Optical system and lithography system

Abstract

The invention relates to an optical system (300) having a plurality of actuable optical elements (310) and a plurality of actuator / sensor devices (200) for actuating and / or sensing the optical elements (310), which optical system has a supply device (400) for providing a supply voltage (VS) for a number of electrical loads (500, L1-L12) of the optical system (300), which comprises a parallel connection of a plurality N, where N ≥ 3, of supply rails (410-440) to a respective power supply unit (450), wherein the respective power supply unit (450) of the N supply rails (410-440) is set up to provide a predetermined power supply unit output power (P1) on the output side at a supply node (K1-K4) in the error-free operation of the supply device (400), and to provide the -fold (P2) of the predetermined power supply unit output power at the supply node (K1-K4) in the faulty operation.

Description

[0001] OPTICAL SYSTEM AND LITHOGRAPHY FACILITY

[0002] The present invention relates to an optical system with a supply device for providing a supply voltage for a number of electrical consumers of the optical system and to a lithography system with such an optical system.

[0003] The content of the priority application DE 10 2023 206 069.8 is incorporated in its entirety by reference.

[0004] Microlithography systems are known that feature actuatable optical elements, such as microlens arrays or micromirror arrays. Microlithography is used to manufacture microstructured components, such as integrated circuits. The microlithography process is carried out using a lithography system that features an illumination system and a projection system.

[0005] 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 refractive optics, i.e., lenses, as was previously the case.

[0006] The image of a mask (reticle) illuminated by the illumination system is projected by the projection system onto a substrate coated with a light-sensitive layer (photoresist) and positioned in the image plane of the projection system, such as a silicon wafer, to transfer the mask structure to the highly sensitive coating of the substrate. Actuable optical elements can be used to improve the image of the mask on the substrate. For example, wavefront errors during exposure that lead to enlarged and / or blurred images can be compensated.

[0007] A MEMS actuator (MEMS; Microelectromechanical System) or a PMN actuator (PMN; Lead Magnesium Niobate), for example, can be used as an actuator. A PMN actuator enables distance positioning in the sub-micrometer or sub-nanometer range. When a direct current is applied, the actuator, whose actuator elements are stacked on top of one another, experiences a force that causes a specific linear expansion. The position set by the direct current (DC) voltage can be negatively influenced by external electromechanical crosstalk at the inherently resulting resonance points of the actuator controlled by the direct current. MEMS mirrors and actuators suitable for controlling them are described, for example, in DE 10 2016 213 025 A1.

[0008] Lithography systems are highly complex systems with a large number of actuators to be controlled. When controlling the actuators, the highest demands are placed on the reliability of the power supply provided by a power supply. The probability of failure in such a system is high, therefore, it is also necessary to ensure that the failure of a subcomponent does not result in the total failure of the system.

[0009] Furthermore, the installation space for the power supply unit within the lithography system is severely limited. To increase reliability, redundant interconnection of multiple power supplies is conventionally used. However, redundant interconnection of power supplies typically requires more power. The power supply power can be correlated with the required installation space. Therefore, more power supply power requires more installation space. Consequently, redundant interconnection of power supplies typically requires twice the power supply power, which in turn doubles the required installation space.

[0010] Furthermore, a short circuit in one load can cause a power supply failure for all other loads. Furthermore, a short circuit in a component or power supply in the power supply path of the power supply device can cause the entire power supply to fail.

[0011] Against this background, one object of the present invention is to improve the supply of electrical consumers of the optical system.

[0012] According to a first aspect, an optical system with a plurality of actuatable optical elements and a plurality of actuator / sensor devices for actuating and / or sensing the optical elements is proposed. The optical system comprises a supply device for providing a supply voltage for a number of electrical consumers of the optical system. The supply device comprises a parallel connection of a plurality N, with N > 3, of supply rails with a respective power supply. The respective power supply of the N supply rails is configured to provide a predetermined power supply output power at the output side of a supply node during faulty operation of the supply device and to provide the times the predetermined power supply output. With this power supply for the optical system, power supplies are intelligently interconnected redundantly, ensuring optimum reliability and space savings.

[0013] Furthermore, the interconnection of the existing parallel connection of the N plurality (with N > 3) of supply rails with a respective power supply ensures that the failure of a single power supply in the power supply path allows continued operation without restrictions. This results in increased reliability compared to a conventional power supply. Even the failure of one load is tolerated and, in particular, has no impact on the power supply of the other loads.

