DE102024207222A1 - CONTROL DEVICE, OPTICAL SYSTEM AND LITHOGRAPHY SYSTEM - Google Patents

Abstract

Control device (100) for controlling an actuator (200) controllable via a first interface (Int1) and via a second interface (Int2), with
a first switching amplifier (110) coupled to the first interface (Int1) with two switching elements (111, 112) and a diode (113, 114) connected in parallel,
a second switching amplifier (120) coupled to the second interface (Int2) with two switching elements (121, 122) and a diode (123, 124) connected in parallel,
a supply unit (130) coupled to the first switching amplifier (110) and the second switching amplifier (120) via a first node (K1) for providing a supply voltage (V2) for the first switching amplifier (110) and the second switching amplifier (120), wherein a switch (140) for connecting the supply unit (130) is connected between the first node (K1) and the supply unit (130),
a measuring resistor (R) coupled between the actuator (200) and the first switching amplifier (110) or the second switching amplifier (120),
a measuring circuit (150) arranged in parallel with the measuring resistor (R) and supplied with a direct voltage, and
a first measuring device (160) coupled to the first node (K1), a second measuring device (170) coupled to the first interface (Int1) and/or a third measuring device (180) coupled to the second interface (Int2), which are configured to determine at least one state of the actuator (200) by means of the DC voltage supplying the measuring circuit (150) when the switch (140) is in the open state.

Description

The present invention relates to an optical system, a lithography system with such an optical system and a method for producing such an optical system.

Microlithography is used to manufacture microstructured components, such as integrated circuits. The microlithography process is carried out using a lithography system equipped with an illumination system and a projection system. The image of a mask (reticle) illuminated by the illumination system is projected by the projection system onto a substrate, such as a silicon wafer, coated with a light-sensitive layer (photoresist) and positioned in the image plane of the projection system. This transfers the mask structure to the light-sensitive coating of the substrate.

Driven by the pursuit of ever smaller structures in the production of integrated circuits, EUV lithography systems are currently being developed that use light with a wavelength in the range of 0.1 nm to 30 nm, particularly 13.5 nm. Since most materials absorb light at this wavelength, such EUV lithography systems must use reflective optics, i.e., mirrors, instead of the previously used refractive optics, i.e., lenses.

Control devices for controlling actuators used in lithography systems to actuate optical elements, such as mirrors, comprise a large number of electronic components. As with all electronic components, electronic components in such control devices can wear out and no longer function properly. Furthermore, situations can arise in which an electrically conductive connection, for example, to the actuator itself, is defective, or the connection between the actuator and such a conductive connection becomes loose.

Against this background, it is an object of the present invention to provide an improved control device for actuating an optical element of an optical system of a lithography system.

Accordingly, a control device for controlling an actuator controllable via a first interface and via a second interface is proposed, comprising
a first switching amplifier coupled to the first interface with two switching elements and a diode connected in parallel,
a second switching amplifier coupled to the second interface with two switching elements and a diode connected in parallel,
a supply unit coupled to the first switching amplifier and the second switching amplifier via a first node for providing a supply voltage for the first switching amplifier and the second switching amplifier, wherein a switch for connecting the supply unit is connected between the first node and the supply unit,
a measuring resistor coupled between the actuator and the first switching amplifier or the second switching amplifier,
a measuring circuit arranged in parallel with the measuring resistor and supplied with a DC voltage, and
a first measuring device coupled to the first node, a second measuring device coupled to the first interface and/or a third measuring device coupled to the second interface, which are configured to measure at least one state in the open state of the switch
of the actuator using the DC voltage supplying the measuring circuit.

The supply unit of the control device is configured to supply a high voltage, for example, 50 V, during operation of the control device. Since a switch is provided between the first node and the supply unit, it can be ensured that the supply unit does not feed any voltage into the control device. Instead of the supply unit, the measuring circuit, which is supplied with a direct voltage, for example, 5 V, is configured to supply the control device with a voltage, wherein the voltage provided by the control device is lower than the voltage provided by the control device during operation.

By using the lower voltage of the measuring circuit, the electronic components and in particular the condition of the actuator in the control device can be checked without damaging other electronic components in the event of a malfunction of one electronic component.

