Component in a microlithographic projection exposure system

Abstract

The invention relates to an assembly in a microlithographic projection exposure system, wherein the assembly (100, 200, 300, 400) comprises an optical element (101, 201, 301, 401), at least one weight force compensation device (110, 210, 310, 410) with a passive magnetic circuit (111, 211, 311, 411) for generating a magnetic field which causes a force for at least partial compensation of the weight force acting on the optical element, and an active component for generating an actively controllable force transmitted to the optical element, and at least three Lorentz actuators (120, 130, 220, 230, 320, 330, 340, 420, 430, 440) each designed to exert a controllable force on the optical element. exhibits, wherein at least one of these Lorentz actuators is directly fixed to the optical element.

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The invention relates to a component in a microlithographic projection exposure system. State of the art

[0002] Microlithography is used to manufacture microstructured components, such as integrated circuits or LCDs. The microlithography process is carried out in a projection exposure system, which includes an illumination unit and a projection lens. The image of a mask (= reticulum) illuminated by the illumination unit is projected by the projection lens onto a substrate (e.g., a silicon wafer) coated with a photosensitive layer (photoresist) and positioned in the image plane of the projection lens. This transfers the mask structure onto the photosensitive coating of the substrate.

[0003] In a projection imaging system designed for EUV (e.g., for wavelengths of approximately 13 nm or 7 nm), mirrors are used as optical components for the imaging process due to the lack of translucent materials. These mirrors can be mounted on a support frame and designed to be at least partially manipulable, allowing movement of the respective mirror in six degrees of freedom (i.e., with respect to displacements in the three spatial directions x, y, and z, as well as rotations R). x , R y and R z to enable adjustments along the relevant axes. This allows for the compensation of changes in optical properties that may occur during the operation of the projection exposure system, for example, due to thermal influences.

[0004] It is known, for example, that in a projection lens of an EUV projection exposure system, optical elements such as mirrors can be manipulated in up to six degrees of freedom – as schematically shown in Fig. 13 indicated - to use three actuator arrangements, each of which has at least two Lorentz actuators 1302 and 1303, 1304 and 1305, or 1306 and 1307 (i.e., each with two actively controllable axes of motion). Furthermore, the setup of Fig. 13 For each of these actuator arrangements or for each associated force application point, a weight force compensation device (also referred to as "MGC" = "Magnetic Gravity Compensator") supporting the mass of an optical element or mirror 1300 is provided in order to minimize the energy consumption of the active or controllable actuators, so that no permanent energy flow with the associated heat generation is required. The weight compensation device can be adjusted to a certain holding force, which is transmitted to the mirror 1300 via a mechanical element (pin) 1315, 1325 or 1335 mechanically coupled to the mirror 1300. Furthermore, it is also known, for example, to design the weight compensation device to additionally exert a controllable force.

[0005] Various approaches exist for connecting the Lorentz actuators and the weight force compensation device. A problem that arises during operation is that, depending on the specific configuration, comparatively high parasitic moments or forces are transmitted to the mirror, particularly via the Lorentz actuators. This, in turn, leads to undesirable deformations of the optical surface of the mirror in question and thus to an impairment of the optical system's performance.

[0006] As the demands on the projection exposure system increase with regard to resolution and contrast, and the associated increase in numerical apertures and mirror sizes, the coupling of both the Lorentz actuators and the weight force compensation device presents an increasingly demanding challenge.

[0007] For examples of the state of the art, reference is made only to DE 10 2009 054 549 A1, WO 2012 / 084675 A1, DE 10 2018 202 694 A1 and DE 10 2018 207 949 A1. SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to provide an assembly in a microlithographic projection exposure system which enables the most disturbance- and deformation-free actuation of an optical element while at least largely avoiding the problems described above.

[0009] This problem is solved according to the features of independent claim 1.

[0010] An assembly according to the invention, particularly in a microlithographic projection exposure system, comprises: • an optical element; • at least one weight force compensation device with - a passive magnetic circuit for generating a magnetic field which produces a force to at least partially compensate the weight force acting on the optical element, and - an active component for generating an actively controllable force transmitted to the optical element; • and at least three Lorentz actuators each designed to exert a controllable force on the optical element, wherein at least one of these Lorentz actuators is fixed directly to the optical element.

