Method for reducing the effects of parasitic forces and / or moments on the imaging quality of a projection-exposure apparatus, and projection-exposure apparatus with a module

Abstract

The invention relates to a projection-exposure apparatus (1, 101) with at least one module (40, 50), - wherein the module (40, 50) comprises a fluid channel (41, 51) which at least at times contains a pressurized fluid (42, 52), and - the fluid channel (41, 51) is connected to supply lines (471, 47.2, 57.1, 57.2), and - the supply lines (47.1, 47.2, 57.1, 57.2) are connected by bearing points (48.1, 48.2, 58.1, 58.2) to a supporting frame (66), wherein the projection-exposure apparatus (1, 101) is distinguished by the fact that the module (40, 50) is symmetrically formed. The invention also relates to a method for reducing the effect on the imaging quality of a projection-exposure apparatus (1, 101) that is brought about by parasitic forces (Fres) and / or moments (Mres) caused by pressure fluctuations induced by flow and / or transferred via a fluid (42, 52) and acting on a module (40, 50) of the projection-exposure apparatus (1, 101), comprising the following method steps: - determining the parasitic forces (Fres) and / or moments (Mres), - defining at least two at least partially compensating forces (Fuw) and / or moments (MVTxz, MATxz), - creating the module (40, 50) for producing the compensating forces (Fuw) and / or moments (MVTxz, MATxz).

Description

[0001] Method for reducing the effects of parasitic forces and / or moments on the image quality of a projection exposure system and projection exposure system with a module

[0002] The invention relates to a method for reducing the effects of parasitic forces and / or moments on the image quality of a projection exposure system and to a projection exposure system with a particularly symmetrically designed module.

[0003] Projection exposure systems must meet increasing demands for accuracy and precision with each generation. Such systems are used to create extremely fine structures, particularly on semiconductor devices or other microstructured components. The operating principle of these systems is based on creating extremely fine structures down to the nanometer range by means of a generally reduced-size image of structures on a mask, a so-called reticle, on an element to be structured, a so-called wafer, which is provided with photosensitive material. The minimum dimensions of the created structures depend directly on the wavelength of the light used. The light sources used in previous systems have an emission wavelength in the range of 100 nm to 300 nm, in particular 193 nm, the so-called DUV range.In recent times, however, light sources with an emission wavelength in the range of a few nanometers, for example, between 1 nm and 120 nm, especially in the 13.5 nm range, have been increasingly used, enabling higher resolution. This wavelength range is also referred to as the EUV range.

[0004] The imaging quality of projection exposure systems is particularly influenced by how precisely their components can assume a desired or rest position in space. From a dynamic perspective, in order to meet these requirements, it is important to reduce the influence of interference, for example in the form of mechanical vibrations, on these components, such as support and reference structures and / or optical modules. This applies in particular to the optical modules with the optical elements used for imaging, such as lenses or mirrors, but also to support structures for a wafer, such as a module for holding and positioning the wafer or a part of the module, such as an electrostatic holder for the wafer, or for reference structures that serve, for example, as a reference for the positioning of the optical elements.

[0005] The disturbance, for example a mechanical vibration, can be divided into a low-frequency component and a higher-frequency component.

[0006] When imaging a structure of a reticle onto a wafer, the low-frequency component causes a quasi-static deviation from a target position of the optical element, which can, for example, cause a shift in the position of the image on the wafer.

[0007] The higher frequency component corresponds to a mechanical vibration, which blurs the image and reduces the contrast of the image.

[0008] The above-mentioned disturbances can be caused, for example, by fluids flowing into components of the projection exposure system, such as water, which are usually used for temperature control, in particular for cooling.

[0009] For effective cooling, a specific flow rate of fluid in the cooling lines is required. This is typically achieved by using a pump to generate a pressure p in the cooling system.

[0010] This pump can, in particular, cause local pressure fluctuations in the fluid. These pressure fluctuations propagate as cooling fluid sound (water sound) throughout the entire cooling circuit; this type of dynamic disturbance is referred to as flow-induced vibration (FIV). Flow-induced vibrations can also be caused, for example, by cross-sectional changes, deflections, valves in the cooling system, or in other cooled components. In addition to disturbances caused by fluid flow, the fluid can also transmit pressure fluctuations without flowing; these are referred to as transferred vibrations. These transferred vibrations can be caused by the flowing fluid itself (see above) or can be transmitted to the fluid from outside via the cooling system's cooling lines.The cooling lines are usually rigidly connected to the support structures of the projection exposure system, so that mechanical vibrations of the support structure can be transmitted to the fluid and thus to another component. The cooling line and the cooling fluid itself can thus be viewed as a dynamic short circuit between the support structures and the components.

[0011] Each of the disturbances mentioned generates a local pressure fluctuation that propagates as a longitudinal fluid sound wave through the fluid throughout the cooling system. When this sound wave reaches a temperature-controlled component, it is also referred to as received vibrations, i.e., that portion of the disturbance that is generated elsewhere and is transmitted to the temperature-controlled component via fluid sound. The pressure fluctuations cause dynamic reaction forces and moments in the temperature-controlled component, which can lead to a change in the position and / or orientation of the component in up to six degrees of freedom. Furthermore, the pressure fluctuations can cause high-frequency mechanical vibrations in all six degrees of freedom. Both disturbances can negatively impact the image quality of the associated projection exposure system.

[0012] State-of-the-art solutions focus on decoupling the rigid connections to the structures and / or optimizing the cable geometries. However, it has been shown that these measures are not always sufficient to meet the ever-increasing demands on component positional stability.

[0013] The object of the present invention is to provide a device that eliminates the above-described disadvantages of the prior art. A further object is to provide a method for reducing the effects of pressure waves on the image quality of a projection exposure system. This object is achieved by a method and a projection exposure system having the features of the independent claims. The subclaims relate to advantageous developments and variants of the invention.

[0014] A method according to the invention for reducing the effect of parasitic forces and / or moments acting on a module of a projection exposure system caused by flow-induced and / or fluid-transferred pressure fluctuations on the image quality of the projection exposure system comprises the following method steps:

[0015] - Determination of parasitic forces and / or moments,

[0016] - Definition of at least two at least partially compensating forces and / or moments,

[0017] - Design of the module for generating the compensating forces and / or moments.

[0018] In particular, the module can be designed as an optical module or as a module for holding and positioning the wafer.

[0019] The design of the module according to the invention therefore enables the parasitic forces and / or moments caused during operation to be designed in such a way that they have only a slight or no influence on the image quality.

