Faceted mirror for a lighting optic for projection lithography, suitable for use as a second faceted mirror

Abstract

A faceted mirror (7) for an illumination optic for projection lithography is suitable for use as a second faceted mirror such that first facets of a first faceted mirror are imaged, by means of a transmission optic comprising second facets (25) of the second faceted mirror (7), at least into subfields of an object field of the illumination optic in which an object can be arranged that is displaced through the object field along an object displacement direction during a projection exposure. The faceted mirror (7) has at least two pre-tilt types (431, 432, 433, 434) of second facets (25). A first pre-tilt type (431) has second facets (25) which, in a neutral position, exhibit a first pre-tilt angle relative to a basic tilt angle defined by a support geometry of the faceted mirror (7). A second forward tilt type (432) has second facets (25) with a different forward tilt angle.The result is a faceted mirror in which the requirements for a tilting actuator for tilting individual mirrors of the faceted mirror are reduced.

Description

The invention relates to a facet mirror for an illumination optics for projection lithography, suitable for use as a second facet mirror.The invention further relates to an illumination optical unit having such a facet mirror, an illumination system having such an illumination optical unit, an optical system having such an illumination optical unit, a projection exposure apparatus having such an optical system, a method for producing a micro- or nanostructured component with the aid of such a projection exposure apparatus, and a micro- or nanostructured component produced by the method.A facet mirror of the type mentioned at the beginning is known from DE 10 2015 208 512 A1.It is an object of the present invention to further develop a facet mirror of the type mentioned at the beginning in such a way that requirements placed on a tilting actuator system for tilting individual mirrors of the facet mirror are reduced.This object is achieved according to the invention by a facet mirror having the features specified in claim 1.According to the invention, it has been recognized that providing at least two pretilt types of facets of the facet mirror reduces structural requirements which are placed in particular on a tilting actuator system of the facet mirror. In particular, a necessary tilting range can then be reduced. The pretilt type is also referred to as switching class.Tilt angle ranges of the second facets can differ, insofar as a tilt about two different tilt or rotation axes is provided. A ratio between these tilt angle ranges may be in the range between 1.1 and 10 and, in particular, in the range between 2 and 5. Different types of pretilt can have different tilt angle ranges and also different tilt angle range ratios about the optionally several tilt or rotation axes provided.The facet mirror has at least two pretilt types which differ in pretilt angle relative to the base tilt angle. The pretilt angles can be in the range between 10 mrad and 500 mrad, for example between 20 mrad and 200 mrad, in particular between 30 mrad and 80 mrad.Due to the reduced requirements placed on the tilting actuator system for tilting the individual mirrors of the individual mirror units, which arise due to the pre-tilting of the individual mirror groups, tilting actuators with a smaller total tilting range can be used. This makes available types of tilting actuators which can be produced in particular within the scope of mass production technologies.Both a reduction of a maximum angle of incidence and a reduction of a maximum angle of incidence stroke on the second facets can be realized. This can optimize a reflection yield of the facet mirror.In an embodiment of the facet mirror according to Claim 2 having individual mirror units which are in turn designed as a sub-array of individual mirrors, each of the individual mirror units can represent exactly one second facet. Alternatively, each of the single mirror units can also form a plurality of second facets. If, for example, one of the individual mirror units is designed as a sub-array of 24 x 24 individual mirrors and each of the second facets thereof occupies a sub-array of 6 x 6 individual mirrors, it is possible to specify 16 (4 x 4) second facets per individual mirror unit. If in such a case 8 x 8 individual mirrors are to be used for each second facet, then nine (3 x 3) second facets can be formed for each individual mirror unit with 24 x 24 individual mirrors. Each of the individual mirror units can form, for example, 1 to 100 second facets, which can in turn have exactly one individual mirror or are in turn embodied as an individual mirror sub-array.The facet mirror can have two pretilt types or else as more than two pretilt types, for example three, four, five or even more pretilt types, for example eight, nine, ten or even more pretilt types.The pretilt types can alternate regularly in a checkerboard or raster manner and be arranged on the facet mirror. Relative to a field height arrangement coordinate of the facet mirror, which corresponds to a field height coordinate that is imaged by means of the illumination optical unit into a field height coordinate perpendicular to an object displacement direction coordinate of the object field, such a checkerboard or grid-like arrangement can be arranged at an angle between 10° and 80°, for example at an angle between 30° and 60°, for example at an angle of 45° or else of 37°.An assignment of the individual mirror units to pretilt types according to claim 3 enables good intermixing of the guidance of illumination light sub-beams through an illumination optical unit to which the facet mirror belongs. The condition that adjacent single mirror units belong to different pretilt types does not have to apply to any pairs of adjacent single mirror units, but it is sufficient if the facet mirror with a corresponding array arrangement of single mirror units has mutually adjacent regions each with a plurality of single mirror units of the same pretilt type which are mutually adjacent, wherein the pretilt types of the different regions differ from one another.A configuration of the second facets as monolithic facets according to claim 4 has proven to be effective in practice. In this case, the second facets are not themselves divided into a plurality of individual mirrors.The advantages of a configuration in which adjacent second facets belong to different pretilt types according to claim 5 correspond in principle to those explained above with reference to the plurality of pretilt types. Even if the different pretilt types are used in monolithic second facets, these pretilt types can alternate regularly in a checkerboard or raster manner on the facet mirror. Here too, an angle relationship between the coordinates of the facet mirror and the coordinates of the object field can again be present at an angle between 10° and 80° corresponding to the angle ranges and angle values which have already been discussed in connection with the single mirror unit embodiment of the second facet mirror.Numbers of the single mirror units or second facets belonging to each of the pretilt types may be such that they differ by not more than 50%. A difference can be smaller, can be, for example, at most 40%, at most 30%, at most 25%, at most 20%, at most 15%, at most 10%, at most 5%, at most 2%, or even at most 1%. In the limit, there are equal numbers of individual mirror units or of second facets which belong to different pretilt types. In the further limit, each of the different pretilt types comprises exactly the same number of individual mirror units or second facets. When providing corresponding numbers of individual mirror units or second facets, which belong to one of the pretilt types in each case, it is possible to take into account how large starting surface regions are on a first facet mirror of an illumination optical unit to which the facet mirror belongs as a further facet mirror. Such an output surface region serves for guiding illumination light sub-beams within the illumination optics via a pretilt type of the second facet mirror in each case. Within the respective output surface region, there are a number of individual mirrors of the first facet mirror. The number of second facets of the respective pretilt type can be proportional, for example, to the number of individual mirrors in the associated output surface region. When using the second facet mirror within a specular reflector, each second facet can be weighted with a maximum subfield size which can be supported by the respective second facet, wherein this weighting then enters into a determination of the number of second facets of the respective pretilt type provided. Correspondingly determined weighted sums can be proportional to the number of illuminated individual mirrors of the first facet mirror within the respective starting surface region.Also in the embodiment with monolithic second facets, the numbers of second facets which each belong to one of the pretilt types can be the same and differ, for example, by not more than 10%, by not more than 5%, by not more than 2% or else by not more than 1%, or else be exactly the same.A facet mirror according to Claim 6 enables optimized adaptation to angle-of-incidence intervals to be expected on the individual mirrors of the individual mirror groups of the respective coating types. The different coating types may be matched to pretilt angles of the pretilt types, resulting in a reduction of an absolute interval size of the angle of incidence intervals to which the coating types are matched. The result is an overall improved light throughput in the reflection of the illumination light at the second facet mirror. The various coating types are also referred to as layer classes.The various types of pretilt are also referred to as switching classes.Such a facet mirror having a plurality of coating types can simultaneously also have a plurality of pretilt types in accordance with the embodiment of the facet mirror having a plurality of pretilt types already explained above.The facet mirror designs described above can also be combined with one another.The facet mirror can have exactly two coating types or else more than two coating types, for example three, four, five or even more coating types. The facet mirror usually has less than 20 coating types.The advantages of an illumination optical unit according to claim 7 correspond to those already explained above with reference to the facet mirror.An arrangement of the mirror surface coating types according to claim 8 can take account of the fact that, due to an extension of the first facet mirror along the field height arrangement coordinate, without a corresponding subdivision into starting surface regions, too large angle of incidence intervals would result for a respective coating type. The subdivision thus reduces a bandwidth of the angles of incidence to be expected on the individual mirrors of the respective coating type of the second facet mirror.An arrangement of the output surface regions according to claim 9 can take account of a folding geometry of a guidance of the illumination light by the illumination optical unit and otherwise has corresponding advantages as already explained above. A corresponding subdivision of the starting surface regions along the object displacement coordinate makes it possible to execute the respective starting surface region along the object displacement coordinate in