Illumination optics for projection microlithography

Illumination optics that can be used, for example, for EUV projection microlithography are disclosed. Also disclosed are illumination systems provided with such illumination optics, projection exposure apparatuses provided with such illumination systems, related methods of manufacturing microstructured elements, and microstructured elements obtained by these methods.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to German patent application serial number 10 2006 056 035.3, filed Nov. 28, 2006, which is hereby incorporated by reference.

FIELD

The disclosure relates to illumination optics that can be used, for example, for EUV projection microlithography. The disclosure also relates to illumination systems provided with such illumination optics, projection exposure apparatuses provided with such illumination systems, related methods of manufacturing microstructured elements, and microstructured elements obtained by these methods.

BACKGROUND

Projection exposure apparatuses are known and are disclosed, for example, in U.S. Pat. No. 6,658,084.

SUMMARY

In one aspect, the disclosure features illumination optics configured to illuminate an illumination field in a reticle plane with radiation. The illumination optics include a facet mirror and a changing device. The facet mirror includes a plurality of facets configured to generate a defined illumination setting in the illumination field. Each facet is configured to be allocated to a partial beam of the radiation, and the facet mirror has subunits which themselves are comprised of facet groups having at least one facet each. The changing device is configured to interchange at least one of the sub-units of the facet mirror with at least one interchangeable subunit. The illumination optics are configured to be used in EUV microlithography.

In another aspect, the disclosure provides an illumination system that includes illumination optics as described in the preceding paragraph and an EUV light source.

In a further aspect, the disclosure provides a projection exposure apparatus that includes an illumination system as described in the preceding paragraph and projection optics configured to image the illumination field in an image field of an image plane.

In an additional aspect, the disclosure features a method that includes using a projection exposure apparatus as described in the preceding paragraph to make a microstructured element.

In some embodiments, the disclosure provides illumination optics which offer the possibility of changing between several illumination settings with less technical effort.

In certain embodiments, the disclosure provides illumination optics having a facet mirror divided into subunits which themselves are composed of facet groups having at least one facet each. A changing device is provided for interchanging at least one of the subunits of the facet mirror with at least one interchangeable subunit.

To provide several illumination settings, it is possible to interchange individual subunits of the facet mirror with other subunits leading to different illumination conditions. In practice, the illumination conditions can be altered by changing the illumination of the illumination field, i.e. the distribution of the illumination angles (illumination setting) by which field points are illuminated. Illumination of the illumination field, i.e. its illuminated surface area, often remains unchanged in practice. Interchanging subunits of the facet mirror on a block-by-block basis can provide a mechanical solution for changing the illumination settings which requires much less technical effort than tilting individual facets. Cooling of the facet mirror, which often is often desirable, can also be ensured while maintaining interchangeability of the subunits. The illumination settings can be changed via just a few actuators of the changing device. Groups of facets, such as groups of facets possessing a larger number of individual facets, can remain mechanically connected, thus helping to ensure an efficient cooling of the facets. Depending on the desirable properties in terms of, for example, throughput or structural resolution of a projection exposure apparatus, the illumination optics can provide the right illumination setting for each of these properties.

In some embodiments, the disclosure provides an illumination optics where at least one facet mirror is configured as a field facet mirror having a plurality of field facets to generate secondary light sources. A pupil facet mirror is provided in the vicinity of at least some of the secondary light sources generated by the field facet mirror. The pupil facet mirror has a plurality of pupil facets which are impinged by EUV radiation via their corresponding field facets. The pupil facet mirror is a part of an optical equipment required to image the field facet mirror in the reticle plane. Illumination of the pupil facet mirror can be altered by interchanging individual subunits of the field facet mirror with other subunits, thus resulting in a different illumination setting. The facet mirror, which is provided with interchangeable subunits, is configured as the field facet mirror. It is not necessary for the pupil facet mirror to be disposed at the exact same location of the secondary light source which is generated. Optionally, the pupil facets of the pupil facet mirror are arranged at a specific distance to the location of the secondary light source, as described in, for example, U.S. Pat. No. 6,611,574.