The at least one measuring device integrated in the control device is particularly advantageous in that no external measuring device is required to test the control device. This simplifies the testing of the control device. Furthermore, by using at least two measuring devices, measured variables can be measured at different points in the control device and thus a relationship between measured variables can be considered.

In particular, the present control device can determine the state of an actuator. Actuator states include, for example, "connected," "not connected," "short-circuited," and "grounded."

By determining the status of the actuator, it can be determined whether the control device is functioning properly and can be used, or whether the control device needs to be repaired.

According to one embodiment, each of the switching amplifiers is designed as a half H-bridge and/or the switching elements are transistors.

A half H-bridge corresponds to one half of an H-bridge circuit. For example, this circuit comprises two switching elements, which can be implemented as transistors. The switching elements are preferably switched alternately during operation of the control device, so that only one switching element is switched on at a time. The switching elements are switched, in particular, depending on a pulse-width modulation signal from a modulation device.

Preferably, the switching elements are transistors, with field-effect transistors, in particular MOSFETs, preferably being used as switching elements.

According to a further embodiment, a filter is coupled between the first switching amplifier and the first interface and between the second switching amplifier and the second interface.

The filter is, in particular, a low-pass filter that temporally smooths the signal amplified by the switching amplifier. Preferably, the filtered signal corresponds to a temporal average of the amplified signal.

According to a further embodiment, the filter is a 2nd order low-pass filter.

Preferably, the filter is configured at least as a second-order filter. In particular, an input node of the filter is coupled to a center tap of the half H-bridge, and an output node of the filter is coupled to the actuator. A series circuit comprising a resistor and a coil is coupled between the input node and the output node of the filter, and a series circuit comprising a resistor and a capacitor is coupled between the output node and ground.

According to a further embodiment, at least one manipulation device is coupled to at least one switching amplifier and the manipulation device is configured to change a switching state of at least one switching element of the switching amplifier into a conductive or non-conductive state.

By changing the switching state of the switching element, the function of the switching element in the state of the open switch can be checked.

According to a further embodiment, the measuring circuit is configured to provide a first voltage value, in particular 4.7 V, in the open state of the switch.

According to a further embodiment, the diodes connected in parallel are freewheeling diodes, each having a freewheeling voltage of a second voltage value, in particular 0.7 V.

According to a further embodiment, when the switch is in the open state and when the actuator is connected to the first interface and to the second interface, a voltage value indicative of the state of the actuator connected to the first interface and to the second interface is present at the first measuring device, the second measuring device and/or the third measuring device.

According to a further embodiment, when the switch is in the open state and the actuator is not connected to the first and second interfaces, a voltage value indicative of the state of the actuator not connected to the first interface and not connected to the second interface is present at the first measuring device, the second measuring device and/or the third measuring device.

According to a further embodiment, when the switch is in the open state and when the first interface is conductively connected to the second interface, a voltage value indicative of the state of a conductive connection between the first interface and the second interface is present at the first measuring device, the second measuring device and/or the third measuring device.

A conductive connection between the first interface and the second interface corresponds to a “short-circuited” state of the actuator.

According to a further embodiment, in the open state of the switch and when the first interface or the second interface is conductively connected to ground, a third voltage value, in particular 0 V, is present at the first measuring device, at the second measuring device and/or at the third measuring device.

According to a further embodiment, in the open state of the switch and when the manipulation device changes at least one switching state of at least one of the switching elements, a voltage value, which is in particular different from the first voltage value, is present at the first measuring device, the second measuring device and/or the third measuring device.

According to a second aspect, an optical system with a number of actuatable optical elements is proposed. Each of the number of actuatable optical elements is assigned an actuator, and each actuator is assigned a control device for controlling the actuator according to the first aspect or one of the embodiments of the first aspect. Furthermore, each of the actuators comprises a capacitive and/or an inductive load.

