Facet system and lithographic apparatus

Abstract

A facet system (300A, 300B, 300C) for a lithographic apparatus (100A, 100B), comprising a facet element (304) having an optically active surface (306), a first piezo actuator device (364) for tilting the facet element (304) about an axis in a first spatial direction (x), and a second piezo actuator device (366) for tilting the facet element (304) about an axis in a second spatial direction (y) oriented perpendicular to the first spatial direction (x), wherein the first piezo actuator device (364) and the second piezo actuator device (366) are arranged in a common plane (E) subtended by the first spatial direction (x) and the second spatial direction (y).

Description

[Technical Field]

[0001] The present invention relates to a faceting system for a lithographic apparatus and to a lithographic apparatus comprising such a faceting system.

[0002] The content of the earlier German patent application No. 10 2021 202 768.7 is incorporated by reference in its entirety. [Background technology]

[0003] Microlithography is used in the manufacture of finely structured components, such as integrated circuits. The microlithography process is carried out using a lithography apparatus having an illumination system and a projection system, in which an image of a mask (reticle), illuminated by the illumination system, is projected by the projection system onto a substrate, e.g., a silicon wafer, that is coated with a photosensitive layer (photoresist) and positioned in the image plane of the projection system, in order to transfer the mask structure into the photosensitive coating on the substrate.

[0004] Due to the desire for further miniaturization of structures in the manufacture of integrated circuits, EUV lithography systems (extreme ultraviolet, EUV) using light with wavelengths in the range of 0.1 nm to 30 nm, particularly 13.5 nm, are currently under development. Since most materials exhibit high absorption of light at this wavelength, in such EUV lithography systems, reflective optical units, i.e., mirrors, must be used instead of the previous refractive optical units, i.e., lens elements. The mirrors operate at near-normal incidence or at oblique incidence.

[0005] The illumination system comprises, inter alia, a field facet mirror and a pupil facet mirror. The field facet mirror and the pupil facet mirror may be in the form of so-called facet mirrors, which often have several hundred facets each. The facets of the field facet mirror are also called "field facets", and the facets of the pupil facet mirror are also called "pupil facets". Several pupil facets can be assigned to one field facet. In order to obtain good illumination in conjunction with a high numerical aperture, it is desirable to switch said one field facet between the pupil facets assigned to it. Summary of the Invention [Problem to be solved by the invention]

[0006] Against this background, the object of the present invention is to propose an improved field facet system. [Means for solving the problem]

[0007] Therefore, a field facet system for a lithographic apparatus is proposed, which comprises a facet element having an optically active surface, a first piezo actuator device for tilting the facet element about an axis in a first spatial direction, and a second piezo actuator device for tilting the facet element about an axis in a second spatial direction oriented perpendicular to the first spatial direction, wherein the first piezo actuator device and the second piezo actuator device are arranged in a common plane subtended by the first and second spatial directions.

[0008] As a result of the provision of the first and second piezo actuator devices, the facet element can be tilted about both the first and second spatial directions. By appropriately actuating the first and second piezo actuator devices, a combined tilt about the first and second spatial directions can be obtained, which allows the facet element to be switched into any number of different tilt positions.

[0009] The facet system may comprise a field facet system or a pupil facet system. The facet system may also be part of a specular reflector. The facet elements may be field facet elements or pupil facet elements. The facet system is in particular part of a beam shaping and illumination system of a lithographic apparatus. In particular, the facet system is part of a facet mirror, in particular a field facet mirror. Such a facet mirror preferably comprises a plurality of such facet systems arranged in the form of a grid or pattern. That is to say, the facet systems are preferably arranged above, below, to the left and to the right of each other in a matrix. Such a field facet mirror may comprise any number of facet systems. For example, a field facet mirror may comprise hundreds of thousands of facet systems. Each facet element can be independently tilted to a plurality of different tilt positions.

[0010] A coordinate system having a first spatial direction or x-direction, a second spatial direction or y-direction, and a third spatial direction or z-direction is assigned to the facet system. The spatial directions are positioned perpendicular to each other. The third spatial direction can be oriented perpendicular to the optically effective surface. The first spatial direction and the second spatial direction can be oriented parallel to the optically effective surface.

[0011] The facet elements are manufactured from a mirror substrate or substrate. The substrate may in particular comprise silicon. The optically effective surface is provided on the front side of the facet elements, i.e. on the side opposite the piezo actuator device. The optically effective surface reflects light. The optically effective surface may be a mirror surface. The optically effective surface may be produced using a coating applied to the facet elements. In particular, the facet elements themselves are opaque to light. The optically effective surface is suitable for reflecting the used light or light, in particular EUV radiation. However, this does not prevent heat from being introduced into the facet elements as a result of at least part of the light being absorbed by the facet elements.

[0012] In particular, the first piezo actuator device serves to tilt the facet element about an axis in a first spatial direction, which is preferably oriented parallel to the optically effective surface. Accordingly, the second piezo actuator device serves to tilt the facet element about an axis in a second spatial direction, which is preferably oriented parallel to the optically effective surface and perpendicular to the first spatial direction. The optically effective surface is preferably planar. However, the optically effective surface can also be curved. By way of example, the optically effective surface can be cylindrical or toroidal.

[0013] Piezoelectric actuator devices can also be referred to as piezoelectric element devices or piezoelectric actuation element devices. In this case, "piezoelectric actuator" or "piezoelectric element" should be understood to mean a component that utilizes the so-called piezoelectric effect to perform mechanical movement as a result of the application of a voltage. The terms "piezoelectric actuator" and "piezoelectric element" can be interchangeable as desired. Each piezoelectric actuator device can include multiple piezo actuators. Preferably, two piezo actuators are assigned to each piezoelectric actuator device. Piezoelectric actuators can be or be referred to as so-called bending transducers.

[0014] In plan view, i.e. in a viewing direction perpendicular to the optically effective surface, the facet elements completely conceal both the first and the second piezoelectric actuator devices, i.e. light entering the facet system preferably only enters the optically effective surface and not further components of the facet system, such as the piezoelectric actuator devices, as a result of which a high degree of filling of the facet elements or the optically effective surface can be achieved.

[0015] In particular, the first piezo actuator device is suitable for pivoting or tilting the facet element only about an axis in a first spatial direction or an axis oriented parallel to the first spatial direction, and the second piezo actuator device is accordingly suitable for tilting the facet element only about an axis in a second spatial direction or an axis oriented parallel to the second spatial direction. Using the first and second piezo actuator devices, any number of tilted states or positions of the facet element can be set.

[0016] Preferably, the facet system comprises a control unit suitable for actuating the piezo actuator devices or the piezo actuators assigned to the piezo actuator devices. For actuation, a voltage is applied to each piezo actuator. By applying a voltage, each piezo actuator is deformed in order to tilt the facet element. In this case, each piezo actuator can be changed from a non-deformed or non-flexed state to a deformed or flexed state. Any number of intermediate states can be provided between the non-flexed state and the flexed state. That is, the piezo actuator can be continuously deformed or flexed between the non-flexed state and the flexed state.

