force Fx which acts on the mirror 102 due to the pressure D of the liquid 112.

For example, the detected disturbance variables d(t) are transmitted to the disturbance variable switching device 306. For example, one or more models, algorithms for simulation methods or other calculations and/or predetermined measurement data are stored in the disturbance variable switching device 306. As an example, the model 400 may be stored in the disturbance input device 306. The disturbance variable switching device 306 determines, for example based on the model 400, an effect of the disturbance variables d(t) on the position P of the mirror 102.

In a sixth step S6 of the method, a second manipulated variable u _s (t) is determined for switching on the disturbance variables. In particular, the second manipulated variable u _s (t) is determined based on the detected disturbance variable d(t) and the predicted change in the position P of the mirror 102 due to the detected disturbance variables d(t). The second manipulated variable u _s (t) is fed to a further summation unit 316, for example. For example, the second manipulated variable u _s (t) is fed negatively to the further summation unit 316 (minus sign in the control loop 300 in 4 ).

In a seventh step S7 of the method, a total manipulated variable u(t) is determined based on the first manipulated variable u _r (t) and the second manipulated variable u _s (t). The total manipulated variable u(t) is determined, for example, by subtracting the second manipulated variable u _s (t) from the first manipulated variable u _r (t). The overall manipulated variable u(t) is therefore composed in particular of a component u _s (t) of a feedforward control (feedback) and a component u _r (t) of a feedback control.

In an eighth step S8 of the method, the actuator system 308 of the controlled system 304 (ie the actuator device 114, 2 ) based on the first and second manipulated variables u _r (t), u _s (t), in particular based on the overall manipulated variable u (t).

In 5 a control device 128 of the positioning system 100 is shown. The control device 128 includes a first determination device 130 (positioning controller device 302 in 4 ) for determining the first manipulated variable u _r (t) based on the deviation e (t) of the actual value y (t) from the setpoint value r (t) of the position P of the mirror 102. The control device 128 includes a second determination device 132 (interference switching Facility 306 in 4 ) for determining the second manipulated variable u _s (t) for feeding the disturbance variable based on the detected disturbance variable d(t) and the predicted change in the position P of the mirror 102 due to the detected disturbance variable d(t). The control device 128 further comprises a third determination device 134 (further summation unit 316 in 4 ) to determine the total manipulated variable u(t). In addition, the control device 128 includes a control device 136 for controlling the actuator device 114 based on the determined total manipulated variable u(t). For example, the control device 136 sends a corresponding control signal A to the actuator device 114.

The control circuit 300 ( 4 ) can optionally include a further pilot control 318, which takes into account a change in the setpoint r(t) over time. As described above, the setpoint r(t) can be a time-dependent trajectory (e.g. in three-dimensional space). The setpoint r(t) can also describe an unsteady spatial course ben, which has setpoint jumps. Without forward consideration of a previously known setpoint jump, such a setpoint jump in the setpoint position r(t) can initially lead to a large control deviation e(t). To improve the control behavior of the control circuit 300, the additional pilot control 318 can optionally be used. The feedforward control 318 determines the expected manipulated variable requirement depending on the planned change in the setpoint r(t). Furthermore, the expected manipulated variable requirement is supplied to the controlled system 304 by the manipulated variable u _v (t). In particular, a new first manipulated variable u' _r (t) can be determined from the first manipulated variable u _r (t) and the further manipulated variable u _v (t). Since no further feedback loop is introduced into the control loop 300, the stability of the control loop 300 is not influenced by the feedforward control 318.

The proposed method allows the position P of the mirror 102 to be better regulated even in the event of dynamic disturbance excitation d(t). In particular, the effects of interference excitations d(t), such as mechanical vibration excitations, acoustic excitations and electromagnetic excitations, on the mirror 102 can be better compensated. This leads to greater precession of the optical properties of the mirror 102 and thus to better imaging properties of the lithography system 1.

Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

REFERENCE SYMBOL LIST

1

Projection exposure system

2

Lighting system

3

light source

4

Illumination optics

5

Object field

6

Object level

7

Reticule

8th

Reticle holder

9

Reticle displacement drive

10

Projection optics

11

Image field

12

Image plane

13

wafers

14

wafer holder

15

Wafer displacement drive

16

Illumination radiation

17

collector

18

Intermediate focal plane

19

Deflecting mirror

20

first facet mirror

21

first facet

22

second facet mirror

23

second facet

100

Positioning system

102

optical component

104

Coating

106

optically active surface

108

Substrate

110

Fluid line

112

liquid

114

Actuator device

116

Support frame

118

Actor

120

Sensor device

122

laser beam

124

sensor

128

Control device

130

Investigation facility

132

Investigation facility

134

Investigation facility

136

Control device

200

Cooling circuit

202

Cooling device

204

Cooling unit

206

Fluid line

208

pump

210

Valve

212

Deflection

300

control loop

302

Position controller facility

304

Controlled system

306

Disturbance switching device

308

Actuators

310

Sensor technology

312

Summation unit

314

Disturbance transmission

316

Summation unit

318

Pilot control

400

Model

402

linear function

A

signal

b

Magnetic field

d(t)