The optical system is preferably a projection optics system of the projection exposure system. However, the optical system can also be an illumination system. The projection exposure system can be an EUV lithography system. EUV stands for "Extreme Ultraviolet" and refers to a wavelength of the working light between 0.1 nm and 30 nm. The projection exposure system can also be a DUV lithography system. DUV stands for "Deep Ultraviolet" and refers to a wavelength of the working light between 30 nm and 250 nm.

The optical system comprises in particular a micromirror array and/or a microlens array with a plurality of independently actuatable optical elements.

According to a third aspect, a lithography system with an optical system according to the second aspect or an embodiment of the second aspect is proposed.

A lithography system, for example, comprises an illumination system and an imaging system. The illumination system, in particular, comprises a light source and beam-shaping optics. The imaging system, in particular, comprises imaging optics for imaging the mask onto the substrate.

The optical system can be used in the illumination system, in the beam shaping optics, as well as in the imaging system.

According to a fourth aspect, a method for determining a state of a control device is proposed. The method for determining a state of a control device for controlling an actuator controllable via a first interface and a second interface, wherein the control device comprises a first switching amplifier coupled to the first interface and having two switching elements and a diode connected in parallel with each other, a second switching amplifier coupled to the second interface and having two switching elements and a diode connected in parallel with each other, a supply unit coupled to the first switching amplifier and the second switching amplifier via a first node for providing a supply voltage for the first switching amplifier and the second switching amplifier, wherein a switch for connecting the supply unit is connected between the first node and the supply unit, a measuring resistor coupled between the actuator and the first switching amplifier or the second switching amplifier, and a measuring circuit arranged in parallel with the measuring resistor and supplied with a DC voltage, comprises the following steps:

Opening the switch that the first node is disconnected from the deployment unit, and
Determining, in the open state of the switch, at least one state of the actuator by means of the DC voltage supplying the measuring circuit using a measuring device coupled to the first node, a second measuring device coupled to the first interface and/or a third measuring device coupled to the second interface.

In this case, "one" is not necessarily limited to exactly one element. Rather, multiple elements, such as two, three, or more, may be included. Any other counting term used here should also not be understood as implying a limitation to the exact number of elements stated. Rather, numerical deviations, both upward and downward, are possible unless otherwise stated.

The embodiments and features described for the first aspect apply accordingly to the second, third and fourth aspects and vice versa.

Further possible implementations of the invention also include combinations not explicitly mentioned above or below. The features or embodiments described in the exemplary embodiments are described below. 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;
• 2 zeigt eine schematische Darstellung einer Ausführungsform eines optischen Systems;
• 3 zeigt eine schematische Darstellung einer Ansteuervorrichtung gemäß einer ersten Ausführungsform;
• 4 zeigt eine schematische Darstellung einer Ansteuervorrichtung gemäß einer weiteren Ausführungsform; und
• 5 zeigt eine schematische Darstellung eines Verfahrens zum Ermitteln eines Zustands einer Ansteuervorrichtung gemäß einer Ausführungsform.

Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will be explained in more detail below using preferred embodiments with reference to the accompanying figures.

• 1 shows a schematic meridional section of a projection exposure system for EUV projection lithography;
• 2 shows a schematic representation of an embodiment of an optical system;
• 3 shows a schematic representation of a control device according to a first embodiment;
• 4 shows a schematic representation of a control device according to a further embodiment; and
• 5 shows a schematic representation of a method for determining a state of a control device according to an embodiment.

In the figures, identical or functionally equivalent elements are provided with 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 an illumination system 2 of the projection exposure system 1 has, in addition to a light or 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 separate module from the remaining illumination system 2. In this case, the illumination 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 is shown with an x-direction x, a y-direction y and a z-direction z. The x-direction x runs perpendicular to the plane of the drawing. The y-direction y runs horizontally and the z-direction z runs vertically. The scanning direction runs in the 1 along the y-direction y. The z-direction z runs 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 image plane 12 in the region of the image field 11. 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 of the reticle 7, on the one hand, via the reticle displacement drive 9, and the displacement of the wafer 13, on the other hand, via the wafer displacement drive 15, can be synchronized with each other.