The illumination optics can optionally be designed in a way as to generate the secondary light sources sagittally and tangentially in planes which are located at a distance to one another. Such an arrangement is known, for example, from U.S. Pat. No. 6,507,440.

In some embodiments, the illumination optics is provided with a single facet mirror having interchangeable subunits. At the same time, the single facet mirror provides for a defined illumination of the illumination field. A corresponding facet mirror is described in, for example, EP 1 024 408 A2.

In certain embodiments, the disclosure provides a field facet arrangement, where the field facets of the field facet mirror are oriented in a way as to enable a subunit of the field facet mirror to illuminate pupil facets which are arranged in a relatively small area of the pupil facet mirror when compared with the entire aperture of the pupil facet mirror. It is possible to change between principal settings, e.g. changing between a conventional and an annular setting, by interchanging subunits of the field facet mirror. Changing between principal settings may not be possible if pupil facets, which are distributed over the entire aperture of the pupil facet mirror, were illuminated by each subunit of the field facet mirror.

In some embodiments, the disclosure provides a changing device with an interchanging drive for interchanging displacement of a subunit carrier in a way as to change between two subunits of the field facet mirror and being provided with a positioning drive for positioning displacement of a base body of one of the subunits of the changing device between a mirror position, where the subunit is situated in a fixed position in the field facet mirror, and a neutral position for interchanging displacement of the subunit carrier, can be realized via a simple drive technology.

In certain embodiments, the disclosure provides a swivel drive that enables the subunit carrier to be rotated about a swivel axis and being part of the interchanging drive provides for the implementation of several interchangeable subunits, with the changing device requiring a tiny amount of space.

In some embodiments, the disclosure provides an arrangement of the swivel axis, wherein the swivel axis coincides with a central axis of the field facet mirror, allows for a compact arrangement of the changing device in the vicinity of, and particularly downstream of the field facet mirror.

In certain embodiments, the disclosure provides a cooling arrangement of the changing device that has a delivery line system for a cooling medium for cooling the interchangeable subunits, in which a line section extends along the swivel axis avoids problems with the cooling line arrangement when the changing device is displaced. The cooling system can be designed in a closed-loop manner.

Optionally, at least one line section of the delivery line system may be configured as a flexible line section. In that case, the base body of the interchangeable subunits is displaceable between the mirror position and the neutral position with minimal technical effort.

In some embodiments, the disclosure provides a positioning drive with a lever arm a free end of which is attached to a base body and is rotatable about a swivel joint via a motor, thus providing for a change of its position. This can, for example, be realized in a structurally simple manner.

In certain embodiments, the disclosure provides changing device arrangements including at least one stop for defining the mirror position and/or comprising at least one snap-in locking unit for fixing the mirror position, which can enable the subunit to be positioned in the mirror position in an exact position and an exact angle.

In some embodiments, at least one of one area of the pupil facet mirror and the illumination field may be illuminated by stationary, i.e. non-interchangeable, subunits of the facet mirror. Such subunits can illuminate areas of the pupil facet mirror which must be illuminated at any given illumination setting, and/or illuminate the illumination field in always the same way. This can result in a simpler structural design of the illumination optics.

In certain embodiments, the disclosure provides local area illumination by the interchangeable subunits, wherein an interchangeable subunit illuminates a central area of the pupil facet mirror or a first annular area surrounding a central area of the pupil facet mirror or an external annular area of the pupil facet mirror or an adjacent annular area of the pupil facet mirror. The adjacent annular area adjoins an external annular area or two opposite external boundary areas of the pupil facet mirror. The boundary areas have the shape of a pitch circle or a segment or two opposite adjacent boundary areas of the pupil facet mirror. The adjacent boundary areas have the shape of a pitch circle or a segment. Adjoining the external boundary areas of the pupil facet mirror or opposite areas adjoining the central area, have proved particularly suitable when different illumination settings are to be provided. Corresponding local area illumination settings can also be implemented in embodiments of the illumination optics in which secondary light sources are generated sagittally and tangentially in planes that are located at a distance to one another, or which are provided with a single facet mirror comprising interchangeable subunits. In the latter case, corresponding areas of the illumination field are illuminated to different extents when the subunits are interchanged.

