Faceted Mirror Assembly

Abstract

The facet mirror assembly (20) comprises a plurality of individual mirrors (28 i ) and a carrier body (39) for the individual mirrors (28 i The reflective surface of each mirror is tilted by an assigned tilt actuator along at least one tilt axis (33) within an individual mirror tilt angle range centered on a neutral tilt position between a maximum angle and a minimum angle. i ;36 i ) can be tilted individually around the mirror (28 i ) has at least two different neutral tilt positions in a range around the mean value of the total tilt angle range. A facet mirror assembly is obtained which reduces the requirements on the tilt actuator system of the facet mirror assembly.

Description

[Technical Field]

[0001] This patent application claims priority from German Patent Application No. 10 2022 207 546.3, the content of which is incorporated herein by reference.

[0002] The present invention relates to a facet mirror assembly, an illumination optical unit for projection lithography comprising such a facet mirror, an optical system comprising such an illumination optical unit, a projection exposure apparatus comprising such an optical system, a method for producing a microstructured or nanostructured component, and a component produced by this method. [Background technology]

[0003] A facet mirror assembly of the type mentioned in the opening paragraph is known from DE 10 200 043 133. Illumination optical units for projection lithography are known from DE 10 200 043 133 A1, DE 10 200 043 133 A1 and DE 10 200 043 133 A1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] DE 10 2018 207 103 [Patent Document 2] U.S. Patent No. 9,977,335 [Patent Document 3] International Publication No. 2009 / 100856 [Patent Document 4] International Publication No. 2008 / 011981 Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the invention is to develop a facet mirror assembly of the type mentioned in the introduction in such a way that the requirements on the tilt actuator of the facet mirror assembly are reduced. [Means for solving the problem]

[0006] This object is achieved according to the invention by a facet mirror assembly having the features of claim 1.

[0007] The facet mirror assembly according to the present invention allows a total tilt angle range covered by the individual mirrors that is larger than the individual mirror tilt angle range of each individual mirror. Because the neutral tilt positions are different, the different individual mirror tilt angle ranges, which are respectively shifted due to the different neutral tilt positions, can cover a large total tilt angle range. This makes it possible to use tilt actuator systems for the individual mirrors, which, due to the small tilt angle range requirement, can be designed to meet other requirements for the facet mirror assembly, in particular the requirement regarding good thermal conductivity between the reflective surfaces of the individual mirrors and the carrier body of the facet mirror assembly. Therefore, the small individual mirror tilt angle range compared to the total tilt angle range makes it possible to reduce the surface temperature of the reflective surfaces of the individual mirrors in the event of residual absorption of reflected light during reflection by the individual mirrors, which is the case in particular when the facet mirror assembly is used to reflect EUV light.

[0008] The substrate bodies of the individual mirrors are fixed to the carrier body of a facet mirror assembly, which may have a MEMS structure as described for example in German patent application no.

[0009] The individual mirrors assigned to a carrier body have different neutral tilt positions if a particular one of these individual mirrors has one neutral tilt position and other individual mirrors have different neutral tilt positions.

[0010] The facet mirror assembly may have a plurality of carrier bodies. The individual mirrors of the facet mirror assembly are assigned to at least one of the carrier bodies, to which a substrate body is fixed, each having at least two different neutral tilt positions. It is also possible for the individual mirrors fixed to the same carrier body of the facet mirror assembly to have three or more different neutral tilt positions, for example three, four, five or even more neutral tilt positions. In limited cases, each of the individual mirrors fixed to the same carrier body of the facet mirror assembly may have an individual neutral tilt position.

[0011] In the case of a facet mirror assembly according to claim 2, the concept of an individual mirror tilt angle range that is small compared to the total tilt angle range applies to two tilt angle dimensions about two tilt axes, with corresponding advantages being obtained in both tilt angle dimensions.

[0012] The grouping of individual mirrors as claimed in claim 3 simplifies the configuration of the facet mirror assembly. Such individual mirror groups can be embodied as rows or columns, i.e., as 1D groups, or as an array of at least two rows and at least two columns, i.e., as 2D groups. A facet mirror assembly can have several groups of such individual mirrors, each having the same group neutral tilt position, the group neutral tilt positions of at least two of these groups, each fixed to the same carrier body of the facet mirror assembly, being different from one another. Furthermore, such a facet mirror assembly can be provided with individual mirrors with individual neutral tilt positions, which are fixed to the same carrier body of the facet mirror assembly as the individual mirror groups.