[0014] In the faultless operation of the supply facility, the respective supply rail - the total output power of the supply device on the output side.

[0015] The faulty operation of the supply device is characterized in that one, in particular exactly one, of the supply rails is faulty and cannot provide its predetermined power supply output power on the output side. During faulty operation of the supply device, the respective supply rail, except for the faulty supply rail, provides ^j-' times the predetermined power supply output power on the output side. If, for example, the predetermined power supply output power is 25% of the total output power of the supply device, then the -fold, in this example, 33% of the total output power of the supply. Consequently, the respective supply busbar, excluding the faulty supply busbar, provides 33% of the total output power of the supply on the output side during faulty operation of the supply. This compensates for the failure of the faulty supply busbar, and the same electrical power is provided at the load's input node both during faulty operation of the supply and during faulty operation.

[0016] The supply rail can also be referred to as a rail or a supply path. A failure of a component in part of a supply path advantageously does not result in a failure of the power supply. The current required by the consumer is in particular distributed approximately equally among the remaining supply paths. The actuator is in particular a MEMS actuator, a capacitive actuator, for example a PMN actuator (PMN; lead magnesium niobate) or a PZT actuator (PZT; lead zirconate titanate) or a LiNbO3 actuator (lithium niobium at). The actuator is in particular designed to actuate an optical element of the optical system. Examples of such an optical element include lenses, mirrors and adaptive mirrors.

[0017] The optical system is preferably a projection optics system of the lithography system or 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.

[0018] According to one embodiment, the respective power supply is designed such that it provides a maximum output power of at most 180%, preferably at most 150%, particularly preferably at most 120%, of the predetermined power supply output power. This creates an optimum in terms of reliability of the power supply and the installation space required for the power supply.

[0019] According to a further embodiment, the respective power supply is designed as a DC / DO converter or as an AC / DC converter.

[0020] According to a further embodiment, the N supply rails are coupled on the input side to an input node of the supply device for receiving an input voltage. Each supply rail has a respective fuse coupled between the power supply of the supply rail and the input node. The fuse advantageously protects the input voltage supply in the event of a fault in the supply path. The respective power supply is configured to convert the input voltage received at the input node into the supply voltage. In some embodiments, the power supply also converts the input voltage received at the input node into the supply voltage in multiple steps.

[0021] According to a further embodiment, the respective consumer is coupled to M supply rails of the N supply rails of the supply device, with M < N. The respective consumer has an input node for receiving the power supply output powers provided by the M coupled supply rails.

[0022] According to a further embodiment, a series circuit comprising an electronic fuse and a diode is connected between the respective supply node of the supply device and the input node of the load. The electronic fuse can also be referred to as an e-fuse and preferably provides the functions of overcurrent protection and / or overvoltage protection. The diode acts in particular as a current valve and allows current flow only in the direction of the load.

[0023] In the event of a short circuit in a consumer, the electronic fuse assigned to the consumer disconnects the defective consumer from the power supply. This ensures that the power supply remains uninterrupted for the remaining consumers.

[0024] According to a further embodiment, the respective consumer is coupled to all supply rails of the N supply rails of the supply device, with M = N.

[0025] According to a further embodiment, the respective consumer is coupled to a subset M of the N supply rails of the supply device, with M < N, preferably with M = 0.5*N, particularly preferably M = 2. M = 2 advantageously means the lowest effort for simple redundancy.

[0026] According to a further embodiment, an interface device is provided which is designed to couple the consumers to the M supply rails of the N supply rails of the supply device.

[0027] According to a further embodiment, the respective load is coupled, in particular connected, to a first subset of the N supply rails during faulty operation of the supply device, and coupled, in particular connected, to a second subset of the N supply rails during faulty operation of the supply device. The second subset of the N supply rails comprises exclusively those supply rails that are faultless even during faulty operation of the supply device and can thus provide their predetermined power supply output power at their supply node.

[0028] According to a further embodiment, the interface device is configured to couple, in particular connect, the respective consumer to the first subset of the N supply rails during fault-free operation of the supply device, and to couple, in particular connect, the respective consumer to the second subset of the N supply rails during faulty operation of the supply device.