[0011] According to one embodiment, the active component of the weight force compensation device comprises at least one coil that can be energized with an electric current. This coil can be arranged in the stray field of the passive magnetic circuit. In further embodiments, the active component can also include mechanically connected additional Lorentz actuators, a unit (e.g., implemented with piezo actuators) for adjusting magnet positions in the passive magnetic circuit, or a device for manipulating the magnetic field strength in the passive magnetic circuit by actively changing the temperature.

[0012] The invention is based in particular on the concept of designing a weight force compensation device in an assembly for actuating an optical element (especially a mirror, e.g., in a microlithographic projection exposure system) for at least partially compensating the weight force acting on the optical element, with an active component provided in addition to an existing passive magnetic circuit for generating an actively controllable force transmitted to the optical element. In combination with this "active" design of the weight force compensation device, the invention further includes the principle of designing, in one or more of the Lorentz actuators designed to exert a controllable force on the optical element, with regard to the actuator component mechanically connected to and movable with the optical element (e.g.,to forego any articulated connection (e.g., in the form of a articulated pin) in favor of direct fixation to the optical element (e.g., of the magnet in a magnet coil pair forming the respective Lorentz actuator).

[0013] With the combination described above, the invention takes advantage of the fact that, due to the aforementioned "active" design of the weight force compensation device (i.e., with an active component comprising, for example, a coil that can be energized), a precise force transmission to the optical element along the (vertical) force transmission direction of this active component can already be achieved via said weight force compensation device. This relieves the Lorentz actuators of the transmission of static forces to the optical element, so that parasitic forces and moments transmitted to the optical element via the Lorentz actuators are significantly reduced.At the same time, on the Lorentz actuator side – due to the at least partial elimination of a pivotally mounted pin for their connection – the transmission of parasitic forces and moments, which would occur in the case of a connection via solid-state joints, is also partially or completely avoided. With regard to the connection of the Lorentz actuators to the optical element to be actuated, the disadvantages associated with a connection via solid-state joints are thus avoided, and the problems inherently associated with the direct fixation according to the invention (utilizing the "active" design of the weight force compensation device) are minimized.

[0014] According to the invention, the disadvantage of increased effort for the (among other things, for the active component of the weight force compensation device) increased number of actuators used, as well as associated supply line or amplifier components and required control or regulation electronics, is deliberately accepted in order to achieve the advantages described above, in particular the reduction of parasitic forces and moments transmitted to the optical element.

[0015] According to one embodiment, at least three, in particular six, of the Lorentz actuators are fixed directly to the optical element (101). In other words, for at least three, in particular six, of the Lorentz actuators, the actuator component (typically the magnet of the magnet-coil pair forming the Lorentz actuator) which is mechanically connected to and movable together with the optical element is fixed directly to the optical element.

[0016] According to one embodiment, the weight force compensation device is coupled to the optical element via a pivotally mounted pin. Preferably, the natural frequency of this coupling is less than three times, more particularly less than two times, and further, more particularly less than 1.5 times the control bandwidth.

[0017] According to one embodiment, the assembly has at least two, in particular at least three, weight force compensation devices.

[0018] According to one embodiment, the assembly has three actuator units, each of which has a weight force compensation device and two Lorentz actuators, wherein these Lorentz actuators and the weight force compensation device each extend to a common force application point.

[0019] According to another embodiment, the assembly has three actuator units, each of which has a weight force compensation device, a Lorentz actuator and an inertial actuator, wherein the Lorentz actuator, the inertial actuator and the weight force compensation device each extend to a common force application point.

[0020] According to one embodiment, the assembly has more than three, in particular more than six, Lorentz actuators for exerting a controllable force on the optical element in a vertical direction.

[0021] According to one embodiment, the assembly for exerting a controllable force on the optical element comprises at least three inertial actuators, and in particular at least six inertial actuators, for partially decoupling a reaction path associated with the exertion of the controllable force on the optical element. In this context, reference is made by way of example to DE 10 2016 202 408 A1 and DE 10 2013 201 081 A1.