[0013] It has been found that the tilt angle range ratio according to claim 4 is suitable in practice to enable reduced requirements on the tiltability of the individual mirrors on the one hand and on the mechanical and actuator systems due to the small individual mirror tilt angle range on the other hand. The ratio of the total tilt angle range to the individual mirror tilt angle range can be approximately 1.2, can be approximately 1.5, can be 2 or more and is usually less than 100.

[0014] The configuration of the facet mirror assembly according to claim 5 allows for the predefinition of a neutral tilt position by means of a corresponding wedge shape of the substrate body of each individual mirror. This variant allows for the use of otherwise identically configured individual mirrors, thereby reducing the manufacturing costs of the facet mirror assembly. The substrate body can also be two-dimensionally wedge-shaped in order to predefine each neutral tilt position around the two tilt axes of each individual mirror. The configuration according to claim 6 also allows for different neutral tilt positions to be predefined for the individual mirrors. Thus, a two-dimensional wedge-shaped mirror plate design for predefining neutral tilt positions around the two tilt axes of each individual mirror is also possible here. For example, a combination of a first wedge-shaped mirror plate and a second wedge-shaped substrate body of each individual mirror is also possible in order to decouple the predefinition of the neutral tilt positions of the individual mirrors around the two tilt axes. The neutral tilt position around one of the two tilt axes can be predefined by the wedge shape of the substrate body, and the neutral tilt position around the other of the two tilt axes can be predefined by the wedge shape of the mirror plate.

[0015] The configuration of the facet mirror assembly has been found to be meaningful for a field facet mirror, a pupil facet mirror, or a specular reflector.

[0016] The advantages of the illumination optical unit according to claim 8, the optical system according to claim 9, the projection exposure apparatus according to claim 10, the method for manufacturing a microstructured or nanostructured component according to claim 11, and the microstructured or nanostructured component manufactured thereby correspond to those already mentioned above with reference to the facet mirror assembly. The illumination optical unit can be part of an illumination system to which a light source, in particular an EUV light source, also belongs.

[0017] The component to be manufactured may be a semiconductor device, in particular a microchip, in particular a memory chip.

[0018] At least one exemplary embodiment of the invention is described below with reference to the drawings. [Brief explanation of the drawings]

[0019] [Figure 1] 1 shows a schematic meridian section of a projection exposure apparatus for EUV projection lithography; [Figure 2] Schematically illustrates the transmission of a partial field predefined by adjacently arranged first facets of a first facet mirror of a facet mirror assembly of the illumination optical unit to a partial section of the object field of an imaging optical unit downstream of the projection exposure apparatus, via a transmission optical unit including a further facet mirror and a transmission mirror, as implemented using the illumination optical unit of the projection exposure apparatus shown in FIG. [Figure 3] 1 shows the basic configuration of the individual mirrors of a facet mirror assembly in cross section taken along a plane perpendicular to the reflecting surface. [Figure 4] 4 illustrates an embodiment of the arrangement of individual mirrors shown in FIG. 3 having individually different neutral tilt positions of the individual mirrors relative to the carrier body of the facet mirror assembly for the individual mirrors, the individual neutral tilt positions being predefined by corresponding wedge shapes of the substrate body of the individual mirrors. [Figure 5] 10 shows yet another embodiment of a group of individual mirrors of an embodiment of a facet mirror assembly, in which the individual mirrors have the same neutral tilt position predefined by the wedge shape of the common base body of the individual mirrors. [Figure 6] 1 shows a graphical rendering of the full tilt angle range of individual mirrors of one embodiment of a facetted mirror assembly, including each individual mirror tilt angle range, in one tilt axis dimension. [Figure 7] 10 shows a graphical rendering of the total tilt angle range of the individual mirrors of one embodiment of a facetted mirror assembly, including each individual mirror tilt angle range, in two tilt axis dimensions. DETAILED DESCRIPTION OF THE INVENTION

[0020] The essential components of a microlithography projection exposure apparatus 1 are exemplarily described below, initially with reference to Figure 1. The description of the basic configuration of the projection exposure apparatus 1 and its components is to be understood here as non-limiting.

[0021] In addition to the radiation source 3, an embodiment of the illumination system 2 of the projection exposure apparatus 1 comprises an illumination optical unit 4 which illuminates an object field 5 in an object plane 6. In an alternative embodiment, the light source 3 can also be provided as a module separate from the rest of the illumination system. In this case, the illumination system does not include the light source 3.

[0022] The object field 5 is embodied in an arc shape. The object field 5 may also be embodied in a partial circular shape.