[0017] According to one embodiment, the first piezo actuator device and / or the second piezo actuator device is configured to effect a stroke movement of the facet element in a third spatial direction oriented perpendicular to the optically active surface.

[0018] This provides an additional degree of freedom. The facet element thus has at least three degrees of freedom, specifically a rotational degree of freedom about an axis in the first spatial direction, a rotational degree of freedom about an axis in the second spatial direction, and a translational degree of freedom in a third spatial direction. To cause the facet element to perform a stroke movement, the piezo actuators assigned to each piezo actuator device are simultaneously activated and deflected to the same extent to produce a stroke movement in the third spatial direction. A combined stroke-tilt movement of the facet element can also be performed. If the optically effective surface is curved, the third spatial direction can be, for example, perpendicular to the vertex of the optically effective surface.

[0019] The first piezo actuator device and the second piezo actuator device are arranged in a common plane spanned by the first spatial direction and the second spatial direction.

[0020] The common plane can also be arranged parallel to the plane subtended by the first spatial direction and the second spatial direction. For example, the lower or upper surfaces of the piezo actuators of the piezo actuator device are all arranged in a common plane. As soon as one of the piezo actuators is actuated or an electric current is applied, said piezo actuator deforms out of the common plane, resulting in a tilt of the facet element.

[0021] According to yet another embodiment, the first piezo actuator device comprises at least two piezo actuators configured to selectively tilt the facet element about the first spatial direction in two opposing tilting movements.

[0022] The tilting movement may also be referred to as a tilting direction. By way of example, the tilting movement may be clockwise and counterclockwise around the first spatial direction. By way of example, the first tilting movement is counterclockwise and the second tilting movement is clockwise. By way of example, the facet element may be tilted at a tilt angle of, for example, 100 mrad. If both piezo actuators of the first piezo actuator device are activated simultaneously and deflected to the same extent, the facet element will perform the stroke movement described above. As mentioned above, a combination of tilting and stroking movements may also be performed.

[0023] According to yet another embodiment, the second piezo actuator device comprises at least two piezo actuators configured to selectively tilt the facet element about the second spatial direction with two opposing tilting movements.

[0024] The tilting motions may be clockwise and counterclockwise around the second spatial direction. For example, a third tilting motion may be clockwise and a fourth tilting motion may be counterclockwise. The first and second tilting motions are oriented perpendicular to the third and fourth tilting motions. As mentioned above, the tilting motions may also be referred to as tilt directions.

[0025] According to yet another embodiment, the piezo actuator of the first piezo actuator device and the piezo actuator of the second piezo actuator device are arranged side by side.

[0026] In particular, this means that all piezo actuators are arranged one behind the other. Preferably, the piezo actuators of the first piezo actuator device and the piezo actuators of the second piezo actuator device are of identical construction. In particular, piezo actuators are known as piezoelectric bending transducers, which change their curvature but not their length when an electric current is applied to them.

[0027] According to yet another embodiment, the piezo actuators of the first piezo actuator device and the piezo actuators of the second piezo actuator device are arranged alternately.

[0028] In particular, this means that a piezo actuator of the first piezo actuator device is respectively arranged between two piezo actuators of the second piezo actuator device, and vice versa. Preferably, a first piezo actuator, a second piezo actuator, a third piezo actuator and a fourth piezo actuator are provided, the second piezo actuator being arranged between the first and third piezo actuators. In particular, the third piezo actuator being arranged between the second and fourth piezo actuators.

[0029] According to yet another embodiment, the piezo actuators of the first piezo actuator device are arranged parallel to and spaced apart from one another, and the piezo actuators of the second piezo actuator device are likewise arranged parallel to and spaced apart from one another.

[0030] In particular, the piezo actuators of the first piezo actuator device are arranged spaced apart and parallel to one another when viewed in the second spatial direction. Accordingly, the piezo actuators of the second piezo actuator device are arranged parallel and spaced apart from one another when viewed in the first spatial direction. In particular, the piezo actuators are in the form of elongated rod- or strip-shaped components. The piezo actuators have their greatest geometric extent along their main direction of extension or longitudinal direction. The piezo actuators of the first piezo actuator device are in particular arranged such that their main direction of extension extends in the first spatial direction. Accordingly, the piezo actuators of the second piezo actuator device are arranged such that their main direction of extension extends in the second spatial direction.

[0031] According to yet another embodiment, the piezo actuators of the first piezo actuator device and the piezo actuators of the second piezo actuator device are arranged at right angles to each other.

[0032] This therefore results in a helical or spiral arrangement of the piezo actuators. In particular, as mentioned above, a first piezo actuator, a second piezo actuator, a third piezo actuator, and a fourth piezo actuator are provided. In this case, the second piezo actuator is arranged perpendicular to the first piezo actuator. Furthermore, the third piezo actuator is arranged perpendicular to the second piezo actuator. The fourth piezo actuator is arranged perpendicular to the third piezo actuator. The first piezo actuator and the third piezo actuator are assigned to the first piezo actuator device. Therefore, the second piezo actuator and the fourth piezo actuator are assigned to the second piezo actuator device. In this case, "perpendicularly" should be understood to mean that the main extension directions of the piezo actuators are perpendicular to each other. In this case, "perpendicularly" is further understood to mean an angle of 90°±10°, preferably 90°±5°, more preferably 90°±1°, more preferably exactly 90°.

[0033] According to yet another embodiment, the facet system further comprises a first piezo actuator, a second piezo actuator, a third piezo actuator, and a fourth piezo actuator, wherein the first piezo actuator and the third piezo actuator are assigned to a first piezo actuator device, and the second piezo actuator and the fourth piezo actuator are assigned to a second piezo actuator device.

[0034] That is, the first piezo actuator device includes a first piezo actuator and a third piezo actuator. Accordingly, the second piezo actuator device includes a second piezo actuator and a fourth piezo actuator. The number of piezo actuators can be any number. However, in particular, exactly four piezo actuators are provided.

[0035] According to yet another embodiment, the facet system further comprises a substrate, and only the first piezo actuator is connected to the substrate.

[0036] The substrate may also be referred to as the body of the facet system. The substrate preferably consists of silicon. However, the substrate may also comprise copper, in particular a copper alloy, an iron-nickel alloy such as Invar, silicon, or any other suitable material. In this case, "only" the first piezo actuator is connected to the substrate, which means that the second to fourth piezo actuators are not fixedly connected to the substrate. In particular, gaps may be provided between the second to fourth piezo actuators and the substrate, respectively. The piezo actuator device is arranged between the substrate and the facet element.

[0037] According to yet another embodiment, the first piezo actuator is connected only to the substrate and the second piezo actuator, the second piezo actuator is connected only to the first piezo actuator and the third piezo actuator, the third piezo actuator is connected only to the second piezo actuator and the fourth piezo actuator, and the fourth piezo actuator is connected only to the third piezo actuator and the facet element.