[0020] Furthermore, the design can be realized through the arrangement and / or alignment and / or material selection of components of the module, in particular of at least one supply line and one fluid channel of the module. As a result, the course of the fluid channels, which run for example in a module designed as a mirror module, as well as the bends, cross-sections and other variable parameters of the supply lines and fluid channels can be designed in such a way that the caused parasitic forces and / or moments are reduced on the one hand and / or on the other hand the sum of their effect is influenced in such a way that the remaining resulting forces and / or moments have a minimal influence on the image quality. The forces and / or moments can, for example, be designed in such a way that two or more forces and / or moments compensate each other, so that the resulting parasitic forces and / or moments are reduced.

[0021] In particular, the resulting parasitic forces and / or moments can be reduced for at least a portion of the module of the projection exposure system. In other words, for example, only the supply lines can be designed such that no parasitic forces and / or moments act on the module, but the fluid lines within the mirror of a mirror module are optimized not with respect to reducing the parasitic forces and / or moments, but rather, for example, toward a homogeneous temperature of the optical effective surface.

[0022] In a further embodiment, the resulting parasitic forces and / or moments for a module can be reduced. In this case, the proportion of the impact of this module can be reduced within the scope of design freedom, i.e., without considering the image quality of the entire projection exposure system.

[0023] In particular, a displacement and / or rotation of the optical module caused by the resulting parasitic forces and / or moments can be reduced. The displacements and / or rotations can be designed such that the contribution to the imaging quality of the optical module and thus to the imaging quality of the projection exposure system is reduced. A rigid-body displacement of an optical element of the optical module designed as a mirror in the direction of the useful light can, for example, be relatively easily corrected by moving another optical element, whereas a displacement of the mirror parallel to an optical effective surface formed on the mirror requires further corrective measures.

[0024] Furthermore, an optical effect of the optical module can be determined by multiplying the displacement and / or rotation of the optical module by corresponding optical sensitivities. This has the advantage that the effects of disturbances on the imaging quality of the projection exposure system can be directly detected. This advantageously enables the resulting parasitic forces and / or moments to be designed in such a way that the parasitic optical effect of the optical module is reduced. This can, for example, lead to a situation where, due to different optical sensitivities for different degrees of freedom of a mirror, weighting the resulting displacements and / or rotations at the module level leads to a smaller parasitic optical effect than a reduction based solely on the magnitude of the parasitic forces and / or moments.

[0025] In the case of a high optical sensitivity for a displacement of the optical element parallel to the optical effective surface and a low optical sensitivity for a rotation of the optical element about an optical axis formed at the vertex of the optical effective surface and perpendicular to the optical effective surface, the module can, for example, be designed such that the parasitic forces and / or moments cause a comparatively small or no displacement parallel to the optical effective surface at the expense of a comparatively large rotation about the optical axis.

[0026] In a further embodiment of the method, the resulting parasitic optical effects of the optical modules can be added to a resulting parasitic optical effect of a projection optics of the projection exposure apparatus, thereby determining an overall effect relevant for the imaging.

[0027] In particular, the resulting parasitic forces and / or moments can be designed in such a way that the resulting parasitic optical effect of the projection optics is reduced, whereby the impact of the resulting parasitic optical effect of all optical modules can be reduced to a minimum.

[0028] This advantageously reduces the contribution of the projection optics of the projection exposure system to a minimum.

[0029] A projection exposure system according to the invention comprises at least one module, wherein the module comprises a fluid channel containing a pressurized fluid at least temporarily. The fluid channel is further connected to supply lines, which are connected to a support frame via bearing points. The projection exposure system is characterized in that the module is symmetrically designed.

[0030] Symmetrical in the sense of the invention includes, for example, not only a purely geometric symmetry but also a design symmetry, i.e., an effective symmetry or effective symmetry, which is characterized by a reduction of parasitic effects, such as parasitic optical effects of an optical module. For example, the causes of the parasitic effects, such as parasitic forces and / or moments, can be realized by compensation or mutual cancellation of the cause. The effective symmetry can refer to forces and / or moments, displacements and / or rotations, and to the optical effects of multiple modules designed as optical modules.

[0031] In a further embodiment, the supply lines can be arranged in a single plane. This has the advantage that parasitic forces occurring in the plane, in particular the parasitic forces resulting from the superposition of all parasitic forces, do not cause any moments due to the single-plane arrangement and the lack of a lever arm. This advantageously prevents tilting of the module around the two mutually perpendicular axes of the plane.

[0032] In particular, the plane can be configured perpendicular to an axis that has a minimal optical impact on the image when the module rotates about this axis. In the case of a flat optical effective surface, for example, the axis would be arranged perpendicular to this axis. Because the optical elements are typically rotationally symmetrical, rotation about this axis can cause no or only a negligible parasitic optical effect. Tilting or rotation about this axis, which can be caused by the parasitic forces generated in the plane, thus has no effect on the image quality of the projection exposure system.

[0033] In a further embodiment of the invention, the supply lines can run in the plane at least up to the bearing points. Due to the connection to the support frame, parasitic forces also act at the bearing points, which are part of the resulting parasitic forces acting on the module. Forces caused in the supply lines downstream of the bearing points are supported by the bearing points and thus do not act on the module, which means that the supply lines can be routed in any desired direction downstream of the bearing points, meaning they no longer have to run in the plane. This has the advantage that the supply lines can be adapted to the often limited installation space.

[0034] In a further embodiment of the invention, at least one decoupling element arranged in the supply lines can be arranged within the plane. This serves to decouple the parasitic forces and moments introduced by the support frame via the bearing points and / or caused in the supply lines.

[0035] Furthermore, at least two decoupling elements arranged perpendicular to each other can be arranged in front of the connection of the supply line to the bearing point, wherein, for example, the decoupling elements can advantageously be designed to be stiff in the axial direction and soft in the lateral direction.

[0036] In this context, "stiff" means that the stiffness of the decoupling elements is designed to be as high as possible within the scope of the design and technical properties of the material used, such as yield strength or fatigue strength, and / or component geometries, such as wall thicknesses. In contrast, "soft" is understood as a stiffness designed to be as low as possible within the scope of the design and technical properties of the material used and / or component geometry.

[0037] The decoupling elements are designed, for example, as corrugated hoses, in which the axial and lateral stiffness can be adjusted depending on the wall thickness, the radii and spacing of the individual corrugations, and the length of the corrugated hose. In particular, the component can be decoupled from the bearing points in all six degrees of freedom. This can be achieved, for example, by the 90° arrangement described above, although other arrangements and / or decoupling elements can also enable decoupling in all six degrees of freedom.