[0023] A reticle 7 arranged in the object field 5 is exposed. The reticle 7 is held by a reticle holder 8. The reticle holder 8 is displaceable, in particular in the scanning direction, by a reticle displacement drive 9.

[0024] For illustrative purposes, a Cartesian xyz coordinate system is shown in Figure 1. The x direction extends perpendicular to the plane of the drawing. The y direction extends horizontally and the z direction extends vertically. In Figure 1, the scanning direction extends in the y direction. The z direction extends perpendicular to the object plane 6.

[0025] The projection exposure apparatus 1 comprises a projection optical unit 10. The projection optical unit 10 serves to image the object field 5 into an image field 11 in an image plane 12. The image plane 12 extends 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.

[0026] The structures on the reticle 7 are imaged onto a photosensitive layer of a wafer 13, which is arranged in the region of the image field 11 of the image plane 12. The wafer 13 is held by a wafer holder 14. The wafer holder 14 is displaceable, in particular in the y-direction, by a wafer displacement drive 15. The displacement of the reticle 7, firstly, by the reticle displacement drive 9 and, secondly, by the wafer displacement drive 15, can be performed synchronously with respect to one another.

[0027] The radiation source 3 is an EUV radiation source. The radiation source 3 in particular emits EUV radiation 16, also referred to in the following as working radiation, illumination radiation or illumination light or imaging light. In particular, the working radiation has a wavelength in the range of 5 nm to 30 nm. The radiation source 3 may be a plasma source, such as an LPP (Laser Produced Plasma) source or a GDPP (Gas Discharge Plasma) source. It may also be a synchrotron-based radiation source. The radiation source 3 may be a Free Electron Laser (FEL).

[0028] The illumination radiation 16 from the radiation source 3 is focused by the collector 17. The collector 17 may have one or more ellipsoidal and / or hyperbolic reflecting surfaces. The illumination radiation 16 may be incident on at least one reflecting surface of the collector 17 at grazing incidence (GI), i.e., at an angle of incidence greater than 45° relative to the direction normal to the mirror surface, or at normal incidence (NI), i.e., at an angle of incidence less than 45°. The collector 17 may be structured and / or coated, firstly to optimize its reflectivity for the radiation used and secondly to suppress extraneous light. Together with the light source 3, the collector 17 may form a source-collector module.

[0029] Downstream of the collector 17, the illumination radiation 16 propagates through an intermediate focus in an intermediate focal plane 18. The intermediate focal plane 18 may represent a separation point between the source module, including the radiation source 3 and the collector 17, and the illumination optics unit 4.

[0030] The illumination optical unit 4 comprises a deflection mirror 19 and a first facet mirror 20 arranged downstream thereof in the beam path, which will be explained in more detail below.

[0031] The deflection mirror 19 can be a plane deflection mirror or a mirror with beam-influencing effects beyond a pure deflection effect. Alternatively or additionally, the deflection mirror 19 can be embodied as a spectral filter that separates the used optical wavelength of the illumination radiation 16 from extraneous light of wavelengths outside of it. If the first facet mirror 20 is arranged in a plane of the illumination optical unit 4 that is optically conjugate with the object plane 6 as a field plane, this facet mirror is also referred to as a field facet mirror. The first facet mirror 20 comprises a plurality of individual first facets 21, also referred to as field facets in the following. Figure 1 shows only some of these facets 21 by way of example.

[0032] The first facet mirror 20 is positioned in the far field of the illumination light 16. The far field may be positioned approximately in a Fourier conjugate plane relative to the light source or radiation source 3.

[0033] The first facets 21 can be embodied as macroscopic facets, in particular as rectangular facets, or as facets with an arcuate or part-circular edge profile. The first facets 21 can be embodied as planar facets or as convexly or concavely curved facets. The first facets 21 can be individually tiltable by means of assigned actuators.

[0034] The first facet 21 itself can also consist of a number of individual mirrors, in particular a number of micromirrors, as is known, for example, from DE 10 2008 009 600. The first facet mirror 20 can in particular be configured as a microelectromechanical system (MEMS system). See DE 10 2008 009 600 for further details.

[0035] Between the collector 17 and the deflection mirror 19, the illumination radiation 16 travels horizontally, i.e. in the y direction.