[0029] According to a further embodiment, the respective load is coupled, in particular connectable, to a main supply rail of the N supply rails and to a backup supply rail of the N supply rails. If the main supply rail of a load fails, this load is supplied with electrical power via the backup supply rail.

[0030] According to a further embodiment, a respective backup supply rail of the N supply rails is assigned to the respective main supply rail of the respective consumer. The interface device is configured to connect the consumer to the assigned backup supply rail in the event of a failure of the consumer's main supply rail. The interface device thus advantageously ensures that each consumer is coupled to a functioning supply rail, either the main supply rail or, in the event of a fault, the backup supply rail, for electrical power supply.

[0031] According to one embodiment, the optical system is designed as an illumination optical system or as a projection optical system of a lithography system. The optical system comprises, in particular, a micromirror array and / or a microlens array with a plurality of independently actuatable optical elements. These are examples of the electrical loads that can be supplied with electrical energy by the present supply device.

[0032] According to a further embodiment, the optical system comprises a vacuum housing in which the actuatable optical elements, the actuator / sensor devices and the supply device are arranged.

[0033] According to a second aspect, a lithography system is proposed which has an optical system according to the first aspect or according to one of the embodiments of the first aspect.

[0034] The lithography system is, for example, an EUV lithography system whose working light lies in a wavelength range from 0.1 nm to 30 nm, or a DUV lithography system whose working light lies in a wavelength range from 30 nm to 250 nm.

[0035] "One" in this case is not necessarily limited to a single element. Rather, multiple elements, such as two, three, or more, may also be included. Any other counting term used here should not be understood as implying a limitation to the exact number of elements mentioned. Rather, numerical deviations upwards and downwards are possible, unless otherwise stated.

[0036] Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0037] 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.

[0038] Fig. 1 shows a schematic meridional section of a projection exposure system for EUV projection lithography;

[0039] Fig. 2 shows a schematic representation of an embodiment of an optical system;

[0040] Fig. 3 shows a schematic block diagram of a first embodiment of a supply device of an optical system;

[0041] Fig. 4 shows the supply device according to Fig. 3 in the event of a fault and its subsequent reaction;

[0042] Fig. 5 shows a schematic block diagram of a second embodiment of a supply device of an optical system;

[0043] Fig. 6 shows a schematic block diagram of a third embodiment of a supply device of an optical system;

[0044] Fig. 7 shows a schematic block diagram of a fourth embodiment of a supply device of an optical system; Fig. 8 shows the supply device according to Fig. 7 in the event of a fault and its subsequent reaction.

[0045] Fig. 9 shows a schematic block diagram of a fifth embodiment of a supply device of an optical system; and

[0046] Fig. 10 shows the supply device according to Fig. 9 in the event of a fault and its subsequent reaction.

[0047] In the figures, identical or functionally equivalent elements are provided with the same reference numerals unless otherwise indicated. Furthermore, it should be noted that the representations in the figures are not necessarily to scale.

[0048] Fig. 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 rest of the illumination system 2. In this case, the illumination system 2 does not include the light source 3.

[0049] 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.

[0050] For illustrative purposes, Fig. 1 shows a Cartesian coordinate system with an x-direction (x), a y-direction (y), and a z-direction (z). The x-direction (x) runs perpendicular to the drawing plane. The y-direction (y) runs horizontally, and the z-direction (z) runs vertically. The scanning direction in Fig. 1 runs along the y-direction (y). The z-direction (z) runs perpendicular to the object plane (6).

[0051] 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.

[0052] 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.

[0053] 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, plasma generated with the aid of a laser) or a DPP source (Gas Discharged Produced Plasma, plasma generated by gas discharge). 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 bundled by a collector 17.The collector 17 can be a collector with one or more ellipsoidal and / or hyperboloidal reflection surfaces. The at least one reflection surface of the collector 17 can be exposed to the illumination radiation 16 at grazing incidence (Gl), 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.

[0054] 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.

[0055] 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. Only a few of these first facets 21 are shown in Fig. 1 as examples.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.

[0056] As is known, for example, from DE 10 2008 009 600 A1, 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.

[0057] Between the collector 17 and the deflecting mirror 19, the illumination radiation 16 runs horizontally, i.e. along the y-direction y.