[0038] In a further embodiment of the invention, the fluid channels and / or supply lines can be designed such that the resulting parasitic forces and / or moments generated by the pressurized fluid within a module are reduced. In this case, the symmetrical design of the module does not necessarily refer to the geometric arrangement, but rather to the symmetry of the resulting parasitic forces and moments, whereby they at least partially compensate for each other. The greater the symmetry of the forces, the lower the resulting parasitic forces and / or moments.

[0039] In a further embodiment of the invention, the fluid channels and / or the supply lines can be designed such that displacement and / or rotation of the optical module caused by the resulting parasitic forces and / or moments is reduced. Here, the symmetry refers to an effective symmetry of the resulting parasitic forces and / or moments, which advantageously minimizes the displacements and / or rotations (tiltings) caused by the resulting parasitic forces and / or moments.

[0040] Due to the scanning movement carried out in projection exposure systems when imaging the structure of a reticle onto a wafer in the y-direction, a displacement in the scanning direction, i.e. in the y-direction, has a less pronounced effect on the image of the structure on the wafer than in the x-direction, which is perpendicular to the scanning direction. This is because a displacement in the scanning direction is averaged out by the scanning process, whereby a displacement perpendicular to the scanning direction causes a displacement of the image. The design of the module can therefore take this aspect into account in particular, so that the resulting force acts in the y-direction, which in turn corresponds to an effective symmetry. In particular, the fluid channels and / or the supply lines can be designed such that the resulting parasitic forces and / or moments are designed such that the resulting parasitic optical effect of the optical module is reduced.As above, symmetry refers to the effective symmetry of the displacements and / or rotations multiplied by the optical sensitivities due to the resulting parasitic forces and / or moments. The higher the symmetry of the individual optical effects, the smaller the remaining parasitic optical effect of the module. Symmetry refers, for example, to opposing optical effects; the optical effects of a displacement and a rotation of the module are thus mirror-symmetrical to each other, whereby at least the symmetrical components compensate each other.For example, based on the optical sensitivities, displacements and / or tilts in degrees of freedom with a low optical sensitivity, such as the rotation about the axis perpendicular to the plane explained above, can become comparatively large in favor of a displacement and / or rotation in a direction with high optical sensitivities.

[0041] In a further embodiment, the fluid channels and / or the supply lines can be designed such that the resulting parasitic forces and / or moments are formed such that the resulting parasitic optical effect of the projection optics is reduced. Here, the symmetrical design of the module refers to the effective symmetry of the individual modules with respect to one another. As with the intramodular symmetry explained above, this refers here to an intermodular symmetry of the optical effects. The optical effect of one module can be mirror-symmetrical to the optical effect of a second module from the perspective of the projection optics, so that at least the symmetrical components of the optical effects of the modules compensate each other.

[0042] Furthermore, the module can be designed as an optical module and / or as a module for holding and positioning a wafer.

[0043] Alternatively, the module can also be designed as another component of the projection exposure system, in particular as a reference structure. The reference structure can serve in particular as a reference for the positioning of the optical modules and / or other components of the projection exposure system. As a result, the requirements for the positional stability and dimensional stability of the reference structure are comparatively high, since any movement of a reference element and / or sensor arranged on the reference structure leads to a parasitic movement of the corresponding mirror module or another component. In particular, the module can have a symmetrical structure with respect to a reference point formed on the module. The reference point can, for example, be the origin of an optical coordinate system to which the optical sensitivities refer.The optical coordinate system can be used to adjust the optical element in the optical module and, in the case of a positionable module, to control the position of the optical module. This has the advantage that the reduction is independent of the position of the optical module, thus ensuring a constant reduction of the effects.

[0044] In the following, embodiments and variants of the invention are explained in more detail with reference to the drawings.

[0045] Figure 1 shows a meridional section of a projection exposure system for EUV projection lithography,

[0046] Figure 2 shows a meridional section of a projection exposure system for DUV projection lithography,

[0047] Figure 3 is a schematic representation of a mirror module known from the prior art,

[0048] Figure 4 shows a further schematic representation of a mirror module known from the prior art, and

[0049] Figure 5 is a schematic representation of a mirror module according to the invention, and

[0050] Figure 6 shows a schematic representation of another mirror module according to the invention. The following describes, by way of example, the essential components of a projection exposure system 1 for microlithography with reference to Figure 1. The description of the basic structure of the projection exposure system 1 and its components is not intended to be limiting.

[0051] One embodiment of an illumination system 2 of the projection exposure system 1 has, in addition to a 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. In this case, the illumination system does not include the light source 3.

[0052] A reticle 7 arranged in the object field 5 is illuminated. The reticle 7 is held by a reticle holder 8. The reticle holder 8 can be displaced, in particular in a scanning direction, via a reticle displacement drive 9.

[0053] Figure 1 illustrates a Cartesian xyz coordinate system. The x-direction runs perpendicular to the drawing plane. The y-direction runs horizontally, and the z-direction runs vertically. The scanning direction in Figure 1 runs along the y-direction. The z-direction runs perpendicular to the object plane 6.

[0054] 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.

[0055] 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, via a wafer displacement drive 15. The displacement of the reticle 7, on the one hand, via the reticle displacement drive 9, and of the wafer 13, on the other hand, via the wafer displacement drive 15, can be synchronized with one another. The radiation source 3 is an EUV radiation source. The radiation source 3 emits, in particular, EUV radiation 16, which is also referred to below as useful radiation, illumination radiation, or illumination light.

[0056] The useful radiation has a wavelength in the range between 5 nm and 30 nm. Radiation source 3 can be a plasma source, for example, an LPP (Laser Produced Plasma) or a DPP (Gas Discharged Produced Plasma) source. It can also be a synchrotron-based radiation source. Radiation source 3 can be a free-electron laser (FEL).

[0057] The illumination radiation 16 emanating from the radiation source 3 is focused by a collector 17. The collector 17 can be a collector with one or more ellipsoidal and / or hyperboloidal reflection surfaces. The at least one reflection surface of the collector 17 can be exposed to the illumination radiation 16 at grazing incidence (Gl), i.e., at angles of incidence greater than 45° relative to the normal direction of the mirror surface, 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.

[0058] 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 radiation source 3 and the collector 17, and the illumination optics 4.

[0059] 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 are also referred to below as field facets. Only a few of these facets 21 are shown in Fig. 1 as examples.

[0060] 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.

[0061] 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.