[0036] In the beam path of the illumination optical unit 4, a second facet mirror 22 is arranged downstream of the first facet mirror 20. The second facet mirror 22 is positioned away from an entrance pupil plane downstream of the projection optical unit 10, which is shown by way of example in Fig. 1 between the two facet mirrors 20, 22. The entrance pupil EP is the image of the entrance side of the aperture-limiting stop of the projection optical unit 10. Alternatively, the second facet mirror can also be arranged at or in the region of this entrance pupil EP, in which case it is called a pupil facet mirror and which, together with the field facet mirror 20, forms the illumination optical unit like a fly's eye condenser.

[0037] The entrance pupil plane EP of the projection optical unit 10 can be arranged upstream or downstream of the second facet mirror 22 in the beam path of the illumination light 16, if the second facet mirror 22 is arranged away from the entrance pupil plane EP. The distance between the entrance pupil plane and the arrangement plane of the second facet mirror 22 is at least 5% of the distance between the two facet mirrors 20, 22.

[0038] If the second facet mirror 22 is arranged away from the entrance pupil EP, 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 in principle from US Pat. No. 9,977,335 or US Patent Application Publication No. 2006 / 0132747, EP 1 614 008 and US Pat. No. 6,573,978.

[0039] The second facet mirror 22 comprises a plurality of second facets 23, also called specular facets in the case of its embodiment as a specular reflector, so that the illumination optical unit 4 forms a double-facet system.

[0040] The second facet 23 may likewise be a macroscopic facet, which may have, for example, a circular, rectangular or hexagonal boundary, or may be a facet made up of individual mirrors or micromirrors. In this respect, reference is also made to DE 10 2008 009 600 A1.

[0041] The second facets 23 may have a planar reflecting surface or a convexly or concavely curved reflecting surface. The second facets 23 are individually tiltable by means of assigned actuators. In alternative embodiments of the illumination optical unit, the second facets can also be designed as non-tiltable facets.

[0042] A transmission mirror 24, which contributes to the imaging of the first facet 21 into the object field 5, is arranged in the beam path between the second facet mirror 22 and the object field 5. The transmission mirror 24 is embodied as a grazing incidence mirror (GI mirror). The minimum angle of incidence of the illumination light 16 on the transmission mirror 24 is greater than 45°, and can be greater than 60°, greater than 65°, greater than 70°, greater than 75°, or even greater. Such a transmission mirror 24 is not mandatory, since the illumination light 3 can also be guided directly to the object field 5 after reflection at the second facet 23 of the second facet mirror 22, in particular without further mirror reflections.

[0043] 1, the illumination optical unit 4 has exactly four mirrors downstream of the collector 17, in particular a deflection mirror 19, a field facet mirror 20, a further facet mirror 22 and a transmission mirror 24. Depending on the embodiment of the illumination optical unit 4, the deflection mirror 19 can also be omitted, so that the first facet mirror 20 is the first beam-guiding component for the illumination light 16 downstream of the intermediate focal plane 18. The reflective surface of the transmission mirror 24 deviates from a plane, i.e. extends in a curved rather than a planar manner.

[0044] The transmitting mirror 24 has a beam-shaping effect on the overall beam of illumination light 16. Depending on the embodiment, the transmitting mirror 24 has an imaging effect with an imaging magnification that has a magnification or demagnification effect. An imaging magnification of less than 1 represents a demagnification imaging magnification: An imaging magnification of more than 1 represents a magnification imaging magnification:

[0045] In yet another alternative, the imaging magnification can be 1, or the transmit mirror 24 can provide imaging with different imaging magnifications in the x and y directions. The imaging magnification of the transmit mirror 24 can have a value in the x and / or y directions in the range of 0.1 to 10. In particular, the imaging magnification can be in the range of 0.125 to 8, can be 0.25 to 4, can be 0.33 to 3, can be 0.5 to 2, can be 0.75 to 1.25, or can be 0.9 to 1.1.

[0046] The projection optical unit 10 comprises a number of mirrors Mi, which are numbered consecutively according to their location in the beam path of the projection exposure apparatus 1 .

[0047] 1, the projection optical unit 10 includes six mirrors M1 to M6. 4, 8, 10, 12 or any other number of mirrors Mi are equally possible. The projection optical unit 10 is a double-shielded optical unit. The penultimate mirror M5 and the final mirror M6 each have a passage aperture for the illumination radiation 16. The projection optical unit 10 has an image-side numerical aperture that is greater than 0.5, may be greater than 0.6, and may be, for example, 0.7 or 0.75.

[0048] The reflective surface of the mirror Mi can be embodied as a freeform surface without an axis of rotational symmetry. Alternatively, the reflective surface of the mirror Mi can be designed as an aspheric surface, with exactly one axis of rotational symmetry of the reflective surface shape. Like the mirrors of the illumination optical unit 4, the mirror Mi can have a coating that is highly reflective with respect to the illumination radiation 16. These coatings can be designed as multilayer coatings, in particular with alternating layers of molybdenum and silicon.