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 has, in particular, 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) 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 emanating 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 hyperboloidal reflection surfaces. The at least one reflection surface of the collector 17 can be exposed to the illumination radiation 16 at grazing incidence (GI), i.e., at angles of incidence greater than 45°, or at normal incidence (NI), i.e., at angles of incidence less than 45°. 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 light source 3 and the collector 17, and the illumination optics 4.

The illumination optics 4 comprises a deflecting mirror 19 and, downstream of this in the beam path, a first facet mirror 20. The deflecting mirror 19 can be a flat deflecting mirror or, alternatively, a mirror with a beam-influencing effect beyond the pure deflection effect. Alternatively or additionally, the deflecting mirror 19 can be designed as a spectral filter that separates a useful light wavelength of the illumination radiation 16 from stray light of a different wavelength. If the first facet mirror 20 is arranged in a plane of the illumination optics 4 that is optically conjugate to the object plane 6 as the 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 can also be referred to as field facets. Of these first facets 21, 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 convexly or concavely curved facets.

As for example from the DE 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, reference is made to DE 10 2008 009 600 A1 referred to.

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

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 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, or alternatively facets composed of micromirrors. In this regard, reference is also made to the DE 10 2008 009 600 A1 referred to.

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

The illumination optics 4 thus form a double-faceted system. This basic principle is also known as a 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 may be arranged tilted relative to a pupil plane of the projection optics 10, as is shown, for example, in the DE 10 2017 220 586 A1 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 bundle-forming mirror or actually the last mirror for the illumination radiation 16 in the beam path before 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 transmission optics 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 illumination optics 4. The transmission optics can 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, grazing 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 first facet mirror 20 and the second 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 a different number of mirrors M1 are also possible. The projection optics 10 is a doubly obscured optic. 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 greater than 0.5 and can also be greater than 0.6, for example, 0.7 or 0.75.

Reflection surfaces of the mirrors Mi can be designed as freeform 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, 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 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 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. It has, in particular, different imaging scales Bx, By in the x and y directions x, y. The two imaging scales Bx, By of the projection optics 10 are preferably (Bx, By) = (+/- 0.25, +/- 0.125). A positive imaging scale β means imaging without image inversion. A negative sign for the imaging scale B means imaging with image inversion.

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

Other magnifications are also possible. Magnifications with the same sign and absolutely identical 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 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-directions x, y are known from US 2018/0074303 A1 .

Each of the second facets 23 is assigned to exactly one of the first facets 21 to form a respective illumination channel for illuminating the object field 5. This can, in particular, result in illumination according to the Köhler principle. The far field is divided into a plurality 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 associated second facet 23, superimposed on 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%. Field uniformity can be achieved by superimposing different illumination 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 exit pupil of the projection optics 10. This intensity distribution is also referred to as illumination setting or illumination 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 of 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 usually be precisely illuminated with the second facet mirror 22. When the projection optics 10 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, a surface can be found in which the pairwise determined distance of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugate to it in spatial space. In particular, this surface exhibits a finite curvature.

It is possible that the projection optics 10 have different entrance pupil positions 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 1 In the illustrated 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 arranged tilted relative to the object plane 6. The first facet mirror 20 is arranged tilted relative to an arrangement plane defined by the deflection mirror 19. The first facet mirror 20 is arranged tilted relative to an arrangement plane defined by the second facet mirror 22.

2 shows a schematic representation of an embodiment of an optical system 300 for a lithography system or projection exposure system 1, as described, for example, in 1 In addition, the optical system 300 of the 2 for example, can also be used in a DUV lithography system.

The optical system 300 of the 2 has a plurality of actuatable optical elements 310. The optical system 300 is embodied here as a micromirror array, wherein the optical elements 310 are micromirrors. Each micromirror 310 can be actuated by means of an associated actuator 200. For example, a respective micromirror 310 can be tilted about two axes and/or displaced in one, two, or three spatial axes by means of the associated actuator 200. For reasons of clarity, the reference numerals are shown only for the top row of these elements.

The control device 100, 100' controls the respective actuator 200, for example, with a control voltage V3. This adjusts a position of the respective micromirror 310. The control device 100, 100' is supplied with a high voltage V1, for example, 50 V, from a supply unit 130.

The control device 100, 100' is particularly described with reference to the 3 and 4 described.