[0062] Between the collector 17 and the deflecting mirror 19, the illumination radiation 16 runs horizontally, i.e. along the y-direction.

[0063] 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.

[0064] The second facet mirror 22 comprises a plurality of second facets 23. In the case of a pupil facet mirror, the second facets 23 are also referred to as pupil facets.

[0065] 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 102008 009 600 A1 in this regard.

[0066] The second facets 23 can have planar or alternatively convex or concave curved reflection surfaces.

[0067] The illumination optics 4 thus form a double-faceted system. This basic principle is also known as a honeycomb condenser (fly's eye integrator).

[0068] It may be advantageous to arrange the second facet mirror 22 not exactly in a plane that is optically conjugated to a pupil plane of the projection optics 10. In particular, the pupil 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.

[0069] 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.

[0070] 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 (NL mirrors, normal incidence mirrors) and / or one or two mirrors for grazing incidence (GL mirrors, grazing incidence mirrors).

[0071] 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 field facet mirror 20 and the pupil facet mirror 22.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] In the example shown in Figure 1, the projection optics 10 comprises six mirrors S1 to S6. Alternatives with four, eight, ten, twelve, or a different number of mirrors Si are also possible. The penultimate mirror S5 and the last mirror M6 each have a passage opening for the illumination radiation 16. The projection optics 10 are doubly obscured optics. The projection optics 10 has an image-side numerical aperture that is greater than 0.5 and can also be greater than 0.6, for example, 0.7 or 0.75.

[0076] Reflection surfaces of the mirrors Si can be designed as freeform surfaces without a rotational symmetry axis. Alternatively, the reflection surfaces of the mirrors Si can be designed as aspherical surfaces with exactly one rotational symmetry axis of the reflection surface shape. The mirrors Si, 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.

[0077] The projection optics 10 has a large object-image offset in the y-direction 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 can be approximately as large as a z-distance between the object plane 6 and the image plane 12.

[0078] The projection optics 10 can, in particular, be anamorphic. It has, in particular, different image scales ßx, ßy in the x and y directions. 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.

[0079] The projection optics 10 thus leads to a reduction in the ratio 4:1 in the x-direction, i.e. in the direction perpendicular to the scanning direction.

[0080] The projection optics 10 results in a reduction of 8:1 in the y-direction, i.e. in the scanning direction.

[0081] Other magnifications are also possible. Magnifications with the same sign and absolutely identical in the x and y directions, for example, with absolute values ​​of 0.125 or 0.25, are also possible.

[0082] The number of intermediate image planes in the x- and y-directions 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 are known from US 2018 / 0074303 A1.

[0083] Each of the pupil facets 23 is assigned to exactly one of the field 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 field facets 21. The field facets 21 generate a plurality of images of the intermediate focus on the pupil facets 23 assigned to them.

[0084] The field facets 21 are each imaged onto the reticle 7 by an associated pupil facet 23, superimposed on one another, to illuminate the object field 5.

[0085] 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.

[0086] By arranging the pupil facets, 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 pupil facets that guide light, the intensity distribution in the entrance pupil of the projection optics 10 can be adjusted. This intensity distribution is also referred to as the illumination setting.

[0087] 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.

[0088] 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.

[0089] The projection optics 10 can, in particular, have a homocentric entrance pupil. This can be accessible. It can also be inaccessible.

[0090] The entrance pupil of the projection optics 10 cannot usually be precisely illuminated with the pupil facet mirror 22. When the projection optics 10 images the center of the pupil facet mirror 22 telecentrically onto the wafer 13, the aperture rays often do not intersect at a single point. However, a surface can be found in which the pairwise determined distance of the aperture rays is minimized. This surface represents the entrance pupil or a surface conjugate to it in spatial space. In particular, this surface exhibits a finite curvature.

[0091] 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.

[0092] In the arrangement of the components of the illumination optics 4 shown in Figure 1, the pupil facet mirror 22 is arranged in a surface conjugated to the entrance pupil of the projection optics 10. The field 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.

[0093] The first facet mirror 20 is arranged tilted to an arrangement plane which is defined by the second facet mirror 22.

[0094] Figure 2 shows schematically in meridional section a further projection exposure system 101 for DUV projection lithography, in which the invention can also be used.

[0095] The structure of the projection exposure system 101 and the principle of imaging are comparable to the structure and procedure described in Figure 1. Identical components are designated by a reference numeral that is 100 higher than in Figure 1; thus, the reference numerals in Figure 2 begin with 101.

[0096] In contrast to an EUV projection exposure system 1 as described in Figure 1, due to the longer wavelength of the DUV radiation 116 used as useful light in the range from 100 nm to 300 nm, in particular from 193 nm, refractive, diffractive and / or reflective optical elements 117, such as lenses, mirrors, prisms, cover plates and the like, can be used in the DUV projection exposure system 101 for imaging or illumination.The projection exposure system 101 essentially comprises an illumination system 102, a reticle holder 108 for receiving and precisely positioning a reticle 107 provided with a structure, by means of which the later structures on a wafer 113 are determined, a wafer holder 114 for holding, moving and precisely positioning this wafer 113 and a projection lens 110 with a plurality of optical elements 117, which are held via mounts 118 in a lens housing 119 of the projection lens 110.

[0097] The illumination system 102 provides DUV radiation 116 required for imaging the reticle 107 on the wafer 113. A laser, a plasma source, or the like can be used as the source for this radiation 116. The radiation 116 is shaped in the illumination system 102 via optical elements such that the DUV radiation 116, upon impinging on the reticle 107, exhibits the desired properties with regard to diameter, polarization, wavefront shape, and the like.

[0098] The structure of the subsequent projection optics 101 with the lens housing 119 does not differ in principle from the structure described in Figure 1, except for the additional use of refractive optical elements 117 such as lenses, prisms, end plates, and is therefore not described further.

[0099] Figure 3 shows a plan view of a schematic representation of a mirror module 30 known from the prior art, with an optical element designed, in the embodiment shown, as a mirror S3, as can be used in the projection exposure system 1 explained in Figure 1. The mirror S3 has a fluid channel 31, which is shown in dashed lines in Figure 3 and through which flows a fluid designed as water 32. The fluid channel 31 comprises an inlet 35 and an outlet 36, which can be connected to a device for treating and providing the water via a supply line 37.1, 37.2 (Figure 4).

[0100] In the example shown, the water 32 in the fluid channel 31 is subjected to a constant pressure p and the mirror S3 is assumed to be infinitely stiff. The pressure p acts equally in all spatial directions, so that per partial area A Tvthe inner surface 33 of the fluid channel 31 a force F TV acts on the fluid channel 31 and thus on the mirror S3.