a slightly extended manner compared to the total extent of the first front mirror along the object displacement coordinate, so that a corresponding reduction in the angle of incidence interval for the associated coating types is the consequence.Overlapping output surface regions according to claim 10 increase an assignment flexibility between the mirrors or facets of the two facet mirrors, which increases degrees of freedom in a desired light mixing.The starting surface areas can be rectangular, elliptical or also circularly bordered. Polygonal delimiting of the starting surface regions is also possible. The starting surface regions can have an aspect ratio which is different from 1 and can have a smaller extent in particular along the object displacement coordinate than perpendicular thereto. This may result in a desired reduction of angle-of-incidence intervals of the illumination light onto the second facet mirror. Such starting surface regions with an aspect ratio different from 1 can also be present in mixed form on the first facet mirror, that is to say for example at least one lying and at least one standing ellipse. This can be used to generate maximally large intersection regions between adjacent starting surface regions, which increases the degrees of freedom of an assignment of first to second facets within the illumination optical unit for presetting a corresponding illumination setting and thus increases the possibilities of a desired intermixing of the illumination light.Tilt angle range ratios of the individual mirrors that differ from 1 in accordance with what has already been explained above can be used to adapt to the shape of the respective output surface region.In particular, an aspect ratio between the tilt angle regions about different rotational or tilt axes of the respective individual mirror can be adapted to the aspect ratio of the output surface region to be covered.The advantages of an illumination system according to claim 11, an optical system according to claim 12, a projection exposure apparatus according to claim 13, a production method according to claim 14 and a nanostructured component according to claim 15 correspond to those already explained above with reference to the illumination optics. The component produced can be a semiconductor element, in particular a microchip, in particular a memory chip.Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. In these show: FIG. 1 shows a highly schematic meridional section of a projection exposure apparatus for EUV microlithography with a light source, an illumination optical unit and a projection optical unit, wherein a plan view of an object field of the projection exposure apparatus is illustrated in an insert; FIG. 2 shows schematically and likewise in meridional section a beam path of selected individual beams of illumination light within the illumination optics according to FIG. 1, starting from an intermediate focus up to a reticle or object arranged in the object plane of the projection optics in the region of the illumination or object field; FIG. 3 shows a plan view of a first facet mirror of the illumination optical unit, which is arranged in a field plane of the illumination optical unit and in an illumination far field of the light source and is also referred to as a field facet mirror, wherein an array arrangement of individual mirror units, which are each formed from a sub-array of individual mirrors of the first facet mirror, which sub-array is not visible in FIG. 1, is illustrated; FIG. 4 is an enlarged view, by way of example and more in detail, but still schematically, of one of the individual mirror units in comparison with FIG. 3 embodied as a sub-array of the individual mirrors; FIG. 5 shows a plan view of an illumination-specification facet mirror of the illumination optical unit, which is arranged at a distance from a pupil plane of the illumination optical unit and is also referred to as a second facet mirror; FIG. 6 again schematically shows, in a plan view of an embodiment of the first facet mirror of the illumination optical unit, a variant of a column-by-column assignment of the individual mirrors of a variant of the first facet mirror to field heights x of the object field in which the object can be arranged, wherein the column-by-column assignment is illustrated in an idealized manner and the assignment of the individual mirrors to the field heights x leads to a total of eight individual mirror columns, wherein the column-by-column assignment is such that a boundary between two adjacent middle individual mirror columns runs through a center of an entire individual mirror arrangement of the first facet mirror; FIG. 7 shows a detail according to detail VII in FIG. 6, wherein, additionally and deviating from the idealised representation of FIG. 6, an assignment of illuminated individual mirror groups on the first facet mirror is emphasized in detail for the case of a y-dipole illumination setting of the illumination optical unit, said groups representing virtual first facets to which second facets of the second facet mirror are assigned via illumination channels, wherein some of the individual mirror groups (virtual first facets) use free spaces within the column-wise assignment according to FIG. 6, which free spaces are not used within the scope of the column-wise assignment, that is to say do not correspond to an ideal reference column assignment; FIG. 8 shows, in a view similar to FIG. 7, the detail section VIII in FIG. 6 ; FIG. 9 shows a diagram which shows a correlation N (ordinate) of the field height coordinates x within the respective column of the first facet mirror (abscissa), when the illumination setting "y-dipole" according to FIGS. 6 to 8 is set; FIG. 10 shows a representation similar to FIG. 7 of the detail section X in FIG. 6 for the case of a column-by-column assignment for an annular illumination setting, set via tilting positions of the two facet mirrors of the illumination optical unit; FIG. 11 shows, in a representation similar to FIG. 7, the detail section XI in FIG. 6 ; FIG. 12 is a diagram showing a correlation (ordinate) of the field height coordinates within the respective column of the first facet mirror (abscissa) when the "annular" illumination setting according to FIGS. 10 and 11 is set; FIG. 13 shows a representation similar to FIG. 7 of the detail section XIII in FIG. 6 for the case of a column-by-column assignment for an illumination setting "x-dipole", set via tilting positions of the two facet mirrors of the illumination optical unit; FIG. 14 shows, in a view similar to FIG. 7, the detail section XIV in FIG. 6 ; FIG. 15 shows a diagram which shows a correlation (ordinate) of the field height coordinates within the respective column of the first facet mirror (abscissa) when setting the illumination setting "x-dipole" according to FIGS. 13 and 14 ; FIG. 16 shows, in a representation similar to FIG. 6, a column-by-column assignment of the first facets to field heights (x-coordinate) of an object field with a smaller field height extent compared to FIG. 6, such that a total of eleven individual mirror columns result in the column-by-column assignment; FIG. 17 shows, in a representation similar to FIG. 6, a column-by-column assignment of the individual mirrors of the first facet mirror to field heights of the object field, wherein the column-by-column assignment is such that a central individual mirror column results; FIGS. 18A-18T show various illumination settings which can be set with the illumination optical unit according to FIGS. 1 to 5, illustrated as regions of a pupil of the projection optical unit of the projection exposure apparatus which are exposed to illumination light; FIG. 19 shows a portion A (ordinate) of all individual mirrors of the first facet mirror assigned column by column, which fall below a predefined maximum deviation D, plotted over the abscissa, from an ideal field height assignment (deviation Δx=0), that is to say deviate by less than the maximum deviation from the field height coordinate of an ideal reference column assignment of the individual mirrors of the first facet mirror, illustrated for illumination settings according to FIG. 18 ; FIG. 20 shows, in a representation similar to FIG. 3, the first facet mirror of the illumination optical unit, wherein the individual mirror units belonging to a specific pretilt type of two different pretilt types differing in terms of a pretilt angle are shaded differently; FIG. 21 shows, in a representation similar to FIG. 5, a plan view of the second facet mirror, wherein target surface regions of the second facet mirror, which can be illuminated by means of a respective pretilt type of the individual mirror units of the first facet mirror, are again shaded differently; FIG. 22 is a view similar to FIG. 20 showing the first facet mirror of the illumination optical system, wherein single mirror units of different coating types optimized for different angles of incidence of the illumination light are shaded differently, resulting in a combination of the pretilt types according to FIG. 20 and the coating types for the respective single mirror units; FIG. 23 is a representation similar to FIG. 21 and again shows differently shaded target surface regions which can be impinged on the second facet mirror by means of the individual mirror groups of the different pretilt and coating types according to FIG. 22 ; FIG. 24 shows, in a representation corresponding to FIG. 6, a line-by-line subdivision of the individual mirrors of the first facet mirror into three different pretilt types; FIG. 25 shows, in a representation corresponding in principle to FIG. 21, the three target surface regions on the second facet mirror, which can be impinged on by the three pretilt types according to FIG. 24 on the second facet mirror; FIG. 26 again shows, in a representation corresponding to FIG. 6, the first facet mirror with a quadrant-by-quadrant subdivision of the individual mirrors into two different pretilt types (quadrants I / III on the one hand and II / IV on the other hand); FIG. 27 shows, in a representation corresponding to FIG. 22, a further variant of a subdivision of the individual mirrors of the first facet mirror into different coating types; FIG. 28 shows, in a representation corresponding to FIGS. 20, 22, 24 and 27, the subdivision of the individual mirrors of the first facet mirror on the one hand into pretilt types and on the other hand into coating types; FIG. 29 shows, in a representation corresponding to FIG. 22, a further variant of a subdivision of the individual mirrors of the first facet mirror into different coating types; FIG. 30 shows, in a representation corresponding to FIGS. 20, 22, 24 and 27, the subdivision of the individual mirrors of the first facet mirror on the one hand into pretilt types and on the other hand into coating types; FIG. 31 shows, in a representation similar to FIG. 27 or 29, a further variant of a division of the individual mirrors of the first facet mirror into different coating types in columns in this case; FIG. 32 is a plan view of an embodiment of the first facet mirror of the illumination optical system, wherein a total of four output surface regions for guiding illumination light sub-beams via the corresponding alignment channels are each configured via a pretilt type of second facets of the second facet mirror, wherein the pretilt types again differ with respect to the basic tilt angles on the second facets for which the respective pretilt types are optimized; FIG. 33 shows a further embodiment of a second facet mirror in a plan