Measurement illumination optical unit for guiding illumination light into the object field of a projection exposure system for EUV lithography

Abstract

The measurement illumination optical unit serves to guide the illumination light (3) into an object field of a projection exposure apparatus for EUV lithography, in which a lithography mask can be arranged. The field facet mirror of the illumination optical unit includes a plurality of field facets (7, 7'), and the pupil facet mirror of the illumination optical unit includes a plurality of pupil facets (11). The latter serve to superimpose field facet images (12) of the field facets (7) in the object field. A field facet imaging channel (12a) of the illumination light (3) is guided via one of the field facets (7) and one of the pupil facets (11). A field stop (29) serves to define the field boundary of an illumination field (31) in an object plane (17) in which the object field is arranged. The illumination field (31) has an extent along one field dimension (y) that is greater than that of any one of the field facet images (12). At least some of the field facets (7') include tilt actuators (7a) that ensure guidance of the illumination light (3) into the illumination field (31) via the various field facets (7, 7') and one and the same pupil facet (11). This results in a measurement illumination optical unit that facilitates total illumination of the illumination field (31) having an extent along one field dimension that is greater than the field facet image in the object plane.

Description

[Technical field]

[0001] This patent application claims the priority of German patent applications No. 10 2019 206 057.9 and No. 10 2019 217 158.3, the contents of which are incorporated herein by reference.

[0002] The invention relates to a measurement illumination optical unit for guiding illumination light into an object field of a projection exposure apparatus for EUV lithography. Furthermore, the invention relates to an illumination system comprising such a measurement illumination optical unit, a projection exposure apparatus comprising such an illumination system, a method for producing a micro- or nanostructured component using such a projection exposure apparatus, and a structured component produced using such a production method. [Background technology]

[0003] Projection exposure apparatuses having a generating illumination optical unit are known from DE 10 2011 004 615 A1, DE 10 2012 213 368 A1, DE 10 2012 218 076 A1, DE 10 2016 201 317 A1, DE 10 2011 076 145 B4, DE 10 2012 208 016 A1 and DE 10 2011 006 003 A1. Summary of the Invention

[0004] The present invention aims to provide a measurement illumination optical unit that facilitates full illumination of an illumination field having an extent along one field dimension that is greater than the image of a field facet in the object plane.

[0005] In known projection exposure apparatuses, the generating illumination optical unit is configured such that the entire object field capable of being imaged by the projection optical unit of the projection exposure apparatus is at least along one field dimension larger than any one of the field facet images and therefore also larger than the superposition of all field facet images in the object plane, also referred to as the illumination field, as generated by the generating illumination optical unit. Along the field dimension, the illumination field is also larger than any one of the field facet images. Therefore, a total illumination of the entire illumination field is not possible with the generating illumination optical unit. By way of example, such a total illumination is required to completely measure the imaging properties of the downstream projection optical unit over the entire illumination field and possibly over an even larger object field along this field dimension. The illumination field and the object field can therefore represent a measurement field to be measured. Such a total measurement can be used for the subsequent production of optical components for correcting the imaging aberrations of the projection optical unit, in particular for producing corrective aspheric surfaces.

[0006] The object set out at the beginning is achieved according to the present invention in a first aspect by means of a measurement illumination optical unit having the features specified in claim 1 and in a second aspect by means of a measurement illumination optical unit having the features specified in claim 8.

[0007] In some embodiments of the measurement illumination optical unit, through the assignment of the respective field facet imaging channels that contribute to the total measurement field illumination, it is possible to adapt the illumination performance variables, such as uniformity, illumination settings and crosstalk between the various channels, to the requirements of the wavefront measurement technology used in the measurement illumination optical unit. To this end, it is possible, in particular, to add or remove certain field facet imaging channels in a targeted manner for the total measurement field illumination and for the subsequent measurement of the imaging properties of the downstream projection optical unit. In particular, it is also possible to specify the illumination settings that are also used in the generating projection illumination. This can also result in specific settings that allow the detection of channel crosstalk between the different field facet imaging channels. Finally, the dark field illumination can also be set in a targeted manner. In this case, only the light diffracted in the structuring is guided through the projection optical unit, and not the directly reflected light. By way of example, the results of the measurement with the measurement illumination optical unit can be used to correct the ellipticity that is produced due to a pupil imaging that deviates from isomorphy.

[0008] According to a first aspect, it has been found that the displacement of optical components, which guide the illumination light to generate sequential illumination of the entire measurement field by the field facet imaging channels, facilitates an effective total illumination of the measurement field, which results in dynamic illumination of the entire measurement field.

[0009] The measurement illumination optical unit or the imaging optical unit may comprise a field stop for specifying a field boundary of the measurement field in an object plane in which the object field is located. Along the total illumination field dimension, the measurement field may have an extent that is larger than any one of the field facet images. At least some of the (field) facet images may be displaceable together along the total illumination field dimension relative to the measurement field through at least one displacement actuator for at least one component of the illumination optical unit.

[0010] The field stop may specify a field boundary of a measurement field, which may be located in an object plane in which the object field is located.

[0011] The displacement actuators may be configured as tilt actuators and / or as translation actuators for the optical components.

[0012] The optical component may be held via vibration damping means. The movement of the displacement actuator may be subject to closed-loop control. To this end, the measurement illumination optical unit may comprise a sensor system, in particular for capturing the position of the optical surface of the optical component.

[0013] The measurement information is measured in a spatially resolved, non-scanning manner by a detection device of the measurement illumination optical unit. Illuminating the object plane in which the object field is arranged outside the object field does not negatively affect the measurement of the properties of the projection optical unit for points within the object field.

[0014] At least some displacement of the field facet images relative to the illumination field or measurement field can be used for effective total illumination of the illumination field or measurement field, in which case the total illumination of the illumination field or measurement field can be performed sequentially by displacing the facet images through the illumination field or measurement field.

[0015] The displacement actuator can be configured as a tilt actuator for the pupil facet mirror. The measurement illumination optical unit can comprise a collector mirror as part of the imaging optical unit for creating the field facet mirror. The displacement actuator can be configured as a tilt actuator for the collector mirror. The displacement actuator can be configured as a translation actuator for the illumination optical unit relative to the field plane. Such an embodiment of the displacement actuator and / or an embodiment of the displacement actuator according to claim 3 is particularly suitable for a common relative displacement of at least some facet images relative to the illumination field or the measurement field. The displacement actuator according to claim 3 can for example bring about the displacement of just one bar of the field facet mirror, i.e. of a field facet group. The displacement device of the displacement actuator according to claim 3 can be perpendicular to the arrangement plane of the field facets on the field facet mirror or on the part of the field facet mirror to be displaced.

[0016] The displacement by the displacement actuator can be performed in the normal direction at the point of incidence on the optical surface of the component of the field facet mirror to be displaced.

[0017] The displacement device of the displacement actuator according to claim 4 can be perpendicular to the arrangement plane of the pupil facets on the pupil facet mirror or on the part of the pupil facet mirror to be displaced. Alternatively or additionally, the displacement actuator can be configured such that an individual displacement of individual pupil facets of the pupil facet mirror is possible. Hence, the actuator areas of the displacement actuator individually assigned to the individual pupil facets can be jointly controllable, so that this can also result in a common displacement of the pupil facets.