[0058] 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, EP 1 614 008 B1, and US Pat. No. 6,573,978.

[0059] The second facet mirror 22 comprises a plurality of second facets 23.

[0060] 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, for example, be round, rectangular, or hexagonal, or alternatively, facets composed of micromirrors. Reference is also made to DE 10 2008 009 600 A1 in this regard.

[0061] The second facets 23 can have planar or alternatively convex or concave curved reflection surfaces.

[0062] The illumination optics 4 thus form a double-faceted system. This basic principle is also known as a honeycomb condenser (EnglJ Fly's Eye Integrator).

[0063] It may be advantageous to arrange the second facet mirror 22 not 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 described, for example, in DE 10 2017 220 586 A1.

[0064] 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 before the object field 5.

[0065] 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 (Gl mirrors, grazing incidence mirrors).

[0066] In the embodiment shown in Fig. 1, the illumination optics 4 has exactly three mirrors after the collector 17, namely the deflection mirror 19, the first facet mirror 20 and the second facet mirror 22.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] In the example shown in Fig. 1, the projection optics 10 comprises six mirrors M1 to M6. Alternatives with four, eight, ten, twelve or a different number of mirrors Mi 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 and can be, 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.

[0071] 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.

[0072] The projection optics 10 can, in particular, be anamorphic. It has, in particular, different image scales ßx, ßy in the x and y directions x, y. The two image scales ßx, ßy of the projection optics 10 are preferably (ßx, ßy) = (+ / - 0.25, / +- 0.125). A positive image scale ß means an image without image inversion. A negative sign for the image scale ß means an image with image inversion.

[0073] 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.

[0074] The projection optics 10 results in a reduction of 8D in the y-direction (y), i.e., in the scanning direction. Other image scales are also possible. Image scales 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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

[0079] Illumination setting or illumination pupil filling.

[0080] 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.

[0081] 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.

[0082] The projection optics 10 can, in particular, have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

[0083] The entrance pupil of the projection optics 10 cannot usually be precisely illuminated with the second facet mirror 22. When imaging the projection optics 10, which telecentrically images the center of the second facet mirror 22 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 spacing of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugated to it in spatial space. In particular, this surface exhibits a finite curvature.

[0084] 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. In the arrangement of the components of the illumination optics 4 shown in Fig. 1, the second facet mirror 22 is arranged in a surface conjugated 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 to an arrangement plane which is defined by the second facet mirror 22.

[0085] Fig. 2 shows a schematic representation of an embodiment of an optical system 300 for a lithography system or projection exposure system 1, as shown, for example, in Fig. 1. Furthermore, the optical system 300 of Fig. 2 can also be used, for example, in a DUV lithography system.

[0086] The optical system 300 of Fig. 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 is actuatable by means of an associated actuator 200. The actuator 200 is an example of an actuator / sensor device for actuating and / or sensing the optical elements 310. 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.

[0087] The control device 100 controls the respective actuator 200, for example, with a control voltage V2. This adjusts a position of the respective micromirror 310. The control device 100 is supplied with electrical energy by a supply device 400. The supply device 400 provides the control device 100 with a supply voltage VS. The control device 100 is an example of an electrical load of the optical system 300. Examples of the supply device 400 are described with reference to FIGS. 3 to 10.

[0088] Here, Fig. 3 shows a schematic block diagram of a first embodiment of a supply device 400 of an optical system 300. The supply device 400 is configured to provide a supply voltage VS for a number of electrical consumers 500. Without limiting the generality, the number of electrical consumers 500 is equal to one in Fig. 3.

[0089] The supply device 400 comprises a parallel connection of a plurality N, with N > 3, of supply rails 410'440. Without restricting generality, N = 4 in Fig. 3. The supply rail 410-440 can also be referred to as a rail. The respective supply rail 410-440 comprises a respective power supply unit 450. The respective power supply unit 450 is configured to provide a predetermined power supply output power PI on the output side at a supply node K1-K4 during fault-free operation of the supply device 400 and to provide the -times P2 of the predetermined power supply output power.