[0101] The index "v" comprises in the first place a consecutive number of the areas or forces and in the second place the direction of action of the force or orientation of the area in the Cartesian coordinate system shown in Figure 3. Opposing areas / forces comprise a two-digit number, with the first consecutive digit representing the location of the area / force and a second number to distinguish the areas / forces, as in the example shown in the opposing forces F A THX, F T i2x. The area A Tv acting forces F ATv result from the pressure p, the partial area A Tv and the normal vector n, where the normal vector n has been omitted for clarity in the figures and formulas, resulting in a force FATv to F ATv “ P*ATV results.

[0102] For reasons of clarity, Figure 3 shows the action of the forces F ATv only as an example two opposite surfaces A T11x , A T12x and the two to the areas A T11x , A T12x corresponding forces F AT11x , F AT12x in the x-direction are designated by reference symbols.

[0103] The forces F ATv each act on a force application point Py, which follows the same nomenclature as the areas / forces and is located in the center of gravity of the areas A Tv The two forces F AT11x , F AT12x are ATUX, A for equal areas T i2x are also equal and act in opposite directions, so that the forces F AT n x , F AT i2x and cause no resultant force on the mirror S3.

[0104] The other force couples FATv , F ATv , which are perpendicular to the pipe and cancel each other out, are shown in Figure 3 as dotted arrows only for the drawing plane designated as the xy plane and, as explained above, are not provided with reference symbols. Exceptions are forces F AT2x , F AT2y , F AT3x , F AT3y with the force application points P 2x , P 2y , Pßx, Pßy, which are located in the deflections of the fluid channel 31. These have no directly opposing surfaces and therefore no compensating force. The forces F AT 2x and F AT 3 X lift themselves at constant pressure p even over the large distance between the force application points P 2x , P 3x so that no resultant force acts in the x-direction on the mirror S3.

[0105] In the example of Figure 3, the mirror S3 is open at the entrance 35 and exit 36, ie there is no surface A within the mirror S3Tv , at which a force F ATV This allows the forces F opposing the input 35 and output 36 to be AT2y , F AT3y cannot be compensated in the mirror S3.

[0106] This results in a resulting force F acting on the mirror S3 res , which is the sum of the two forces F AT2y , F AT3y and acts in the y-direction in Figure 3. The force F res acts on a reference point P Ko s of the mirror S3 and causes a displacement of the mirror S3 from its desired position.

[0107] The reference point P Ko In the example shown, s corresponds to the origin of the mirror coordinate system, which is used on the one hand for the adjustment of the optical mirrors Si (Figure 1 ) to each other and on the other hand as a basis for the positioning of the mirror S3 to a reference.

[0108] The resulting force F resthus acts on the mirror S3 as a function of the pressure p, which varies over time due to the pressure fluctuations in the water 32 explained above. The resulting displacement of the mirror S3 from its target position or the vibration about a target position is therefore not constant, but changes over time with the change in the pressure p. As explained above, this has a negative effect on the image quality of the projection exposure system 1.

[0109] The forces F A T2y, F A T3y and the lever arms 34.1 , 34.2 between the points of application P 2y , Pßy of the forces F AT 2y, F T 3 y and the reference point P Kos moments M acting on the mirror S3 AT3z , M AT4z cancel each other out due to the symmetry of the mirror module 30.

[0110] Due to the infinite stiffness of the mirror S3, the forces F caused by the pressure p in the fluid channel 31 cause ATv no deformation of the mirror S3 or of an optical active surface 29 arranged on the mirror S3 and used to image the structures onto the wafer 13 (Figure 1).

[0111] Figure 4 shows a schematic representation of the mirror module 30 known from the prior art, as explained in Figure 3. In the example shown, the mirror module 30 comprises, in addition to the embodiment in Figure 3, a supply line 37.1 and a discharge line 37.2 for supplying the fluid channel 31 with water 32, which are referred to below as supply lines 37.1, 37.2. The supply lines 37.1, 37.2 are connected on one side to the inlet 35 and outlet 36 of the fluid channel 31, respectively, and on the other side, comparable to the mirror S3 in Figure 3 to illustrate the effect of the forces F acting on the fluid channel 31. ATv open, so that at this end due to the missing area A Tv no forces can be caused.

[0112] The supply lines 37.1 , 37.2 are designed in such a way that the forces F resulting in Figure 3 AT2y , F AT3yby a force FV caused by a deflection of the supply lines 37.1, 37.2 designed as a 90° elbow 39.1, 39.2 V Ti y , FV V T2y are compensated. The index “V” stands for a force generated in the supply line 37.1 , 37.2, to distinguish the forces F generated in the mirror S3 ATv . In the further course of the supply lines 37.1, 37.2 running in the z-direction after the angle pieces 39.1, 39.2, further 90° angle pieces 39.3, 39.4 are formed, at which, as described, the forces F V T3y, F V T4y. The further course of the supply lines 37.1 , 37.2 runs at a 45° angle to the x-axis, whereby in Figure 4 only the force components F acting in the y-direction are shown. V T3y, F V T4y are shown.

[0113] These forces F V T3y, F VT4y cause a moment M via the lever arms 44.1 , 44.2 formed in the z-direction V T3X, M V T4X around the rotation axes R Ex at the input 35 and the rotation axis R Ax at output 36, which act on the mirror S3. The resulting force F acting on the mirror S3 res and the moment M res , which as shown in Figure 3 at the reference point P Ko s of the mirror coordinate system or a reference point P Ko s axis of rotation R x cause a translation and / or rotation of the mirror S3. This causes a deviation of the mirror S3 from its desired position, which negatively affects the image quality of the projection exposure systems 1.

[0114] Figure 5 shows a schematic representation of a mirror module 40 according to the invention with a mirror S3 and supply lines 47.1, 47.2, wherein, where appropriate, corresponding elements are designated by reference numerals increased by 10 compared to the designation in Figure 4. The supply lines 47.1, 47.2 are designed such that the deflections of the supply lines 47.1, 47.2, which are also designed as 90° angle pieces 49.1, 49.2, 49.3, 49.4, 49.5, 49.6, lie in a plane with the fluid channel 31, wherein the plane is parallel to the xy plane of the mirror coordinate system. The supply lines 47.1 , 47.2 are designed in such a way that all forces F caused at the angle pieces 49.1 , 49.2, 49.3, 49.4, 49.5, 49.6 uw in the xy plane.