In some embodiments, the disclosure provides illumination systems with the illumination optics, projection exposure apparatuses with the illumination systems, methods of manufacturing microstructured elements using the projection exposure apparatuses, and microstructured elements obtained by the methods.

In certain embodiments, the disclosure provides an illumination system having illumination optics and an EUV light source. In some embodiments, the disclosure provides a projection exposure apparatus having such an illumination system and projection optics configured to image the illumination field in an image field of an image plane. In certain embodiments, the disclosure provides a method of manufacturing a microstructured element via a process that includes: providing a projection exposure apparatus as aforesaid, providing a substrate to at least part of which a layer of a light-sensitive material is applied, providing a mask or a reticle provided with structures to be imaged, projecting of at least a part of the reticle to an area of the light-sensitive layer via the projection exposure apparatus or via: implementing the facet mirror of the illumination optics of the projection exposure apparatus in a first configuration of subunits during a first projection step, interchanging one of the subunits of the facet mirror by an interchangeable subunit so as to create a second configuration of subunits of the facet mirror, projecting at least a part of the reticle to an area of the light-sensitive layer via the projection exposure apparatus or by the aforesaid method where at least two subunits of the facet mirror are interchanged with interchangeable subunits for creating the second configuration. In some embodiments, the disclosure provides a microstructured element.

In the following, exemplified embodiments will be described in detail in conjunction with the drawings.

DETAILED DESCRIPTION

FIG. 1is a schematic representation of a projection exposure apparatus1for EUV projection microlithography. The projection exposure apparatus1serves to image a structure, which is situated in a reticle plane on a reticle2, onto a light-sensitive layer of a wafer4in a wafer plane5.

An illumination optics, the entirety of which is designated by the reference number6, serves to illuminate an illumination field in the reticle plane3. Together with an EUV light source7, the illumination optics6is configured as an illumination system of the projection exposure apparatus1.

EUV radiation8emitted by the EUV light source7is initially collected by a collector9which is schematically represented inFIG. 1. Subsequently, the collimated EUV beam hits a field facet mirror10provided with a plurality of schematically indicated field facets11. The field facets11serve to generate secondary light sources. The field facets11are allocated to particular partial beams12of the EUV radiation8.

A pupil facet mirror13is disposed at the location of the secondary light sources generated by the field facet mirror10. The pupil facet mirror13is provided with a plurality of pupil facets14which are schematically indicated inFIG. 1and are impinged by the EUV partial beams12via their respective field facets11.

The pupil facet mirror13is part of an optical equipment15that serves to image the field facet mirror in the reticle plane3. The optical equipment15is further provided with two imaging mirrors16,17.

The structure of the illumination system is schematically represented inFIG. 1and serves to demonstrate the functions of the field facet mirror10and the pupil facet mirror13. The collector9as well as the optical equipment15can also be configured in a different arrangement and composed of differently-shaped components as well as different numbers of components.

EUV radiation8reflected by the reticle2is imaged in an image field in the wafer plane5via a schematically indicated projection optics18.

FIG. 2shows a plan view of the field facet mirror10. The individual field-facets11have the shape of an arc. It is also possible to provide straight, i.e. rectangular field facets. The field facets11are arranged in groups19of ten field facets11each. The groups19of field facets are again arranged in five columns of field facets which are numbered from the left to the right as20,21,22,23, and24inFIG. 2. The columns20and24comprise three groups of field facets of ten field facets11each and a residual group25of three field facets11each. The columns21and23comprise five groups19of field facets as well as a residual group26of five field facets11. The central column22comprises six groups19of field facets. The columns of field facets20to24are arranged symmetrically in such a way as to fill a boundary circle27, in which the columns22to24are inscribed, to the greatest possible extent. The groups of the field facet mirror10can also be arranged in a different way. The field facets can in particular be divided into a different number of columns. Moreover, it is possible to arrange less or more than ten field facets per group.