[0049] Projection optical unit 10 has a large object-image offset in the y direction between the y coordinate of the center of object field 5 and the y coordinate of the center of image field 11. This object-image offset in the y direction can be approximately as large as the z distance between object plane 6 and image plane 12.

[0050] In particular, the projection optical unit 10 can have an anamorphic configuration, in particular this allows for different imaging scales b in the x and y directions. x , b y The two imaging scales b of the projection optical unit 10 x , b y is preferably (b x ,b y ) = (+ / -0.25, + / -0.125). A positive imaging scale b means imaging without image inversion. A negative sign of the imaging scale b means imaging with image inversion.

[0051] The projection optical unit 10 results in a size reduction in the x-direction, ie perpendicular to the scanning direction, by a ratio of 4:1.

[0052] The projection optical unit 10 provides a size reduction of 8:1 in the y-direction, ie the scan direction.

[0053] Other imaging scales are possible as well, including imaging scales of the same sign and magnitude in the x and y directions, for example 0.125 or 0.25.

[0054] 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 may be the same or may differ depending on the design of the projection optical unit 10. An example of a projection optical unit with a different number of such intermediate images in the x and y directions is known from US Patent Application Publication No. 2018 / 0074303.

[0055] The first facet 21 of the first facet mirror 20 is illuminated by the illumination optical unit 4 in a corresponding embodiment of the illumination optical unit 4 through a partial section 25 of the object field 5 . i 2, the second facet mirror 22 may serve to predefine the partial field of view that is transmitted to the second facet mirror 22. This transmission may be imaging. Each second facet 23 may further comprise a number of individual mirrors, also referred to as virtual partial field facets 23, which are used to direct each component beam 16 at the second facet mirror 22.

[0056] FIG. 2 shows a total of nine first facets 21 arranged in three rows (i=1, 2, 3) and three columns (j=1, 2, 3). ij 2 clearly shows this transmission by the first facets 21 to the partial sections 25 of the object field 5. Thus, FIG. 2 shows a total of nine first facets 21 ij 1 shows a cross section of a first facet mirror 20 having a first facet 21. In practice, the number of first facets 21 of the first facet mirror 20 may be much larger, for example in the range of several hundred.

[0057] Each first facet 21 may consist of a series of macroscopic reflective surfaces. Alternatively, each first facet 21 may consist of a number of adjacent individual mirrors or micromirrors.

[0058] component beams 16 of the total beam of illumination light 16 i is the first facet 21 ij and the first facet 21 ij is thus transmitted to the partial sections 251, 252, 253 of the object field 5. The transmission optical unit used for this purpose, formed by the second facet mirror 22 and the transmission mirror 24, is only shown diagrammatically in FIG.

[0059] 1st facet 21 ij is the first facet 21 ij The partial field of view predefined by can be realized with a rectangular reflective surface boundary so that the partial field of view predefined by can be rectangular.

[0060] 1st facet 21 11 ,twenty one 21 , and 21 33 Component beam 16 reflected by i are superimposed and transmitted by the transmission optical units 22, 24 onto the partial section 251 shown on the left side of the object field 5 in FIG. 12 ,twenty one 23 , and 21 32 Component beam 16 reflected by i are transmitted by the transmission optical units 22, 24 onto a central subsection 252 of the object field 5 in FIG. 13 ,twenty one 22 , and 21 31 Component beam 16 reflected by i are superimposed and transmitted by the transmission optical units 22, 24 to the subsection 253 shown on the right side of the object field 5 in FIG.

[0061] In a direction transverse to the object displacement direction y, i.e. along the x direction, the subsection 25i has an extent that is 1 / 3 of the extent of the object field. Depending on the embodiment of the illumination optical unit 4, this x extent of the subsection can be 50% or less, 40% or less, 30% or less, 25% or less, 10% or less, for example 5% or possibly even less. This x extent of the subsection 25 is typically more than 1% of the x extent of the object field 5.

[0062] The subsections 25 span the entire object field 5 along the object displacement direction y. Alternatively, there can be several adjacent subfields along the y direction, for example two, three or even more such subfields.