[0022] According to one embodiment, the assembly further comprises a controller, wherein this controller is designed to separately control the weight force compensation device for exerting static forces and the Lorentz actuators for exerting dynamic forces.

[0023] According to one embodiment, the weight force compensation device is controlled via an integrator branch (I-component), and the Lorentz actuators are controlled via a separate PD branch.

[0024] According to one embodiment, the optical element is a mirror.

[0025] The invention further relates to an optical system, in particular a microlithographic projection exposure system, which has at least one assembly with the features described above.

[0026] Although the invention has been described above – merely by way of example – with reference to an application in optical components for EUV projection exposure systems, an application in optical components for other optical systems is of course also conceivable, in particular also for higher operating wavelengths, e.g. in DUV projection exposure systems (DUV = deep ultraviolet) with typical wavelength ranges between 240 nm and 255 nm, or for optical systems with operation in a VUV range (vacuum ultraviolet range) lying between EUV and DUV.

[0027] Further embodiments of the invention can be found in the description and the dependent claims.

[0028] The invention is explained in more detail below with reference to exemplary embodiments shown in the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] They show: Fig. 1-4c schematic representations to illustrate possible embodiments of an assembly according to the invention; Fig. 5-11 schematic representations to illustrate possible configurations of a control loop for controlling an assembly according to the invention in different embodiments; Fig. 12 a schematic representation of a projection exposure system designed for operation in EUV; and Fig. 13 A schematic representation to explain a conventional setup for manipulating a mirror in six degrees of freedom. DETAILED DESCRIPTION OF PREFERRED EXECUTION FORMS

[0030] In the following, different embodiments of an assembly according to the invention are described with reference to the schematic representations in Fig. 1-3 described.

[0031] These embodiments have in common that, firstly, a weight force compensation device present in the respective assembly is designed to at least partially compensate the weight force acting on an optical element such as a mirror (in addition to the existing passive magnetic circuit) and is "active", i.e., with an active component for generating an actively controllable force transmitted to the optical element, and secondly, in one or more of the Lorentz actuator(s) further designed to exert a controllable force on the optical element, any articulated connection to the optical element (e.g., in the form of a pivotally mounted pin) is dispensed with in favor of direct fixation to the optical element.

[0032] Fig. Figure 1 shows a schematic representation of an assembly 100 with an optical element 101 in the form of a mirror, a support frame 105, and one of, for example, a total of three actuator units, wherein this actuator unit comprises a weight force compensation device 110 and two Lorentz actuators 120, 130 (each consisting of a coil 121 or 131 and a magnet 122 or 132, respectively). "ACP" denotes a common force application point of the Lorentz actuators 120, 130 and the weight force compensation device 110. The mechanical connection of the weight force compensation device 110 (with a Fig. The connection of the passive magnetic circuit 111 (also indicated) to the optical element 101 is effected via a pin 115 mounted on solid-state joints. Furthermore, in addition to the passive magnetic circuit 111, the weight force compensation device 110 comprises an active component for generating an actively controllable force on the optical element 101. In the exemplary embodiment (though the invention is not limited to this), this active component has a coil 112 that can be energized with an electric current and is arranged in the stray field of the passive magnetic circuit 111. In further embodiments, the active component can also include mechanically connected additional Lorentz actuators, a unit (e.g., implemented with piezo actuators) for adjusting magnet positions in the passive magnetic circuit, or a device for manipulating the magnetic field strength in the passive magnetic circuit by actively changing the temperature.

[0033] Unlike the mechanical connection of the weight force compensation device 110, the coupling via the Lorentz actuators 120 and 130 is such that the magnet 122 and 132, respectively, which couples to the coil 121 and 131 fixed to the support frame via magnetic forces, are directly and immediately fixed to the optical element 101 in the Lorentz actuators 120 and 130. The coil and magnet can also be reversed. Thus, with regard to the Lorentz actuators 120 and 130, a mechanically guided, articulated connection of the respective magnets of the Lorentz actuators via a pivotally mounted pin is dispensed with in favor of direct fixation to the optical element 101. Consequently, the transmission of parasitic moments via solid-state joints is also avoided.