The field facet mirror10is divided into a stationary subunit28and an interchangeable subunit29. A boundary between the subunits28,29is shown dashed inFIG. 2. The interchangeable subunit29comprises the two bottom groups19,26of the columns21and23as well as the two bottom groups19of the central column22.

FIG. 3shows a schematic plan view of the pupil facet mirror13. The pupil facets14are circular in shape and form hexagonal close packed units inscribed in a boundary circle30. Other close packed configurations of the pupil facet mirror are also possible. The chosen configuration depends on the optical design and also on the shape of the individual pupil facets. Also,FIG. 3indicates schematically the illumination of several groups of the pupil facets14via the field facets11of one of the groups19of field facets of the interchangeable subunit29, e.g. the upper of the two groups19of field facets of the central column22of the interchangeable subunit29inFIG. 2. The ten field facets11of this group19illuminate ten pupil facets14awhich are arranged in a central area of the pupil facet mirror13and are shown diagonally hatched inFIG. 3. This central area is a tiny fracture of the entire aperture of the pupil facet mirror13. In-between the field facets14athus illuminated, there are non-illuminated field facets14in this group19which are illuminated by other field facets of the interchangeable sub-unit29. All in all, the field facets11of the interchangeable subunit29completely illuminate a central area31of the pupil facet mirror13, as indicated inFIG. 4. The field facets11of the stationary subunit28of the field facet mirror10according toFIG. 2illuminate a first annular area32surrounding the central area31.

The boundary between the stationary subunit28and the interchangeable subunit29of the field facet mirror10is also indicated by dashed lines inFIG. 1. Here, the interchangeable subunit29is shown in a mirror position complementary to the stationary subunit28, thus forming a complete field facet mirror10. In the mirror position, the respective interchangeable sub-unit is situated in an exact position and an exact angle. A base body33of the interchangeable subunit29is attached to a free end of a lever arm34, as shown in greater detail but still schematically inFIG. 8. The lever arm34is rotatable about a swivel joint35via a motor, thus allowing for a displacement of the interchangeable subunit29between the mirror position and a lower neutral position shown hatched inFIG. 8, thus ensuring a positioning displacement of the interchangeable subunit29. A gear motor serves as a positioning drive36. A pinion gear37driven by the gear motor engages with a rack38whose free end bears against the underside of the lever arm34at a distance to the swivel joint35.

As shown schematically inFIG. 9, the base body33of the interchangeable subunit29is provided with oblique lateral guide surfaces40which are formed complementary to guide surfaces41of a base body42of the stationary subunit28of the field facet mirror10. The mirror position of the interchangeable subunit29is moreover exactly determined by stops43bearing against the underside of the base body42from below when situated in the mirror position. Additionally, the mirror position is fixable via a snap-in locking unit which is not described here.

The positioning drive36is part of a changing device44for interchanging the interchangeable subunit29of the field facet mirror10with at least one further interchangeable subunit. The subunit which may serve as a replacement for the interchangeable subunit29is hereinafter referred to as29′. The changing device44will be described in greater detail together with further embodiments of the field facet mirror. The changing device44is connected a central control device46of the projection exposure apparatus1via a signal which is sent along a signal line45.

An interchanging drive44aenables the changing device44to be rotated about a central swivel axis44bwhich extends vertically downwards inFIG. 1. The interchangeable subunit29is thus interchangeable with the second interchangeable subunit29′, which is attached to another lever arm34, once the interchangeable subunit29has been lowered to a neutral position. Since the swivel axis44bis arranged eccentrically to the field facet mirror10, the interchangeable subunits29,29′ are oriented tangentially to the stationary part of the field facet mirror. The changing device44is therefore also referred to as a tangential changing device.