[0018] The displacement actuator according to claim 5 can be embodied as a translation or tilt actuator. The displacement direction of the displacement actuator can be perpendicular to the optical surface of the mirror component. The mirror component can be a collector mirror as part of an imaging optical unit for generating the field facet image.

[0019] The displacement actuator according to claim 6 may be embodied as a translation and / or tilt actuator.

[0020] The displacement actuator according to claim 7 can in particular be configured as a translation actuator with a displacement direction perpendicular to the object plane and / or as a tilt actuator.

[0021] According to a second aspect, it was recognized that the guiding of illumination light through various field facets and one and the same pupil facets provides the option of illuminating the illumination field even in areas where no illumination is present by superimposed imaging of the field facets through guiding through the field facet imaging channels. Due to unavoidable spatial changes in the relative positions of the field facet imaging channels, this results in a mix in the positioning of the appearing additional field facet mirrors arranged in the vicinity of the field facet images imaged in a superimposed manner, resulting in a complete illumination of the illumination field.

[0022] The pupil facets may result in the superposition generation of the entire field facet image or may in any case be part of an imaging optical unit which images the field facets in the object plane.

[0023] Using the measurement illumination optical unit, it is possible to provide a pupil that is uniform within a specified tolerance at all illumination field points.

[0024] The field facets which, through their inclination, will be imaged into the illumination field via one and the same pupil facet can be directly adjacent field facets of the field facet mirror.

[0025] An embodiment as defined in claim 9 facilitates a particularly efficient total illumination of the illumination field.

[0026] In particular, the displacement actuator can have a hexapod support connection. Through such a hexapod support connection, the displacement actuator can be connected to the main body of the optical component to be displaced. Individual control of the contractible or extendable hexapod legs of the hexapod support connection allows realization of different tilt and / or translation adjustments of the optical surface of the main body and / or of the optical component to be displaced by the displacement actuator.

[0027] Firstly, one of the optical components of the measurement illumination optical unit and, secondly, the assembly made of the displacement actuator can be part of the subject matter of the present invention, independently of further components of the measurement illumination optical unit.

[0028] A measurement illumination optical unit which is simultaneously used as a production illumination optical unit results in a particularly flexible projection exposure apparatus. The advantages of the measurement illumination optical unit according to claim 10 and the illumination system according to claims 11 and 12 otherwise correspond to those already explained above.

[0029] The displacement actuator according to claim 13 represents a further advantageous variant for displacing the facet image relative to the illumination field.

[0030] In a further variant of the measurement-illumination optical unit which serves to guide illumination light into an object field of a projection exposure apparatus for EUV lithography, in which a lithography mask can be arranged, the measurement-illumination optical unit - a detection device for spatially resolved capture of the illumination light intensity within a measurement field; - a displacement actuator for displacing at least one optical component of a measurement illumination optical unit, which guides the illumination light between the illumination light source and the object field; a sensor for capturing the position of an optical surface of the optical component; Equipped with For the controlled movement of the displacement actuators, the latter are signal-connected to sensors and / or detection devices.

[0031] In particular, such a measurement illumination optical unit can be used for the controlled movement of a displacement actuator.

[0032] The advantages of the optical system according to claim 13 or 14, the projection exposure apparatus according to claim 14, the manufacturing method according to claim 15 and the microstructured or nanostructured component according to claim 16 correspond to those already explained above with reference to the illumination optical unit according to the invention. The component to be manufactured can be a semiconductor chip, in particular a memory chip.

[0033] The projection exposure apparatus can have an object holder with an object displacement drive for displacing the object to be imaged in an object displacement direction. The projection exposure apparatus can have a wafer holder with a wafer displacement drive for displacing a wafer, on which the structures of the object to be imaged are to be imaged, in an image displacement direction. The object displacement direction can run parallel to the image displacement direction.

[0034] The above-mentioned subjects may be part of the subject matter of the present invention either in combination with one another or separately.

[0035] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. [Brief description of the drawings]

[0036] [Figure 1] 1 shows, both diagrammatically and in a meridional section relative to the measurement-illumination optical unit, a microlithography projection exposure apparatus which uses this measurement-illumination optical unit; [Diagram 2] 2 shows a diagram of a facet arrangement of a field facet mirror of an illumination optical unit of a projection exposure apparatus according to FIG. 1 in a "rectangular field" embodiment; [Diagram 3] FIG. 3 shows in a view similar to FIG. 2 the facet arrangement of a further embodiment of a field facet mirror in an “arcuate field” embodiment; [Figure 4] FIG. 2 shows an embodiment of a facet arrangement of a pupil facet mirror. [Figure 5A] FIG. 4 shows very diagrammatically the beam guidance of illumination light transmitted from three adjacent field facets of the field facet mirror according to FIG. 3 via one and the same pupil facet into an illumination field in the object plane of the measurement illumination optical unit to a field facet image. [Figure 5B] 1 shows a schematic representation of different field areas in an object plane of a projection exposure apparatus and of a measurement illumination optical unit; [Figure 5C] FIG. 2 shows different viewing areas in the image plane of a projection exposure apparatus. [Figure 6] FIG. 1 shows the positional and size relationship of, firstly, the object field of the measurement illumination optical unit, in which there is a superimposed image of the field facet images of the field facets, and, secondly, the illumination field specified through the field boundaries of the field stop of the measurement illumination optical unit, this positional relationship being shown during normal operation of the measurement in the area of ​​the center of the illumination field. [Figure 7] 7 shows a view similar to FIG. 6 in which the positional relationships are shown for measurements with a measurement illumination optical unit at the edge of the illumination field. [Figure 8]A diagram similar to FIG. 5 showing the beam guidance of illumination light in the case of an alternative embodiment of the measurement illumination optical unit, again via one and the same pupil facets of the pupil facet mirror, although only two facets and their field facet images are shown. [Figure 9] FIG. 2 shows a further embodiment of a measurement illumination optical unit having two facet mirrors and a downstream transfer optical unit having three mirrors. [Figure 10] 5 shows diagrammatically an axial cross-section through a portion of the pupil facet mirror according to FIG. 4, according to the line XX in said figure; [Figure 11] Schematically shows a side view of the body of a facet mirror, for example of a field facet mirror according to Figure 2 / 3 or of a pupil facet mirror according to Figure 4, including a hexapod support connection from the body to the frame body, with the hexapod support connection in an initial position. [Figure 12] FIG. 12 shows the mechanism according to FIG. 11 with the hexapod support connection in a first tilted position. [Figure 13] FIG. 12 shows the arrangement according to FIG. 11 in a second tilted position, in which the hexapod support connection has a further linear displacement perpendicular to the facet placement surface of the body relative to the first tilted position. [Figure 14] FIG. 2 shows a schematic view of an object to be illuminated by an illumination optical unit in a view similar to FIG. 1, the object being shown in a first position indicated using solid lines and in a second position displaced perpendicular to the object plane. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The microlithography projection exposure apparatus 1 serves for manufacturing micro- or nanostructured electronic semiconductor components. A light source 2 emits, for example, EUV radiation used for illumination in the wavelength range of 5 nm to 30 nm. The light source 2 can be a GDPP (gas discharge produced plasma) source or an LPP (laser produced plasma) source. Radiation sources based on synchrotrons or free electron lasers (FEL) can also be used for the light source 2. Information on such light sources can be found by the skilled person, for example, in US 6 859 515 B2. EUV illumination light or illumination radiation in the form of an illumination light beam or imaging light beam 3 is used for illumination and imaging in the projection exposure apparatus 1. The imaging light beam 3 downstream of the light source 2 first passes through a collector 4, which can be, for example, a nested collector having a multi-shell structure known from the prior art, or alternatively an elliptical collector then arranged downstream of the light source 2. A corresponding collector is known from EP 1 225 481 A. Downstream of the collector 4, the EUV illumination light 3 first passes through an intermediate focal plane 5, which can be used to separate the imaging light beam 3 from unwanted radiation or particle portions. After passing through the intermediate focal plane 5, the imaging light beam 3 first impinges on a field facet mirror 6, which constitutes the first facet mirror of the projection exposure apparatus 1. The field facet mirror 6 comprises a number of field facets (see also Figures 2 and 3), which are arranged on a first mirror carrier 6a. The mirror carrier 6a is also referred to as the body of the field facet mirror 6.