[0115] In the nomenclature of forces F uw the index “u” denotes a consecutive number for each force pair, such as the force pair Fn F12 , and the index “w” represents the two forces Fn F belonging to the force pair “u” 12 . The arrangement of the supply lines 47.1, 47.2 in the plane of the fluid channel 41 has the further advantage that in the case of parasitic resulting forces within the plane, no moments about the x-axis or the y-axis can be introduced into the mirror S3 due to the missing lever arm.

[0116] The supply lines 47.1, 47.2 are firmly connected to a support frame 66 of the projection exposure system 1 (Figure 1) via bearings 48.1, 48.2. The forces F 12 , F 82 are therefore caused by bearing forces Fn, F acting at the bearing points 48.1 , 48.2 81compensated. Assuming a constant pressure p in the fluid channel 41 and the supply lines 47.1 , 47.2 and an infinitely stiff mirror S3 and infinitely stiff supply lines 47.1 , 47.2 , no resulting forces F act on the mirror S3 res by uncompensated forces F uw This obviously represents an idealized situation and serves to explain the operation of the invention in terms of reducing the effects of the forces F uw on the imaging quality of the projection exposure system 1 (Figure 1) by a symmetrical arrangement of the fluid channel 41 and the supply lines 47.1, 47.2, as well as the bearing points 48.1, 48.2. The invention particularly includes the design of the components comprised by the mirror module 40, such as the fluid channel 41, the supply lines 47.1, 47.2 and the bearing points 48.1,

[0117] 48.2, as well as others to reduce the effects of forces F uw components that can be designed to ensure the image quality of the projection exposure system 1.

[0118] Figure 6 shows a plan view of a schematic representation of a mirror module 50 according to the invention with a mirror S3 and supply lines 57.1,

[0119] 57.2, as explained in Figure 5, where appropriate, corresponding elements are designated by reference numerals increased by 10 compared to the designation in Figure 5. In contrast to the idealized conditions in Figure 5, the pressure p in the supply lines 57.1, 57.2 and in the fluid channel 51 in Figure 6 drops in the flow direction (indicated by an arrow in Figure 6). The pressure p is therefore greater at the beginning of the supply line 57.1 than at the end of the supply line 57.2, whereby the forces F acting on the deflections 59.1, 59.2, 59.3, 59.4 ATvare no longer the same size. In contrast to the idealized representation of the mirror module 40 in Figure 5, the supply lines 57.1, 57.2 of the mirror module 50 run in the plane (xy plane) of the fluid channel 51 up to the connection to the bearing points 58.1, 58.2, thereby preventing tilting of the mirror S3 about the x-axis or y-axis due to the parasitic force caused by the pressure difference between the inlet and outlet.

[0120] The supply lines 57.1, 57.2 also comprise bellows 65, which serve to decouple the mirror S3 from the support frame 66, which is rigidly connected via the bearing points 58.1, 58.2, and are also arranged in the xy plane. The supply lines 57.1, 57.2, in particular the bellows 65, are not ideally rigid, in contrast to, for example, in Figure 5, and deform due to the pressure p, whereby the magnitude and direction of the forces F acting on the supply lines 57.1, 57.2 VTef are influenced, the forces F V Tef therefore depends, among other things, on the stiffness of the bellows 65. The index “e” of the nomenclature stands for a consecutive number of an area 61, 62, 63, 64, where various forces, such as F V TIX, F V Tiy, at power application points P 1x , Pi y attack and moments such as M V TIZ, around a rotation axis R Ez at the inlet 55 of the fluid channel 51. The index “f” of the nomenclature stands for the direction of the force FVTIX, F V Tiy or the rotation axis R Ez of the caused moment M V TIZ-Di® nomenclature also applies to the force application points P efThe bellows 65 are arranged in front of the connection to the bearing points 58.1, 58.2, thereby ensuring decoupling of the mirror S3 from the support frame 66. The bellows 65 are arranged perpendicular to one another and are stiff in the axial direction and soft in the lateral direction, thereby ensuring decoupling of the mirror S3 in all six degrees of freedom. The forces F, which become increasingly smaller in the different areas 61, 62, 63, 64 due to the decreasing pressure p on the supply lines 57.1, 57.2 and the mirror S3 V Tef therefore cause different magnitudes of moments M V Tef, which creates both a resultant force F res , as well as a resulting moment M res on the mirror S3 at point P Ko s or by the angle through the point P Kos axis of rotation in the z-direction.

[0121] Using the example of force F V TIX in x-direction at force application point P1x The effects will be explained below. The force F V TIX causes via the lever arm H V Tiy a moment M V TIZ around a rotation axis R Ez at the entrance 55 of the mirror S3. This moment M V TIZ is due to the pressure difference between the force application point P 1x of FVTIX and the force application point P 4x of F T4X greater than the corresponding force F AT3x caused moment M AT4z around a rotation axis R AZ at the output 56 of the mirror S3 in the area 64. In the case of a constant pressure p, the moment M V TIZ, M V T4Z due to the equal length lever arms HvTiy, H V T4y compensate (see idealized explanation Figure 5).

[0122] It should be noted that in addition to the pressure drop across the supply lines 57.1, 57.2 and the fluid channel 51, even at constant pressure p, a deformation of the supply lines 57.1, 57.2 leads to forces F of different magnitudes. V Tef, which also has a resulting moment M res cause.

[0123] The further moments M AT2z , M AT3z , which are caused by the different forces F AT2x , F AT2y , F AT3X , F AT3y and the lever arms 54.1, 54.2, 54.3, 54.4, influence the direction of rotation of the resulting M res not, since in the case of equal lever arms 54.1 , 54.2, 54.3, 54.4 the moments M T 2z, M T 3 Z equal in size and opposite in direction, thus compensating each other.

[0124] Furthermore, the difference between F V Ti y and F AT2yforce (not shown) as well as the force resulting from the difference between F T 3 y and F V T4y formed force (not shown) a moment (not shown) with the same direction of rotation, whereby these add up and result in the moment M res contribute.

[0125] All forces F shown in Figure 6 V TIX, F AT2X , F AT3X , F V T4X therefore cause a resultant force F on the mirror S3 res and the forces F V TIX, F AT2X , F AT3X , F V T4X caused moments M V TIZ, M AT2Z , M AT3Z , M V T4Z a resulting moment M res , which negatively influences the image quality of the projection exposure system 1 (Figure 1 ).