Disturbance variable

D

Pressure

e(t)

deviation

E

electric field

Fx

Power

M1-M6

Mirror

P

position

r(t)

Setpoint

S1-S8

Procedural steps

t

Time

u(t)

manipulated variable

ur(t)

manipulated variable

u'r(t)

manipulated variable

us(t)

manipulated variable

uv(t)

manipulated variable

U

Vicinity

X

Direction

y(t)

actual value

Y

Direction

Z

Direction

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 assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008009600 A1 [0085, 0090]
• US 20060132747 A1 [0088]
• EP 1614008 B1 [0088]
• US 6573978 [0088]
• DE 102017220586 A1 [0093]
• US 20180074303 A1 [0107]

Claims (15)

Method for controlling a position (P) of an optical component (102) of a lithography system (1), with the steps: a) determining (S3) a first manipulated variable (u _r ) based on a deviation (e) of an actual value (y) from a setpoint (r) of the position (P) of the optical component (102), b) determining (S6) a second manipulated variable (u _s ) for switching on the disturbance variable based on a detected disturbance variable (d) and a predicted change in the position (P) of the optical component (102) based on the detected disturbance variable (d), and c) controlling (S8) an actuator device (114) for positioning the optical component (102) based on the first and second manipulated variables (u _r , u _s ). Procedure according to Claim 1 , wherein the first manipulated variable (u _r ) is an output variable of a position controller device (302), and the second manipulated variable (u _s ) between the position controller device (302) and the actuator device (114) to the first manipulated variable (u _r ) is applied. Procedure according to Claim 1 or 2 , wherein a total manipulated variable (u) is determined based on the first and second manipulated variables (u _r , u _s ) (S7), and the actuator device (114) of the optical component (102) is controlled based on the total manipulated variable (u). Procedure according to one of the Claims 1 - 3 , wherein the optical component (102) comprises a carrier element (108) with at least one liquid line (110), in particular a cooling line, and the detected disturbance variable (d) is a change in a pressure (D) of a liquid (112) in the at least one liquid line (110). Procedure according to Claim 4 , wherein the change in the pressure (D) of the liquid (112) is a pressure wave transported in the liquid (112), a periodic pressure fluctuation of the liquid (112) and / or a pressure fluctuation of the liquid (112) with a frequency in the range of 1 Hz and 2 kHz. Procedure according to Claim 4 or 5 , wherein the change in pressure (D) of the liquid (112) causes a flow-induced vibration of the optical component (102). Procedure according to one of the Claims 1 - 3 , wherein the disturbance variable (d) has a change in a magnetic field (B) and / or an electromagnetic field (BE) in an environment (U) of the optical component (102). Procedure according to one of the Claims 1 - 3 , wherein the disturbance variable (d) has a movement of further components (8, 14) and / or elements of the lithography system (1) that are different from the optical component (102). Procedure according to one of the Claims 1 - 8th , whereby the setpoint (r) follows the position (P) of the optical component (102) of a trajectory. Procedure according to one of the Claims 1 - 9 , wherein the first manipulated variable (u' _r ) is based on the deviation (e) of the actual value (y) of the position (P) of the optical component (102) from the setpoint (r) and additionally based on a precontrol (318), which a temporal change in the setpoint (r) is taken into account. Procedure according to one of the Claims 1 - 10 , comprising the steps: detecting (S4) the disturbance variable (d), and predicting (S5) the change in the position (P) of the optical component (102) due to the detected disturbance variable (d). Procedure according to Claim 11 , wherein predicting the change in the position (P) of the optical component (102) due to the detected disturbance (d) includes predicting using a predetermined model (400), a simulation and / or a calculation based on the detected disturbance (d). . Control device (128) for controlling a position (P) of an optical component (102) of a lithography system (1), comprising: a first determination device (130, 302) for determining a first manipulated variable (u _r ) based on a deviation (e). Actual value (y) of a setpoint (r) of the position (P) of the optical component (102), a second determination device (132, 306) for determining a second manipulated variable (u _s ) for the disturbance variable feed-in based on a detected disturbance variable (d) and a predicted change in the position (P) of the optical component (102) due to the detected disturbance variable (d), and a control device (136) for controlling an actuator device (114) of the optical component (102) based on the first and second manipulated variables (u _r , u _s ). Positioning system (100) for rule-based positioning of an optical component (102) of a lithography system (1), comprising: an optical component (102), an actuator device (114) for moving the optical component (102), and a control device (128). Claim 13 . Lithography system (1), in particular EUV lithography system, with a control device (128). Claim 13 or a positioning system Claim 14 .

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