[0038] Preferably, a rod-shaped connection part with a connection part is provided on the fourth piezo actuator, to which the facet element is fixed. By way of example, the facet element can be materially connected to the connection part. In a material connection, the connection partners are held together by atomic or molecular forces. A material connection is an irreleasable connection that can only be separated by destruction of the connection means and / or the connection partners. The material connection can be implemented, for example, by gluing or soldering. By way of example, the facet element can be connected to the connection part using any joining method.

[0039] According to yet another embodiment, the facet elements are square in plan view.

[0040] In this case, "plan view" should be understood to mean a viewing direction perpendicular to the optically active surface. However, the facet elements may have any other desired geometric shape in plan view. By way of example, the facet elements are elongated rectangular, circular, hexagonal, or elongated and curved in an arc.

[0041] According to yet another embodiment, the facet system is an integral component.

[0042] In this case, "integral" or "one piece" is understood to mean that the facet system does not consist of several separable components but forms a common or integral component. By way of example, the facet system can be realized by microelectromechanical manufacturing methods (microelectromechanical systems, MEMS). In this case, a three-dimensional microstructure composed of several base layers is realized using different coating methods, microstructuring and etching techniques, and bonding methods. By way of example, the microstructure can consist of silicon. By way of example, the piezo actuator can be based on a piezoelectric ceramic such as lead zirconate titanate (PZT).

[0043] According to yet another embodiment, a sensor is integrated into the facet system.

[0044] The sensors may include any number of sensors, particularly capacitive sensors.

[0045] Furthermore, a lithographic apparatus is proposed which comprises the facet system described above.

[0046] A lithography apparatus may comprise a plurality of the facet systems described above. The lithography apparatus may be an EUV lithography apparatus or a DUV lithography apparatus. EUV stands for "extreme ultraviolet" and refers to a wavelength of light used between 0.1 nm and 30 nm. DUV stands for "deep ultraviolet" and refers to a wavelength of light used between 30 nm and 250 nm.

[0047] In this case, "a (an)" should not necessarily be understood as limiting to exactly one element. Rather, there can be a plurality of elements, e.g., two, three, or more. Any other numbers used herein should not be understood as limiting to a precise number of elements. Rather, the number can be increased or decreased unless otherwise indicated.

[0048] The embodiments and features described with respect to the facet system also apply to the proposed lithographic apparatus as appropriate and vice versa.

[0049] Further possible implementations of the invention also include unstated combinations of the features or embodiments described above or below with respect to the exemplary embodiments, in which case a person skilled in the art may add individual aspects as improvements or supplements to each basic form of the invention.

[0050] Further advantageous configurations and aspects of the invention are the subject of the dependent claims and also of the exemplary embodiments of the invention that will be described below. The invention will be explained in more detail below on the basis of preferred embodiments and with reference to the attached drawings. [Brief explanation of the drawings]

[0051] [Figure 1A] 1 shows a schematic diagram of an embodiment of an EUV lithography apparatus; [Figure 1B] 1 shows a schematic diagram of an embodiment of a DUV lithography apparatus; [Figure 2] 1C shows a schematic diagram of an embodiment of an optical system of the lithographic apparatus shown in FIG. 1A or FIG. 1B. [Figure 3] 1C shows a schematic diagram of yet another embodiment of the optical device of the lithographic apparatus shown in FIG. 1A or FIG. 1B. [Figure 4] 3 shows a schematic plan view of an embodiment of a field facet mirror of the optical arrangement shown in FIG. 2; [Figure 5] Detail V of FIG. 4 is shown. [Figure 6] 3 shows yet another schematic diagram of the optical device shown in FIG. 2. [Figure 7] 4 shows a schematic plan view of an embodiment of the optical system of the optical device shown in FIG. 2 and the optical device shown in FIG. 3. [Figure 8] 8 shows a schematic cross-sectional view of the optical system taken along the cross-sectional line IIX-IIX in FIG. 7. [Figure 9] 9 shows a schematic cross-sectional view of the optical system taken along the cross-sectional line IX-IX in FIG. 7. [Figure 10] 8 shows a schematic cross-sectional view of an embodiment of a piezo actuator of the optical system shown in FIG. 7. [Figure 11] 4 shows a schematic perspective view of yet another embodiment of the optical system of the optical device shown in FIG. 2 and the optical device shown in FIG. 3. [Figure 12] 12 shows yet another schematic perspective view of the optical system shown in FIG. 11. [Figure 13] 4 shows a schematic perspective view of yet another embodiment of the optical system of the optical device shown in FIG. 2 and the optical device shown in FIG. 3. [Figure 14] 14 shows yet another schematic perspective view of the optical system shown in FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0052] Unless otherwise indicated, identical or functionally identical elements are provided with the same reference numerals throughout the figures. It should also be noted that the illustrations are not necessarily to scale.

[0053] FIG. 1A shows a schematic diagram of an EUV lithography apparatus 100A equipped with a beam shaping and illumination system 102 and a projection system 104. In this case, EUV stands for "extreme ultraviolet" and refers to the wavelength of light used, which is between 0.1 nm and 30 nm. The beam shaping and illumination system 102 and the projection system 104 are each provided in a vacuum housing (not shown), and each vacuum housing is evacuated using an exhaust device (not shown). The vacuum housing is surrounded by a machine room (not shown) in which drive devices that mechanically move or set optical elements are provided. Furthermore, an electrical controller and the like may also be provided in the machine room.

[0054] The EUV lithography apparatus 100A includes an EUV light source 106A. The EUV light source 106A can be, for example, a plasma source (or a synchrotron) that emits radiation 108A in the EUV range (extreme ultraviolet), i.e., in a wavelength range of, for example, 5 nm to 20 nm. In the beam shaping and illumination system 102, the EUV radiation 108A is focused and a desired operating wavelength is filtered from the EUV radiation 108A. The EUV radiation 108A generated by the EUV light source 106A has a relatively low transmittance in air, and for this reason, the light-conducting spaces of the beam shaping and illumination system 102 and the projection system 104 are evacuated.

[0055] 1A includes five mirrors 110, 112, 114, 116, and 118. After passing through beam shaping and illumination system 102, EUV radiation 108A is directed to photomask (also called reticle) 120. Photomask 120 may also be embodied as a reflective optical element and may be located external to systems 102, 104. Furthermore, EUV radiation 108A may be directed to photomask 120 by mirror 122. Photomask 120 has a structure that is imaged by projection system 104 at a reduced size, such as onto wafer 124.

[0056] The projection system 104 (also referred to as a projection lens) has six mirrors M1-M6 for imaging the photomask 120 onto the wafer 124. In this case, the individual mirrors M1-M6 of the projection system 104 may be arranged symmetrically about the optical axis 126 of the projection system 104. It should be noted that the number of mirrors M1-M6 in the EUV lithography apparatus 100A is not limited to the number shown. More or fewer mirrors M1-M6 may be provided. Furthermore, the mirrors M1-M6 generally have curved front surfaces for beam shaping.