[0034] At the same time, due to the fact that, as a result of the “active” design of the weight force compensation device 110, static forces on the optical element 101 can be “taken over” by said weight force compensation device 110 and the Lorentz actuators 120, 130 are accordingly relieved of the transmission of static forces to the optical element 101, a transmission of parasitic forces and moments which is generally associated with the direct fixing of the Lorentz actuators 120, 130 to the optical element 101 is also significantly reduced.

[0035] Furthermore, the "active" design of the weight force compensation device 110 only needs to be used to exert static forces on the optical element 101, with the result that the mechanical connection of the weight force compensation device 110 to the optical element 101 via the articulated pin 115 can be designed to be comparatively flexible. In particular, the (actuator) natural frequency of this coupling can be less than three times, more specifically less than two times, and furthermore, less than 1.5 times the control bandwidth. The actuator natural frequency is understood to be the natural frequency of the modes in the direction of action of the actuator, whereby these modes are formed by the axial compliance of the pin and its joints and the connected magnetic mass (or coil mass in the case of reversed installation) of the actuator.

[0036] Fig. Figure 2a shows a further embodiment of an assembly 200 according to the invention in a schematic representation, wherein in comparison to Fig. 1 analogous or essentially functionally identical components are designated with reference digits increased by “100”.

[0037] The embodiment according to Fig. 2a differs from the one from Fig. 1 by arranging the Lorentz actuators 220, 230 at different positions relative to the optical element 201 to be actuated. In particular, the Lorentz actuators 220, 230 can be arranged outside the actuator unit comprising the weight force compensation device 310, wherein the weight force compensation device 210 and the Lorentz actuators 220, 230 preferably continue to have one and the same force application point on the mirror (or on bushings mechanically connected to the mirror).

[0038] According to Fig. 2a The Lorentz actuator 220 serves to exert vertical force, and the Lorentz actuator 230 serves to exert horizontal force. The direct vertical and horizontal fixation of the Lorentz actuators 220 and 230 to the optical element 201 – in contrast to the one described in section 2a – allows for the application of force vertically and horizontally. Fig. The mounting of the optical element 101 at an angle to the optical element 101 or the pin 115 eliminates the need for a corresponding socket ("yoke") and thus enables a comparatively rigid and close mechanical connection to the optical element 201. Furthermore, the positioning, independent of the position of the weight force compensation device 210 or the associated actuator unit, also provides additional freedom in placing the Lorentz actuators according to the specific requirements of any desired targeted excitation of certain vibration modes, thereby achieving even more effective prevention of unwanted deformations of the optical element 210.

[0039] Furthermore, the total number of Lorentz actuators can also be greater than six, whereby one or more of these Lorentz actuators can also differ from the respective weight force compensation device or the other Lorentz actuators with respect to the respective force application point. Here, the invention can again take advantage of the fact that no static forces are exerted on the optical element via the Lorentz actuators in question, so that the exertion of parasitic forces and moments, which is generally associated with different force application points, can be kept negligibly small.

[0040] Furthermore, the placement of the Lorentz actuators according to the invention can be selected in such a way that – according to the known concept of “overactuation” – individual vibration modes are selectively excited to a greater or lesser degree. In particular, the Lorentz actuators can be positioned such that the tasks existing in the specific configuration, especially position control, feedforward control of a scan movement of the optical element, and vibration damping, can be optimally fulfilled.

[0041] Fig. 2b shows a comparison to Fig. 2a modified embodiment insofar as the (in Fig. 2b (designated 220' and 230') Lorentz actuators are also arranged within the actuator unit comprising the weight force compensation device 210.

[0042] Fig. Figure 3a shows a further embodiment of an assembly 300 according to the invention in schematic representation, wherein in comparison to Fig. 1 analogous or essentially functionally identical components are designated with reference digits increased by "200".