3 shows a first embodiment of a control device 100 for controlling an actuator 200.

The actuator 200 in the control device 100 can be controlled via a first interface Int1 and a second interface Int2. A measuring resistor R is coupled to the first interface Int1, and a measuring circuit 150 is arranged in parallel with the measuring resistor R. The measuring circuit 150 provides a DC voltage as the supply voltage V2. Furthermore, a first switching amplifier 110 and a filter 190 are coupled to the first interface Int1 via the measuring resistor R. In this case, the supply voltage V2 has a first voltage value of 4.7 V.

A filter 190' and a second switching amplifier 120 are coupled to the second interface Int2. A provision unit 130 is coupled to the first switching amplifier 110 and the second switching amplifier 120 via a first node K1.

A first measuring device 160 is arranged between the first node K1 and the second switching amplifier 120, a second measuring device 170 is arranged between the measuring resistor R and the filter 190 and a third measuring device Device 180 is arranged between the second interface Int2 and the filter 190'.

The 3 The switching amplifiers 110, 120 shown are each designed as half an H-bridge and each have two switching elements 111, 112, 121, 122. The switching elements 111, 112, 121, 122 are transistors and in particular MOSFETs. Alternatively, the transistors can also be designed as n-channel MOSFETs, p-channel MOSFETs, silicon MOSFETs, GaN FETs, IGBTs, and/or bipolar transistors.

A diode 113, 114, 123, 124 is arranged in parallel with each of the switching elements 111, 112, 121, 122. Each of the diodes 113, 114, 123, 124 is designed as a freewheeling diode and has a second voltage value as a specific freewheeling voltage. In this case, the second voltage value is 0.7 V.

The switching amplifiers 110, 120 are each controlled by a control unit 200. The control unit 200 is configured to control the capacitors 111, 112, 121, 122 using a modulation signal.

The two filters 190, 190' of the 3 The control device 100 shown is designed as a second-order low-pass filter and each has an inductance, a capacitance, and two resistors. In particular, the inductance, for example a coil, is coupled in series to the actuator 200. Furthermore, the first resistor is also coupled in series to the actuator 200, and the capacitance and the second resistor are coupled in parallel to the actuator 200.

It should be noted that instead of the ground potential GND, any potential provided by a voltage source can serve as ground.

To determine a state of the control device 100, and in particular a state of the actuator 200, in a first step, the switch 140 connected between the supply unit 130 and the first node K1 is opened. This ensures that the high voltage V1 of the supply unit 130 is not applied to the control device 100.

When switch 140 is open, measuring circuit 150 provides a first voltage. In this case, the first voltage is 4.7 V.

By means of the control device 100, at least four states of the actuator 200 can be determined.

If the actuator 200 is connected to the first interface Int1 and the second interface Int2, a voltage of 3.3 V is present at the first measuring device 160. A voltage of 4.7 V is present at the second measuring device 170, and a voltage different from 4.7 V is present at the third measuring device 180 and is determined in particular by the resistance represented by the actuator 200. This distribution of the voltage values across the first measuring device 160, the second measuring device 170, and the third measuring device 180 allows the "connected" state of the actuator 200 to be derived.

If the actuator 200 is not connected to the first interface Int1 and not to the second interface Int2, a voltage of 4 V is present at the first measuring device 160. A voltage of 4.7 V is present at the second measuring device 170, and a voltage of 0 V is present at the third measuring device 180. This distribution of the voltage values across the first measuring device 160, the second measuring device 170, and the third measuring device 180 allows the "not connected" state of the actuator 200 to be determined.

If the first interface Int1 is conductively connected to the second interface Int2, a voltage of 3.3 V is applied to the first measuring device 160. A voltage of 4.7 V is applied to the second measuring device 170 and the third measuring device 180. This distribution of the voltage values across the first measuring device 160, the second measuring device 170, and the third measuring device 180 allows the "short-circuited" state of the actuator 200 to be determined.

If the first interface Int1 or the second interface Int2 is connected to ground GND, a third voltage value is present at the first measuring device 160, the second measuring device 170, and the third measuring device 180. In this case, the third voltage value is 0 V.