view corresponding to FIG. 5, wherein the second facet mirror has individual mirror units in an array arrangement which correspond to those of the first facet mirror according to FIG. 3, and wherein an assignment of the respective individual mirror units of the second facet mirror to a total of four different pretilt types is emphasized by different hatchings; FIG. 34 shows, in a representation similar to FIG. 32, a further embodiment of a subdivision of the first facet mirror into four starting surface regions, assigned to different pretilt types of the second facet mirror; FIG. 35 shows, in a representation similar to FIG. 32, a further embodiment of a subdivision of the first facet mirror into four starting surface regions, assigned to different pretilt types of the second facet mirror; FIG. 36 shows, in a representation similar to FIG. 32, a further embodiment of a subdivision of the first facet mirror into output surface regions assigned to different pretilt types of the second facet mirror, wherein here a subdivision into a total of five output surface regions is shown, which are assigned in accordance with five different pretilt types of the second facet mirror; FIG. 37 shows, in a representation similar to FIG. 32, a further embodiment of a subdivision of the first facet mirror into output surface regions assigned to different pretilt types of the second facet mirror, wherein here a subdivision into a total of nine output surface regions is shown, which are assigned correspondingly to nine different pretilt types of the second facet mirror; FIG. 38 is a view similar to FIG. 33 for dividing the second facet mirror into individual mirror groups belonging to five pretilt types; FIG. 39 shows a section of a further embodiment of the second facet mirror, embodied with monolithic second facets which are therefore in turn not divided into individual mirrors, these monolithic second facets in turn belonging to five pretilt types, which are emphasized in FIG. 39 by different hatchings; FIG. 40 shows, in a representation similar to FIG. 39, a corresponding assignment of the monolithic second facets to a total of nine pretilt types, for example designed for reflecting illumination light which originates from the nine output surface regions according to FIG. 37 ; and FIGS. 41 and 42 show variant embodiments of the first facet mirror with monolithic first facets which are transferred into the object field via respectively assigned second facets of the second facet mirror.A projection exposure apparatus 1 for microlithography, which is illustrated in a highly schematic manner in FIG. 1 and in a meridional section, has a light source 2 for illumination light 3. This can be an LPP (laser produced plasma) light source, a DPP (discharge produced plasma) light source or a synchrotron radiation-based light source, for example a free electron laser (FEL).A transmission optics 4 is used for guiding the illumination light 3, starting from the light source 2, and this optics have a collector 5, which is illustrated in FIG. 1 only with regard to its reflecting effect, and a transmission facet mirror 6, which is described in more detail below and is also referred to as a first facet mirror or as a field facet mirror. Between the collector 5 and the transmission facet mirror 6, an intermediate focus 5 aof the illumination light 3 is arranged. A numerical aperture of the illumination light 3 in the region of the intermediate focus 5 ais, for example, NA=0.182. Arranged downstream of the transfer facet mirror 6 and thus of the transfer optics 4 is an illumination-specification facet mirror 7, which is also referred to as a second or further facet mirror and is likewise explained in more detail below. The optical components 5 to 7 are components of an illumination optical unit 11 of the projection exposure apparatus 1.The transmission facet mirror 6 is arranged in a field plane of the illumination optical unit 11.The illumination-specification facet mirror 7 of the illumination optical unit 11 is arranged at a distance from pupil planes of the illumination optical unit 11. Such an arrangement is also referred to as a specular reflector. Alternatively, the illumination specification facet mirror 7 can also be arranged in the region of a pupil plane of the illumination optical unit 11 and is then referred to as a pupil facet mirror.Arranged downstream of the illumination specification facet mirror 7 in the beam path of the illumination light 3 is a reticle 12 which is arranged in an object plane 9 of a downstream projection optical unit 10 of the projection exposure apparatus 1. The projection optical unit 10 is a projection objective. With the illumination optics 11, an object field 8 on the reticle 12 is illuminated in a defined manner in the object plane 9. The object field 8 simultaneously represents an illumination field of the illumination optical unit 11. In general, the illumination field is designed such that the object field 8 can be arranged in the illumination field.The illumination-specification facet mirror 7 is, like the transmission facet mirror 6, part of a pupil illumination unit of the illumination optical unit and serves for illuminating an entry pupil 12 ain a pupil plane 12 bof the projection optical unit 10 with the illumination light 3 having a predefined pupil intensity distribution. The entrance pupil 12 aof the projection optical unit 10 can be arranged in the illumination beam path upstream of the object field 8 or else downstream of the object field 8. FIG. 1 shows the case in which the entry pupil 12 ais arranged in the illumination beam path downstream of the object field 8. A pupil distance PA of the second facet mirror 7 from the pupil plane 12 bis obtained in this case as the sum of a z-distance PA 1 of the second facet mirror 7 from the object plane 9 and the z-distance PA 2 of the object plane 9 from the pupil plane 12 b. Thus, PA=PA1+PA2 applies. The pupil distance PA can alternatively also be measured in the beam direction.To facilitate the representation of positional relationships, a Cartesian xyz-coordinate system is used below. The x-direction extends in FIG. 1 perpendicularly to the plane of the drawing into the latter. The y-direction extends to the right in FIG. 1. The z-direction runs downward in FIG. 1. Coordinate systems used in the drawing each have x-axes running parallel to one another. The course of a z-axis of these coordinate systems follows a respective main direction of the illumination light 3 within the respectively observed figure.The object field 8 has an arcuate or partially circular shape and is bounded by two circular arcs parallel to one another and two straight side edges which run 0 in the y direction with a length y and are at a distance x 0 to one another in the x direction. The aspect ratio x 0 / y 0 is 13 to 1. an insert of FIG. 1 shows a top view, not to scale, of the object field 8. In an alternative and likewise possible object field 8, its boundary shape is rectangular, likewise with aspect ratio x 0 / y 0.During a projection exposure, the reticle 12 is displaced along an object displacement direction y through the object field 8.The projection optical unit 10 is indicated only partially and strongly schematically in FIG. 1. An object field-side numerical aperture 13 and an image field-side numerical aperture 14 of the projection optical unit 10 are illustrated. The image field-side numerical aperture 14 can lie in the range between 0.2 and 0.8 and can be, for example, 0.3, 0.33, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7 or else 0.75. Between indicated optical components 15, 16 of the projection optical unit 10, which can be designed, for example, as mirrors reflecting for the EUV illumination light 3, there are further optical components of the projection optical unit 10, not shown in FIG. 1, for guiding the illumination light 3 between these optical components 15, 16.The projection optical unit 10 images the object field 8 into an image field 17 in an image plane 18 on a wafer 19 which, like the reticle 12, is carried by a holder, not shown in detail. Both the reticle holder and the wafer holder can be displaced both in the x direction and in the y direction by means of corresponding displacement drives. A structural space requirement of the wafer holder is illustrated in FIG. 1 at 20 as a rectangular box. The installation space requirement 20 is cuboidal with an extent in the x-, y- and z-directions which is dependent on the components to be accommodated therein. The installation space requirement 20 extends, for example, from the center of the image field 17, in the x-direction and in the y-direction by 1 m. The installation space requirement 20 extends, for example, from the image plane 18 in the z-direction too by 1 m. The illumination light 3 must be guided in the illumination optical unit 11 and the projection optical unit 10 in such a way that it is guided past the installation space requirement 20, respectively.The transfer facet mirror 6 has a plurality of transfer facets 21, also referred to as first facets. The transfer facet mirror 6 can be embodied as a MEMS mirror. The transfer facets 21 are individual mirrors which can be switched at least between two tilting positions and are designed as micromirrors. The transfer facets 21 can be designed as tiltable micromirrors driven about two mutually perpendicular axes of rotation.Possible switching amplitudes of the individual mirrors 21 about the two axes of rotation can differ from one another. When a reflection surface of the single mirror 21 is disposed in an xy plane, for example, a tilt angle range Δx about a tilt axis along the x coordinate may be larger or smaller than a tilt angle range Δy about a tilt axis along the y coordinate. A direction-dependent tilt angle range can thus be present. A ratio between these tilt angle ranges may be in the range between 1.1 and 10. In particular, the respective individual mirror can have a suspension for the pivotable mounting of its mirror body with two tilting degrees of freedom and with an actuator device for pivoting the mirror body in such a way that the mirror body has a direction-dependent tilting angle range.Of these individual mirrors or transfer facets 21, a line with a total of nine transfer facets 21 is schematically shown in the yz section according to FIG. 2, which are indexed from left to right by 21 1 to 21 9 in FIG. 2. In fact, the transfer facet mirror 6 has a substantially larger plurality of the transfer facets 21. The transfer facets 21 are grouped into a plurality of transfer facet groups, not shown in more detail in FIG. 2 (cf. also FIGS. 7 and 13 for example in this regard). These transfer facet groups are also referred to as single mirror groups, virtual field facets or virtual facet groups.Each of the transmission facet groups guides a portion of the illumination light 3, which is also referred to as illumination light sub-bundle, via an illumination channel for partial or complete illumination of the object field 8, Via this illumination channel and an illumination light sub-bundle 3 i guided via it, in each case one of the individual mirror groups or transmission facet groups is assigned exactly one illumination specification facet 25 of the illumination specification facet mirror 7. In principle, each of the illumination specification facets 25 can in turn be constructed from a plurality of individual mirrors. The illumination specification facets 25 are also referred to below as second facets. If the second facet mirror 7 is arranged in the region of a pupil plane of the