[0090] As shown in Fig. 3, the N supply rails 410-440 are coupled on the input side to an input node K5 of the supply device 400 for receiving an input voltage VI. The respective supply rail 410-440 has a fuse 460, which is coupled between the power supply 450 of the supply rail 410-440 and the input node K5. The respective power supply 450 is configured to convert the input voltage VI received at the input node K5 into the supply voltage VS. The respective power supply 450 is designed, for example, as a DC / DC converter or as an AC / DC converter. In particular, the respective power supply 450 is designed such that it has a maximum output power of at most 180%, preferably at most 150%, particularly preferably at most 120%, of the -times P2 of the predetermined This provides optimum reliability for the power supply unit 400 and the required installation space for the power supply unit 400.

[0091] A series circuit comprising an electronic fuse 470 and a diode 480 is connected between the respective supply node K1-K4 of the supply device 400 and the input node K6 of the consumer 500.

[0092] During fault-free operation of the supply device 400, the respective supply rail 410,440 provides - of the total output power of the supply device 440 on the output side. If, for example, N = 4 and the total output power is designated as 100%, the respective supply rail 410,440 provides a quarter (25%) of the total output power. Fault-free operation of the supply device 400 is characterized in that all N supply rails 410,440 are fault-free and the respective supply rail 410,440 can provide its predetermined power supply output power PI on the output side, in particular 25% of the total output power of the supply device 400.

[0093] The faulty operation of the supply device 400 is characterized in that one, in particular exactly one, of the supply rails 410,440 is faulty and cannot provide its predetermined power supply output power PI on the output side. During faulty operation of the supply device 400, the respective supply rail 410,440, except for the faulty supply rail, provides -times P2 of the predetermined power supply output power on the output side. If, as shown above, the predetermined power supply output power is 25% of the total output power of the supply device 400 (PI = 25%), then -times P2 for this example is 33% of the total output power of the supply device 400 (P2 = 33%).In other words, the respective supply rail 410-440, except for the faulty supply rail, provides 33% of the total output power of the supply device 400 on the output side during faulty operation of the supply device 400.

[0094] This is illustrated by a comparison of Figs. 3 and 4. Fig. 3 shows the first embodiment of the supply device 400 in fault-free operation, whereas Fig. 4 shows the first embodiment of the supply device 400 in faulty operation.

[0095] As Fig. 3 shows, during fault-free operation of the supply device 400, the respective supply rail 410-440 provides the predetermined power supply output power PI on the output side at the respective supply node K1-K4, which is in particular 25% of the total output power of the supply device 400. If, as shown in Fig. 4, one of the supply rails fails, in the example of Fig. 4 the supply rail 440, this faulty supply rail 440 provides no power on the output side. The faulty supply rail 440 in Fig. 4 is marked in Fig. 4 with an arrow indicating the fault. As Fig. 4 further shows, the remaining fault-free supply rails 410, 420, 430 at the respective supply node K1-K3 provide 1 / 2 times P2 of the predetermined power supply output power, in this case 33% of the total output power of the supply device 400. This is shown in Fig. 3 and Fig.4, the identical electrical power is provided at node K6, which is the input node of load 500. In the example of Fig. 3, each of the supply rails 410-440 supplies 25% of the total output power, whereas in the example of Fig. 4, the three upper supply rails 410, 420, 430 each provide 33% of the total output power of the supply device 400 at node K6. Thus, as Fig. 4 illustrates, the failure of the faulty supply rail 440 is compensated.

[0096] Fig. 5 shows a schematic block diagram of a second embodiment of a supply device 400 of an optical system 300. The supply device 400 of Fig. 5 is based on the first embodiment of the supply device 400 of Figs. 3 and 4 and, in particular, includes all of its features. As Fig. 5 shows, the supply device 400 supplies a plurality of loads 500 with power. The number of loads 500 is purely exemplary and can be very large in embodiments, for example, several dozen or several hundred. Since Fig. 5 shows faultless operation of the supply device 400, all supply rails 410, 440 of the supply device 400 provide the predetermined power supply output power PI on the output side. Since N = 4 in Fig. 5 as well, the predetermined power supply output power PI is, in particular, 25% of the total output power of the supply device 400.The faulty operation of the supply device 400 according to Fig. 5 corresponds to that described for Figs. 3 and 4.