4 shows a second embodiment of a control device 100'. The 4 The control device 100' shown differs from the control device 100 of 3 in that the measuring resistor R is coupled to the second interface Int2. As a result, the measuring circuit 150 is now also coupled to the second interface Int2.

Through the 4 With the illustrated control device 100', as with the control device 100, at least four states of the actuator 200 can be determined. However, different voltage distributions result at the first measuring device 160, the second measuring device 170, and the third measuring device 180.

If the actuator 200 is connected to the first interface Int1 and the second interface Int2, a voltage of 3.3 V is present at the first measuring device 160. A voltage of 4.7 V is present at the third measuring device 180, and a voltage different from 4.7 V is present at the second measuring device 170, which is determined in particular by the resistance represented by the actuator 200. This distribution of the voltage values across the first measuring device 160, the second measuring device 170, and the third measuring device 180 allows the "connected" state of the actuator 200 to be derived.

If the actuator 200 is not connected to the first interface Int1 and not to the second interface Int2, a voltage of 4 V is present at the first measuring device 160. A voltage of 0 V is present at the second measuring device 170, and a voltage of 4.7 V is present at the third measuring device 180. This distribution of the voltage values across the first measuring device 160, the second measuring device 170, and the third measuring device 180 allows the "not connected" state of the actuator 200 to be determined.

If the first interface Int1 is conductively connected to the second interface Int2, a voltage of 3.3 V is applied to the first measuring device 160. A voltage of 4.7 V is applied to the second measuring device 170 and the third measuring device 180. This distribution of the voltage values across the first measuring device 160, the second measuring device 170, and the third measuring device 180 allows the "short-circuited" state of the actuator 200 to be determined.

If the first interface Int1 or the second interface Int2 is connected to ground GND, a third voltage value is present at the first measuring device 160, the second measuring device 170, and the third measuring device 180. In this case, the third voltage value is 0 V.

Another difference to the control device 100 from 3 This involves a manipulation device 210 being coupled to the second switching amplifier 120. In particular, the manipulation device 210 is coupled to the switching element 121 and the switching element 122 of the second switching amplifier 120.

The manipulation device 210 is configured to change the switching state of the switching elements 121, 122 into a conductive or a non-conductive state.

In addition to the determination of the state of the actuator 200, which is carried out in the control device 100' 4 As described above, the function of the switching elements 121, 122 can be checked by means of the manipulation device 210. The check of the switching elements 121, 122 is described below.

The switch 140, which couples the supply unit 130 to the first node K1, is open, as is the case when determining the state of the actuator 200, so that the connection to the supply unit 130 is interrupted. The measuring circuit 150, which provides a DC voltage as supply voltage V2, is, as is the case with respect to the control device 100 of 3 described, connected to the second interface Int2 via the measuring resistor R.

The first measuring device 160, the second measuring device 170 and the third measuring device 180 of the control device 100' and the control device 100 from 3 are arranged identically.

If the switching elements 121, 122 are now closed and their switching state is not changed by the manipulation device 210, a voltage value is present at the first measuring device 160, the second measuring device 170, and the third measuring device 180. Assuming that the actuator 200 is connected to the first interface Int1 and the second interface Int2, a voltage of 3.3 V is present at the first measuring device 160, a voltage of 4.7 V is present at the third measuring device 180, and a voltage different from 4.7 V is present at the second measuring device 170 and is determined in particular by the resistance represented by the actuator 200.

If the manipulation device 210 now changes the switching state of the switching element 121 to a closed state, the voltage applied to the first measuring device 160, the second measuring device 170, and the third measuring device 180 also changes. This is caused by the current proportional to the voltage now choosing the path via the closed switching element 121 and no longer via the diode 123, which has a freewheeling voltage of 0.7 V.

If, despite the change in the switching state of the switching element 121, the voltage applied to the first measuring device 160, the second measuring device 170 and the third measuring device 180 does not change, the current proportional to the voltage chooses the path via the diode 123 and not via the closed switching element 121. Accordingly, the resistance across the switching element 121 is greater than across the diode 123, so that it can be concluded that the switching element 121 is damaged.