illumination optical unit 11, the illumination specification facets 25 are also referred to as pupil facets.A single mirror group is a group of the single mirrors 21 of the first facet mirror 6, which is imaged into the object field 8 by the same second facet 25.For further details of possible embodiments of the transfer facet mirror 6 and of the projection optical unit 10, reference is made to WO 2010 / 099 807 A.At least some of the illumination specification facets 25 illuminate only a sub-region or sub-field of the object field 8. These sub-fields are shaped very individually and also depend on the desired illumination direction distribution (pupil shape) in the object field 8, i.e. the illumination setting. The illumination specification facets 25 are therefore illuminated by virtual field facets of very different shapes, the shape of which corresponds precisely to the shape of the respective sub-field to be illuminated. Each illumination specification facet 25 also contributes to different regions of the pupil depending on the location in the object field 8.The illumination specification facet mirror 7 can be designed as a MEMS mirror in particular when each of the illumination specification facets 25 is constructed from a plurality of individual mirrors. The illumination specification facets 25 are micromirrors switchable between at least two tilt positions. The illumination specification facets 25 are designed as micromirrors which can be tilted in two dimensions and in particular continuously and independently driven about two tilting axes which are perpendicular to one another, that is to say can be set into a multiplicity of different tilting positions.The tilt angle ranges Δx, Δy about the tilt or rotation axes of these micro mirrors or individual mirrors of the illumination specification facets 25 apply, which was explained above with respect to the individual mirrors 21 of the transmission facet mirror 6. Here too, direction-dependent tilt angle ranges can be present.An example of a predefined assignment of individual transfer facets 21 to the illumination specification facets 25 is illustrated in FIG. 2. The illumination specification facets 25 assigned to the transmission facets 21 1 to 21 9 in each case are indexed in accordance with this assignment. The illumination specification facets 25 are illuminated from left to right on the basis of this assignment in the order 25 6, 258, 253, 254, 251, 257, 255, 252 and 25 9.Indices 6, 8 and 3 of facets 21, 25 include three illumination channels 3 6, 38 and 3 3, which illuminate three object field points OF 1, OF 2, OF 3, which are numbered from left to right in FIG. 2, from a first illumination direction. The indices 4, 1 and 7 of the facets 21, 25 belong to three further illumination channels 3 4, 31, 37, which illuminate the three object field points OF 1 to OF 3 from a second illumination direction. The indices 5, 2 and 9 of the facets 21, 25 belong to three further illumination channels 3 5, 32, 39, which illuminate the three object field points OF 1 to OF 3 from a third illumination direction. Corresponding illumination light sub-beams 3 1 to 3 9 are assigned to the illumination channels 3 1 to 3 9 respectively.The illumination directions,the illumination channels 3 6, 38, 33,the illumination channels 3 4, 31, 37 andthe illumination channels 3 5, 32, 39The respective components are assigned to them, are identical. The assignment of the transmission facets 21 to the illumination specification facets 25 is therefore such that telecentric illumination of the object field 8 results in the illumination example illustrated in the figure.The illumination of the object field 8 via the transmission facet mirror 6 and the illumination-specification facet mirror 7 can take place in the manner of a specular reflector. The principle of the specular reflector is known from US 2006 / 0132747 A1.FIG. 3 shows a plan view of the first facet mirror 6, which has a regular array arrangement of individual mirror units 26 which are bounded squarely in FIG. 3. Each of the individual mirror units 26 is designed as a sub-array of N x M of the individual mirrors 21. This sub-array has a plurality of array lines extending along a line direction corresponding to a bisector of the xy-coordinate system. Some of the mutually adjacent array lines are offset with respect to one another by a part of an extent of one of the individual mirror units 26, in particular by half of this extent of the respective individual mirror unit 26 along the array line. Depending on the embodiment of the facet mirror 6, such an offset can be completely omitted, resulting in an array arrangement composed completely of rows and columns. Alternatively, all array lines may be offset from each other. Different amounts of offset between different, adjacent array parts are also possible depending on the design of the facet mirror 6 and depending on the requirements placed on positioning the individual mirror units 26.The first facet mirror 6 is designed for arrangement in a useful region of a far field of the light source 2.Figure 4 shows one of the single mirror units 26 still schematically, but more in detail. The illustration shows a subdivision of the single mirror unit 26 into the sub-array of 6 x 6 of the single mirrors 21 in this case. Each of the single mirror units 26 thus has 36 of the single mirror 21 in the embodiment illustrated. In the example according to FIG. 4, N=6 and M=6. N and M can be the same for the N x M sub-array arrangement, can be different and can each lie in the range between 2 and 64, for example at 4, 8, 16, 32 or 64. Values other than powers of two are also possible for N and M, for example 25 or 50.In the embodiment shown in FIG. 3, the first facet mirror 6 has an arrangement of the individual mirror units 26 within a circular envelope. Alternatively, the first facet mirror 6 can also have the individual mirror units 26 within an elliptical, rectangular or else polygonally bordered envelope.In each case one of the individual mirror units 26 can contain a plurality of complete or partial individual mirror groups which guide the illumination light 3 to different second facets 25 and are imaged in the object field 8 in a manner overlapping one another. The single mirror groups may extend over a plurality of the single mirror units 26.FIG. 5 again shows the second facet mirror 7 in a plan view.The second facets 25 of the second facet mirror 7 are embodied in a circular-edged manner and are present in the form of a hexagonally densest packing. Alternatively to circularly bordered second facets 25, rectangular or polygonal, in particular hexagonal, bordered second facets 25 can also be present. The second facets 25 can in turn be embodied as individual mirror units in the manner of the individual mirror units of the first facet mirror 6 and in this case be divided into a plurality of individual mirrors in the manner of the individual mirrors 21. In principle, a structure of the second facet mirror 7, as far as the subdivision into individual mirrors and individual mirror units is concerned, can correspond to the structure of the first facet mirror 6.In the embodiment according to FIG. 5, each of the second facets 25 can also be embodied as a monolithic facet.The second facets 25 are arranged in the case of the second facet mirror 7 within an elliptically bordered envelope. Alternatively, other envelope shapes are also possible here, for example a circular envelope, a rectangular envelope and also a polygonally bordered envelope.Selected ones of the second facets 25 are assigned to an illumination light sub-bundle 3 i and thus to an individual mirror group of the individual mirrors 21 of the first facet mirror 6.FIG. 6 and the more detailed enlargements of the detail VII, VIII, X, XI, XIII, XIV of FIG. 6, reproduced as FIGS. 7, 8, 10, 11, 13, 14 illustrate an assignment of the individual mirrors of the first facet mirror 6 to field heights x of the object field 8. The field height x is perpendicular to the object displacement direction y. An edge contour which has an approximately keyhole-shaped cut at the position "9 o'clock" indicates in FIG. 6 a surface region of the first facet mirror 6 which can be used for guiding the illumination light 3.Similar to FIG. 3, the individual individual mirrors 21 are also not visible in FIGS. 6, 7, 8, 10, 11, 13, 14, but at most the diamond-shaped, square individual mirror units 26.In the first facet mirror 6 according to FIGS. 6, 7, 8, 10, 11, 13, 14, the individual mirror units are arranged in the form of a sub-array having array rows and array columns which are each tilted by 45° with respect to the xy-coordinate axes. There is no offset of the single mirror units 26 along the row direction between adjacent array rows, resulting in completely continuous array rows and completely continuous array columns.The assignment of the individual mirrors 21, which are not shown resolved within the individual mirror units 26 in FIGS. 7, 8, 10, 11, 13, 14, to the respective field height x is shown in FIGS. 7, 8, 10, 11, 13, 14 by alternating hatchings, wherein each of the hatchings stands for a specific field height x between a left field edge x l( cf. also the insert in FIG. 1 ) and a right field edge x r between which a total original image field width x SP is measured, which is imaged into the object field width x 0 by means of the transmission optics, which is arranged downstream of the first facet mirror 6 within the illumination optical unit 11, wherein the field height x, along which the object field width x 0 is measured, runs perpendicular to the object displacement direction y. This original image field height x is reproduced in the hatching legend on the right in FIG. 7, between values "52 mm" and "+52 mm", i.e. over the entire field width of the object field 8. The object field 8 has a field width x 0 of 104 mm along the x-coordinate in the example corresponding to the individual mirror assignment according to FIGS. 7, 8, 10, 11, 13, 14.A respective illumination light partial beam 3 i, which is guided via a correspondingly assigned individual mirror, impinges on the object field at the respectively assigned field height x.The assignment of the individual mirrors of the individual mirror units 26 to the respective field height x is reproduced in FIGS. 7 and 8 for an illumination angle distribution "y-dipole leaves", the illumination intensity distribution of which is reproduced in FIG. 18C in a pupil plane of the projection optical unit 10 which is conjugate to the entry pupil plane 12 a.FIG. 6 illustrates a rough, idealised assignment of the individual mirrors of the individual mirror units 26 to the respective field height x, divided into a total of eight individual mirror columns 27 1 to 27 8, which run along a y-coordinate of the first facet mirror 6. This idealised column-by-column individual mirror assignment corresponds to a reference column arrangement or reference column assignment of the individual mirrors of the first facet mirror.At the transition between two adjacent single mirror columns 27 i, 27i+1 an assignment of the respective single mirror changes from one field edge of the object field 8 to the opposite field edge of the object field 8.A width of the respective single mirror column 27 i along the x-coordinate of the field facet mirror 6, which is mapped into the x-coordinate of the object field 8, corresponds to the original image field width x SP. The original image field width x SP thus corresponds to the object field width x 0 multiplied by the inverse imaging scale of the imaging