[0097] For reasons of clarity, no further components or devices are shown for the respective consumer 500 to the right of the input node K6, as they are not necessary for understanding the invention in this case. The respective electronic fuse 470 and the respective diode 480 are assigned to the respective consumer 500 in this case. Since the structure of the respective consumer 500 in Fig. 5 in the direction of the supply device 400 is identical to the components 470 and 480, only the lowest consumer 500 in Fig. 5 is provided with the respective reference numerals.

[0098] In general, the respective load 500 is coupled to M supply rails 410-440 of the N supply rails 410-440 of the supply device 400, with M < N. As illustrated in Fig. 5, an interface device 490 may be provided. The interface device 490 is configured to couple the loads 500 to the M supply rails 410-440 of the N supply rails 410-440 of the supply device 400.

[0099] The respective load 500 has an input node K6 for receiving the power supply output power PI provided by the M coupled supply rails 410-440. In the embodiment according to Fig. 5, M = N, so that the respective load 500 is coupled to all supply rails 410-440 of the supply device 400.

[0100] A different coupling between loads 500 and the supply device 400 is shown in Fig. 6. In Fig. 6, six loads 500 are supplied with electrical power by the supply device 400. The respective load 500 of Fig. 6 is coupled to a subset M of the N supply rails 410, 440 of the supply device 400. In the embodiment of Fig. 6, N = 4 and M = 2. Thus, M = 0.5 * N in Fig. 6.

[0101] Regarding the selection of the number of consumers 500 which are supplied with electrical power by the supply device 400, the following rule can preferably be applied: where N denotes the number of supply rails of the supply device 400 and M denotes the number of supply rails to which the respective consumer 500 is coupled. For the present example in Fig. 6 with N = 4 and M = 2, applying the above rule for an optimized selection of the number of consumers 500 results in the following:

[0102] According to this rule and as shown above, the supply device 400 of Fig. 6 supplies six consumers 500.

[0103] In detail, the first consumer 500 (from the top) of Fig. 6 is supplied via the supply rails 410 and 420, the second consumer 500 is supplied via the supply rails 410 and 430, the third consumer 500 is supplied via the supply rails 420 and 430, the fourth consumer 500 is supplied via the supply rails 410 and 440, the fifth consumer 500 is supplied via the supply rails 420 and 440 and the sixth consumer 500 is supplied via the supply rails 430 and 440.

[0104] Fig. 7 shows a schematic block diagram of a fourth embodiment of a supply device 400 of an optical system 300, and Fig. 8 shows the supply device 400 according to Fig. 7 in the event of a fault and its subsequent reaction.

[0105] In Fig. 7 and Fig. 8, the supply rails 410'440 of the supply device 400 are shown only schematically by their reference numerals 410'440 and the supply nodes K1-K4. In detail, the supply device 400 is constructed as in the aforementioned embodiments.

[0106] As Fig. 7 further shows, the supply device 400 of Fig. 7 supplies six loads L1-L6, wherein the respective load L1-L6 is coupled to two supply rails (M = 2) of the N supply rails 410-440 (N = 4). Load L1 is supplied via supply rails 410 and 420, load L2 is supplied via supply rails 410 and 430, load L3 is supplied via supply rails 420 and 430, load L4 is supplied via supply rails 410 and 440, load L5 is supplied via supply rails 420 and 440, and load L6 is supplied via supply rails 430 and 440.

[0107] If, as shown above, the total output power of the supply device is 100%, then in fault-free operation each of the supply devices 410,440 provides 25% of the total output power of the supply device 400. If, as illustrated in Fig. 7, 25% of the total output power is provided at the respective supply node K1-Kd and three of the loads L1-L6 are connected to the respective supply node K1-K4, then the respective load draws one-third of the 25% of the total output power of the supply device 400 provided at the supply node K1-K4 and thus 8.33% (rounded) of the total output power of the supply device 400 (25% × 3 = 8.33%). The supply of the respective loads L1-L6 by the fault-free supply rails 410,440 according to Fig. 7 is summarized in Table 1 below.

[0108] Table 1

[0109] If, as shown in Fig. 8, supply bus 440 fails, it cannot provide electrical power to the connected loads L4, L5, and L6. This is then taken over by the faultless supply busses 410, 430, as shown in Fig. 8. Thus, in Fig. 8, load L4 is supplied exclusively via supply bus 410, load L5 is supplied exclusively via supply bus 420, and load L6 is supplied exclusively via supply bus 430. The supply of the respective loads L1-L6 by the faultless supply busses 410, 430 according to Fig. 8 is shown in Table 2 below.