[0057] 1B shows a schematic diagram of a DUV lithography apparatus 100B comprising a beam shaping and illumination system 102 and a projection system 104. In this case, DUV stands for "deep ultraviolet" and refers to the wavelength of the light used, which is between 30 nm and 250 nm. As already described with reference to FIG. 1A, the beam shaping and illumination system 102 and the projection system 104 may be enclosed by a machine room with corresponding drive devices.

[0058] The DUV lithography apparatus 100B comprises a DUV light source 106B, which may be, for example, an ArF excimer laser emitting radiation 108B in the DUV range, for example at 193 nm.

[0059] 1B, beam shaping and illumination system 102 directs DUV radiation 108B to photomask 120. Photomask 120 may be formed as a transmissive optical element and may be located external to systems 102, 104. Photomask 120 has structures that are imaged by projection system 104 at a reduced size, such as onto wafer 124.

[0060] The projection system 104 has a plurality of lens elements 128 and / or mirrors 130 for imaging the photomask 120 onto the wafer 124. In this case, the individual lens elements 128 and / or mirrors 130 of the projection system 104 may be arranged symmetrically with respect to the optical axis 126 of the projection system 104. It should be noted that the number of lens elements 128 and mirrors 130 in the DUV lithography apparatus 100B is not limited to the number shown. More or fewer lens elements 128 and / or mirrors 130 may be provided. Furthermore, the mirrors 130 generally have curved front surfaces for beam shaping.

[0061] The gap between the final lens element 128 and the wafer 124 can be replaced with a liquid medium 132 having a refractive index greater than 1. The liquid medium 132 can be, for example, high-purity water. This configuration is also referred to as immersion lithography and has high photolithographic resolution. The medium 132 can also be referred to as an immersion liquid.

[0062] 2 shows a schematic diagram of one embodiment of an optical apparatus 200. The optical apparatus 200 is a beam shaping and illumination system 102, particularly a beam shaping and illumination system 102 of an EUV lithography apparatus 100A. Thus, the optical apparatus 200 can also be referred to as a beam shaping and illumination system, and the beam shaping and illumination system 102 can be referred to as an optical apparatus. The optical apparatus 200 can be located upstream of the projection system 104 as described above.

[0063] However, optical apparatus 200 can also be part of DUV lithography apparatus 100B. However, in the following, it will be assumed that optical apparatus 200 is part of EUV lithography apparatus 100A. In addition to optical apparatus 200, Figure 2 also shows an EUV light source 106A, as previously described, emitting EUV radiation 108A, and a photomask 120. EUV light source 106A can be part of optical apparatus 200.

[0064] Optical device 200 includes a plurality of mirrors 202, 204, 206, and 208. Additionally, an optional deflecting mirror 210 may be provided. Deflecting mirror 210 operates at grazing incidence and may also be referred to as a grazing incidence mirror. Deflecting mirror 210 may correspond to mirror 122 shown in FIG. 1A. Mirrors 202, 204, 206, and 208 may correspond to mirrors 110, 112, 114, 116, and 118 shown in FIG. 1A. In particular, mirror 202 corresponds to mirror 110, and mirror 204 corresponds to mirror 112.

[0065] Mirror 202 is a so-called facet mirror, in particular a field facet mirror, of optical device 200. Mirror 204 is also a facet mirror, in particular a pupil facet mirror, of optical device 200. Mirror 202 reflects EUV radiation 108A to mirror 204. At least one of mirrors 206, 208 can be a condenser mirror of optical device 200. The number of mirrors 202, 204, 206, 208 can be any number. By way of example, it is possible to provide five mirrors 202, 204, 206, 208, i.e., mirrors 110, 112, 114, 116, 118, as shown in FIG. 1A, or four mirrors 202, 204, 206, 208, as shown in FIG. 2. However, preferably, at least three mirrors 202, 204, 206, 208 are provided, i.e., a field facet mirror, a pupil facet mirror, and a condenser mirror.

[0066] The mirrors 202, 204, 206, 208 are disposed within a housing 212. The housing 212 can be evacuated during operation of the optical apparatus 200, particularly during exposure operations, i.e., the mirrors 202, 204, 206, 208 are disposed in a vacuum.

[0067] During operation of the optical arrangement 200, the EUV light source 106A emits EUV radiation 108A. By way of example, a tin plasma can be generated for this purpose. To generate the tin plasma, a laser pulse can be impinged on a tin body, such as a tin bead or tin droplet. The tin plasma emits EUV radiation 108, which is collected using a collector, such as an ellipsoidal mirror, of the EUV light source 106A and directed toward the optical arrangement 200. The collector focuses the EUV radiation 108A to an intermediate focus 214, which can also be referred to as an intermediate focal plane or is within the intermediate focal plane.

[0068] Upon passing through the optical arrangement 200, the EUV radiation 108A is reflected by each of the mirrors 202, 204, 206, 208 and by the deflection mirror 210. In this case, not all of the mirrors 202, 204, 206, 208 are required. In particular, the deflection mirror 210 is not required. The beam path of the EUV radiation 108A is indicated by the reference numeral 216. The photomask 120 is positioned in an object plane 218 of the optical arrangement 200. An object field 220 is positioned in the object plane 218.

[0069] 3 shows a schematic diagram of yet another embodiment of an optical apparatus 400. Like the optical apparatus 200, the optical apparatus 400 is a beam shaping and illumination system 102, particularly a beam shaping and illumination system 102 of an EUV lithography apparatus 100A. Therefore, the optical apparatus 400 can also be referred to as a beam shaping and illumination system, and the beam shaping and illumination system 102 can be referred to as an optical apparatus.

[0070] However, the optical apparatus 400 can also be part of the DUV lithography apparatus 100B, however, in the following it will be assumed that the optical apparatus 400 is part of the EUV lithography apparatus 100A.

[0071] EUV radiation 108A from radiation source 402 is focused by collector 404. Downstream of collector 404, EUV radiation 108A propagates through intermediate focal plane 406 before being incident on beam-shaping facet mirror 408, which serves for targeted illumination of specular reflector 410. Since specular reflector 401 is a mirror, it can also be referred to as a mirror. By means of beam-shaping facet mirror 408 and specular reflector 410, EUV radiation 108A is shaped to completely illuminate an object field 414 in object plane 412, and a predetermined, e.g., uniformly illuminated, circular-boundary pupil illumination distribution, i.e., a corresponding illumination setting, appears in pupil plane 416 of projection system 104, which is arranged downstream of the reticle.