of the individual mirror groups into the object field 8.FIG. 7 shows the single mirror assignment in more detail (detail VII in FIG. 6 ). FIG. 7 shows a y-section of the first facet mirror 6 over an entire x-width of the single mirror column 27 5. It can be seen that the assignment of the individual mirrors of the individual mirror units 26 to the respective field heights x comprises, in addition to the basic column-by-column assignment within the individual mirror columns 27 i also partial regions 28 i in which the column-by-column assignment according to the individual mirror columns 27 i is not observed. The displayed partial regions 28 1 to 28 3 show respective groups of individual mirrors which are assigned field heights in the region of the left field edge x l. The partial regions 28 4 and 28 5 are again assigned field heights in the region of the right field edge x:. These partial regions 28 i are also referred to as exception partial regions. With these exception subareas 28 i gaps in the regular, column-by-column individual mirror assignment can still be filled in order to optimize a total proportion of the individual mirrors used for illumination light exposure and thus a reflection efficiency of the first facet mirror 6.The individual mirror columns 27 i can also be understood as control subareas of the assignment of the individual mirrors of the first facet mirror 6.At least 80% of the individual mirrors within the individual mirror column 27 5 of the section of the first facet mirror 6 shown in FIG. 7 follow the column-by-column assignment according to the individual mirror column 27 5, i.e. the reference column assignment. A sum of the areas of the exception subareas 28 i is therefore not more than 20% of the section area of the single mirror column 27 5. shown in FIG. 7.Highlighted by way of example in FIG. 7 by a dashed boundary is a complete single mirror group 30, which is imaged into the object field 8 during the illumination via the second facet mirror 7.In this single mirror group 30, the sequence of hatchings between the field height to the left field edge x l and the field height to the right field edge x r can be reproduced. The single mirror group 30 thus represents a original image of the object field 8.FIG. 8 again shows an enlarged detail of the assignment according to FIG. 6 corresponding to the detail VIII therein. Two y-sections of the individual mirror columns 27 6 and 27 7. are shown in particular. Particularly within the single mirror column 27 7 a plurality of subareas 29 i(291, 292) not used for guiding the illumination light 3 are illustrated, which do not represent either control subareas or exception subareas.Also emphasized in FIG. 8 are two exemplary, complete single mirror groups 30 1 and 30 2, which are each imaged into the complete object field during the illumination.FIG. 9 shows a correlation N of an assignment of the individual mirrors 21 of the first facet mirror 6 to the respective individual mirror column 27 i in the case of illumination setting y-dipole leaflets according to FIG. 18C. The correlation N between the field height assignments of the individual mirrors within the regular individual mirror columns 27 i and the exception subareas 28 i within the total of eight individual mirror columns 27 1 to 27 8. is shown. To the right, the respective x-coordinate within the respective single mirror column 27 is shown in i and to the top, as a measure of the correlation, a number N of the single mirrors 21 for which the respective correlation applies.The respective maxima in FIG. 9 illustrate the numbers N of those individual mirrors 27 i, in which the assignment is perfect, that is to say which belong to the control subareas within the individual mirror columns 27 i.Only a few individual mirrors are removed from these ideal correlations within the individual mirror columns 27 i in the x-direction by more than one fifth of the original image field width of the object field 8.Between the maxima of the correlation representation according to FIG. 9 assigned to the respective individual mirror columns 27 i the correlation curve falls in each case to a plateau value close to zero.The column-by-column assignment of the individual mirrors 21 into the individual mirror groups of the first facet mirror 6 guiding the illumination light sub-beams 3 i is such that more than 80% of the individual mirrors 21 deviate by less than 40% of a original image field width x SP from the field height coordinate x of the reference column assignment of the individual mirror groups of the first facet mirror 6 formed by the individual mirror columns 27 i.In the y-dipole leaflet illumination angle distribution for which the assignment according to FIGS. 7 to 8 is present, as an example of a multipole illumination angle distribution, the column-by-column arrangement of the individual mirror groups of the first facet mirror 6 is even such that more than 80% of the individual mirrors deviate by less than 20% and in particular by less than 10% of the original image field width x SP from field height coordinates x of the reference column assignment of the individual mirror columns 27 i of the first facet mirror 6.This assignment condition of a minimum number of individual mirror groups of the first facet mirror 6, which deviates less than a limit percentage of a original image field width x SP from the field height coordinate x of the reference column assignment of the individual mirror columns 27 i of the first facet mirror 6, applies separately to each of the facet columns 27 i in the assignment explained above with reference to FIGS. 6 to 8.With reference to FIGS. 10 to 12, which correspond in principle to FIGS. 7 to 9, the assignment of the individual mirrors 21 to the field heights x is described below for a further example of "angular illumination setting", the desired illumination intensity distribution of which is reproduced in a pupil plane of the projection optical unit 10 in FIG. 18A.Since very narrow illuminated sections in wide sections, in particular along a pupil coordinate σ x of this illumination setting according to FIG. 18A, a significantly greater fragmentation of individual mirror groups assigned to respective illumination light sub-beams results on the field facet mirror 6.FIG. 10 shows the detail X of the field facet mirror 6 according to FIG. 6, The number of exception subareas 28 i, which do not correspond to the rule assignment according to the individual mirror columns 27 i is significantly increased in this assignment for the angular illumination setting in comparison with the assignment according to FIGS. 7 and 8 for the dipole illumination setting. Nevertheless, the rule assignment via the single mirror column 27 i can still be clearly seen in FIG. 10. In this extreme case of angular illumination setting as well, the column-by-column arrangement of the individual mirror groups of the first facet mirror 6 is still such that more than 80% of the individual mirrors 21 deviate by less than 40% of the original image field width x SP from the field height coordinate x of the reference column assignment of the individual mirror columns 27 i of the first facet mirror 6.FIG. 11 shows the detail section XI of the field facet mirror 6 according to FIG. 6 with y sections of the single mirror columns 27 4 and 27 5. Here too, a comparatively strongly split subdivision with relatively many exception subareas 28 i can be seen, wherein at the same time the rule assignment via the individual mirror columns can still be clearly seen.FIG. 12 shows, in a representation similar to FIG. 9, the correlation N of the individual mirrors 21 to the individual mirror columns 27 1 to 27 8. The greater fragmentation with a greater proportion of exception partial regions 28 i results in the maximum number N of the individual mirrors 21 which form the peaks to the individual mirror columns 27 1 being lower by a factor of approximately 2.5 than in the correlation according to FIG. 9 In addition, a distinct background which is formed by the individual mirrors 21 of the exception partial regions 28 i can be seen between these peaks assigned to the individual mirror columns 27 i.FIGS. 13 and 14 show, in representations similar to FIGS. 6 to 8 and 10 and 11, the individual mirror / field height assignment on further detail sections XIII and XIV of the field facet mirror 6 according to FIG. 6 for an illumination setting "x-dipole" according to FIG. 18D.Here, the number of exception subareas 18 i(181, 182) is greatly reduced in comparison with the annular illumination setting according to FIGS. 10 to 12. FIG. 13 shows individual mirror groups 30 i which transfer corresponding illumination light sub-beams into the object field 8. These single mirror groups 30 i are shaped curved in a similar manner to the object field 8 because of the mapping into the object field 8.FIG. 13 shows a y-section of the field facet mirror 6 again in the region of the individual mirror groups 27 4 and 27 5.FIG. 14 shows the assignment again for the illumination setting "x-dipole" in detail section XIV of FIG. 6 in the region of the single mirror column 27 4. Here, single mirror groups can be partially seen which, apart from the transitions between the single mirror units 26, cover the entire original image width x SP of the single mirror column 27 4. These individual mirror groups are not actually groups which are imaged in the object field 8 overall via exactly one illumination light partial beam 3 i and exactly one second facet 25, but rather they are actually a plurality of individual mirror groups 30 i, which are puzzled to one another exactly matching with respect to the x assignment of the individual mirrors 21 and are imaged into the corresponding field heights x via different second facets 25 into corresponding partial fields of the object field 8.Single mirror groups 30 i can also be seen, which are shifted only by a comparatively small x value for ideal field height assignment (peak positions of the correlations). Such a single mirror group is highlighted at 30 2 in FIG. 14. This single mirror group 30 2 is an example of a single mirror group which does not belong to the reference column assignment but yet meets the assignment condition according to which a deviation of the single mirrors 21 associated with this single mirror group 30 2 from the field height coordinate x of the reference column assignment is less than 10% of the original image field width x SP.FIG. 15 shows, in a manner comparable to FIGS. 9 and 12, the assignment correlation individual mirror / field height for the case of x-dipole illumination setting, that is to say for the individual mirror group occupancy of the field facet mirror 6 according to FIGS. 13 and 14.FIG. 16 shows a further example of the assignment of individual mirrors / field heights for an object field 8 with an x-object field width x 0. reduced in comparison with the assignment according to FIG. 6. Due to the smaller x-field width x 0 of the object field 8, a correspondingly smaller original image field width x SP is obtained in the arrangement plane of the field facet mirror 6 and thus an occupancy of the field facet mirror 6, i.e. a reference column assignment, with a larger number of individual mirror columns 27 i. Overall, this assignment assignment assignment assignment in accordance with FIG. 16 yields eleven individual mirror columns 27 1 to 27 11.The illumination setting for which the assignment according to FIG. 16 applies is an x-dipole setting according to FIG. 18D.FIG. 17 shows a further assignment of individual mirror / field