[0110] Table 2

[0111] Table 2 also shows that the faultless supply rails 410, 420 and

[0112] 430 together provide the total output power of the utility 400 (33.33% + 33.33% + 33.33% = 100%).

[0113] Fig. 9 shows a schematic block diagram of a fifth embodiment of a supply device 400 of an optical system 300, and Fig. 10 shows the supply device 400 according to Fig. 9 in the event of a fault and its subsequent reaction. In Fig. 9 and Fig. 10, the supply rails 410'440 of the supply device 400 are only shown schematically via their reference numerals 410'440 and the supply nodes K1-K4. In detail, the supply device 400 is constructed as in the aforementioned exemplary embodiments. Furthermore, Fig. 9 shows in particular that the respective load L1-L12 is coupled to a main supply rail of the N supply rails 410'440 and to a backup supply rail of the N supply rails 410-440. Table 3 below shows the coupling of the respective load L1-L12 to its respective main supply rail and its respective backup supply rail.

[0114] Table 3

[0115] As shown in Table 3 above, consumer LI has supply busbar 410 as its main supply busbar and supply busbar 420 as its backup supply busbar. Consumer L2 has supply busbar 410 as its main supply busbar and supply busbar 430 as its backup supply busbar. The further assignments for consumers L3-L12 are derived analogously from Table 3 above.

[0116] Thus, Table 3 above also shows that a respective backup supply rail is assigned to the respective main supply rail of the respective load L1-L12. The interface device (not shown in Fig. 9 and Fig. 10) is configured to connect the load L1-L12 to the assigned backup supply rail in the event of a failure of the main supply rail of the load L1-L12.

[0117] For the present example, it is assumed that supply bus 440 (see Fig. 10) has failed. During fault-free operation of supply device 400, supply bus 440 supplied loads L10, L11, and L12. Since this is no longer possible after the failure of supply bus 440, as shown in Fig. 10, load L10 is supplied via backup supply bus 410, load L11 is supplied via backup supply bus 420, and load L12 is supplied via backup supply bus 430.

[0118] Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

[0119] LIST OF REFERENCE SYMBOLS

[0120] 1 projection exposure system

[0121] 2 lighting system

[0122] 3 Light source

[0123] 4 Lighting optics

[0124] 5 Object field

[0125] 6 Object level

[0126] 7 reticles

[0127] 8 reticle holders

[0128] 9 Reticle displacement drive

[0129] 10 Projection optics

[0130] 11 Image field

[0131] 12 Image plane

[0132] 13 wafers

[0133] 14 wafer holders

[0134] 15 Wafer relocation drive

[0135] 16 Illumination radiation

[0136] 17 Collector

[0137] 18 Intermediate focal plane

[0138] 19 Deflecting mirrors

[0139] 20 first facet mirror

[0140] 21 first facet

[0141] 22 second facet mirror

[0142] 23 second facet

[0143] 100 control device

[0144] 200 actuator

[0145] 300 optical system

[0146] 310 optical element 400 supply device

[0147] 410 supply rail (Rail)

[0148] 420 supply rail (Rail)

[0149] 430 supply rail (Rail)

[0150] 440 supply rail (Rail)