[0063] Figure 3 shows one basic configuration of a mirror of the first facet mirror 20 and / or the second facet mirror 22 in a cross section perpendicular to the reflective surface 26 with the reflective coating 27. This mirror can be the first facet 21 of the first facet mirror 20 and / or the second facet 23 of the second facet mirror 22. Alternatively, the individual mirror of Figure 3 can be an individual mirror or micromirror that is part of this type of first or second facet 23 together with further individual mirrors of this type, as already mentioned above. The configuration shown in Figure 3 will be explained on the basis of this type of individual mirror 28.

[0064] The individual mirror 28 has a mirror plate 29 that is coated with a reflective coating 27. Furthermore, the individual mirror 28 has a substrate body 30. The mirror plate 29 and the substrate body 30 are mechanically connected to each other by a suspension 31. In one embodiment of the individual mirror 28, the mirror plate 29, the substrate body 30, and the suspension 31 are one-piece components, i.e., are integrated with each other.

[0065] The individual actuators 28 further comprise tilt actuators 321 and 322, respectively, arranged between the mirror plate 29 and the substrate body 30. The tilt actuators 321 and 322 are arranged on both sides of the suspension 31. The tilt actuators 321 and 322 are embodied capacitively, i.e., each has a mirror plate-side electrode and a substrate-side electrode, with an air gap between them. The tilt actuators 321 and 322 enable tilting of the mirror plate 29 relative to the substrate 30 around a tilt axis 33 perpendicular to the plane of FIG. 3 in the region of the suspension 31.

[0066] The tilt actuators 321 and 322 can be assigned sensor units 341 and 342, respectively. The tilt angle of the mirror plate 29 with respect to the substrate body 30 can be measured by these sensor units 341 and 342. i are signal connected to a central control / regulation unit 35 shown diagrammatically in FIG.

[0067] The individual mirror 28 is connected to two further tilt actuators 32 for tilting the mirror plate 29 relative to the substrate body 30 about a further tilt axis 36 which is perpendicular to the tilt axis 33 and which is in the drawing plane of FIG. i 3, which are located in front of and behind the plane of the drawing of FIG. 3, and the suspension 31 is connected to these two further tilt actuators 32 i The two tilt axes 33, 36 subtend a plane in which the reflecting surface 26 is arranged parallel in the neutral tilt position shown in FIG.

[0068] 4 shows a variant embodiment of a facet mirror assembly 37 with a total of four individual mirrors 281, 282, 283, 284, like the individual mirror 28 of FIG. 3. This facet mirror assembly 37 can be used as part of the facet mirror 20 and / or as part of the facet mirror 22. In this case, the individual mirrors 28 imay be individual mirrors which together constitute a virtual facet, in particular of the first facet mirror 20 , or may be a facet as a whole, in particular the first facet 21 of the first facet mirror 20 .

[0069] Individual mirrors 28 i is assigned to tilt actuator 32 i 4. In one tilt angle dimension, i.e., each individual mirror 28 perpendicular to the plane of the drawing in FIG. 4, can be tilted individually about each tilt axis 33, 36 within the individual mirror tilt angle range centered on the neutral tilt position shown in FIG. 4 between the maximum angle and the minimum angle. i tilt axis 33 i In the case of tilting around α, this is represented for two different neutral tilt positions, e.g., β1 for individual mirror 281 in FIG. 4 and β4 for individual mirror 284 in FIG. 4. Individual mirror 281 is tiltable around its neutral tilt position β1 through a tilt angle range around tilt axis 331 between a minimum angle β1-β and a maximum angle β1+β. Individual mirror 284 is tiltable around its neutral tilt position β4 between a minimum angle β4-β and a maximum angle β4+β. The two neutral tilt positions β1 and β4 differ in absolute tilt angle around tilt axes 331 and 334. The two tilt angle ranges [β1-β;β1+β] and [β4-β;β4+β] lie within the full tilt angle range ([-α;+α]) around a mean value α, which is defined as α=0.

[0070] Individual mirrors 28 i Different neutral tilt positions β i This is achieved by the corresponding wedge shapes of the wedge-shaped connectors 381, 382, 383, and 384 of the substrate bodies 301 to 304 of the individual mirrors 281 to 284. i Through, individual mirror 28 i is connected to the carrier body 39 of the facet mirror assembly 37. The two tilt axes 38 i and 36 i Neutral tilt position β around i In order to predefine the wedge-type connection 38 i These wedge-shaped joints 38 are designed as two-dimensional wedge shapes.i The wedge angle of is not only the drawing plane of FIG. 4 but also perpendicular to it and the tilt axis 36 i can also be in the drawing plane to which is perpendicular.