[0043] The embodiment according to Fig. 3a differs from the one from Fig. 1. Initially, this is achieved by controlling the Lorentz actuators 320 and 330, which are arranged at an angle to the optical element 301 or force application point, in opposite directions, with the result that a horizontal force is exerted on the optical element 301 by these two Lorentz actuators 320 and 330. The dynamic vertical force is exerted according to Fig. 3a via a separate Lorentz actuator 340, which is located outside the actuator unit comprising the weight force compensation device 310 and the Lorentz actuators 320, 330.

[0044] Fig. 3b shows a comparison to Fig. 3a modified embodiment insofar as instead of the one according to Fig. 3a provided “bipod configuration” a horizontal Lorentz actuator (in Fig. 3b (designated as “320’”). In particular, by dispensing with a vertical Lorentz actuator within the actuator unit comprising the weight force compensation device 310 – and a corresponding reduction in the installation space required within the actuator unit – a vertical Lorentz actuator 340 as well as further additional actuators can be placed outside the actuator unit.

[0045] Fig. Figure 4a shows a further embodiment of an assembly 400 in schematic representation, wherein in comparison to Fig. 2a analogous or essentially functionally identical components are designated with reference digits increased by “200”.

[0046] The embodiment according to Fig. 4a differs from the one from Fig. 2a by providing, in addition to the Lorentz actuator 420 for applying vertical force to the optical element 401 and the Lorentz actuator 430 for applying horizontal force, inertial actuators 440 and 450 are provided, each of which comprises an auxiliary mass 441 or 451 mechanically connected to the optical element 401 via a spring 442 or 452, respectively, in a manner known per se. The reaction path associated with the application of force to the optical element 401 can be partially interrupted by means of the respective auxiliary mass 441 or 451, namely above a certain threshold frequency (e.g., 50 Hz).

[0047] The use of inertial actuators 440, 450 in an assembly according to the concept of the invention, as described above, is also advantageous insofar as the fact can be exploited that, due to the “active” design of the weight force compensation device 410, the forces below the said limit frequency of the inertial actuators 440, 450 can be transmitted by the weight force compensation device 410, so that – unlike the usual case when using inertial actuators – no additional Lorentz actuators are required for the low-frequency force transmission.

[0048] The concept of overactuation described above can also be combined with the one based on... Fig. The use of inertial actuators described in section 4a can be combined, resulting in a particularly advantageous implementation of position control, active vibration damping, and scan motion feedforward control, while simultaneously decoupling the reaction path due to inertial actuation and control. A suitable division of tasks can be such that the application of feedforward forces for a scan motion is carried out via the Lorentz actuators, the active vibration damping is implemented solely by the inertial actuators, and a crossover network for the combined use of Lorentz actuators and inertial actuators is used for position control according to the known inertial actuation and control concepts.The placement of the inertial actuators can therefore be chosen with regard to the most optimal implementation of the position control and the active vibration damping, whereas the Lorentz actuators can be placed independently with regard to an optimal realization of the scan motion feedforward control.

[0049] Fig. 4b shows a comparison to Fig. 4a is a modified embodiment in that all of the actuators shown (i.e. both Lorentz actuators and inertial actuators) are arranged within the actuator unit comprising the weight force compensation device 410.

[0050] Fig. 4c shows one to Fig. 4a modified embodiment insofar as according to Fig. 4c (as already in Fig. 4b) both the horizontal Lorentz actuator 430' and the horizontal inertial actuator 450' are arranged within the actuator unit comprising the weight force compensation device 410, whereas a vertical inertial actuator 440, unlike Fig. 4b is located outside the actuator unit.

[0051] The following will refer to Fig. 5-11 suitable controller architectures are described by which an assembly according to the invention can be controlled or regulated according to the embodiments described above. A key feature of the controller architecture according to the invention is the separation of the (especially vertical) static forces from the (especially vertical) dynamic forces, wherein, as described above, the weight force compensation device is controlled to exert the static forces, whereas the Lorentz actuators are controlled to exert the dynamic forces.