[0038] To facilitate the explanation of the positional relationships, a Cartesian global xyz coordinate system is shown in the drawings in each case. In FIG. 1, the x-axis runs perpendicular to the plane of the drawing and out of the latter. The y-axis runs towards the right in FIG. 1. The z-axis runs towards the top in FIG. 1.

[0039] In order to facilitate the description of the positional relationships for the individual optical components of the projection exposure apparatus 1, a Cartesian local xyz or xy coordinate system is in each case used in the following figures as well. The respective local xy coordinate system extends, unless otherwise stated, in the respective main arrangement surface of the optical component, e.g. a reflecting surface. The x-axes of the global xyz coordinate system and of the local xyz or xy coordinate system run parallel to one another. The respective y-axis of the local xyz or xy coordinate system forms an angle with the y-axis of the global xyz coordinate system that corresponds to the tilt angle of the respective optical component around the x-axis.

[0040] 2 shows in an exemplary manner the facet arrangement of the field facets 7 of the field facet mirror 6 in an embodiment of a "rectangular field". The field facets 7 are rectangular and in each case have the same x / y aspect ratio. The x / y aspect ratio is greater than 2. The x / y aspect ratio can for example be 12 / 5, 25 / 4, 104 / 8, 20 / 1 or 30 / 1.

[0041] The field facets 7 predetermine the reflecting surface of the field facet mirror 6 and are grouped into four rows with six to eight field facet groups 8a, 8b each. The field facet groups 8a have seven field facets 7 each. At the edges of the two central field facet rows, two additional field facet groups 8b have four field facets 7 each. The facet arrangement of the field facet mirror 6 has gaps 9 between the two central facet rows and between the third and fourth facet lines, through which the field facet mirror 6 is in the shadow of the retaining spokes of the collector 4. Insofar as an LPP source is used as the light source 2, a corresponding shadow may also appear from a tin droplet generator, which is arranged adjacent to the collector 4 and is not shown in the drawing.

[0042] The field facets 7 are in each case repositionable between a number of different tilt positions, for example between three tilt positions. Depending on the embodiment of the field facet mirror 6, all or otherwise some of the field facets 7 can also be repositionable between two different tilt positions or between more than three different tilt positions. To this end, each of the field facets is connected to a respective actuator 7a, shown very diagrammatically in FIG. 2. The actuators 7a of all tiltable field facets 7 can be actuated through a central control device 7b, also shown diagrammatically in FIG. 2.

[0043] The actuators 7a can be designed such that they tilt the field facets 7, 7', 7" (see FIG. 5) through discrete absolute tilt values. By way of example, this can be ensured by a tilt between two end stops. A continuous tilt or a tilt between a larger number of discrete tilt positions is also possible.

[0044] After reflection at the field facet mirror 6, the imaging light beam 3, which has been split into imaging light partial beams assigned to the individual field facets 7, impinges on a pupil facet mirror 10. Each imaging light partial beam of the entire imaging light beam 3 is guided along a respective imaging light channel, also referred to as an illumination channel or a field facet imaging channel.

[0045] Figure 3 shows a further "arcuate field" embodiment of a field facet mirror 6. Component parts corresponding to those described above with reference to the field facet mirror 6 according to Figure 2 carry the same reference numbers and are only described to the extent that they differ from component parts of the field facet mirror 6 according to Figure 2.

[0046] The field facet mirror 6 according to Fig. 3 comprises a field facet arrangement with arcuate field facets 7. These field facets 7 are arranged in a total of five rows with a number of field facet groups 8 in each case. The field facet arrangement is inscribed in a circular boundary of a mirror carrier 6a of the field facet mirror 6.

[0047] The field facets 7 in the embodiment according to FIG. 3 all have the same area and the same ratio of width in the x direction to height in the y direction, which corresponds to the x / y aspect ratio of the field facets 7 in the embodiment according to FIG.

[0048] 4 shows very diagrammatically an exemplary facet arrangement of pupil facets 11 of a pupil facet mirror 10. The pupil facet mirror 10 constitutes the second facet mirror of the projection exposure apparatus 1. The pupil facets 11 are arranged on a holder plate 10a of the pupil facet mirror 10, which is indicated only in the peripheral part in FIG. 4. The pupil facets 11 are arranged around the center of the facet arrangement on the pupil facet mirror holder 10a. The pupil facet mirror holder 10a is also referred to as the body of the pupil facet mirror 10.

[0049] One pupil facet 11 is associated with each imaging light partial beam of the EUV illumination light 3 reflected by one of the field facets 7 and, as a result, collided in each case, and a facet pair having exactly one of the field facets 7 and exactly one of the pupil facets 11 specifies an imaging light channel for the associated imaging light partial beam of the EUV illumination light 3.

[0050] The channel-by-channel assignment of the pupil facets 11 to the field facets 7 is performed on the basis of the desired illumination by the projection exposure apparatus 1. Through the different possible field facet tilt positions, each of the field facets 7 can address a different imaging light channel. The illumination light partial beams are superimposed on one another and guided via the thus addressed field facet imaging channels into the object field of the projection exposure apparatus 1, which will now be described.

[0051] Via a pupil facet mirror 10 (FIG. 1) and a downstream transfer optical unit 16 with a collector mirror 13 , the field facet 7 is imaged into an object plane 17 of the projection exposure apparatus 1 .

[0052] Fig. 5A shows diagrammatically the conditions for imaging one of the field facets 7 into a field facet image 12 with the example of an embodiment of the "arcuate field". The beam path of the associated field facet imaging channel 12a is shown in Fig. 5A in an expanded manner, the associated pupil facet 11 of this field facet imaging channel 12a being described only as a component of the transfer optical unit 16. Furthermore, in Fig. 5A the field facets 7 on the one hand and the object plane 17 on the other hand are shown in the plane of the drawing, i.e. they are arranged in one plane in Fig. 5A, which is usually not the case in reality.

