Method for installing an EUV collector into an EUV projection exposure apparatus or an assembly therefor, and EUV collector for carrying out the method

Abstract

In order to install an EUV collector, embodied for guiding EUV used light and for suppressing extraneous light, into an EUV projection exposure apparatus (1) which includes an EUV light source and an illumination optical unit, firstly an extraneous light suppression efficiency is measured over a used surface of the EUV collector. A weak-suppression used surface portion (43opt) is identified, in which the measured extraneous light suppression efficiency is less than a given extraneous light suppression efficiency. Furthermore, an extraneous light impingement intensity is measured over an installation target surface (42) in the used light beam path at the location of an arrangement position of the used surface of the EUV collector to be installed. A strong-impingement target surface portion (32) of the installation target surface (42) is identified, in which the measured extraneous light impingement intensity is greater than a given extraneous light impingement intensity. The used surface is oriented relative to the installation target surface (42) into an installation orientation in which the weak-suppression used surface portion (43opt) does not correspond to the strong-impingement target surface portion (32). The EUV collector is installed in the installation orientation. This results in an EUV collector having improved collector efficiency.

Description

[0001] Method for installing an EUV collector into an EUV projection exposure apparatus or an assembly therefor, and EUV collector for carrying out the method

[0002] The content of the German patent application DE 10 2024 205 222.1 is incorporated by reference herein.

[0003] The invention relates to a method for installing an EUV collector into an EUV projection exposure apparatus or into an assembly therefor. Furthermore, the invention relates to an EUV collector for carrying out the method, an illumination system comprising such a collector, an optical system comprising such an illumination system, a projection exposure apparatus comprising such an optical system, a production method for producing a micro structured or nanostructured component, and a microstructured or nanostructured component produced by this method.

[0004] An EUV collector of the type mentioned in the introduction is known from WO 2017 / 174423 Al, from US 2013 / 0335816 Al and from US 7 084412 B2.

[0005] It is an object of the present invention to develop an EUV collector of the type mentioned in the introduction in such a way that the collector efficiency thereof is improved.

[0006] According to the invention, this object is achieved by an EUV collector having the features specified in claim 1.

[0007] The extraneous light radiation may be pump light reflected by the plasma source region, said pump light serving to generate a plasma in the plasma source region. In particular, the extraneous light radiation relates to radiation components of the pump light. According to the invention, it has been recognized that an extraneous light suppression efficiency is regularly not constant over a collector used surface, but rather is subject to fluctuations in a maimer governed by production. Taking this as a departure point, by measuring firstly an extraneous light suppression efficiency over the collector used surface and secondly an extraneous light impingement intensity over an installation target surface, a system parametrization is performed which makes it possible to distinguish which installation orientation out of at least two possible installation orientations of the EUV collector is preferable in comparison with the at least one other installation orientation with regard to an extraneous light suppression efficiency. For a given EUV collector, an optimized extraneous light suppression and hence an improved collector efficiency can thus be obtained, without the need for complex and costly rework of the EUV collector with regard to its extraneous light suppression efficiency.

[0008] With the aid of the identification method steps according to Claims 2 and 3, firstly the weak-suppression used surface portion and / or secondly the strong-impingement target surface portion can be identified in a reproducible manner. An identification limit value, i.e. an upper limit of the mean extraneous light suppression efficiency and / or a lower limit of the mean extraneous light suppression efficiency, can be adapted to a respective suppression efficiency profile or impingement intensity profile. The upper limit of the extraneous light suppression efficiency can be 90%, but can also be lower, and can be for example 80%, 75%, 70%, 60%, 50%, 25% or even 10% of the mean extraneous light suppression efficiency. This upper limit is regularly greater than 0.1% of the mean extraneous light suppression efficiency. The lower limit of the measured extraneous light impingement intensity in relation to the mean extraneous light impingement intensity can be 150%, but can also be greater, for example 160%, 175%, 200%, 250%, 300%, 400%, 500% or even 1000%. This lower limit is regularly less than one hundred times the mean extraneous light impingement intensity.

[0009] The advantages of an EUV collector according to Claim 4 correspond to those which have already been explained above with reference to the installation method.

[0010] The collector mount can have a plurality of mount cantilevers arranged in particular in a maimer distributed uniformly around a circumference of the collector mirror, which enables a corresponding plurality of installation orientations of the EUV collector.

[0011] A difference in orientation according to Claim 5 has proved worthwhile in practice. A difference in orientation can also be at least 90 degrees or even 180 degrees, such that exactly two installation orientations are then possible. This simplifies a design of the collector mount.

[0012] Extraneous light suppression can be realized at the EUV collector with the aid of a diffraction grating for the extraneous light. Such a diffraction grating can be embodied as a laminar grating. The diffraction grating can be embodied as a blazed grating. The diffraction grating can be produced by material-ablating processing or by etching, in particular by mask etching. A diffraction efficiency of the diffraction grating can be very low in the zero order. A suppression of the diffraction grating, i.e. a ratio between a diffraction efficiency in the zero order and a diffraction efficiency in higher orders, can be less than 1 / 100 and, in particular, can be 1 / 1000. The diffraction grating can be produced lithographically on the used surface of the EUV collector.

[0013] The advantages of an illumination system according to Claim 11, of an optical system according to Claim 12, of a projection exposure apparatus according to Claim 13, of a production method according to Claim 14 and of a microstructured or nanostructured component according to Claim 15 correspond to those which have already been explained above with reference to the collector according to the invention.

[0014] In particular, a semiconductor component, for example a memory chip, can be produced using the projection exposure apparatus.