[0071] Individual mirrors 28 arranged as shown in FIG. i Neutral tilt position β i In this case, the applicable ratio is β3<β1<β2(=0)<β4.

[0072] FIG. 7 shows the mirror 28 i For one of the angles, the entire tilt angle range [-α x / y ;+α x / y ] neutral tilt position β 1,x , β 1,y 10 shows a schematic representation of the individual mirror tilt angle range in two tilt angle dimensions x and y, centered on . Here, the individual mirror tilt angle range β i ±β is the tilt angle dimension x (tilt axis 33 i ) and y (corresponding to tilt angle 36i). Therefore, the entire tilt angle range [-α x / y ;+α x / y ] is also the same size in the tilt angle dimension, so the neutral tilt position β 1,x , β 1,y The individual tilt angle ranges centered on the coordinates of the coordinate system α0 and the entire tilt axis range centered on the coordinates of the coordinate system α0 (α0=0) in FIG. 7 are represented by circles.

[0073] In the embodiment shown in FIG. 4, the individual mirrors 28 i Each of these has an individual neutral tilt position β i or β i,x ;β i,y It has.

[0074] Alternatively or additionally, the facet mirror assemblies may each have a neutral tilt position β i A plurality of individual mirrors 28 having the same tilt angle value with respect to iThis will be explained below on the basis of the facet mirror assembly section 40 shown in Figure 5. The facet mirror assembly section 40 has four individual mirrors 285, 286, 287, 288, the basic configuration of which again corresponds to that of the individual mirror 28 shown in Figure 3.

[0075] In the case of the facet mirror assembly section 40, these individual mirrors 285-288 are connected to the facet assembly carrier body 39 via a common wedge-shaped connection 41. The wedge angle of the wedge-shaped connection 41 in this case predefines the neutral tilt positions β5=β6=β7=β8 of the individual mirrors 285-288 of the facet mirror assembly section 40.

[0076] The individual mirrors 285 to 288 are at the same group neutral tilt position β i 28 individual mirrors i A group of

[0077] The facet mirror assembly 20 specifically includes a plurality of such facet mirror assembly sections 40 having different wedge-shaped connections 41, each of which has a different wedge angle and therefore a different wedge angle between the individual mirrors 28 of each facet mirror assembly section 40. i Different neutral tilt positions β i shall be prescribed in advance.

[0078] The total tilt angle range [-α; +α] is the individual mirror tilt angle range [β i -β;β i +β]. The ratio of the total tilt angle range to the tilt angle range of each individual mirror may be in the range of 1.1 to 100, in particular 1.1 to 10, for example 1.1 to 3, in particular about 2.

[0079] In order to satisfy the condition that the tilt angle range of each individual mirror is within the entire tilt angle range, the individual mirrors 28 i Neutral tilt position β i is in the range [α0-α+β;α0+α-β] which is satisfied for both dimensions x and y.

[0080] tilt axis 33 i The amount of change in the tilt angle around the tilt axis 36 i Since the amount of tilt angle change may differ from that of the surrounding area, an elliptical or egg-shaped tilt angle range may also be produced in addition to the circular tilt angle range shown in Fig. 7. The ratio of the amount of tilt angle change about each neutral tilt position in the two tilt angle dimensions x and y may be in the range of 1 to 10, particularly 1 to 2.

[0081] In the embodiment not shown, each individual mirror 28 i Each neutral tilt position β i Each individual mirror has 28 i Mirror Plate 29 i The mirror plate 29 is predefined by the corresponding wedge shape of the mirror plate 29. i In this case, the wedge-shaped connection 38 i or has the function of a wedge-type connection consistent with the function described above in relation to 41.

[0082] For yet another embodiment, also not shown, of each facet mirror assembly section, such as the facet mirror assembly section 37 shown in FIG. 4 and the facet mirror assembly section 40 shown in FIG. 5, the neutral tilt position β i and the neutral tilt position β of the other tilt angle dimension. i Wedge-shaped mirror plate 29 for predefining i In this case, the two tilt axes 33 are connected to the wedge involved. i and 36 i The neutral tilt position around one of these tilt axes, e.g., tilt axis 33, can be predefined by the wedge shape of the substrate body, and the neutral tilt position around the other tilt axis, e.g., tilt axis 38, can be predefined by the wedge shape of the substrate body. i can be predefined by the wedge shape of the mirror plate 29 .