[0052] In the controller architecture of Fig. Section 5 assumes the control of a total of three weight force compensation devices and a total of six Lorentz actuators, with the further use of six position sensors (“PS”). “SPG” is in Fig. 5 is a setpoint generator. "MS" denotes a coordinate transformation of the sensor signals supplied by the position sensors PS to a reference point to be controlled and a coordinate system. According to Fig. 5. Furthermore, a feedforward signal is applied via a feedforward branch designated “FF” to realize a desired movement of the optical element according to a predetermined trajectory via the Lorentz actuators, thereby relieving the rest of the control system of this scan movement.

[0053] The realization of the aforementioned separation of static and dynamic forces is carried out according to Fig. 5 such that a PID controller is split into an I-part (= integrator branch) and a PD-part, wherein the I-part is transformed via a suitable coordinate transformation and decoupling matrix GB aMGC the active weight force compensation device (in Fig. 5 (labeled "aMGC"). The output of the PD component is in turn processed via a suitable coordinate transformation and decoupling matrix GB. LA on the (vertical) Lorentz factors (in Fig. 5 (labeled "LA"). Since the static control error becomes zero due to the integral (I) component of the controller, the static component of the proportional (PD) component also becomes zero. The deflection dependence of the force application point and force direction of the Lorentz actuators LA can be compensated for by deflection-dependent gain scheduling of the feedforward control matrix as well as the coordinate transformation and decoupling matrix.

[0054] In further embodiments, the separation of the static forces from the dynamic forces according to the invention can also be realized via a crossover network with a low-pass filter and a high-pass filter (where the sum of the transfer functions of the low-pass and high-pass filters should be approximately one).

[0055] Fig. 6 shows one to Fig. 5 analog controller architecture for the above described concept with “overactuation”, whereby three weight force compensation devices are still used, but more than six Lorentz actuators. Fig. Figure 7 shows a controller architecture taking additional account of the (e.g., according to the embodiment of Fig. 4a) the use of inertial actuators. This is carried out according to Fig. 7 the application of the feedforward signal analogous to Fig. 5 and Fig. 6. The feedforward signal is distributed via the feedforward branch FF and the Lorentz actuators LA. In alternative embodiments, the feedforward signal can also be distributed to Lorentz actuators and inertial actuators via a further crossover network, in which case potentially larger forces and deflections of the inertial actuators must be accepted. In the case of overactuation, active vibration damping can be achieved solely via the inertial actuators. The position control can distribute the forces to the Lorentz actuators and inertial actuators via a further crossover network according to the known inertial actuation and control concept.

[0056] Fig. 8, Fig. 9 and Fig. Figure 11 shows controller architectures in which, unlike the embodiments described above, the feedforward branch FF for realizing a desired movement of the optical element is in a “vertical” feedforward branch FF. Vand a "horizontal" feedforward branch FF H is subdivided, with the signal of the "vertical" feedforward branch FF being V The active weight force compensation device reduces parasitic forces and moments during the scanning process. The controller architectures are designed according to... Fig. 8 and Fig. 11 - insofar as analogous to Fig. 7 - taking additional account of (e.g., according to the embodiments of Fig. 4a-4c) the subsequent use of inertial actuators.

[0057] Fig. Figure 10 shows a controller architecture in which, analogous to Fig. 7. A crossover network with a low-pass filter and a high-pass filter is used, whereby, in contrast to... Fig. 7. No inertial actuators are present.

[0058] To simplify the wiring, the actuators can be controlled via local amplifiers, which are controlled via a fieldbus. In this case, only one fieldbus cable and one power supply cable are required.

[0059] Fig. Figure 12 shows a purely schematic representation of a projection exposure system 1200 designed for operation in the EUV, in which the present invention can be implemented by way of example.

[0060] According to Fig. Figure 12 of the projection exposure system 1200 includes a field facet mirror 1203 and a pupil facet mirror 1204. The light from a light source unit, comprising a plasma light source 1201 and a collector mirror 1202, is directed onto the field facet mirror 1203. A first telescope mirror 1205 and a second telescope mirror 1206 are arranged in the light path after the pupil facet mirror 1204. A deflecting mirror 1207, operated at grazing incidence, is arranged downstream in the light path. This deflecting mirror directs the incident radiation onto an object field in the object plane of a [missing information - likely a specific object or device]. Fig.The projection lens is directed by 12 mirrors 1251-1256, which are only indicated. At the location of the object field, a reflective, structure-bearing mask 1221 is arranged on a mask table 1220, which is imaged into an image plane by means of a projection lens. In this plane, a substrate 1261 coated with a light-sensitive layer (photoresist) is located on a wafer table 1260.