[0126] In a first method for reducing the effects of flow-induced vibrations transferred in the fluid 52 on the image quality of a projection exposure system 1, 101, in a first step the mirror S3 is divided into three regions 60, 61, 64, which correspond to the mirror S3, the supply line 57.1 and the discharge line 57.2.

[0127] In a second step, each of the areas 60, 61, 64 is optimized individually, i.e. the areas A Te f acting pressure p caused forces F V Tef, F Te f and the resulting moments M V Tef reduced to a minimum.

[0128] The reduction can be realized by adapting the geometry, arrangement and orientation of the supply lines 57.1, 57.2, the bellows 65 and the fluid channel 51, as well as by adapting the stiffness and other physical properties of the supply lines 57.1, 57.2 and the bellows 65.

[0129] In a third step, the individual forces F V Tef, F ATef caused resultant force F res and the resulting moment M res determined and reduced to a minimum.

[0130] The third step can also be an adjustment of the forces FvTef and moments M optimized in the first step V Tef towards larger values ​​and directions different from those of the local optimization. Therefore, the forces in the areas 60, 61, 64 cannot reach the local minimum F V Tef, although the resulting movement of the mirror S3 is minimized.

[0131] In particular, the resulting force F res , in addition to the magnitude of the force F res and / or moment M res also the direction of the force F res and / or moment Mres play a decisive role. Due to the scanning movement described in Figure 1 during the imaging of the structure of the reticle 7 onto the wafer 14 in the y-direction, a displacement in the scanning direction, i.e. in the y-direction, has less of an effect on the imaging of the structure on the wafer 14 than in the x-direction perpendicular to the scanning direction, since a displacement in the scanning direction is averaged out by the scanning process, with a displacement perpendicular to the scanning direction causing a displacement of the image.

[0132] The method described using an optical module designed as a mirror M3 also applies analogously to a module for holding and positioning a wafer and can also be applied to this.

[0133] In a further method for reducing the effects of flow-induced and transferred vibrations on the image quality of a projection exposure system 1, 101, in addition to the optimization of the resulting force F based purely on the magnitude and direction, res and the resulting moment M res The optical sensitivities relevant for imaging are also taken into account. The optical sensitivities shown in the following table are compared with the optical sensitivities determined by the resulting force F res and the resulting moment M res caused displacements and / or rotations of the optical effective surface 29 are multiplied and a sum for the optical effect of deflections of the mirror S3 is formed from the optical effects thus determined.

[0134] The optical effect of deflections of the cooled mirror S3 is determined by adjusting the forces FV Tef is reduced to a minimum, whereby the forces F V Tef may not correspond to the local minimum of the individual regions 60, 61, 64 or the minimized displacement and / or rotation of the mirror S3 described in the previous method.

[0135] The optical effect can be determined, for example, using models based on a pressure p acting in the supply line 57.1, 57.2 and the fluid channel 51. The determination can be carried out at different pressures p, so that an optimal compromise for the design and arrangement of the supply lines 57.1, 57.2 can be found for all pressures examined. This method can be carried out for each of the six mirrors S1, S2, S3, S4, S5, S6 in the example in Figure 1.

[0136] In a further method, the reduction of the effects of flow-induced and transferred vibrations on the imaging quality of the projection exposure system 1 (Figure 1 ) is based on the optimization of the imaging quality of the projection optics 10 (Figure 1 ).

[0137] The optimization of the individual mirrors S1, S2, S3, S4, S5, S6 can be done, as above with the reduction of the forces F VTef, be adjusted in such a way that when viewing the individual mirror S1, S2, S3, S4, S5, S6, the minimum parasitic optical effect is not set, but rather the projection optics 10 with the mirrors S1, S2, S3, S4, S5, S6 causes a minimal parasitic optical effect. The optical effects of deflections of the mirrors S1, S2, S3, S4, S5, S6 therefore at least partially compensate each other. The fundamentally symmetrical structure or the symmetrical formation of the forces with respect to the origin of the mirror coordinate system advantageously minimizes these forces through at least partial compensation. Convolution of the displacements and / or rotations of the mirror caused by the forces with the corresponding optical sensitivities further minimizes the effect of the fluid-induced and transferred vibrations on the imaging quality of the projection exposure system 1.

[0138] List of reference symbols

[0139] 1 projection exposure system

[0140] 2 Lighting system

[0141] 3 Radiation source

[0142] 4 Lighting optics

[0143] 5 Object field

[0144] 6 Object level

[0145] 7 reticles

[0146] 8 reticle holders

[0147] 9 Reticle displacement drive

[0148] 10 Projection optics

[0149] 11 Image field

[0150] 12 Image plane

[0151] 13 wafers

[0152] 14 wafer holders

[0153] 15 Wafer relocation drive

[0154] 16 EUV radiation

[0155] 17 Collector

[0156] 18 Intermediate focal plane

[0157] 19 Deflecting mirrors

[0158] 20 facet mirrors

[0159] 21 facets

[0160] 22 facet mirrors

[0161] 23 facets

[0162] 29 optical effective area

[0163] 30 mirror module

[0164] 31 Fluid channel

[0165] 32 Fluid

[0166] 33 Inner surface of fluid channel

[0167] 34.1 ,34.2 Lever arm forces F A T2y, F A T3y entrance

[0168] Exit

[0169] supply line, discharge line

[0170] 90° elbow

[0171] Mirror module

[0172] Fluid channel

[0173] Fluid

[0174] inner surface

[0175] Lever arm forces F A Tiy, F A T2y

[0176] Entrance

[0177] Exit

[0178] supply line, discharge line

[0179] Storage supply line, discharge line

[0180] 90° elbow

[0181] Mirror module

[0182] Fluid channel

[0183] Fluid

[0184] inner surface

[0185] Lever arm forces FAT1y , F AT2y

[0186] Entrance

[0187] Exit

[0188] supply line, discharge line

[0189] Storage supply line, discharge line 90° elbow

[0190] Mirror area

[0191] Supply area

[0192] Deflection area 1

[0193] Deflection area 2

[0194] Derivation area

[0195] bellows

[0196] Support frame 101 projection exposure system

[0197] 102 Lighting system

[0198] 107 reticles

[0199] 108 reticle holders

[0200] 110 Projection optics

[0201] 113 wafers

[0202] 114 wafer holders

[0203] 116 DUV radiation

[0204] 117 optical element

[0205] 118 versions

[0206] 119 lens housings

[0207] S1-S6 mirrors

[0208] P pressure in the fluid channel

[0209] AT11X> A T1 2X, A T 2X, A T 2y, A T3X , A T3y Partial surface inner surface fluid channel

[0210] Pef force application points

[0211] F Atef forces on the mirror

[0212] FvTef forces on supply lines

[0213] F uw force couple

[0214] F res resulting force

[0215] MvTef moment at the mirror

[0216] MAtef moment on supply line

[0217] M r the resulting moment

Claims

Patent claims 1. Projection exposure system (1, 101) with at least one module (40, 50), - wherein the module (40, 50) comprises a fluid channel (41, 51) which at least temporarily has a pressurized fluid (42, 52) - wherein the fluid channel (41,51) is connected to supply lines (47.1,47.2,57.1,57.2), - whereby the supply lines (47.1, 47.2, 57.1, 57.2) are connected via bearing points (48.1 .48.2.58.1 .58.2) are connected to a support frame (66), characterized in that the module (40,50) is designed symmetrically.