[0072] The reflective surface of the specular reflector 410 is subdivided into individual mirrors. Depending on the illumination requirements, these individual mirrors of the specular reflector 410 are grouped to form individual mirror groups, i.e., facets of the specular reflector 410. Each individual mirror group forms an illumination channel that does not, by itself, fully illuminate the reticle field. Only the sum of all illumination channels results in a complete and uniform illumination of the reticle field. Both the individual mirrors of the specular reflector 410 and the facets of the beam-shaping facet mirror 408 can be tilted by an actuator system to set different field and pupil illuminations.

[0073] 4 shows a schematic plan view of one embodiment of the mirror 202 as described above in the form of a faceted mirror, and in particular a field facet mirror. The mirrors 204, 408 and the specular reflector 410 may also be in the form of faceted mirrors. However, only the mirror 202 will be described below. However, all discussion regarding the mirror 202 also applies to the mirrors 204, 408 and the specular reflector 410.

[0074] Figure 5 shows detail IV of Figure 4. In the following, reference will be made simultaneously to Figures 4 and 5. The facet mirror or field facet mirror is therefore designated in the following with the reference number 202. A coordinate system with a first spatial direction or x-direction x, a second spatial direction or y-direction y, and a third spatial direction or z-direction z is assigned to the field facet mirror 202.

[0075] The field facet mirror 202 comprises a plurality of facets 222, only two of which are referenced in FIG. 5. The facets 222 are arranged in the form of a pattern, in the form of a grid or in a checkerboard pattern. In particular, this means that the facets 222 are arranged above, below and to the left and right of each other in rows and columns. The facets 222 are preferably arranged in so-called bricks. Each brick may have 25×25 of said facets 222. A distance of 40 μm to 50 μm may be provided between the facets 222 of a brick. A distance of 100 μm may be provided between the individual bricks.

[0076] The facets 222 are in particular field facets and will also be referred to as such in the following. By way of example, the field facet mirror 202 may include hundreds of thousands of field facets 222. Each field facet 222 may be individually tiltable. The facets 222, when assigned to a mirror, may also be referred to as pupil facets.

[0077] In the plan view shown in Figures 4 and 5, the field facets 222 may be polygonal, for example rectangular. In particular, the field facets 222 may be square, as shown in Figure 5. If the field facets 222 are square, they may have a side length of, for example, 1 mm. However, the field facets 222 may also be circular or hexagonal. In principle, the geometric shape of the field facets 222 is as desired. By way of example, the field facets 222 may also have the geometric shape of an elongated rectangle. The field facets 222 may also be curved in plan view, in particular curved in the shape of a circular arc.

[0078] Figure 6 shows a greatly enlarged excerpt from the optical arrangement 200 shown in Figure 2. The optical arrangement 200 includes an EUV light source 106A (not shown) emitting EUV radiation 108A, an intermediate focus 214, a field facet mirror 202, and a mirror 204 in the form of a pupil facet mirror. Mirror 204 will be referred to hereinafter as the pupil facet mirror. Mirrors 206, 208, deflection mirror 210, and housing 212 are not shown in Figure 6. Pupil facet mirror 204 is at least approximately located in an entrance pupil plane of projection system 104 or in a conjugate plane therewith.

[0079] Intermediate focus 214 is the aperture stop of EUV light source 106 A. For simplicity, the following description does not distinguish between the aperture stop for creating intermediate focus 214 and the actual intermediate focus, i.e., the opening of the aperture stop.

[0080] The field facet mirror 202 comprises a carrier or body 224 which carries a plurality of field facets 222A, 222B, 222C, 222D, 222E, 222F as described above. The field facets 222A, 222B, 222C, 222D, 222E, 222F may have the same form, but may also differ from one another, in particular the shape of their boundaries and / or the curvature of their respective optically effective surfaces 226. The optically effective surface 226 is a mirror surface. The optically effective surface 226 is a plane. However, the optically effective surface 226 can also be a curved surface.

[0081] The optically effective surface 226 serves to reflect the EUV radiation 108A towards the pupil facet mirror 204. In Figure 6, only the optically effective surface 226 of the field facet 222A is provided with a reference number. However, the field facets 222B, 222C, 222D, 222E, 222F have such an optically effective surface 226 as well. The optically effective surface 226 may be referred to as a field facet surface.

[0082] Only field facet 222C will be discussed below. However, all discussion regarding field facet 222C also applies to field facets 222A, 222B, 222D, 222E, and 222F. Therefore, only the portion of EUV radiation 108A that strikes field facet 222C is shown. However, the entire field facet mirror 202 is illuminated using the EUV light source 106A.

[0083] The pupil facet mirror 204 comprises a carrier or body 228 that carries a plurality of pupil facets 230A, 230B, 230C, 230D, 230E, and 230F. Each of the pupil facets 230A, 230B, 230C, 230D, 230E, and 230F has an optically effective surface 232, in particular a mirror surface. In Figure 6, only the optically effective surface 232 of the pupil facet 230A is provided with a reference number. The optically effective surface 232 is suitable for reflecting EUV radiation 108A. The optically effective surface 232 can be referred to as a pupil facet surface.

[0084] For switching between different pupils, the field facet 222C can be switched between the different pupil facets 230A, 230B, 230C, 230D, 230E, 230F. In particular, for this purpose, pupil facets 230C, 230D, 230E are assigned to the field facet 222C. This requires that the field facet 222C be tilted. This tilting can be done mechanically, for example, by up to 100 mrad.

[0085] The field facet 222C is tiltable between multiple positions or tilt positions P1, P2, P3 using a single actuator (not shown) or multiple actuators, as described above. In the first tilt position P1, the field facet 222C images the intermediate focus 214 with imaging light beam 234A (shown in dashed lines) onto pupil facet 230C. In the second tilt position P2, the field facet 222C images the intermediate focus 214 with imaging light beam 234B (shown in solid lines) onto pupil facet 230D. In the third tilt position P3, the field facet 222C images the intermediate focus 214 with imaging light beam 234C (shown in dotted lines) onto pupil facet 230E. Each pupil facet 230C, 230D, 230E images the field facet 222C onto or near the photomask 120 (not shown here).

[0086] To allow the field facets 222C to be placed in different tilt positions P1, P2, P3, it is necessary that the field facets 222C can be tilted in two spatial directions in the plane spanned by the x-direction x and the y-direction y, specifically about the x-direction x and the y-direction y. The above allocation of the field facets 222C to the pupil facets 230C, 230D, 230E should not be interpreted as mandatory. The allocation may vary depending on the illumination setup. The pupil facets 230C, 230D, 230E may also be tiltable. At the same time, it is necessary to be able to dissipate the high heat load caused by the EUV radiation 108A. A further requirement is a high positional accuracy of the field facets 222C and an associated low sensitivity to external disturbances, such as temperature changes.

[0087] In order to obtain the highest possible fill factor of the field facet 222C, it is desirable to arrange the actuator system, the sensor system and further mechanical elements entirely below the optically active surface 226. The layer structure of the field facet 222C may be selected to make it possible to realize the drive elements, sensor elements and mechanical elements of the field facet 222C using conventional techniques for manufacturing micro-electromechanical systems (MEMS).