[0053] Variations of the transfer optical unit are also possible, in which only the respective pupil facet 11 ensures the imaging of the associated field facet 7 into the field facet image 12. It is possible to dispense with the transfer optical unit 16, as long as the pupil facet mirror 10 is arranged directly in the entry pupil of the projection optical unit 20. The transfer optical unit 16 can also comprise several mirrors. Arranged in the object plane 17 is an object in the form of a lithographic mask or reticle 18, the illumination field of which is illuminated with EUV illumination light 3 and overlaps with an object field 19 of a projection optical unit 20 downstream of the projection exposure apparatus 1. The illumination field is also referred to below as an illumination field (see FIG. 5A), which will be described below, and like the object field 19 can represent a measurement field of a measurement illumination optical unit, which will be described below. The object field 19 is rectangular or arcuate, depending on the concrete embodiment of the illumination optical unit of the projection exposure apparatus 1. The field facet images 12 of the field facet imaging channel are superimposed in the illumination field. In the case of perfect overlap of all field facet images 12, this overlap region has the same outer contour as exactly one of the field facet images 12. What occurs due to different spatial beam guidance of the various field facet imaging channels is that the overlap of the individual field facet images 12 in the object plane 17 is usually not perfect.

[0054] The EUV illumination light 3 is reflected by a reticle 18. The reticle 18 is held by an object holder 21, which is displaceable in a driven manner in a displacement direction y with the aid of an object displacement drive 22, indicated diagrammatically.

[0055] The projection optical unit 20 images the object field 19 in the object plane 17 into an image field 23 in an image plane 24. Arranged in said image plane 24 is a wafer 25 carrying a photosensitive layer, which is exposed during a projection exposure with the projection exposure apparatus 1. The wafer 25, i.e. the substrate on which imaging is effected, is held by a wafer or substrate holder 26, which is displaceable in a displacement direction y synchronously with the displacement of the object holder 21 with the aid of a wafer displacement drive 27, also indicated diagrammatically. During the projection exposure, both the reticle 18 and the wafer 25 are scanned in the y direction in a synchronized manner. The projection exposure apparatus 1 is embodied as a scanner. The scanning direction y is the object displacement direction.

[0056] The field facet mirror 6, the pupil facet mirror 10 and the collector mirror 13 of the transfer optical unit 16 are part of an illumination optical unit 28 of the projection exposure apparatus 1. Together with the projection optical unit 20, the illumination optical unit 28 forms the illumination system of the projection exposure apparatus 1. The illumination optical unit 28 simultaneously has the function of a measurement illumination optical unit, as will be explained below.

[0057] Each group of pupil facets 11 impinged by the illumination light 3 via the field facets 7 associated with the appropriate illumination channel defines a respective illumination setting, i.e. an illumination angle distribution for illuminating the object field 19, which can be predefined by the projection exposure apparatus 1. By repositioning the tilt position of the field facets 7, it is possible to change between various such illumination settings. Examples of such illumination settings are described in WO 2014 / 075902 A1 and WO 2011 / 154244 A1.

[0058] 5A shows a field stop 29, also referred to as a scanning slit, in the object plane 17 in addition to the field facet image 12. An inner boundary 30 of the field stop 29 specifies the field boundary of the illumination field 31 or the measurement field 19. The object field 19 can correspond to or be part of the illumination field 31 or the measurement field. Therefore, both reference numbers 19 and 31 will be associated with the measurement field in the following.

[0059] The field stop 29 is arranged in the vicinity of the object plane 17 or in a plane conjugate thereto. The arrangement of the field stop 29 in the vicinity of the object plane 17 is indicated in FIG.

[0060] 5B and 5C are used below to explain the size relationships between the various above-mentioned regions, firstly in the object plane 17 (FIG. 5B) and secondly in the image plane 24 (FIG. 5C).

[0061] The projection optical unit 20 images the region of the object plane 17, in which the reticle 18 is located, onto the image plane 24. The quality of the imaging is high enough for a certain region of the object plane 17, so that this region can be used to image structures onto the reticle 18. This region in the object plane 17 is the object field 19. The region of the image plane 24, which is conjugate with the object field 10 and into which the object field 19 is imaged by the projection optical unit 20, is the image field 23.

[0062] EUV illumination light 3 entering the projection optical unit 20 slightly outside the object field 19 can likewise reach the image plane 24 and thus expose a photosensitive layer on the wafer 35. However, imaging by the projection optical unit 20 for the regions outside the object field 19 is inferior to the imaging of the object field 19, and therefore the outer regions are not used.

[0063] The illumination optical unit 28 illuminates a region of the object plane 17. This region is the illumination field 31. The illumination field 31 arises as the union of all field facet images 12, of which two field facet images 121 and 122 are shown in an exemplary manner in Fig. 4B. As a rule, each field facet image 12 is smaller than the illumination field 31.

[0064] During the scanning procedure, the image field 23 is moved relative to the wafer 25 along a scanning or object displacement direction y, and thus the photosensitive layer on the wafer 25 is exposed. Each individual scanning movement allows structuring a specific area 31a on the wafer, which area 31a is called the exposure field and corresponds to an image of the entire structure in the structure area 31b on the reticle 18. Typically, the width of the structure area 31b on the reticle 18 is matched to the width of the object field 19 in the x-dimension, i.e. the dimension perpendicular to the scanning direction y. In particular, the x-width of the structure area 31b is equal to the x-width of the object field 19 or the x-width of the structure area 31b on the reticle 18, and is only slightly smaller than the width of the object field 19.

[0065] The x-width of the exposure field 31a is given by the x-width of the image field 23. The EUV illumination light 3 entering the projection optical unit 20 in the cross-scan direction x shortly next to the object field 19 can expose areas shortly next to the exposure field 31a. Such adverse effects of crosstalk in the x-direction can be prevented firstly thanks to small intervals 31c that are not used for projection exposure remaining free in the cross-scan direction x between adjacent exposure fields 31a and secondly thanks to the reticle 18 being designed to be absorbent outside the structure areas 31b, such that the EUV illumination light 3 does not impinge next to the object field 19 in the cross-scan direction x.

[0066] The illumination field 31 is wider in the x-direction than the object field 19. If the illumination field 31 is too small in the x-direction, due to tolerances, certain areas of the reticle 18 will not be illuminated and therefore cannot be imaged by the projection optical unit 20. Due to necessarily existing tolerances, the illumination field 31 must therefore be wider in the x-direction than the object field 19.

[0067] In the cross-scan direction x, the boundaries of the image field 23 are identical to the boundaries of the exposure field 31a. Problems with EUV illumination light 3 outside the object field 19 can therefore be avoided by the spacing 31c between the exposure fields 31a and / or by absorbing regions on the reticle 18. This is not possible in the scan direction y, since in that direction the exposure field 31a extends farther than the image field 23.

[0068] In the scan direction, the EUV illumination light 3 must be prevented from entering the projection plane 20 outside the object field 19. This is ensured by virtue of having an embodiment in which the illumination field 31 is shorter than the object field 19 in the scan direction.