[0061] Even though the invention has been described with reference to specific embodiments, numerous variations and alternative embodiments are apparent to the person skilled in the art, for example, through the combination and / or exchange of features of individual embodiments. Accordingly, it is understood to the person skilled in the art that such variations and alternative embodiments are included in the present invention, and that the scope of the invention is limited only to the extent of the appended claims and their equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2009 054 549 A1

[0007] WO 2012 / 084675 A1

[0007] DE 10 2018 202 694 A1

[0007] DE 10 2018 207 949 A1

[0007] DE 10 2016 202 408 A1

[0021] DE 10 2013 201 081 A1

[0021]

Claims

[1] Assembly in a microlithographic projection exposure system, the assembly (100, 200, 300, 400) comprising: • an optical element (101, 201, 301, 401); • at least one weight force compensation device (110, 210, 310, 410) with - a passive magnetic circuit (111, 211, 311, 411) for generating a magnetic field which causes a force to at least partially compensate for the weight force acting on the optical element (101, 201, 301, 401), and - an active component for generating an actively controllable force transmitted to the optical element (101, 201, 301, 401); and • at least three Lorentz actuators (120, 130, 220, 230, 320, 330, 340, 420, 430, 440) each designed to exert a controllable force on the optical element (101, 201, 301, 401), wherein at least one of these Lorentz actuators is fixed directly to the optical element (101, 201, 301, 401). [2] Assembly according to claim 1, characterized by that the active component comprises at least one coil (112, 212, 312, 412) which can be supplied with electrical current. [3] Assembly according to claim 1 or 2, characterized by that at least three, in particular at least six of these Lorentz actuators (120, 130, 220, 230, 320, 330, 340, 420, 430, 440) are fixed directly to the optical element (101, 201, 301, 401). [4] Assembly according to one of claims 1 to 3, characterized by that the at least one weight force compensation device (110, 210, 310, 410) is coupled to the optical element (101, 201, 301, 401) via an articulated pin (115, 215, 315, 415). [5] Assembly according to claim 4, characterized by that a natural frequency of this coupling is less than 3 times, in particular less than 2 times, further in particular less than 1.5 times the control bandwidth. [6] Assembly according to one of the preceding claims, characterized by that it has at least two, in particular at least three such weight force compensation devices (110, 210, 310, 410). [7] Assembly according to one of claims 1 to 6, characterized by that it has three actuator units, each of these actuator units having a weight force compensation device and two Lorentz actuators, these Lorentz actuators and the weight force compensation device each running towards a common force introduction point. [8] Assembly according to one of claims 1 to 6, characterized by that it has three actuator units, each of these actuator units having a weight force compensation device, a Lorentz actuator and an inertial actuator, the Lorentz actuator, the inertial actuator and the weight force compensation device each running towards a common force introduction point. [9] Assembly according to one of the preceding claims, characterized by that it has more than three, in particular more than six Lorentz actuators for exerting a controllable force on the optical element (101, 201, 301, 401) in the vertical direction. [10] Assembly according to one of the preceding claims, characterized by in that, in order to exert a controllable force on the optical element (401), it has at least three inertial actuators, in particular at least six inertial actuators for partially decoupling a reaction path associated with the exertion of the controllable force on the optical element (401). [11] Assembly according to one of the preceding claims, characterized by that it further comprises a controller, said controller being designed to separately control the weight force compensation device for exerting static forces and the Lorentz actuators for exerting dynamic forces. [12] Assembly according to claim 11, characterized by that the weight force compensation device is controlled via an integrator branch (I component) and the Lorentz actuators are controlled via a separate PD branch. [13] Assembly according to one of the preceding claims, characterized by that the optical element (101, 201, 301, 401) is a mirror. [14] Optical system, in particular of a microlithographic projection exposure system, characterized by that it has at least one assembly according to one of the preceding claims.

Images