[0083] In order to manufacture microstructured components, in particular highly integrated semiconductor components, such as memory chips, using the projection exposure apparatus 1, a reticle 7 and a wafer 13 are first prepared. The structure on the reticle 7 is then projected onto a photosensitive layer on the wafer 13 using the projection optical unit of the projection exposure apparatus 1. The photosensitive layer is then developed, thereby creating a microstructure on the wafer 13, from which a microstructured or nanostructured component can be manufactured.

Claims

1. A facet mirror assembly (20), comprising: A plurality of individual mirrors (28 ｉ ) a carrier body (39) for The individual mirror (28 ｉ ) reflecting surface (26) of the tilt actuator (32) assigned to ｉ ) to find the maximum angle (β ｉ +β) and the minimum angle (β ｉ -β) and the neutral tilt position (β ｉ The individual mirror tilt angle range ([β ｉ -β; β ｉ +β]) about at least one tilt axis (33; 36), The individual mirror (28 ｉ ) is the total tilt angle range ([α ０ -α;α ０ + α]) average value (α ０ ) centered on the range ([α ０ -α + β; α ０ +α−β]) ｉ ) a facet mirror assembly having

2. 2. A facet mirror assembly according to claim 1, wherein the individual mirrors (28 ｉ The reflective surface (26) of the tilt actuator (32) ｉ ) to find the maximum angle (β ｉ +β) and the minimum angle (β ｉ -β) and the neutral tilt position (β ｉ ) centered on each tilt angle range ([β ｉ -β; β ｉ +β]) about two tilt axes (33, 36), The individual mirrors (28) are arranged to predefine the respective tilt angle ranges around the two tilt axes (33, 36), respectively. ｉ ) is the total tilt angle range ([α ０ -α;α ０ + α]) average value (α ０ ) centered on the range ([α ０ -α + β; α ０ +α−β]) ｉ ) a facet mirror assembly.

3. 3. The facet mirror assembly according to claim 1, wherein the group neutral tilt positions (β ｉ ) a facet mirror (28) ５ ~28 ８ 1. A facet mirror assembly comprising: a plurality of groups (40) including:

4. 4. A facet mirror assembly according to claim 1, wherein the magnitude of the total tilt angle range is at least 1.1 times the magnitude of the individual mirror tilt angle range.

5. A facet mirror assembly according to any one of claims 1 to 4, wherein the individual mirrors (28 ｉ ) each of the mirror plates (29 ｉ ) and the substrate body (30 ｉ ), and the individual mirror (28) ｉ ) the tilt actuator (32 ｉ ) is the mirror plate (29 ｉ ) and the substrate body (30 ｉ ) and The individual mirror (28 ｉ ) one of the neutral tilt positions (β ｉ ) is the individual mirror (28 ｉ ) the substrate body (30 ｉ ) wedge-type connection (38 ｉ ) a facetted mirror assembly, characterized in that the facetted mirror assembly is predefined by a corresponding wedge shape of the facetted mirror.

6. A facet mirror assembly according to any one of claims 1 to 5, wherein the individual mirrors (28 ｉ ) each of the mirror plates (29 ｉ ) and the substrate body (30 ｉ ), and the individual mirror (28) ｉ ) the tilt actuator (32 ｉ ) is the mirror plate (29 ｉ ) and the substrate body (30 ｉ ) and The individual mirror (28 ｉ ) one of the neutral tilt positions (β ｉ ) is the individual mirror (28 ｉ ) the mirror plate (29) ｉ ) a facetted mirror assembly, characterized in that the facetted mirror assembly is predefined by a corresponding wedge shape of the facetted mirror.

7. A facet mirror assembly according to any one of claims 1 to 6, embodied as a field facet mirror (20) and / or a pupil facet mirror and / or a specular reflector (22) of a projection exposure apparatus (1).

8. 10. An illumination optical unit (4) for projection lithography, which illuminates an object field (5) of a downstream imaging optical unit (10) in which an object (7) to be illuminated can be arranged with illumination light (16) from a light source (3), the illumination optical unit comprising a facet mirror (20, 22) according to claim 7.

9. 9. An optical system comprising an illumination optical unit (4) according to claim 8 and a projection optical unit (10) for imaging an object field (5) into an image field (11).

10. 10. A projection exposure apparatus comprising an optical system according to claim 9 and a light source (3).

11. Manufacturing a microstructured component, comprising: providing a reticle (7); Providing a wafer (13) having a coating that is sensitive to illumination light (16); - projecting at least a part of the reticle (7) onto the wafer (13) using a projection exposure apparatus (1) according to claim 10; developing the photosensitive layer on the wafer (13) that has been exposed to the illumination light (16); A method comprising:

12. A component manufactured by the method of claim 11.

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