[0151] 450 power supply

[0152] 460 Fuse

[0153] 470 electronic fuse

[0154] 480 diode

[0155] 490 Interface device

[0156] 500 consumers

[0157] Small supply node

[0158] K2 supply node

[0159] K3 supply node

[0160] K4 supply node

[0161] K5 Input node of the utility facility

[0162] K6 Input node of the consumer

[0163] LI Consumer

[0164] L2 consumer

[0165] L3 Consumer

[0166] L4 Consumer

[0167] L5 Consumer

[0168] L6 Consumer

[0169] L7 Consumer

[0170] L8 Consumer

[0171] L9 Consumer

[0172] L10 Consumer

[0173] Lil Consumer

[0174] L12 Consumer Ml Mirror

[0175] M2 mirror

[0176] M3 mirror

[0177] M4 mirror M5 mirror

[0178] M6 mirror

[0179] Pl predetermined power supply output power

[0180] P2 ^j--times the predetermined power supply output power

[0181] VS supply voltage VI input voltage

[0182] V2 control voltage

Claims

PATENT CLAIMS 1. An optical system (300) having a plurality of actuatable optical elements (310) and a plurality of actuator / sensor devices (200) for actuating and / or sensing the optical elements (310), which comprises a supply device (400) for providing a supply voltage (VS) for a number of electrical consumers (500, L1-L12) of the optical system (300), which supply device comprises a parallel connection of a plurality N, with N > 3, of supply rails (410, 440) with a respective power supply unit (450), wherein the respective power supply unit (450) of the N supply rails (410-440) is configured to provide a predetermined power supply output power (P1) on the output side at a supply node (K1-K4) during faulty operation of the supply device (400) and to provide üü-fold (P2) at the supply node (K1-K4) during faulty operation. to provide the predetermined power supply output power.

2. Optical system according to claim 1, wherein the respective power supply (450) is designed such that it provides as maximum output power at most 180%, preferably at most 150%, particularly preferably at most 120%, of üü times (P2) of the predetermined power supply output power.

3. Optical system according to claim 1 or 2, wherein the respective power supply (450) is designed as a DC / DC converter or as an AC / DC converter.

4. Optical system according to one of claims 1 to 3, wherein the N supply rails (410'440) are coupled on the input side to an input node (K5) of the supply device (400) for receiving an input voltage (Vl), wherein the respective supply rail (410-440) a respective fuse (460) which is coupled between the power supply (450) of the supply rail (410'440) and the input node (K5), wherein the respective power supply (450) is configured to convert the input voltage (Vl) received at the input node (K5) into the supply voltage (VS).

5. Optical system according to one of claims 1 to 4, wherein the respective consumer (500, L1-L12) is coupled to M supply rails (410-440) of the N supply rails (410'440) of the supply device (400), with M < N, wherein the respective consumer (500, L1-L12) has an input node (K6) for receiving the power supply output powers (P1, P2) provided by the M coupled supply rails (410'440).

6. Optical system according to claim 5, wherein a series circuit comprising an electronic fuse (470) and a diode (480) is connected between the respective supply node (K1-K4) of the supply device (400) and the input node (K6) of the consumer (500, L1-L12).

7. Optical system according to claim 5 or 6, wherein the respective consumer (500, L1-L12) is coupled to all supply rails (410'440) of the N supply rails (410'440) of the supply device (400), with M = N.

8. Optical system according to claim 5 or 6, wherein the respective consumer (500, L1-L12) is coupled to a subset M of the N supply rails (410'440) of the supply device (400), with M < N, preferably with M = 0.5*N, particularly preferably M = 2.

9. Optical system according to one of claims 5 to 8, wherein an interface device (490) is provided which is configured to couple the consumers (500, L1-L12) to the M supply rails (410-440) of the N supply rails (410'440) of the supply device (400).

10. Optical system according to one of claims 1 to 9, wherein the respective consumer (500, L1-L12) is coupled, in particular connected, to a first subset of the N supply rails (410-440) during faulty operation of the supply device (400), and is coupled, in particular connected, to a second subset of the N supply rails (410-440) during faulty operation of the supply device (400).

11. Optical system according to claim 10, wherein the interface device (490) is configured to couple, in particular to connect, the respective consumer (500, L1-L12) to the first subset of the N supply rails (410-440) during faultless operation of the supply device (400), and to couple, in particular to connect, the respective consumer (500, L1-L12) to the second subset of the N supply rails (410'440) during faulty operation of the supply device (400).

12. Optical system according to one of claims 1 to 11, wherein the respective consumer (500, L1-L12) is coupled, in particular connectable, to a main supply rail of the N supply rails (410'440) and to a backup supply rail of the N supply rails (410-440).

13. Optical system according to claim 12, wherein the respective main supply rail of the respective consumer (500, L1-L12) is assigned a respective backup supply rail of the N supply rails (410'440), wherein the interface device (490) is arranged to is configured to connect the load (500, L1-L12) to the associated backup supply rail in the event of a failure of the main supply rail of the load (500, L1-L12).

14. Optical system according to one of claims 1 to 13, wherein the optical system (300) is designed as an illumination optics (4) or as a projection optics (10) of a lithography system (1).

15. Lithography system (1) with an optical system (300) according to one of claims 1 to 14.

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