height, again for an object field width x 0 as in the assignment according to FIG. 6, this time for the illumination setting "bar-shaped y-dipole". Instead of leaflet-shaped single poles, as in the case of the illumination setting according to FIG. 18C, rectangular poles are present here. This results in an assignment distribution again with eight individual mirror columns as a result, wherein in the assignment according to FIG. 17 a central individual mirror column 27 Z and in the negative x-direction and in the positive x-direction at the edge in each case an individual mirror column with half the original image field width x SP / 2 is present.In the assignments which have been explained above in connection with FIGS. 6 to 17, a proportion of individual mirrors 21 used for guiding the illumination light 3 is in each case greater than 80% and in particular greater than 84%.FIG. 18 shows an overview of possible illumination settings which can be predefined in i by means of the illumination optical unit 11 with a corresponding individual mirror / field height assignment of the individual mirror groups 30 guiding the illumination light sub-beams. What is shown is an illumination intensity distribution in the region of an entry pupil of the projection optical unit 10.The following lighting settings are shown by way of example: FIG. 18A : Angular illumination setting with a large absolute illumination angle; FIG. 18B : Annular illumination setting with a small absolute illumination angle; FIG. 18C: Leaflet-y-Dipole Illumination Setting; FIG. 18D: Leaflet-x-Dipole Illumination Setting; FIG. 18E : Leaflet quadrupole illumination setting with illumination from the four quadrants; FIG. 18F : Leaflet quadrupole illumination setting with illumination from the directions horizontal / vertical; FIG. 18G : Leaflet illumination setting "superposition x-dipole and y-dipole"; FIG. 18H : Leaflet illumination setting "18G rotated by 45°"; FIG. 18I : Leaflet Dipole Illumination Setting "18C rotated by -45°"; FIG. 18J : Leaflet Dipole Illumination Setting "18C rotated by +45°"; FIG. 18K shows: hexapole illumination setting; FIG. 18L : Hexapole illumination setting "18K rotated by 30°"; FIG. 18M: Quasar illumination setting; FIG. 18N: C quad illumination setting (18M rotated by 45°); FIG. 18O: Leaflet-Hexapole-Y-Illumination Setting; FIG. 18P: Leaflet Hexapole X Illumination Setting (18O rotated by 30°); FIG. 18Q: Y dipole illumination setting with medium-sized illumination angles; FIG. 18R: X dipole illumination setting with medium-sized illumination angles; FIG. 18S: Y dipole illumination setting with small illumination angles; FIG. 18T: X dipole illumination setting with small illumination angles.FIG. 19 shows a diagram of a single column correlation partially assigned to the illumination settings 18A to 18T when the single mirrors 21 are assigned to the field heights x on the field facet mirror 6. The correlation curves 19 i shown show which portion A of the individual mirrors 21 of the field facet mirror 6 has at most the deviation D indicated in each case in the abscissa.Curve 19 1 shows the correlation for the illumination setting according to FIG. 18A, i.e. the angular illumination setting with large illumination angles, the assignment assignment of which is also shown in FIGS. 10 and 11. In this illumination setting according to the correlation curve 19 1 only a very small proportion of the individual mirrors 21 does not deviate at all from the ideal individual mirror column position, that is to say from the reference column assignment.The maximum deviation shown in FIG. 19 is the original image deviation corresponding to half the field width x 0. With a field width x 0 of the object field 8 of 104 mm, this is therefore the original image deviation from the object field width 52 mm. A deviation greater than half the field width is theoretically not possible.It can be seen from the curve profile of the correlation curve 19 1 in FIG. 19 that, in the case of the illumination setting of FIG. 18A, 80% of the individual mirrors 21 deviate from the ideal individual mirror column arrangement by less than 40% of the original image field width x SP since the correlation curve 19 1 intersects the mirror portion value 0.8 at approximately the value 37 mm, which corresponds to just 36% of the object field width of 104 mm.For the other illumination settings, the assignment is, as shown in FIG. 19, substantially closer to the ideal single mirror column assignment. The correlation curve 19 15 shows the illumination setting leaflet-Y hexapole according to FIG. 18O, where only slightly extended illumination sections are also present along the σ y- pupil coordinate, so that the correlation shown in FIG. 19 is likewise comparatively weak.The correlation curve 19 16 provides the correlation for the leaflet X hexapole illumination setting of FIG. 18P in direct comparison. There are two poles present which are extended along the σ x- pupil coordinate, for which a single mirror group assignment on the field facet mirror 6 is possible with less large splitting, so that in the case of the leaflet X hexapole illumination setting according to FIG. 18P overall, as a comparison of the correlation curves 19 15 and 19 16 results, a better assignment in the single mirror columns results than in the case of the leaflet Y hexapole illumination setting 18O.The further correlation curves of FIG. 19 show gradual differences with respect to the distribution of the individual mirrors 21 deviating from the ideal individual mirror column assignment.For example, in the illumination setting example according to FIG. 18C (leaflet-Y dipole), which is the most correlated with respect to the single mirror / field height assignment, more than 90% of the single mirrors 19 are different from the ideal single mirror column arrangement in object field height dimensions by less than 5 mm, which corresponds to less than 5% of the original image field width.FIG. 20 shows the field facet mirror 6 in a representation corresponding to FIG. 3. FIG. 20 also illustrates two pretilt types 32 1( unfilled single mirror groups 26) and 32 2( hatched single mirror groups 26) of the single mirror groups 26. The two pretilt types 32 1 and 32 2 each have individual mirror units 26 which in a neural position have a specific pretilt angle relative to a basic tilt angle which is predetermined by a carrier geometry of the field facet mirror 6 as a function of the type. The first pretilt type 32 1 has, for example, a pretilt angle of 30 mrad about a pretilt axis parallel to the y-axis. This pretilt is the same for all single mirror units 26 of the first pretilt type 32 1. The second pretilt type 32 2 has a correspondingly oppositely directed pretilt about a tilting axis 33 2 about -30 mrad which is in turn parallel to the y-axis. In the case of the single mirror units 26 of the second pretilt type 32 2 too, this pretilt angle is in each case the same.The pretilt angle can be in the range between 10 mrad and 12 mrad on the one hand and between -100 mrad and -10 mrad on the other hand.An angle of incidence amplitude of the illumination light 3 on the individual mirrors 21 of the first facet mirror 6 can be ±4° or else ±3°.The pretilt types 32 i are also referred to as switching classes of the single mirror units 26. Assigned to the respective switching classes, individual mirrors 21 of the transmission facet mirror 6 and / or of the illumination-specification facet mirror 7 having different tilt angle ranges Δx, Δy and in particular having a direction-dependent tilt angle range can be used. The tilt angle ranges in the tilt angle dimensions Δx and Δy may be in a ratio of 10:1 to 1:10.In the case of the occupancy according to FIG. 20, half of the individual mirror units 26 respectively belong to the first pretilt type 32 1 and the other half to the second pretilt type 32 2. The numbers of the single mirror units 26 which each belong to one of the pretilt types 32 i are therefore of the same size. Depending on the pretilt type of the field facet mirror 6, these numbers can also be different, but in each case differ regularly by not more than 10%.The individual mirror units 26 of the pretilt types 32 i are arranged in contiguous mirror surface sections 34 1 to 34 6 in the type assignment according to FIG. 20. Here, the pretilt type 32 1 occupies the mirror surface portions 34 1, 343 and 34 5. The pretilt type 32 2 occupies the mirror surface portions 34 2, 344 and 34 6. These three mirror surface sections 34 1, 343 and 34 5 on the one hand, and 34 2, 344 and 34 6 on the other hand, are each present separately from one another by mirror surface sections of the respective other pretilt type.The arrangement of the mirror surface pretilt type portions 34 on the field facet mirror 6 is two times point symmetrical about a center Z of the field facet mirror 6.An extension of the respective mirror surface pretilt type portions 34; along the field height coordinate x of the first facet mirror 6 is greater than the original image width x SP of the object field 8 on the field facet mirror 6.The mirror surface pretilt type portions 34 i are arranged line by line on the facet mirror 6 with respect to the arrangement of the single mirror units 26.FIG. 21 shows which regions of the second facet mirror 7 with the respective pretilt type 32 can be acted upon in i by a respective illumination light sub-bundle. The pretilt is such that individual mirrors 21 of the pretilt type 32 1 can impinge on a target surface region 35 1 on the second facet mirror 7. An extension of the target surface region 35 1 along a pupil coordinate σ x of the second facet mirror 7 corresponding to the x-coordinate of the field facet mirror 6 is more than half as large as a total extension of the second facet mirror 7 along this pupil coordinate σ x. This σ x- extension ratio of the target surface region 35 1 to the total extension is, for example, 60%.A corresponding second target surface region 35 2 on the second facet mirror 7 can be acted upon by the individual mirrors 21 of the second pretilt type 32 2.Each of the second facets 25 of the second facet mirror 7 belongs to at least one of the two target surface regions 35 1 and / or 35 2. In a σ x- region 36, the result is an overlap of the two target surface regions 35 1 and 35 2. The second facets 25 arranged there therefore belong to both target surface regions 35 1 and 35 2 and can be acted upon by the illumination light 3 by individual mirrors 25 of both pretilt types 32 1 and 32 2.Alternatively or in addition to the different pretilt types 32 i the field facet mirror 6 can also have different coating types 37 i which is explained below with reference to FIGS. 22 and 23.FIG. 22 shows the field facet mirror 6 again in a representation corresponding to FIGS. 3 and 20. A subdivision of the field facet mirror 6 according to FIG. 22 into mirror surface pretilt type sections 34 i is as explained above with reference to FIG. 20. The field facet mirror 6 according to FIG. 22 therefore again has two pretilt types 32 1 and 32 2 in accordance with the explanation relating to FIG. 20.Highlighted by different hatchings in FIG. 22 are a total of four different coating types 37 1, 372, 373, 374 of the individual mirror units 26 of the field facet mirror 6.The four coating types 37 i are optimized for four different angle-of-incidence intervals of the illumination light 3 on the individual mirrors of the individual mirror units 36 of this coating type 37 i.The distribution of the pretilt types 32 i on the one hand and of the coating types 37 i on the other hand