The second interchangeable subunit29′, which replaces the interchangeable subunit29of the field facet mirror10according toFIG. 2, is not additionally shown in the drawing. According toFIG. 2, the second interchangeable subunit has the same structure and the same shape as the interchangeable subunit29. The two interchangeable subunits are distinguished by the field facets11which are tilted to different extents. The field facets11of the second interchangeable subunit are tilted in a way as to not illuminate a central area of the pupil facet mirror13but an external annular area47surrounding the first annular area32. Illumination of the pupil facet mirror13via the second interchangeable subunit29′, which replaces the interchangeable subunit29, is shown inFIG. 5. The central area31is no longer illuminated. Instead, the two annular areas32and47are illuminated. A conventional illumination setting is thus interchangeable with an annular illumination setting by interchanging the interchangeable subunit29with the second interchangeable subunit29′.

FIG. 6shows another example of a field facet mirror48. Elements which correspond to those described previously with reference toFIGS. 1 to 5as well as8and9are designated by the same reference numbers, and are not described again.

Along with a stationary subunit49, the field facet mirror48is provided with two interchangeable subunits50,51. Both interchangeable subunits50,51are shown in the mirror position inFIG. 6. The subunits49to51are cooled via a cooling liquid. The latter enters the base body42of the field facet mirror48through an inlet line52and leaves the base body42through a discharge line53.

The interchangeable subunit50shown at the top ofFIG. 6illuminates the central area31of the pupil facet mirror13, as shown inFIG. 10. The interchangeable subunit51shown at the bottom ofFIG. 6illuminates a first annular area54surrounding the central area31. The stationary subunit49illuminates another annular area55surrounding the first annular area54. The areas31,54and55have a total of 155 pupil facets14. The central area31and the annular area66have 49 pupil facets14each. The annular area54and the external annular area65have 54 pupil facets14each. The pupil facet mirror13is thus provided with a total of 257 pupil facets14.

A changing device56schematically shown inFIG. 7is arranged at the side facing away from the EUV radiation8, i.e. below the drawing plane and below the base body42inFIG. 6, by which the interchangeable subunits50,51is interchanged with further interchangeable subunits57,58. The interchangeable subunits50,51,57,58are shown in the lowered neutral position inFIG. 7. Details of the positioning drive, whose structure in the changing device56corresponds to that shown inFIG. 8andFIG. 9, are omitted inFIG. 7.

An interchanging drive59schematically indicated inFIG. 7enables the changing device56to be in particular infinitely rotated about a central swivel axis60by 90°, the swivel axis being perpendicular to the drawing plane inFIG. 7. The interchangeable subunits50,51,57,58are disposed on an annular subunit carrier surrounding the interchanging drive59. The swivel axis60coincides with a central axis60aof the field facet mirror48. Corresponding to the changing devices described hereinafter, the changing device56is thus also referred to as a circular changing device.

The changing device56is provided with a delivery line system61in order to cool the subunits50,51,57,58via a cooling liquid. A line section62of the delivery line system60is arranged along the swivel axis60. Inlet lines63and discharge lines64are connected to the line section62, thus ensuring the transport of cooling liquid to and from the bodies33of the interchangeable subunits50,51,57,58. As indicated inFIG. 8andFIG. 9, the lines63,64are flexible, thus allowing a problem-free displacement of the subunits29or, alternatively,50,51,57,58.

When the interchangeable subunits50,51are to be interchanged with the interchangeable subunits57,58, the interchangeable subunits50,51are initially lowered from the mirror position to the neutral position via their positioning drives36. The interchanging drive59is then rotated about the swivel axis60by 90° in the clockwise direction, i.e. away from the position shown inFIG. 7. Subsequently, the interchangeable subunits57,58are lifted from the neutral position to the mirror position via their positioning drives36until the guide surfaces40,41bear against each other, and the stops43bear against the underside of the base body42of the stationary subunit49. The interchangeable subunits57,58can additionally be locked via the snap-in locking unit (not shown) so as to fix the mirror position.