The state of the switching element 122 can be checked in an analogous manner.

In alternative embodiments, the manipulation device 210 is coupled to the first switching amplifier 110 and/or to the second switching amplifier 120.

The embodiments of the method according to 5 include opening S1 of the switch 140 so that the first node K1 is disconnected from the provision unit 130, and then, in the open state of the switch 140, determining S2 at least one state of the actuator 200 by means of the DC voltage supplying the measuring circuit 150 using a first measuring device 160 coupled to the first node K1, a second measuring device 170 coupled to the first interface Int1 and/or a third measuring device 180 coupled to the second interface Int2.

As already mentioned with reference to the 3 and 4 executed, the provision unit 130 is disconnected from the first node K1 by opening the switch 140. Subsequently, using the DC voltage V2 provided by the measuring circuit 150, a voltage applied to the first measuring device 160, the second measuring device 170, and/or the third measuring device 180 can be determined. A state of the actuator 200 can be determined using the voltage applied to the first measuring device 160, the second measuring device 170, and/or the third measuring device 180.

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

LIST OF REFERENCE SYMBOLS

1

Projection exposure system

2

lighting system

3

light source

4

Lighting optics

5

Object field

6

Object level

7

Reticle

8

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

Illumination radiation

17

collector

18

Intermediate focal plane

19

Deflecting mirror

20

first faceted mirror

21

first facet

22

second facet mirror

23

second facet

100, 100'

Control device

110

first switching amplifier

111

switching element

112

switching element

113

diode

114

diode

120

second switching amplifier

121

switching element

122

switching element

123

diode

124

diode

130

Provisioning unit

140

Switch

150

Measuring circuit

160

first measuring device

170

second measuring device

180

third measuring device

190, 190'

filter

200

Actuator

210

Manipulation device

220

Control unit

300

optical system

310

optical element

V1

Tension

V2

Supply voltage

V3

Control voltage

GND

mass

K1

first node

Int1

first interface

Int2

second interface

R

measuring resistor

M1

Mirror

M2

Mirror

M3

Mirror

M4

Mirror

M5

Mirror

M6

Mirror

S1, S2

Procedural steps

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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 10 2008 009 600 A1 [0052, 0056]
• US 2006/0132747 A1 [0054]
• EP 1 614 008 B1 [0054]
• US 6,573,978 [0054]
• DE 10 2017 220 586 A1 [0059]
• US 2018/0074303 A1 [0073]

Claims (15)