2. Projection exposure system (1, 101) according to claim 1, characterized in that the fluid channel (51) and the supply lines (47.1, 47.2, 57.1, 57.2) lie in one plane (xy plane).

3. Projection exposure system (1, 101) according to claim 2, characterized in that the plane (xy plane) is perpendicular to an axis through a reference point P Kos is formed, which has a minimal optical effect on the image when the module (40,50) rotates about this axis.

4. Projection exposure system (1, 101) according to one of claims 2 or 3, characterized in that the supply lines (57.1, 57.2) extend at least to the bearing points (58.1.58.2) run in the plane (xy-plane).

5. Projection exposure system (1, 101) according to one of claims 2 to 4, characterized in that at least one discharge device arranged in the supply lines (57.1, 57.2) coupling element (65) is arranged within the plane (xy plane).

6. Projection exposure system (1, 101) according to claim 5, characterized in that at least two decoupling elements (65) arranged perpendicular to one another are arranged in front of the connection of the supply lines (57.1, 57.2) to the bearing points (58.1, 58.2).

7. Projection exposure system (1, 101) according to one of claims 5 or 6, characterized in that the decoupling elements (65) are rigid in the axial direction and soft in the lateral direction.

8. Projection exposure system (1, 101) according to one of the preceding claims, characterized in that the module (50) is decoupled from the bearing points (58.1, 58.2) in all six degrees of freedom.

9. Projection exposure system (1, 101) according to one of the preceding claims, characterized in that the fluid channel (41, 51) and / or the supply lines (47.1 ,47.2,57.1 ,57.2) are designed such that the resulting parasitic forces (F res ) and / or moments (M res ) within a module (40,50) are reduced.

10. Projection exposure system (1, 101) according to one of the preceding claims, characterized in that the fluid channel (41, 51) and / or the supply lines (47.1 ,47.2,57.1 ,57.2) are designed in such a way that a resulting parasitic force (F res ) and / or moments (M res ) caused shift movement and / or twisting of the optical module (40,50) are reduced.

11. Projection exposure system (1, 101) according to one of the preceding claims, characterized in that the fluid channels (41, 51) and / or the supply lines (47.1 ,47.2,57.1 ,57.2) are designed in such a way that the resulting parasitic forces (F res ) and / or moments (M res ) are designed such that the resulting parasitic optical effect of the optical module (40,50) is reduced.

12. Projection exposure system (1, 101) according to one of the preceding claims, characterized in that the fluid channels (41, 51) and / or the supply lines (47.1 ,47.2,57.1 ,57.2) are designed in such a way that the resulting parasitic forces (F res ) and / or moments (M res ) are designed such that the resulting parasitic optical effect of the projection optics (10,110) is reduced.

13. Projection exposure system (1, 101) according to one of the preceding claims, characterized in that the module is designed as an optical module (40, 50).

14. Projection exposure system (1, 101) according to one of claims 1 to 12, characterized in that the module is designed as a module for holding and positioning a wafer.

15. Projection exposure system (1, 101) according to one of claims 1 to 12, characterized in that the module is designed as a component of the projection exposure system, in particular as a reference structure for the positioning of a mirror module (40, 50) and / or other components of the projection exposure system (1, 101).

16. Projection exposure system (1, 101) according to one of the preceding claims, characterized in that the module (40, 50) has a symmetrical structure with respect to a reference point (PKOS) formed on the module (40, 50).

17. Method for reducing the effect of parasitic forces (F res ) and / or moments (M res) on the image quality of the projection exposure system (1 , 101 ), comprising the following method steps: - Determination of parasitic forces (F res ) and / or moments (M res ), - Definition of at least two at least partially compensating forces (F uw ) and / or moments (M V TXZ,M A TXZ), - Design of the module (40,50) to generate the compensating forces (F uw ) and / or moments (M V TXZ,M A TXZ)- 18. The method according to claim 17, characterized in that the design is realized by the arrangement and / or alignment and / or the material selection of at least one component (41, 47.1, 47.2, 51, 57.1, 57.2, 48.1, 48.2, 58.1, 58.2, 59, 65) of the module (40, 50), in particular of at least one supply line (47.1, 47.2, 57.1, 57.2) and a fluid channel (41, 51) of the module (40, 50).

19. Method according to claim 17 or 18, characterized in that the resulting parasitic forces (F res ) and / or moments (M res ) for at least a portion of the module (40,50).

20. Method according to one of claims 17 to 19, characterized in that the resulting parasitic forces (F res ) and / or moments (M res ) for a module (40,50).

21. Method according to one of claims 17 to 20, characterized in that the module is designed as an optical module (40, 50).

22. Method according to one of claims 17 to 20, characterized in that the module is designed as a module for holding and positioning a wafer.

23. Method according to one of claims 17 to 22, characterized in that a parasitic force (F res ) and / or moments (M res) caused displacement and / or rotation of the optical module (40,50) is reduced.

24. Method according to one of claims 17 to 23, characterized in that a parasitic optical effect of the optical module (40, 50) is determined by multiplying the displacement and / or rotation of the optical module (40, 50) by corresponding optical sensitivities.

25. Method according to claim 24, characterized in that the resulting parasitic forces (F res ) and / or moments (M res ) are designed such that the resulting parasitic optical effect of the optical module (40,50) is reduced.

26. Method according to claim 25, characterized in that the resulting parasitic optical effects of at least one optical module (40, 50) are added to a resulting parasitic optical effect of a projection optics (10, 110) of the projection exposure system (1, 101).

27. Method according to claim 26, characterized in that the resulting parasitic forces (F res ) and / or moments (M res ) such designed so that the resulting parasitic optical effect of the projection optics (10,110) is reduced.

Images