can be such that a plurality of coating types 37 i are present within a mirror surface pretilt type section 34 i. For example, the mirror surface pretilt type portion 34 1 has the two coating types 37 1 and 37 3.FIG. 23 shows, in a representation corresponding to FIG. 21, the target surface regions 38 1 to 38 4 on the second facet mirror 7, which are provided for guiding the illumination light sub-beams via in each case one of the coating types 37 i of the first facet mirror. The target area 38 1 occupies the fourth quadrant on the second facet mirror 7. the target area 38 2 occupies the second quadrant on the second facet mirror 7. the target area 38 3 occupies the first quadrant on the second facet mirror 7. the target area 38 4 occupies the third quadrant on the second facet mirror 7.Extension coordinates σ x, σ y in an arrangement plane of the second facet mirror 7 are also referred to below as pupil coordinates, although the second facet mirror 7 is regularly not arranged in the region of a pupil plane of the illumination optical unit 11. The arrangement coordinates σ x, σ y of the second facet mirror 7 correspond to the arrangement coordinates x, y of the first facet mirror 6.Along both pupil coordinates σ x and σ y, which are assigned on the one hand to the field height coordinate x and on the other hand to the object displacement coordinate y, there are thus in each case a plurality of target surface regions 38 i for guiding illumination light sub-beams via in each case one coating type 37 i on the second facet mirror 7.Adjacent target surface regions 38 i on the second facet mirror 7 overlap at least partially in overlap regions 39, 40. In these overlap regions 39, 40, there are thus second facets 25 which are assigned to at least two different coating types 37 i, 37j of the first facet mirror 6. In the center of the second facet mirror 7, the two overlap regions 39 and 40 cross one another in a rectangular double overlap region. The second facets 25 located there are accordingly located in all four target surface regions 38 1 to 38 4 and are correspondingly assigned to all four coating types 37 1 to 37 4 of the first facet mirror 6.This quadrant-by-quadrant division of the second facet mirror 7 into target surface regions for the coating types 37 i takes account of the folding of the illumination light in the illumination optical unit 11 and also of the extension aspect ratio of the second facet mirror 7 which differs from 1, and which is approximately twice as large in the σ x- direction than in the σ y- direction.FIG. 24 shows a further variant of a subdivision of the first facet mirror 6 into pretilt types 32 i. The field facet mirror 6 is illustrated in a plan view corresponding to FIG. 6. The assignment of the individual mirrors or the individual mirror groups 26 to the respective pretilt types 32 i is illustrated in FIG. 24 by different symbols.In the embodiment according to FIG. 24, the field facet mirror is divided into three 1, 322, 323 pretilt types 32 which are each tilted by different pretilt angles relative to the basic tilt angle of the respective individual mirror unit 26.Mirror surface pretilt type sections 34 1, 342 and 34 3, on which the respective pretilt types 32 1, 322 and 32 3 are arranged, run line by line along the x-coordinate in the embodiment according to FIG. 24.In total, twice as many individual mirrors of the middle pretilt type 32 2 are present as individual mirrors of the other pretilt types 32 1 and 32 3. These two other types of pretilts 32 1 and 32 3 are not directly adjacent to one another on the first facet mirror 6. Target surface regions 38 i on the second facet mirror 7 (cf. FIG. 25 ) which are assigned to these pretilt types 32 1 and 32 3 have only a small intersection.The single mirrors of the pretilt type 32 1 are tilted, for example, by -30 mrad, those of the pretilt type 32 2 by 0 mrad and those of the pretilt type 32 3 by +30 mrad.In total, in the field facet mirror 6 according to FIG. 24, there are eight mirror surface pretilt type portions 34 2 and four mirror surface pretilt type portions 34 1 and 34 3. each.FIG. 25 shows which target surface regions 38 i on the second facet mirror 7 within a correspondingly designed illumination optical unit 11 can be acted upon by the individual mirrors 21 of the respective pretilt types 32 i of the embodiment according to FIG. 24. The target surface region 38 2 represents an elliptical or also circularly bordered central region of the second facet mirror 7. The two other target surface regions 38 1 and 38 3 which are again of elliptical or also circular design cover the left-hand and right-hand edge section of the second facet mirror 7 in FIG. 25. Adjacent target area regions 38 i, 38i+1 have a large overlap area that is greater than 50% of the area of the respective target area region 38 i. The two extreme target surface areas 38 1 and 38 3 also have a central overlap which is about 25% of the area of the respective target surface area 38 i.By way of example, those facet illumination regions 41 1, 412 of the second facet mirror 7 are highlighted in shaded fashion in FIG. 25, which are used to generate an exemplary y-dipole illumination setting, which represents a variant of the y-dipole illumination setting, which were explained above with reference to FIG. 18. These illumination regions 41 1, 412 are located completely within the edge-side target surface region 38 1 on the one hand and 38 3 on the other hand.FIG. 26 shows, in a representation of the field facet mirror 6 similar to FIG. 6, a further division of the individual mirrors 21 or of the individual mirror groups 26 into two different pretilt types 32 1 and 32 2. The second and fourth quadrants (quadrants II / IV) on the field facet mirror 6 are occupied by single mirrors of the pretilt type 32 1 and the first and third quadrants (quadrants I / III) are occupied by single mirrors of the pretilt type 32 2.FIG. 27 shows a variant of a division of the first facet mirror 6 into coating types 37 i. Different ones of the coating types 37 i are highlighted by different symbols of the single mirror units 26. In the classification according to FIG. 27, exactly two coating types 37 1( symbol: upward arrow) and 37 2( symbol: downward arrow) are present. The single mirror units 26 of the coating type 37 1 are assigned to a first target surface area on the second facet mirror 7, and the single mirror units 26 of the coating type 37 2 are assigned to a second target surface area on the second facet mirror 7.The coating types can be grouped on mirror surface sections in particular row by row.FIG. 28 shows a combination of pretilt types 32 i on the one hand and coating types 37 i on the other hand on a further embodiment of the field facet mirror 6. the division here is into three pretilt types 32 1( symbol: arrow to the left), 32 2( symbol: arrow to the right) and 32 3( symbol: no horizontal arrow) and into two coating types 37 1( symbol: arrow to the top) and 37 2( symbol: arrow to the bottom). Accordingly, six different combinations of pretilt type and associated coating type result.In the arrangement variants according to FIGS. 27 and 28, each mirror surface section which has a specific pretilt type 32 i or a specific coating type 37 i comprises at least two lines of single mirror units 26.Further arrangement variants of pretilt types 32 i or. Combination variants of pretilt types 32 i and coating types 37 i are shown in FIGS. 29 and 30, which are illustrated in accordance with FIGS. 27 and 28.FIGS. 29 and 30 illustrate soft transitions between the two extreme layer classes 37 1( symbol: upward longest arrow) and 37 2( symbol: downward longest arrow). Shorter arrows indicate here that individual mirror units of this coating type are designed to illuminate a larger target surface area on the second facet mirror 7, but always preferably to the target surface area of the coating type 37 associated with the arrow direction i.In the arrangements according to FIGS. 27 and 29, the mirror surface sections of the respective coating types 37 i do not extend over a complete x-extension of the field facet mirror 6, but rather in each case over a half x-extension.By introducing a plurality of pretilt types 32 i or a plurality of coating types 37 i it is possible to reduce an angle of incidence stroke on the respective individual mirror 21 of the first facet mirror 6 and to correspondingly better optimize a coating which is adapted thereto. An absolute angle of incidence on the respective individual mirror 21 can also be reduced.FIG. 31 illustrates a reflectivity dependence via the individual mirrors 21 on a variant of the field facet mirror 6 having two coating types 37 1 and 37 2. A respective legend shown on the right in FIG. 31 is used to show an average reflectivity R of the respective surface section of the field facet mirror 6, which is exposed to the illumination light 3. It is again possible to see the assignment of the individual mirrors to individual mirror columns 27 i. The coating types 37 i are sorted accordingly column by column. Reflectivities in the range between 60% and 65% and in particular in the range between 63% and 64% can be achieved.FIG. 32 shows, in a representation similar to FIG. 25, a division of the first facet mirror 6 into starting surface regions 42 i, which are assigned to pretilt types 43 i of the second facet mirror 7, which are in turn illustrated in FIG. 33 by different hatching fillings of the respective individual mirror units 26. In the division according to FIG. 32, all the starting surface regions 42 are i embodied as lying ellipses. In a central portion of the field facet mirror 6, all four output surface regions 42 1 to 42 4. overlap.In the embodiment of the second facet mirror 7 according to FIG. 33, each of the individual mirror units 26 represents a second facet 25. The configuration of the second facet mirror 7 according to FIG. 33 is an example of a configuration in which one and the same single mirror type having single mirror units 26 can be used both for the first facet mirror 6 and for the second facet mirror 7. Depending on the number of individual mirrors 21 per individual mirror unit 26, a plurality of second facets 25 can also be realized per individual mirror unit 26, for example four second facets 25 (2 x 2 sub-array on the individual mirror unit 26), nine, sixteen or else twenty five second facets 25 per individual mirror unit 26.The individual mirror units 26 are arranged in a checkerboard or grid-like manner, wherein rows or columns of this arrangement are arranged at an angle of, for example, 45° to the coordinates x, y or σ x, σ y respectively. This angle can be in the range between 10° and 80°, in particular in the range between 30° and 60°. This angle can also be 37°, for example.The second facet mirror 7 according to FIG. 33 has a total of four pretilt types 43 1, 432, 433 and 43 4, which transfer illumination light 3 from the respective output surface region 42 1, 422, 423, 424 into the object field 8 by reflection at the respective second facet 25, pretilted in the respective pretilt type 43 i.As regards the pretilt angles of the different pretilt types 43 i the same applies as has been explained above for the pretilt angles in the pretilt types 32 i of the first facet mirror 6.The pretilt types 43 1 to 43 4 alternate along a line of the second facet mirror 7 along the σ x- coordinate, for example. In each case, an equal number of individual mirror units 26 of the second facet mirror 7 belong to in each case one of the pretilt types 43 i.The output surface regions 42 i