A control device (100) for controlling an actuator (200) controllable via a first interface (Int1) and a second interface (Int2), comprising: a first switching amplifier (110) coupled to the first interface (Int1) and having two switching elements (111, 112) and a diode (113, 114) connected in parallel with each other; a second switching amplifier (120) coupled to the second interface (Int2) and having two switching elements (121, 122) and a diode (123, 124) connected in parallel with each other; a supply unit (130) coupled to the first switching amplifier (110) and the second switching amplifier (120) via a first node (K1) for providing a supply voltage (V2) for the first switching amplifier (110) and the second switching amplifier (120), wherein a switch is connected between the first node (K1) and the supply unit (130) (140) for connecting the supply unit (130), a measuring resistor (R) coupled between the actuator (200) and the first switching amplifier (110) or the second switching amplifier (120), a measuring circuit (150) arranged in parallel with the measuring resistor (R) and supplied with a DC voltage, and a first measuring device (160) coupled to the first node (K1), a second measuring device (170) coupled to the first interface (Int1), and/or a third measuring device (180) coupled to the second interface (Int2), which are configured to determine at least one state of the actuator (200) using the DC voltage supplying the measuring circuit (150) when the switch (140) is in the open state. Control device (100) according to Claim 1 , wherein each of the switching amplifiers (110, 120) is designed as a half H-bridge and/or the switching elements (111, 112, 121, 122) are transistors. Control device (100) according to Claim 1 or 2 , wherein a filter (190, 190') is coupled between the first switching amplifier (110) and the first interface (Intl) and between the second switching amplifier (120) and the second interface (Int2). Control device (100) according to Claim 3 , where the filter (190, 190') is a 2nd order low-pass filter. Control device (100) according to one of the Claims 1 - 4 , wherein at least one manipulation device (210) is coupled to at least one switching amplifier (110, 120) and the manipulation device (210) is configured to change a switching state of at least one switching element (111, 112, 121, 122) of the switching amplifier (110, 120) into a conductive or non-conductive state. Control device (100) according to one of the Claims 1 - 5 , wherein the measuring circuit (150) is configured to provide a first voltage value, in particular 4.7 V, in the open state of the switch (140). Control device (100) according to one of the Claims 1 - 6 , wherein the parallel-connected diodes (113, 114, 123, 124) are freewheeling diodes, each having a freewheeling voltage of a second voltage value, in particular 0.7 V. Control device (100) according to one of the Claims 1 - 7 , wherein in the open state of the switch (140) and when the actuator (200) is connected to the first interface (Int1) and to the second interface (Int2), a voltage value indicative of the state of the actuator (200) connected to the first interface (Int1) and to the second interface (Int2) is present at the first measuring device (160), at the second measuring device (170) and/or at the third measuring device (180). Control device (100) according to one of the Claims 1 - 7 , wherein in the open state of the switch (140) and when the actuator (200) is not connected to the first interface (Int1) and not to the second interface (Int2), a voltage value indicative of the state of the actuator (200) not connected to the first interface (Intl) and not to the second interface (Int2) is present at the first measuring device (160), the second measuring device (170) and/or the third measuring device (180). Control device (100) according to one of the Claims 1 - 7 , wherein in the open state of the switch (140) and when the first interface (Intl) is conductively connected to the second interface (Int2), a voltage value indicative of the state of a conductive connection between the first interface (Intl) and the second interface (Int2) is present at the first measuring device (160), at the second measuring device (170) and/or at the third measuring device (180). Control device (100) according to one of the Claims 1 - 7 , wherein in the open state of the switch (140) and when the first interface (Intl) or the second interface (Int2) is conductively connected to ground (GND), at the first measuring device (160), at the second measuring device (170) and/or a third voltage value, in particular 0 V, is present at the third measuring device (180). Control device according to one of the Claims 1 - 7 , wherein in the open state of the switch (140) and when the manipulation device (210) changes at least one switching state of at least one of the switching elements (111, 112, 121, 122), a voltage value, which is in particular different from the first voltage value, is applied to the first measuring device (160), the second measuring device (170) and/or the third measuring device (180). Optical system (300) with a number of actuatable optical elements (310), wherein each of the number of actuatable optical elements (310) is assigned an actuator (200), wherein each actuator (200) has a control device (100) for controlling the actuator (200) according to one of the Claims 1 until 12 is assigned. Lithography system comprising an optical system (300) according to Claim 13 . Method for determining a state of a control device (100) for controlling an actuator (200) controllable via a first interface (Intl) and via a second interface (Int2), wherein the control device (100) comprises a first switching amplifier (110) coupled to the first interface (Int1) with two switching elements (111, 112) and a diode (113, 114) connected in parallel, a second switching amplifier (120) coupled to the second interface (Int2) with two switching elements (121, 122) and a diode (123, 124) connected in parallel, a supply unit (130) coupled to the first switching amplifier (110) and the second switching amplifier (120) via a first node (K1) for providing a supply voltage (V2) for the first switching amplifier (110) and the second switching amplifier (120), wherein between the first node (K1) and the provision unit (130), a switch (140) for connecting the provision unit (130) is connected, a measuring resistor (R) coupled between the actuator (200) and the first switching amplifier (110) or the second switching amplifier (120), and a measuring circuit (150) arranged in parallel with the measuring resistor (R) and supplied with a DC voltage, comprising: opening (S1) the switch (140) so that the first node (K1) is disconnected from the provision unit (130), and determining (S2), in the open state of the switch (140), at least one state of the actuator (200) by means of the DC voltage supplying the measuring circuit (150) using a first measuring device (160) coupled to the first node (K1), a second measuring device (170) coupled to the first interface (Int1), and/or a second measuring device (170) coupled to the second interface (Int2) coupled third measuring device (180).

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