[0088] With regard to the typical requirements for use in an EUV lithography apparatus 100A, previous solutions, for example based on capacitive actuator systems, in this case impose high demands on the process technology. This applies in particular to the high aspect ratio of the structures to be manufactured. Therefore, a design in which the actuator system, sensor system, and mechanics required for the movement of the field facet 222C can be manufactured relatively easily and using few process steps is desirable.

[0089] Fig. 7 shows a schematic diagram of one embodiment of the optical system 300A. Fig. 8 shows a schematic cross-sectional view of the optical system 300A taken along the section line IIX-IIX in Fig. 7. Fig. 9 shows a schematic cross-sectional view of the optical system 300A taken along the section line IX-IX in Fig. 7. Figs. 7 to 9 will be simultaneously referred to below.

[0090] The optical system 300A is part of the optical device 200, 400 as previously described. In particular, the optical device 200, 400 may include a plurality of the above optical systems 300A. The optical system 300A may also be part of, in particular, the field facet mirror 202, the pupil facet mirror 204, the facet mirror 408 or the specular reflector 410 as previously described. However, only the field facet mirror 202 will be described below. However, all descriptions relating to the field facet mirror 202 also apply to the pupil facet mirror 204, the facet mirror 408 or the specular reflector 410, as appropriate.

[0091] The optical system 300A includes the field facets 222A, 222B, 222C, 222D, 222E, 222F as previously described. The optical system 300A can therefore also be referred to as a field facet, a facet system, a field facet system, or a field facet arrangement. The optical system 300A is preferably a facet system, in particular a field facet system. However, the optical system 300A can also be a pupil facet system. However, in the following, the facet system will be referred to as the optical system 300A.

[0092] The optical system 300A includes a body or substrate 302. The substrate 302 may, in particular, comprise silicon. The substrate 302 is part of or is rigidly connected to the body 224 of the field facet mirror 202. As a result, the substrate 302 forms the "fixed world" of the optical system 300.

[0093] Furthermore, optical system 300A includes facet elements 304, in particular field facet elements, having an optically effective surface 306. Optically effective surface 306 is a mirror surface. Optically effective surface 306 is suitable for reflecting EUV radiation 108A. Optically effective surface 306 corresponds in particular to optically effective surface 226 shown in FIG. 6 .

[0094] A plurality of piezo actuators 308, 310, 312, 314 connected side by side are provided between the substrate 302 and the facet element 304. The piezo actuators 308, 310, 312, 314 may also be called piezo elements or piezo actuating elements. All piezo actuators 308, 310, 312, 314 are arranged in a common plane E. The plane E is either subtended by the x-direction x and the y-direction y or is parallel to the plane subtended by the x-direction x and the y-direction y.

[0095] A main extension direction H is assigned to each piezo actuator 308, 310, 312, 314, although only the first piezo actuator 308 is shown in Fig. 7. The main extension direction H of the first piezo actuator 308 is oriented in the x-direction x. In this case, the main extension direction H should be understood to be the direction in which each piezo actuator 308, 310, 312, 314 has the greatest geometric extent.

[0096] The first piezo actuator 308 is rigidly connected to the substrate 302 along its entire length at a connection portion 316. The connection portion 316 is located on a rear surface 318 of the first piezo actuator 308. The other piezo actuators 310, 312, and 314 do not contact the substrate 302. The front surface 320 of the first piezo actuator 308 is rigidly connected to the second piezo actuator 320 at its end connection portion 332. The second piezo actuator 310 similarly has a rear surface 324 and a front surface 326. The front surface 326 is rigidly connected to the third piezo actuator 312 at its end connection portion 328 such that the second piezo actuator 310 is disposed between the first piezo actuator 308 and the third piezo actuator 312. The third piezo actuator 312 also includes a rear surface 330 and a front surface 332.

[0097] The fourth piezo actuator 314 is connected to the front surface 332 of the third piezo actuator 312 by means of an end surface connection part 334. The fourth piezo actuator 314 also includes a rear surface 336 and a front surface 338. Protruding from the front surface 338 is a connection part 340 with a coupling part 342 to which the facet element 304 is rigidly connected.

[0098] 10 shows an embodiment of the first piezo actuator 308. Since the piezo actuators 308, 310, 312, and 314 preferably have the same structure, only the first piezo actuator 308 will be described below. The following description of the first piezo actuator 308 also applies to the piezo actuators 310, 312, and 314, as appropriate. The first piezo actuator 308 includes a carrier layer 344. The carrier layer 344 can be manufactured from silicon, in particular from polycrystalline or monocrystalline silicon. A piezo layer 346 is arranged on the carrier layer 344. The piezo layer 346 can be based on a piezoelectric ceramic, such as lead zirconate titanate (PZT).

[0099] The piezo layer 346 is disposed between a first electrode 348 and a second electrode 350. In this case, the first electrode 348 is disposed between the carrier layer 344 and the piezo layer 346. The electrodes 348, 350 can be energized using a voltage source 352.

[0100] The function of the first piezo actuator 308 is described below. The first piezo actuator 308 is fixed or clamped to the left side in the orientation of FIG. 10. When a voltage is applied to the piezo layer 346 using electrodes 348, 350, an electric field is formed within the piezo layer 346. As a result, the piezo layer 346 contracts or shrinks in the x-direction x and y-direction y parallel to the plane of the layer under tension, resulting in the piezo layer 346 together with the carrier layer 344 bending upward in the orientation of FIG. 10. The first piezo actuator 308 may also be referred to as a unimorph actuator or unimorph piezo actuator.

[0101] When a voltage is applied to or actuated by the first piezo actuator 308, the first piezo actuator 308 transitions from an undeformed or undeflected state Z1 (shown using a solid line) to a deformed or deflected state Z2 (shown using a dashed line). Any number of intermediate states can be provided between the undeflected state Z1 and the deflected state Z2, such that the first piezo actuator 308 is continuously deflectable between the undeflected state Z1 and the deflected state Z2. By way of example, the deflection of the first piezo actuator 308 can be implemented in a voltage-dependent manner, e.g., the greater the voltage applied to the electrodes 348, 350, the greater the deflection of the first piezo actuator 308.

[0102] 7 to 9, the function of the optical system 300A will now be described. The piezo actuators 308, 312 can be used to tilt the facet element 304 in opposite directions about an axis in the x-direction x or about an axis extending parallel to the x-direction x. By way of example, when only the first piezo actuator 308 is actuated, the facet element 304 performs a counterclockwise tilt about the axis in the x-direction x in the orientation shown in FIG. 8, as shown by the tilt movement K1 in FIG.

[0103] In contrast, when only the third piezo actuator 312 is activated, the facet element 304 performs a clockwise tilt around the x-direction x in the orientation of Fig. 8, as shown by the tilt motion K2 in Fig. 8. When both piezo actuators 308, 312 are activated simultaneously and deflected to the same extent, the facet element 304 performs a pure stroke motion H1 in the z-direction z without tilting around the x-direction x. By simultaneously activating the two piezo actuators 308, 312 and deflecting them unequal, a combined motion of the facet element 304 can be obtained from the tilt motions K1, K2 and the stroke motion H1.