on the first facet mirror 6 have elliptical envelopes and are offset with respect to one another both along the x-coordinate and along the y-coordinate. Adjacent starting surface regions 42 i, 42i+1 overlap with one another in overlap regions.In particular, adjacent single mirror units 26 of the second facet mirror 7 belong to different pretilt types 43 i, 43j.The pretilt types 43 i can be arranged on the second facet mirror 7 in a regular checkered or grid-like manner alternately.Adjacent ones of the second facets 25 belong to different pretilt types 43 i and 43 j.With reference to FIGS. 34 and 35, further distributions of the first facet mirror 6 into starting surface regions 42 i corresponding to the distribution according to FIG. 32 are explained.In the division according to FIG. 34, four elliptical-bordered outgan surface areas 42 1, 422, 423 and 42 4 are again present.Two of the starting surface areas, namely the areas 42 1 and 42 2 are designed as horizontal ellipses and the other two starting surface areas 42 3 and 42 4 as stationary ellipses.In the embodiment according to FIG. 34, too, all four output surface regions 42 1 to 42 4 overlap in a central section of the field facet mirror 6.In the division according to FIG. 35, a total of four circularly bordered starting surface areas 42 1 to 42 4 are present.Further examples of a division of the field facet mirror 6 into output surface regions 42 i are shown in FIGS. 36 and 37.In the configuration according to FIG. 36, a total of five starting surface regions 42 1 to 42 5 are present. The output surface regions 42 1 to 42 4 correspond to those according to FIG. 35 In addition, a fifth output surface region 42 5 is provided, which covers an inner circular section of the field facet mirror 6.FIG. 37 shows a division of the field facet mirror 6 into a total of nine output surface regions 42 1 to 42 9. One of the output surface regions, the output surface region 42 5, constitutes a central portion on the field facet mirror 6. The other eight starting surface areas 42 1 to 42 4, and 42 6 to 42 9 are arranged around this central starting surface area 42 5.In each case at least three of the output surface regions 42 i, 42j, 42k overlap with one another in a common section in the above-explained distributions of the field facet mirror 6.FIG. 38 shows, in a representation similar to FIG. 33, an occupancy of the second facet mirror 7 with a total of five pretilt types 43 1 to 43 5. indicated by respective symbols.FIG. 39 shows an occupancy of a variant of the second facet mirror 7 with monolithic second facets 25 in the manner of the embodiment of FIG. 5, wherein in the embodiment of FIG. 39 five different pretilt types 43 1 to 43 5 of these second facets 25 are present. Again, adjacent field facets 25 belong to different pretilt types 43 i, 43j.FIG. 40 shows, in a representation similar to FIG. 39, the configuration of the second facet mirror 7 with a total of nine pretilt types 43 1 to 43 9.In addition to being divided into different pretilt types 43 i there may also be a division of the second facets 25 into different coating types 44 i corresponding to what was explained above on the one hand to the pretilt types 43 i of the second facet mirror 7 and on the other hand to the coating types 37 i of the first facet mirror 6. Each pretilt type 43 i can be assigned its own coating type 44 i on the second facet mirror 7. Alternatively, it is possible to assign different coating types 44 i to one and the same pretilt type 43 i. Again alternatively or additionally, it is possible to assign different pretilt types 43 i to one and the same coating type 44 i.Via the different pretilt types 43 i and the different coating types 44 i of the second facets 25 of the second facet mirror 7, it is possible in turn to realize a reduction of a maximum angle of incidence and a reduction of a maximum angle of incidence stroke on the second facets 25, which helps optimize a reflection yield of the second facet mirror 7.FIGS. 41 and 42 show variants of a first facet mirror 45 which can be used instead of the first facet mirror 6. Components and functions corresponding to those explained above with reference in particular to the first facet mirror 6 are given the same reference numerals and are not discussed in detail again.Instead of single mirror groups 30 i the first facet mirror 45 according to FIGS. 41 and 42 has monolithic first facets 46, which are embodied as rectangular in the configuration according to FIG. 41 and curved in the configuration according to FIG. 42. The first facets 46 are arranged column by column and group by group within the columns. For details of this arrangement, reference is made to DE 10 2009 030 501 A1.In order to produce a microstructured component, in particular a highly integrated semiconductor component, for example a memory chip, with the aid of the projection exposure apparatus 1, the reticle 12 and the wafer 19 are first provided. A structure on the reticle 12 is then illuminated with the illumination light 3 by the illumination optical unit 11 and projected onto a light-sensitive layer on the wafer 19 by the projection optical unit of the projection exposure apparatus 1. By developing the light-sensitive layer, a microstructure is then produced on the wafer 19 and the micro- or nanostructured component is produced therefrom.The component produced can be a microchip, in particular a memory chip.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2015 208 512 A1

[0003] WO 2010 / 099 807

[0049] US 2006 / 0132747 A1

[0056] DE 10 2009 030 501 A1

[0180]

Claims

Facet mirror (7) for an illumination optical unit (11) for projection lithography, suitable for use as a second facet mirror, such that first facets (21) of a first facet mirror (6) are imaged at least in partial fields of an object field (8) of the illumination optical unit (11), with the aid of a transmission optical unit, to which second facets (25) of the second facet mirror (7) belong, in which partial fields an object (12) can be arranged, which object is displaced through the object field (8) along an object displacement direction (y) during a projection exposure, - having at least two pretilt types (43 1 to 43 4; 431 to 43 5; 43_ner 5_to 43 9) of the second facets (25), - wherein a first pretilt type (43 1) has second facets (25) which, in a neutral position, have a first pretilt angle relative to a basic tilt angle predetermined by a carrier geometry of the facet mirror (7), - wherein a second pretilt type (43 2) has second facets (25) which, in the neutral position, have a second pretilt angle relative to the basic tilt angle, - wherein the pretilt angles of the different pretilt types (43 i) differ from one another.Facet mirror according to Claim 1, characterized byan array arrangement of individual mirror units (26), each of the second facets (25) being designed as a sub-array of N x M individual mirrors of the respective individual mirror unit (26), all individual mirrors (21) of an individual mirror unit (26) belonging to exactly one pretilt type.Facet mirror according to Claim 1 or 2, characterized in that adjacent individual mirror units (26) belong to different pretilt types (43 i).Facet mirror according to Claim 1, characterized in that each of the second facets (25) is designed as a monolithic facet.Facet mirror according to Claim 4, characterized in that adjacent second facets (25) belong to different pretilt types.Facet mirror (7) for an illumination optical unit (11) for projection lithography, suitable for use as a second facet mirror, such that first facets (21) of a first facet mirror (6) are imaged at least in subareas of an object field (8) of the illumination optical unit (11), with the aid of a transmission optical unit, to which second facets (25) of the second facet mirror (7) belong, in which object an object (12) can be arranged, which object is displaced through the object field (8) along an object displacement direction (y) during a projection exposure, - having at least two coating types (44 i) of the second facets (25), - wherein a first coating type (44 1) has second facets (25) and / or single-mirror units (26), which are optimized for a first interval of angles of incidence of illumination light (3) on the second facets (25) and / or the single mirror units (26) of this coating type (44 i) - wherein a second coating type (44 2) has second facets (25) and / or single mirror units (26), are optimized for a second interval of angles of incidence of the illumination light (3) on the second facets (25) and / or the single mirror units (26) of this coating type (44 2) - wherein the angle of incidence intervals of the different coating types (44 1, 442) differ from one another.Illumination optical unit (11) - having a first facet mirror (6; 45) with first facets for the reflective guidance of sub-beams of illumination light (3), - having a second facet mirror (7) according to one of Claims 1 to 6 for the reflective guidance of the illumination light (3) reflected by the first facet mirror (6) towards the object field (8), - wherein the second facets (25) of the second facet mirror (7) image first facets at least in sub-fields of the object field (8) via illumination light sub-beams.Illumination optical unit according to Claim 7, characterized in that at least two starting surface regions (42 i) are present on the first facet mirror (6; 45) along a field height coordinate (x) of the first facet mirror (6; 45) of the illumination optical unit (11), which is imaged by means of the illumination optical unit (11) into a field height coordinate (x) perpendicular to the object displacement coordinate (y) of the object field (8), wherein each of the starting surface regions (42 i) is provided for guiding illumination light sub-beams via in each case one pretilt type (43 i) and / or via in each case one coating type (44 i) of the second facet mirror (7).Illumination optical unit according to Claim 7 or 8, characterized in that at least two starting surface regions (42 i) are present on the first facet mirror (6; 45) along an object displacement coordinate (y) of the first facet mirror (6; 45), which is imaged by means of the illumination optical unit (11) into the object displacement direction coordinate (y) of the object field (8), wherein each of the starting surface regions (42 i) is provided for guiding illumination light sub-beams via in each case one pretilt type (43 i) and / or via in each case one coating type (44 i).Illumination optical unit according to Claim 8 or 9, characterized in that the output surface regions (42 i) on the first facet mirror (6) at least partially overlap.Illumination system having an illumination optical unit according to one of Claims 7 to 10 and having a light source (2).Optical system having an illumination optical unit according to one of Claims 7 to 10 and having a projection optical unit (10) for imaging the object field (8) into an image field (17).Projection exposure apparatus having an optical system according to Claim 12 and a light source (2).Method for producing a microstructured component, having the following method steps: - providing a reticle (12), - providing a wafer (19) having a coating sensitive to the illumination light (3), - projecting at least a portion of the reticle (12) onto the wafer (19) with the aid of the projection exposure apparatus (1) according to Claim 13, - developing the photosensitive layer exposed to the illumination light (3) on the wafer (19).Component produced by a method according to Claim 14.

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