The interchangeable subunit58illuminates an external annular area65of the pupil facet mirror13. The interchangeable subunit57illuminates an adjacent annular area66of the pupil facet mirror13adjoining the inside of the external annular area65. When the interchangeable subunits57,58are in use, the areas31and54of the pupil facet mirror13are not illuminated.

When the interchangeable subunits50,51are interchanged with the second interchangeable subunits57,58, a conventional illumination setting is thus interchanged with an annular illumination setting.

FIG. 11shows a field facet mirror67. Elements which correspond to those described previously with reference toFIGS. 1 to 10are designated by the same reference numbers, and are not described again.

The field facet mirror67is provided with a stationary subunit68and two interchangeable subunits69,70. Unlike the edge boundaries of the interchangeable subunits29or, alternatively,50,51,57,58, which have the shape of a segment, the boundaries of the interchangeable subunits69,70are of rectangular shape. The interchangeable subunit70shown at the bottom ofFIG. 11illuminates the central area31of the pupil facet mirror13. The interchangeable subunit69shown at the top ofFIG. 11illuminates two opposite areas71,72adjoining the central area31. The area71is disposed above the central area31inFIG. 13, while the area71is disposed below the central area31inFIG. 13.

Residual areas73,74are illuminated by the stationary subunit68so as to obtain a conventional illumination by all areas31,71,72,73,74. The conventional illumination, also referred to as a conventional setting, corresponds to a circular illumination with an intensity as uniform as possible within the circle. The residual areas73,74form adjacent boundary areas having the shape of a segment and adjoining the central area31.

A changing device75for the field facet mirror, whose structure otherwise corresponds to that of the changing device56, is provided with further interchangeable subunits76,77in addition to the interchangeable subunits69,70. The interchangeable subunit76is shown on the left-hand side ofFIG. 12, while the interchangeable subunit77is shown on the right-hand side ofFIG. 12. Corresponding to the above descriptions with regard to the changing device56, the changing device75is used to interchange the interchangeable subunits69,70with the interchangeable subunits76,77. In order to do so, the changing device75is rotated about the central swivel axis62by 90° in the clockwise direction, i.e. away from the position shown inFIG. 12. When the interchangeable subunits are interchanged, the interchangeable subunit76thus takes the place of the interchangeable sub-unit69, while the interchangeable subunit77takes the place of the interchangeable subunit70. The interchangeable subunit illuminates two opposite external boundary areas78,79of the pupil facet mirror which are shown on the left- and right-hand sides ofFIG. 14and have the shape of a pitch circle. The interchangeable subunit77illuminates two opposite adjacent boundary areas80,81of the pupil facet mirror13shown on the left- and right-hand sides ofFIG. 14, the adjacent boundary areas80,81having the shape of a pitch circle and adjoining the outer boundary areas78,79. When the interchangeable subunits76,77are in use, the areas31as well as71,72of the pupil facet mirror13are not illuminated.

Thus, by inserting the interchangeable subunits76,77into the pupil facet mirror67, a dipole illumination is obtained which provides for two symmetrically illuminated areas (dipole setting).

FIG. 15shows a field facet mirror82. Elements which correspond to those described previously with reference toFIGS. 1 to 14are designated by the same reference numbers, and are not described again.

The arrangement of the field facets11in the field facet mirror82corresponds to the arrangement in the field facet mirror10. The field facet mirror82is provided with a stationary subunit83and two interchangeable sub-units84,85. The interchangeable subunit84is shown at the top ofFIG. 15, while the interchangeable subunit85is shown at the bottom ofFIG. 15. The interchangeable subunits84,85have different sizes and are thus provided with a different number of field facets11. The interchangeable subunit84shown at the top ofFIG. 15has three groups19of field facets formed by the upper groups situated in the columns21,22,23of field facets.