[0104] As shown in Figure 9, the piezo actuators 310, 314 can be used to tilt the facet element 304 in opposite directions about an axis in the y-direction y or an axis extending parallel to the y-direction y. By way of example, when only the second piezo actuator 310 is actuated, the facet element 304 performs a clockwise tilt about the y-direction y in the orientation of Figure 9, as shown by the tilt movement K3 in Figure 9.

[0105] In contrast, when only the fourth piezo actuator 314 is activated, the facet element 304 performs a counterclockwise tilt about the y-direction y axis in the orientation of Figure 9, as shown by the tilt motion K4 in Figure 9. When both piezo actuators 310, 314 are activated simultaneously and deflected equally, the facet element 304 performs a pure stroke motion H2 in the z-direction z. By simultaneously activating the two piezo actuators 310, 314 and deflecting them unequal, a combined motion of the facet element 304 can be obtained from the tilt motions K3, K4 and the stroke motion H2.

[0106] A combined tilt / stroke motion can be achieved about the x-, y-, and z-axes by actuating all of the piezo actuators 308, 310, 312, 314. A control unit 354 is provided to actuate the piezo actuators 308, 310, 312, 314.

[0107] As a result of this sequential arrangement of the piezo actuators 308, 310, 312, 314 as explained above, it is possible to tilt the facet element 304 in two axes, specifically in the x-direction and the y-direction, respectively, in a positive and negative direction, as explained based on the tilt movements K1, K2, K3, K4. As a result of simultaneously operating some or all of the piezo actuators 308, 310, 312, 314, it is possible to realize a combination of tilt movements K1, K2, K3, K4 in the x-direction and the x and y-direction, y, and therefore to set up an overall two-dimensional tilt field on the facet element 304.

[0108] Furthermore, actuation with the piezo actuators 308, 310, 312, 314 offers the option of using stroke movements H1, H2 to move the facet element 304 in a direction perpendicular to the optically active surface 306, in particular along the z-direction z. As an example, if two piezo actuators 308, 312 or 310, 314 assigned to the directions x, y are actuated simultaneously with the same voltage, there will be a translation along the z-direction z, in particular a respective stroke movement H1, H2, rather than a tilt of the facet element 304, as explained above.

[0109] The same is true for the parallel operation of all four piezo actuators 308, 310, 312, 314. As a result, the facet element 304 has three degrees of freedom, namely tilting movements K1, K2, K3, K4 about the x-direction and y-direction, and stroke movements H1, H2 along the z-direction. This property allows for more degrees of freedom and therefore more flexibility in setting the illumination conditions.

[0110] The integration of a sensor system for recording the deflection of, for example, the piezo actuators 308, 310, 312, 314 can be carried out, for example, by capacitive elements, for example in the form of electrodes, or by piezoresistive sensors, for example arranged parallel to the piezo actuators 308, 310, 312, 314. To realize a capacitive sensor system, electrodes can be attached to the upper surfaces of the piezo actuators 308, 310, 312, 314. A corresponding counter electrode can then be attached appropriately to the lower surface of the facet element 304. The distance between the piezo actuators 308, 310, 312, 314 and the electrode on the lower surface of the facet element 304 then changes when the facet element 304 is tilted. As a result, the capacitance changes as a function of the tilt angle of the facet element 304. A capacitive sensor can therefore be implemented.

[0111] If the sensor system is realized by piezoresistive sensors, a sensor 356, 358, 360, 362 is assigned to each piezo actuator 308, 310, 312, 314. By way of example, the sensors 356, 358, 360, 362 are piezoresistive elements whose resistance changes when deformed. The piezoresistive sensors 356, 358, 360, 362 can be integrated into the movable element, e.g., the carrier layer 344, or applied to it at free sites. Alternatively, the piezoresistive sensors 356, 358, 360, 362 can be located in / on an additional bending element parallel to the piezo layer 346.

[0112] Piezo actuators 308, 312 together form a first piezo actuator arrangement 364 of optical system 300A, which facilitates tilt movements K1, K2 about the x-direction, while piezo actuators 310, 314 together form a second piezo actuator arrangement 366 of optical system 300A, which facilitates tilt movements K3, K4 about the y-direction.

[0113] Figures 11 and 12 each show a schematic perspective view of yet another embodiment of optical system 300B, with faceted element 304 not shown in Figure 11. Optical system 300B differs from optical system 300A only in that optical system 300B represents a possible structural embodiment of optical system 300A that is only shown very diagrammatically in Figures 7-9.

[0114] Two strip-shaped coupling elements 368, 370, in particular a first coupling element 368 and a second coupling element 370, are assigned to each piezo actuator 308, 310, 312, 314, and each piezo actuator 308, 310, 312, 314 is arranged between and rigidly connected to its assigned strip-shaped coupling element. In Figure 11, only the coupling elements 368, 370 of the first piezo actuator 308 are provided with reference numbers.

[0115] The coupling elements 368, 370 may be fabricated from the same material as the substrate 302. Only the first coupling element 368 of the first piezo actuator 308 is rigidly connected to the substrate along its entire length. By way of example, the first coupling element 368 of the first piezo actuator 308 is integrally connected to the substrate 302, particularly through a material that is integrally connected.

[0116] In this case, "integral" or "one piece" means that the substrate 302 and the first coupling element 368 of the first piezo actuator 308 form a common component and are not assembled from different components. In this case, "integral in material" means that the first coupling element 368 of the first piezo actuator 308 and the substrate are made entirely from the same material. All other coupling elements 368, 370 are not connected to the substrate 302. The functionality of optical system 300B corresponds to the functionality of optical system 300A.

[0117] 13 and 14 each show a schematic perspective view of yet another embodiment of optical system 300C, with faceted element 304 not shown in Fig. 13. In terms of its structure, optical system 300C corresponds to that of optical system 300B, except that coupling elements 368, 370 of optical system 300C have larger cross-sectional areas than those of optical system 300B. The functionality of optical systems 300B and 300C is identical.

[0118] In order to cope with high thermal loads, it is advantageous to design the piezo actuators 308, 310, 312, 314 and the connection sites 322, 328, 334 so that they have as low a thermal resistance as possible overall. For this purpose, the cross-sectional area of ​​the connection sites 322, 328, 334 should be selected as large as possible. Furthermore, wide piezo actuators 308, 310, 312, 314 are advantageous as they reduce the thermal resistance while only slightly compromising the maximum achievable tilt angle of the facet element 304.

[0119] The described optical systems 300A, 300B, 300C can be realized using conventional microelectromechanical manufacturing methods, in particular where a three-dimensional microstructure composed of multiple base layers made of silicon is realized using different coating methods, microstructuring and etching techniques, and bonding methods.