[0069] Since the reticle 18 is scanned through the object field 19 and therefore the entire structure area 31b of the reticle 18 reaches the illumination field of the object field 19, i.e. due to the overlap between the object field 19 and the illumination field 31, the non-illuminated edge areas of the object field 19, for example the edge areas 19a and 19b arranged outside the illumination field 31 in the scanning direction y, do not impair the generation of the structures in the wafer 25. The edge areas 19a and 19b are likewise arranged in the measurement field of the measurement illumination optical unit 28, as will be explained further below. In both the x-direction and the y-direction, the extent of this measurement field corresponds at least to the object field 19, and therefore this reference number 19 is likewise used for the measurement field in the following.

[0070] The illumination field 31 or measurement field 19 has a larger extent along the field dimension coinciding with the object displacement direction y than the field facet images 12 and also has a larger extent than the overlap region of the various field facet images 12 during superimposition imaging.

[0071] A corresponding field dimension y is also assigned to this object field dimension y in the arrangement plane of the field facet mirrors. In this arrangement plane of the mirror carrier 6a, Fig. 5 shows the two field facets closest to the field facet 7, 7', shown below the field facet 7, and 7", shown above the field facet 7, which are imaged by the field facet imaging channel 12a along this field dimension y.

[0072] In FIG. 5, the field facets 7′, 7″ are aligned along the longitudinal sides of the respective facets 7 L are adjacent to each other through

[0073] The actuators 7a of these further field facets 7', 7" facilitate a tilt of these field facets 7', 7" around an axis parallel to the x-axis to such an extent that the illumination light 3 incident on these field facets 7', 7" can likewise be directed towards the pupil facet 11 shown in Figure 5. The field facet images 12', 12" generated in this case through the pupil facet 11 are likewise shown in Figure 5 above and below the field facet image 12. These field facet images 12', 12" are not guided through a field facet imaging channel in the manner of the channel 12a in Figure 5, i.e. they are not guided superimposed on one another into the object field 19 of the projection exposure apparatus 1.

[0074] The field facet images 12', 12" overlap with the illumination field 31 in an overlap region 32', 32", which is indicated by hatching in FIG. 5. The tilt actuators 7a of the field facets 7', 7" therefore ensure guiding of the illumination light 3 via these field facets 7', 7" and one and the same pupil facet 11 into the illumination field 31 or the measurement field 19, in particular into the overlap region 32', 32" of the illumination field 31 or the measurement field 19.

[0075] FIG. 5 illustrates the illumination of the additional overlap regions 32′, 32″ using the example of just one field facet triplet with field facets 7′, 7″. As shown by the exemplary embodiment in FIGS. 2 and 3, the field facet mirror in practice has a much larger number of field facets 7, which in practice is considerably more than in the illustrated embodiment. Furthermore, as a result of the spatial arrangement relationship of the field facets 7 and the pupil facets 11, both associated with each other through the field facet imaging channels 12a, the field facet images 12, 12′, 12″ of each pupil facet 11 differ from each other in terms of their size, orientation and edge definition. This results in firstly areas in the illuminated field 31 covered by the field facet images 12 of the respective field facet imaging channels 12a and by overlap regions 32′, 32″ which differ from each other. By blending these different ranges, a complete illumination of the illumination field 31 or measurement field 19 results from the sum of all possible field facet imaging channels 12a, so that also the gaps that exist in FIG. 5 between the field facet images 12 and the overlap regions 32′, 32″ are illuminated by the illumination or imaging light 3.

[0076] Therefore, through appropriate position changes of the actuator 7a, a state in which the complete illumination field 31 or measurement field 19 is illuminated can be achieved in the "measurement illumination optics" operating mode, even if each of the field facet images 12 associated through the respective field facet imaging channel 12a has a smaller extent in the field dimension y than the illumination field 31 or measurement field 19.

[0077] This achievable complete illumination of the illumination field 31 or measurement field 19 can be used for the complete measurement of the projection optical unit 20 for the subsequent fabrication of imaging aberration correction components, for example corrective aspheric surfaces.

[0078] In conjunction with Figure 1, further embodiments of the measurement illumination optical unit are described below on the basis of Figures 6 and 7. Components and functions corresponding to those already described above with reference to Figures 1 to 5 bear the same reference numerals and will not be described in detail again.

[0079] Similarly to Fig. 5, Fig. 6 shows both the field facet images 12 imaged in the object plane 17 through the field facet imaging channels 12a as well as the illumination field 31 or measurement field 19 specified by the field stop 29. Again, the illumination field 31 or measurement field 19 has a larger extent along the field dimension y, also referred to as the total illumination field dimension, than the respective field facet images 12. In this case, Fig. 6 shows a momentary situation during operation of the measurement illumination optical unit, in which the measurement illumination optical unit is aligned such that the field facet images 12, and in particular also the overlap of the field facet images 12 generated through the various field facet imaging channels 12a in the object plane 17, are centered within the illumination field 31 or measurement field 19 along the total illumination field dimension y.

[0080] 7 shows a further instantaneous situation during operation of the measurement-illumination optical unit, in which a relative displacement (see double arrow 33) between the field facet image 12 and the illumination field 31 or measurement field 19 has been achieved with the aid of at least one displacement actuator. In the case of this displacement, the field facet image 12 has been displaced in the negative y direction in FIG. 7 relative to the illumination field 31 or measurement field 19. This achieves an illumination of the illumination field 31 or measurement field 19 in the entire illumination area 34 below, which is not covered by the centrally located field facet image 12, indicated by hatching in FIG. 6. As a result of a corresponding displacement of the field facet image 12 in the positive y direction, it is also possible to achieve an illumination of the entire illumination area 35, which is also indicated by hatching in FIG. 6 above the field facet image 12 and in the illumination field 31 or measurement field 19.

[0081] The relative displacement 33 can be produced with the aid of at least one displacement actuator as part of the measurement field illumination device, of which FIG. 1 diagrammatically shows several exemplary embodiments which can be used individually or in any combination.

[0082] The measurement field illumination device, which has at least one of the displacement actuators described below, influences the guiding of the illumination light 3 via the field facet imaging channel 12a in order to generate an illumination of the entire measurement field 31 by the field facet imaging channel 12a. At least one displacement actuator of the measurement field illumination device serves to displace at least one optical component guiding the illumination light 3 between the illumination light source 2 and the object field 19, in particular the field facet mirror 6, the pupil facet mirror 10, the collector mirror 13, the entire illumination optical unit 28 or else the reticle 18, for the purpose of generating a subsequent illumination of the entire illumination field 31 or the measurement field 19 by the field facet imaging channel 12a.

[0083] A first of these displacement actuators is shown at 35 in Fig. 1 and brings about a relative displacement of the entire field facet mirror 6 or of one of the field facet groups 8 of the field facet mirror 6, as indicated by a double arrow 36 in Fig. 1. This relative displacement 36 can run parallel to a facet arrangement plane of the mirror carrier or of the body 6a of the field facet mirror 6. As an alternative or in addition thereto, the displacement actuator 35 can bring about a relative displacement perpendicular to this arrangement plane of the field facets 7 on the body 6a, as indicated by a further double arrow 36a in Fig. 1.