The interchangeable subunit85shown at the bottom ofFIG. 15is configured as the lower boundary of the columns21,22,23of field facets. In the column21of field facets, the interchangeable subunit85possesses one group19of field facets and the residual group26. In the column22of field facets, the interchangeable subunit85comprises two groups19of field facets. In the column23of field facets, the interchangeable subunit85possesses one group19of field facets and the residual group26.

Corresponding to their different sizes and, therefore, different numbers of field facets11, the interchangeable subunits84,85thus also illuminate areas of different sizes of the pupil facet mirror13. This proves useful in situations where the central area31, for example, is provided with a larger number of pupil facets14than the adjacent annular area54(seeFIG. 10).

A changing device86for the field facet mirror82is provided with further interchangeable subunits87,88in addition to the interchangeable subunits84,85. Except for the configuration of the interchangeable subunits84,85,87,88, the structure of the changing device86corresponds to that of the changing device56.

The external contour of the interchangeable subunit87corresponds to that of the interchangeable subunit84. Moreover, the external contour of the interchangeable subunit88corresponds to that of the interchangeable sub-unit85. As previously described in connection with the changing device56, the interchangeable subunits84,85are also interchangeable with the interchangeable subunits87,88via the changing device86, i.e. by rotating the changing device86about the swivel axis60by 90° in the clockwise direction. The interchangeable subunits87,88illuminate other areas on the pupil facet mirror13than the interchangeable subunits84,85. This way, the changing device86also offers the possibility of changing between different illumination settings.

Some embodiments of a changing device can also be provided with a larger number of interchangeable subunits, thus allowing for a change between more than two interchangeable subunit configurations in a corresponding field facet mirror. Such a changing device (not shown) can be used to change, for example, between a conventional setting, an annular setting and a dipole setting. Depending on the configuration of the interchangeable subunits, the interchange of the interchangeable subunits also provides for other illumination settings, for example a quadrupole illumination setting, a conventional illumination setting with different maximum illumination angles (different sigma), or other, more exotic illumination settings. Dipole, quadrupole and annular illumination settings in a projection exposure apparatus, in particular in connection with EUV illumination radiation, provide for the imaging of finer structures than generally possible with conventional settings. The areas illuminated by the interchangeable subunits or the stationary subunit have the shape that is required in order to configure the individual illumination setting. In addition to the area shapes already described above, illumination of areas that have the shape of a sector, for example, or are provided with an entirely different contour at the boundaries is also possible.

It is also possible to provide more than two interchangeable subunits per field facet mirror.

As an alternative to a tangential changing device44as indicated inFIG. 1or to a circular changing device56,75,86, it is also possible to provide a linear changing device in which the individual interchangeable subunits are arranged on a carriage that is displaceable in a longitudinal direction, e.g. in the direction perpendicular to the drawing plane ofFIG. 1.

The interchangeable subunits shown here are provided with several field facets11each which are combined in groups of field facets. In some embodiments, provision can be made for interchangeable subunits having only a single field facet11.

Manufacturing of a microstructured or nanostructured element takes place by positioning the structure to be imaged, i.e. the pattern to be imaged, of the reticle2into the object field of the reticle or object plane. The wafer4is positioned in the image field of the image plane or wafer plane5. While the projection exposure apparatus1is in use, the pattern on the reticle2is projected onto an illumination light-sensitive layer of the wafer4. This layer can then be developed so as to manufacture the microstructured or nanostructured element.

The facet mirror, which is provided with the interchangeable subunits and also referred to as the field facet mirror in the embodiments described above, is implemented in a first configuration of subunits. As soon as another illumination setting is required, a subunit of the facet mirror is interchanged with an interchangeable subunit, thus modifying the configuration of subunits of the facet mirror. Subsequently, another projection cycle is carried out, the subunits of the facet mirror being arranged in a second configuration.

When changing between two illumination settings, it is possible to interchange exactly one subunit of the field facet mirror. However, it is also possible to interchange at least two subunits in order to change the illumination setting.

Other embodiments are in the claims.