[0120] The advantages of the optical systems 300A, 300B, 300C are explained below: The piezo actuators 308, 310, 312, 314 facilitate the realization of large tilt angles. These large tilt angles are obtained by using piezo actuators 308, 310, 312, 314 with high force density and by directly converting the piezo actuators 308, 310, 312, 314 into respective tilt movements K1, K2, K3, I4 of the facet element 304.

[0121] The piezo actuators 308, 310, 312, 314 require little space, thus freeing up space for incorporating a sensor system. By way of example, a sensor can be provided to record the position of the facet element 304. As a result, a coordinated system can be constructed. The optical systems 300A, 300B, 300C are easy to produce, as each design includes only a few components with simple structures, all of which are located in a common plane E. The choice of stroke movements H1, H2 of the facet element 304 provides further flexibility.

[0122] Although the present invention has been described based on exemplary embodiments, it can be modified in many ways. [Explanation of symbols]

[0123] 100A EUV lithography equipment 100B DUV lithography equipment 102 Beam shaping and illumination system 104 Projection system 106A EUV light source 106B DUV light source 108A EUV radiation 108B DUV radiation 100 mirrors 112 Mirror 114 Mirror 116 Mirror 118 Mirror 120 Photomask 122 Mirror 124 wafers 126 Optical axis 128 lens elements 130 Mirror 132 Medium 200 Optical equipment 202 Mirror / Field Facet Mirror 204 Mirror / Eye Faceted Mirror 206 Mirror 208 Mirror 210 Deflecting Mirror 212 Housing 214 intermediate focus 216 Beam Path 218 Object plane 220 Object field of view 222 facets / field of view facets 222A Field Facet 222B Field Facets 222C Field Facets 222D field facets 222E Field of View Facets 222F Field of View Facets 224 Main Unit 226 Optically Effective Surface 228 Main Unit 230A pupil facet 230B pupil facet 230C pupil facet 230D pupil facet 230E pupil facet 230F pupil facet 232 Optically Effective Surface 234A Imaging light beam 234B Imaging light beam 234C Imaging light beam 300A Optics / Facet System 300B Optics / Facet System 300C Optics / Facet System 302 Substrate 304 Facet Element 306 Optically Effective Surface 308 Piezo Actuator 310 Piezo Actuator 312 Piezo Actuator 314 Piezo Actuator 316 Connection site 318 Rear 320 front 322 Connection site 324 Rear 326 Front 328 Connection Site 330 Rear 332 Front 334 Connection Site 336 Rear 338 Front 340 Connection part 342 Connection site 344 Carrier Layer 346 Piezoelectric Layer 348 Electrode 350 electrodes 352 Voltage Source 354 Control Unit 356 Sensors 358 Sensors 360 Sensor 362 Sensors 364 Piezo Actuator Device 366 Piezo Actuator Device 368 Bonding Elements 370 Coupling Elements 400 Optical equipment 402 Radiation source 404 Collector 406 intermediate focal plane 408 Faceted Mirror 410 Specular reflector 412 Object plane 414 Object field of view 416 Pupil plane E plane H Main direction of extension H1 Stroke movement H2 stroke movement K1 tilting motion K2 tilt movement K3 tilt movement K4 tilt movement M1 mirror M2 mirror M3 mirror M4 mirror M5 mirror M6 mirror P1 tilt position P2 tilt position P3 tilt position xx direction yy direction zz direction Z1 state Z2 state

Claims

1. A facet system (300A, 300B, 300C) for a lithographic apparatus (100A, 100B), comprising: a facet element (304) having an optically effective surface (306); a first piezo actuator device (364) for tilting said facet element (304) about an axis in a first spatial direction (x); a second piezo actuator device (366) for tilting the facet element (304) about an axis in a second spatial direction (y) oriented perpendicular to the first spatial direction (x); wherein the first piezo actuator device (364) and the second piezo actuator device (366) are arranged in a common plane (E) subtended by the first spatial direction (x) and the second spatial direction (y), A facet system, wherein the first piezo actuator device (364) and / or the second piezo actuator device (366) are configured to perform a stroke movement (H1, H2) of the facet element (304) in a third spatial direction (z) oriented perpendicular to the optically active surface (306).

2. 2. The facet system of claim 1, wherein the first piezoelectric actuator device (364) comprises at least two piezoelectric actuators (308, 312) configured to selectively tilt the facet element (304) about the first spatial direction (x) with two opposite tilting movements (K1, K2).

3. 3. The facet system of claim 2, wherein the second piezoelectric actuator device (366) comprises at least two piezoelectric actuators (310, 314) configured to selectively tilt the facet element (304) about the second spatial direction (y) with two opposite tilting movements (K3, K4).

4. 4. The facet system of claim 3, wherein the piezo actuators (308, 312) of the first piezo actuator device (364) and the piezo actuators (310, 314) of the second piezo actuator device (366) are arranged side by side.

5. 5. A facet system according to claim 3 or 4, wherein the piezo actuators (308, 312) of the first piezo actuator device (364) and the piezo actuators (310, 314) of the second piezo actuator device (366) are arranged alternately.

6. A facet system according to any one of claims 3 to 5, wherein the piezo actuators (308, 312) of the first piezo actuator device (364) are arranged parallel to and spaced apart from each other, and the piezo actuators (310, 314) of the second piezo actuator device (366) are similarly arranged parallel to and spaced apart from each other.

7. 7. A facet system according to claim 3, wherein the piezo actuators (308, 312) of the first piezo actuator device (364) and the piezo actuators (310, 314) of the second piezo actuator device (366) are arranged perpendicular to each other.

8. A facet system according to any one of claims 3 to 7, comprising a first piezo actuator (308), a second piezo actuator (310), a third piezo actuator (312), and a fourth piezo actuator (314), wherein the first piezo actuator (308) and the third piezo actuator (312) are assigned to the first piezo actuator device (364), and the second piezo actuator (310) and the fourth piezo actuator (314) are assigned to the second piezo actuator device (366).

9. The facet system of claim 8, further comprising a substrate (302), wherein only the first piezo actuator (308) is connected to the substrate (302).

10. 10. A facet system according to claim 9, wherein the first piezo actuator (308) is connected only to the substrate (302) and the second piezo actuator (310), the second piezo actuator (310) is connected only to the first piezo actuator (308) and the third piezo actuator (312), the third piezo actuator (312) is connected only to the second piezo actuator (310) and the fourth piezo actuator (314), and the fourth piezo actuator (314) is connected only to the third piezo actuator (312) and the facet element (304).

11. A facet system according to any one of claims 1 to 10, wherein the facet elements (304) are square in plan view.

12. A faceting system according to any one of claims 1 to 11, wherein a sensor (356, 358, 360, 362) is integrated into the faceting system (300A, 300B, 300C).

13. A lithographic apparatus (100A, 100B) comprising a facet system (300A, 300B, 300C) according to any one of claims 1 to 12.

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