[0084] A further of these displacement actuators is shown in Fig. 1 at 37. It is a tilt actuator for tilting the pupil facet mirror 10 carrying a group of pupil facets 11 or for tilting a portion of the pupil facet mirror 10 as a whole about an axis parallel to the x-axis, as indicated in Fig. 1 by a double arrow 38. As an alternative or in addition, the displacement actuator 37 can bring about a displacement of the pupil facet mirror 10 perpendicular to the arrangement plane of the mirror carrier or body 10a, as indicated in Fig. 1 by a double arrow 38a.

[0085] A further one of these displacement actuators is indicated in Fig. 1 at 39 as a tilt actuator for the collector mirror 13 of the transfer optical unit 16. This tilt actuator brings about a tilt of the collector mirror 13 about an axis parallel to the x-axis, as indicated in Fig. 1 by a double arrow 40. As an alternative or in addition thereto, the displacement actuator can bring about a displacement of the collector mirror 13 perpendicular to its reflective surface, in particular in a direction normal to the point of incidence of the illumination light 3 on the collector mirror 13, as indicated in Fig. 1 by a double arrow 40a.

[0086] A further displacement actuator is indicated diagrammatically at 41 in Figure 1 and effects a translational displacement of the illumination optical unit 28 relative to the field stop 29 or the projection optical unit 20, as indicated by a double arrow 42 in Figure 1. As an alternative or in addition, the displacement actuator 41 can effect a tilt of the entire illumination optical unit 28 relative to the field stop 29 or the projection optical unit 20 about an axis parallel to the x-axis, as indicated by a double arrow 42a in Figure 1.

[0087] Complete or total illumination of the entire illumination field 31 is also ensured, in particular with the aid of the embodiments described above in conjunction with FIGS.

[0088] To illuminate the entire illumination field 31 or the measurement field 19 with the help of the relative displacement 33, it is sufficient to have an absolute displacement along the field dimension y that corresponds to the corresponding y range of the respective field facet image 12 within the range of 20% to 50%.

[0089] The displacement actuators 35, 37, 39 or 41 do not have to be continuously displaceable. A discreet actuation, for example between two end stops, is sufficient. Discrete actuation can also be achieved, for example, by modifying the spacers, for example spacer disks.

[0090] The end stops of the actuators 7a, 35, 37, 39 and 41 may have an adjustable embodiment.

[0091] The design of the illumination light beam path in the illumination optical unit 28 can be such that a displacement of the field facet mirror 6 along the degree of freedom 36 causes a displacement of the illumination of the illumination field 31 by the same absolute value in the y direction. The illumination optical unit 28 can also be designed in such a way that there is an imaging magnification between the field facets 7 and their images 12 with an absolute value not equal to 1. In this case, a displacement of the field facet mirror 6 along the degree of freedom 36 causes a displacement of the illumination of the illumination field 31 that is just greater than the defined imaging magnification.

[0092] Using the displacement degree of freedom 38 to effect a displacement of the illumination of the illumination field 31 in the y direction of, for example, 3 mm, may require a tilt of the body 10a of the pupil facet mirror 10 of approximately 1 mrad, or a tilt of the collector mirror 13 (degree of freedom 40) of approximately 0.5 mrad to 1 mrad.

[0093] A combination of displacements through the above mentioned degrees of freedom to ensure complete or total illumination of the illumination field 31 or the measurement field 19 may also be possible.

[0094] A further embodiment of the measurement illumination optical unit is described below with reference to Figure 8. Components and features already described above with reference to Figures 1 to 7 bear the same reference numerals and will not be described in detail again.

[0095] The measurement illumination optical unit according to FIG. 8 can be considered as a combination of the measurement illumination optical units already described above, in particular with reference to FIGS. 5 to 7. Firstly, the measurement illumination optical unit according to FIG. 8 again comprises a facet field tilt actuator 7a, which allows the illumination light 3 to be guided into the object plane 17 via a number of adjacent field facets 7', 7" and one and the same pupil facet 11. At the same time, the measurement illumination optical unit according to FIG. 8 comprises at least one displacement actuator in the manner of the displacement actuators 35, 37, 39, 41 described above in connection with FIG. 1, so that again a relative displacement 33 between the field facet images 12, 12' and the illumination field 31 or the measurement field 19 is ensured. Thus, a total illumination of the illumination field 31 or the measurement field 19 is achieved by a combination of the measures described above, in particular with reference to FIGS. 5 to 7.

[0096] A further embodiment of a projection exposure apparatus 1, again with a measurement illumination optical unit, is described below with reference to Figure 9. Components and functions corresponding to those already described above with reference to Figures 1 to 8 carry the same reference numbers and will not be described in detail again.

[0097] Instead of a single collector mirror, the transfer optical unit 16 according to FIG. 9 has a total of three EUV mirrors 14a, 14b and 15 for imaging the field facets of the field facet mirror 6 into an object plane 17. The two EUV mirrors 14a, 14b are configured as NI (normal incidence) mirrors with an angle of incidence of the illumination light 3 smaller than 45°. The EUV mirror 15 is embodied as a GI (grazing incidence) mirror with an angle of incidence of the illumination light 3 larger than 45°. The transfer optical unit 16 with the mirrors 14a, 14b and 15 can furthermore bring about the imaging of an illumination pupil plane in the region of the arrangement surface of the pupil facet mirror 10 into an entrance pupil of the projection optical unit 20. In principle, such a construction of an illumination optical unit is known from DE 10 2015 208 571 A1.

[0098] FIG. 9 again illustrates an exemplary embodiment for producing relative displacement 33 (see FIGS. 7 and 8) by use of suitable displacement actuators (not shown in more detail) through the representation of each displacement degree of freedom with arrows.

[0099] One of these degrees of freedom for generating the relative displacement 33 is shown at 45 in FIG. 9 and results in a relative displacement of the entire field facet mirror 6 or of one of the field facet groups of the field facet mirror 6, as already explained in relation to FIG. 1.

[0100] A further of these degrees of freedom is shown in FIG. 9 at 46, which ensures tilt of the entire pupil facet mirror 10 about an axis parallel to the x-axis.

[0101] A further of these degrees of freedom is shown in FIG. 9 at 47, which ensures tilting of the EUV mirror 14a about an axis parallel to the x-axis.

[0102] A further of these degrees of freedom is shown in FIG. 9 at 48, which ensures tilting of the EUV mirror 14b about an axis parallel to the x-axis.

[0103] A further of these degrees of freedom is the displacement degree of freedom 42 already described in connection with FIG. 1 (translational displacement of the illumination optical unit 28 relative to the field stop 29 or the projection optical unit 20).

[0104] A further one of these degrees of freedom 49 ensures tilt of the EUV mirror 15 about an axis parallel to the x-axis.

[0105] A further one of these degrees of freedom 50 ensures the relative displacement of the EUV mirror 15 approximately perpendicular to its GI reflective surface (see double arrow 50 in FIG. 9).

[0106] Now again it can be said that the displacement actuators realizing the degrees of freedom 42 and 45 to 50 do not have to be continuously displaceable, and discrete actuation may be sufficient, as described above in relation to the displacement actuators of the embodiment of the measurement illumination optical unit according to Figures 1 and 8.

[0107] As an alternative to a transfer optical unit 16 with just one mirror as in the embodiment according to Figure 1 or with just three mirrors as in the embodiment according to Figure 9, the transfer optical unit may also comprise, for example, two or else more than three mirrors. In principle, it may also be possible to dispense with the transfer optical unit entirely, so that, for example, the field facet mirror 6 and the pupil facet mirror 10 represent the only components which guide the illumination light 3 between the intermediate focal plane 5 and the object plane 17.

[0108] The first direction of incidence of the illumination light 3 following reflection at the collector 4 can be oblique from above, as shown in the embodiment according to Fig. 1, or oblique from below, as shown in Fig. 9. For example, vertical directions of incidence from above or vertical directions from below are also possible, which are then suitably transformed by the respective illumination optical unit 28 for the purpose of illuminating the object field 19.

[0109] FIG. 10 shows an axial section of a carrier plate or of a portion of the body 10a of the pupil facet mirror 10. The pupil facets 11 are connected to the body 10a via actuator regions 51. Through the actuator regions 51 it is possible to displace the reflecting surfaces of the pupil facets 11 along the displacement degree of freedom 38a (see FIG. 1), i.e. perpendicular to the facet arrangement surface of the body 10a. Through the actuator regions 51 it is possible to displace the pupil facets 11 individually along the degree of freedom 38a. Through a common control of the actuator regions 51 it is also possible to achieve a common displacement of the pupil facets 11 along the degree of freedom 38a. The actuator regions 51 can be configured as piezoelectric actuators. By way of example, the amplitude of the movement can be up to 1 mm. Other actuators for linear movement can also be used, for example linear motors. The amplitude of the movement can range from 1 mm to 100 mm, for example 10 mm.

[0110] Fig. 11 shows a hexapod support connection of one of the bodies 6a or 10a used in the field facet mirror 6 and / or in the pupil facet mirror 10. The bodies 6a, 10a are connected to a frame body 53 of the projection exposure apparatus 1 through a hexapod support connection 52. Fig. 11 shows diagrammatically three hexapod legs 54 of the hexapod support connection 52. Fig. 11 shows the initial spacing z between the centre Z of the facet arrangement on the body 6a, 10a and the corresponding central area of ​​the frame body 53. o 1 shows the bodies 6a, 10a in an initial position having a facet arrangement surface 55 of the bodies 6a, 10a parallel to the frame plane 56 of the frame body 53.

[0111] 12 and 13 show two different measuring positions of the body 6a, 10a displaced with respect to the initial position according to FIG.

[0112] In the first measurement position according to Fig. 12, the hexapod leg 54r shown on the right hand side in Fig. 11 to 13 is slightly stretched and the further hexapod leg 54l shown on the left hand side in Fig. 11 to 13 is contracted in a corresponding manner, so that this causes a tilt of the facet arrangement surface 55 around an axis parallel to the x-axis, i.e. for example the displacement degree of freedom 38. The hexapod leg 54m seen in the middle in Fig. 11 to 13 has the same length in the measurement position according to Fig. 12 as in the initial position according to Fig. 11.

[0113] In the second measurement position according to FIG. 13, the left hexapod leg 54l in FIG. 11-13 has the same length as in the initial position according to FIG. 11. In the second measurement position according to FIG. 13, the central hexapod leg 54m in FIG. 11-13 is extended with respect to the initial position by an absolute value that corresponds approximately to the extension of the right hexapod leg 54r in FIG. 12. In the second measurement position according to FIG. 13, the right hexapod leg 54r in FIG. 11-13 is extended by twice the absolute value compared to the central hexapod leg 54m. This results in a displacement of the body 6a, 10a in the second measurement position according to FIG. 13 that can be understood as an overlap of the displacement degrees of freedom 38 (tilt around an axis parallel to the x-axis) and 36a or 38a (translational displacement perpendicular to the facet arrangement surface 55) compared to the initial position. 13, the distance z1 between the center Z of the facet arrangement on the bodies 6a, 10a and the central area of ​​the frame body 53 is greater than the distance z0 in the initial position according to FIG.

[0114] The collector mirror 13 can also be connected to the frame body of the projection exposure apparatus 1 through a corresponding hexapod support connection.

[0115] Other displacement degrees of freedom as described above, particularly in relation to FIGS. 1 and 9, can also be readily achieved using the hexapod support connections 52.

[0116] 14 shows a displacement 57 of the reticle 18 perpendicular to the object plane 17 as an additional displacement degree of freedom to ensure dynamic full or total illumination of the entire illumination field 31 or of the measurement field 19. Such z-displacement 57 can be provided through the object displacement drive 22.

[0117] A first initial position of the reticle 18 is shown in Fig. 14 using a solid line. The measurement position of the reticle displaced by an absolute value dz perpendicular to the object plane 17 along the displacement degree of freedom 57 (see also Fig. 1) relative to the initial position is shown in Fig. 14 using a dashed line. This results in a displacement dy of the illumination of the illumination field 31 or of the measurement field 19 as explained by the diagram in Fig. 14 of the reflected chief ray CR of the central field point of the illumination light 3 through the reticle 18, firstly in the initial position (solid line) and secondly in the measurement position (dashed line). This displacement can now be used for a dynamic full or total illumination of the entire illumination field 31 or of the measurement field 19. The following formula holds: dy=dz sin(CRA) where CRA is the angle of incidence of the chief ray CR of the central field point on the object plane 17. CRA can range from 3° to 9°, and can be, for example, 6°. For a displacement dy of 3 mm, for example, a dz displacement of approximately 30 mm would be required.

[0118] The value by which the hexapod legs 54 of the hexapod support connections 52 must be stretched or contracted can be within the range of + / - 100 μm or + / - 50 μm.

[0119] A displacement actuator system for providing at least one of the above mentioned degrees of freedom can be combined with active vibration damping. Furthermore, measurement / closed-loop control of the respective displacement motion is possible.

[0120] The measurement illumination optical unit 28 may comprise a detection device 60, indicated diagrammatically in Fig. 1, for spatially resolved capture of the illumination light intensity in the measurement field 19 or 31. Furthermore, the measurement illumination optical unit 28 may comprise a sensor 61 for capturing the positions of the optical surfaces of the respective optical components 6, 10, 13, 28, which sensor is illustrated in an exemplary manner diagrammatically in Fig. 1 for the purpose of capturing the position of the pupil facet mirror 10.

[0121] The detection device 60 can be a CCD sensor onto which the measurement field 19 or 31 is imaged.

[0122] The sensor 61 can be an optical sensor or otherwise any other position sensitive sensor.

[0123] Firstly, a detection device 60 and secondly, a sensor 61 are signal connected to the respective displacement actuators 35 , 37 , 39 , 41 .

[0124] Controlled movement of each displacement actuator can be ensured through appropriate processing through an open / closed loop control unit 62, signal-connected to the actuators and to the detection devices 60 and sensors 61. In this way, lighting performance variables can be maintained, in particular, within specified tolerances. [Explanation of symbols]

[0125] 1. Projection exposure equipment 2 light source 3. Illumination 4. Concentrator 5 intermediate focal plane 6 Field of view facet mirror 6a, 10a Mirror holder 7, 7', 7” Field of View Facets 7a Actuator 7b Central Control Device 7 L Facet Longitudinal Edge 8, 8a, 8b Field Facet Groups 9. Gap 10. Eye Facet Mirror 11 Pupil Facet 12, 121, 122, 12', 12” Field of view facet images 12a Field facet imaging channel 13 Condenser mirror 14a, 14b, 15 EUV mirror 16 Transmission optical unit 17 Object plane 18 Reticle 19 Object field of view 20 Projection optical unit 21 Object holder 22 Object Displacement Drive Device 23 Image field 24 Image plane 25 wafers 26 Wafer or substrate holder 27 Wafer displacement drive device 28 Illumination optical unit 29 Field Aperture 30 Inner Boundary 31 Illumination Field 31a Exposure field 31b Structural area 31c spacing 32', 32" overlap area 33 Relative Displacement 34, 35 Full illumination area 35, 37, 39, 41 Displacement actuator 36, 36a, 38, 38a, 40, 42, 45, 46, 47, 48, 49, 50, 57 degrees of freedom 51 Actuator Area 52 Hexapod support connection 53 Frame body 54, 54r, 54l, 54m hexapod legs 55 Facet placement surface 56 Frame Plane 57 Displacement 60 Detection Devices 61 Sensors 62 Open Loop / Closed Loop Control Unit

Claims

1. A measurement illumination optical unit (28) for guiding illumination light (3) into an object field (19) of a projection exposure apparatus (1) for EUV lithography, in which a lithography mask (18) can be arranged, comprising: - a field facet mirror (6) having a number of field facets (7, 7', 7"), a pupil facet mirror (10) having a plurality of pupil facets (11) for the generation of a superposition in the object field (19) of field facet images (12) of the field facets (7), in which a field facet imaging channel (12a) of the illumination light (3) is guided via every field facet (7) and every pupil facet (11), the measurement field (19, 31) has an extent along one field dimension (y) that is greater than any one of said field facet images (12), at least one measurement field illumination device (35, 37, 39, 41) which influences the guidance of said illumination light (3) through said field facet imaging channel (12) in order to generate an illumination of the entire measurement field (19, 31) by said field facet imaging channel (12), - a measurement illumination optical unit (28), in which the measurement field illumination device (35, 37, 39, 41) comprises at least one displacement actuator for displacing at least one optical component (6, 10, 13, 28) which guides the illumination light (3) between the illumination source (2) and the object field (19) for the purpose of generating a subsequent illumination of the entire measurement field (19, 31) via the field facet imaging channel (12a).

2. 2. The measurement illumination optical unit according to claim 1, characterized in that the displacement actuators (35, 37, 39, 41) are configured such that at least some of the facet images (12; 12, 12') are displaceable together along the field dimension (y) relative to the measurement field (19, 31).

3. 3. The measurement illumination optical unit according to claim 1 or 2, characterized in that the displacement actuator (35) interacts with at least a part of the field facet mirror (6) carrying a field facet group (8), said interaction serving the purpose of displacing the field facet mirror (6) or a part of the field facet mirror.

4. 4. The measurement illumination optical unit according to claim 1, wherein the displacement actuator (37) is configured such that it interacts with at least a portion of the pupil facet mirror (10) having a pupil facet group (8), the interaction serving the purpose of displacing the pupil facet mirror (10) or a portion of the pupil facet mirror.

5. 5. The measurement illumination optical unit according to claim 1, characterized by at least one further mirror component (13) which guides the illumination light (3) between the pupil facet mirror (10) and the object field (19), and wherein the displacement actuator (39) is configured such that it interacts with the mirror component (13) for the purpose of displacing the mirror component (13).

6. The measurement illumination optical unit according to any one of claims 1 to 5, characterized in that the displacement actuator (41) is configured to displace the measurement illumination optical unit (28) with respect to the object field (19) of a projection optical unit (20) which is arranged downstream of the measurement illumination optical unit (28) and serves to image the object field (19) into an image field (23).

7. The measurement illumination optical unit according to any one of claims 1 to 6, characterized in that the displacement actuator (22) is configured to displace the object holder (21) relative to the remainder of the measurement illumination optical unit (28).

8. A measurement illumination optical unit (28) for guiding illumination light (3) into an object field (19) of a projection exposure apparatus (1) for EUV lithography, in which a lithography mask (18) can be arranged, comprising: - a field facet mirror (6) having a number of field facets (7, 7', 7"), a pupil facet mirror (10) having a plurality of pupil facets (11) for superimposed imaging in the object field (19) of a field facet image (12) of the field facets (7), in which a field facet imaging channel (12a) of the illumination light (3) is guided via every single field facet (7) and every single pupil facet (11), a field stop (29) for specifying the field boundaries of an illumination field (31) in an object plane (17) in which said object field (19) is arranged, - said illuminated field (31) has an extent along one field dimension (y) that is greater than any one of said field facet images (12); a measurement illumination optical unit (28), at least some of the field facets (7', 7") comprising tilt actuators (7a) which ensure the guiding of the illumination light (3) via the various field facets (7, 7', 7") and one and the same pupil facet (11) into the illumination field (31).

9. The field facet (7) has a reflective surface with an aspect ratio greater than 2 and has an embodiment of the tilt actuator (7a) whereby one field facet longitudinal side (7 L 9. The measurement illumination optical unit according to claim 8, characterized in that the guiding of the illumination light (3) into the illumination field (31) via one and the same pupil facet (11) is ensured via mutually adjacent field facets (7, 7'; 7, 7") through a pupil facet (11).

10. The measurement illumination optical unit (28) according to any one of the preceding claims, further configured as a generation illumination optical unit for the projection exposure apparatus (1).

11. An illumination system comprising a measurement illumination optical unit (28) according to any one of the preceding claims and a light source (2) for said illumination light (3).

12. 10. An illumination system comprising a measurement illumination optical unit (28) according to any one of claims 1 to 9 and a projection optical unit (20) for imaging the object field (19) into an image field (23) of the projection exposure apparatus (1), in which a substrate (25) can be arranged.

13. 8. An illumination system comprising a measurement illumination optical unit (28) according to any one of claims 1 to 7 and a projection optical unit (20) for imaging the object field (19) into an image field (23) of the projection exposure apparatus (1), in which a substrate (25) can be arranged, characterized in that the displacement actuator (41) is configured as a translation actuator for the illumination optical unit (28) relative to the projection optical unit (20).

14. A projection exposure apparatus (1) comprising an illumination system according to any one of claims 11 to 13.

15. A method for manufacturing a structured component comprising the following steps: providing a wafer (25) at least partially covered with a layer made of a photosensitive material; providing a reticle as an object (18) having a structure to be imaged; - providing a projection exposure apparatus (1) according to claim 14, - projecting at least a part of said reticle (18) onto an area of ​​said layer of said wafer (25) with the aid of said projection exposure apparatus (1); A method comprising:

Images