[0015] Exemplary embodiments of the invention are explained in detail below with reference to the drawing, in which:

[0016] Figure 1 schematically shows a projection exposure apparatus for EUV microlithography;

[0017] Figure 2 shows details of a light source of the projection exposure apparatus in the environment of an EUV collector for guiding EUV used light from a plasma source region to a field facet mirror of an illumination optical unit of the projection exposure apparatus, the EUV collector being depicted in a meridional section;

[0018] Figure 3 schematically shows beam guiding of pump light from a pump light source of the EUV light source of the projection exposure apparatus; Figure 4 shows a plan view of the EUV collector, as seen from viewing direction IV in Figure 3, with illustration of an extraneous light suppression efficiency over a used surface of the EUV collector, specifically a reflectivity of the used surface for infrared extraneous light, depicted in a first orientation of the EUV collector relative to an installation target surface in a used light beam path at the location of an arrangement position of the used surface of the EUV collector;

[0019] Figure 5 shows, in a plan view corresponding to Figure 4, the installation target surface in the used light beam path, with illustration of an extraneous light impingement intensity, specifically an impingement of infrared light from a pump laser of the light source over the installation target surface; and

[0020] Figure 6 shows, in a depiction corresponding to Figure 4, the EUV collector in an installation orientation - which is the result of an installation method - in which a weak-suppression used surface portion of the used surface of the EUV collector does not correspond to a strong-impingement target surface portion of the target surface.

[0021] A projection exposure apparatus 1 for microlithography comprises a light source 2 for illumination light or imaging light 3, which will be explained in yet more detail below. The light source 2 is an EUV light source, which creates light in a wavelength range of, for example, between 5 nm and 30 nm, in particular between 5 nm and 15 nm. The illumination light or imaging light 3 is also referred to as EUV used light below. In particular, the light source 2 can be a light source with a wavelength of 13.5 nm or a light source with a wavelength of 6.9 nm. Other EUV wavelengths are also possible. A beam path of the illumination light 3 is depicted extremely schematically in Figure 1.

[0022] An illumination optical unit 6 is used to guide the illumination light 3 from the light source 2 to an object field 4 in an object plane 5. Said illumination optical unit comprises a field facet mirror FF illustrated highly schematically in Figure 1 and a pupil facet mirror PF disposed downstream in the beam path of the illumination light 3 and likewise illustrated highly schematically. A field-forming mirror 6b for grazing incidence (GI mirror; grazing incidence mirror) is arranged in the beam path of the illumination light 3 between the pupil facet mirror PF, which is arranged in a pupil plane 6a of the illumination optical unit, and the object field 4. Such a GI mirror 6b is not mandatory.

[0023] Pupil facets (not illustrated in any more detail) of the pupil facet mirror PF are part of a transfer optical unit, which transfer, and in particular image, field facets (likewise not illustrated) of the field facet mirror FF into the object field 4 in a maimer being superimposed on one another. An embodiment known from the prior art can be used for the field facet mirror FF on the one hand and the pupil facet mirror PF on the other hand. By way of example, such an illumination optical unit is known from DE 10 2009 045 096 Al.

[0024] Using a projection optical unit or imaging optical unit 7, the object field 4 is imaged into an image field 8 in an image plane 9 with a predefined reduction scale. Projection optical units which can be used for this purpose are known from e.g. DE 10 2012 202 675 Al.

[0025] In order to facilitate the description of the projection exposure apparatus 1, a Cartesian xyz-coordinate system is indicated in the drawing, from which system the respective positional relationship of the components illustrated in the figures is evident. In Figure 1, the x-direction runs perpendicular to the plane of the drawing into the latter. The y-direction runs towards the left in Figure 1 and the z-direction runs upwards in Figure 1. The object plane 5 runs parallel to the xy-plane.

[0026] The object field 4 and the image field 8 are rectangular. Alternatively, it is also possible for the object field 4 and the image field 8 to have a bent or curved embodiment, that is to say, in particular, a partial ring shape. The object field 4 and the image field 8 have an x / y-aspect ratio of greater than 1. Therefore, the object field 4 has a longer object field dimension in the x- direction and a shorter object field dimension in the y-direction. These object field dimensions extend along the field coordinates x and y.

[0027] One of the exemplary embodiments known from the prior art can be used for the projection optical unit 7. What is imaged in this case is a portion of a reflection mask 10, also referred to as reticle, coinciding with the object field 4. The reticle 10 is carried by a reticle holder 10a. The reticle holder 10a is displaced by a reticle displacement drive 10b.

[0028] The imaging by way of the projection optical unit 7 is implemented on the surface of a substrate 11 in the form of a wafer, which is carried by a substrate holder 12. The substrate holder 12 is displaced by a wafer or substrate displacement drive 12a. Figure 1 schematically depicts, between the reticle 10 and the projection optical unit 7, a beam 13 of illumination light 3 that enters into said projection optical unit and, between the projection optical unit 7 and the substrate 11, a beam 14 of illumination light 3 that emerges from the projection optical unit 7. An image field-side numerical aperture (NA) of the projection optical unit 7 is not reproduced to scale in Figure 1.

[0029] The projection exposure apparatus 1 is of the scanner type. Both the reticle 10 and the substrate 11 are scanned in the y-direction during the operation of the projection exposure apparatus 1. A stepper type of the projection exposure apparatus 1, in which a stepwise displacement of the reticle 10 and of the substrate 11 in the y-direction is effected between individual exposures of the substrate 11, is also possible. These displacements are effected synchronously with one another by an appropriate actuation of the displacement drives 10b and 12a.

[0030] Figure 2 shows details of the light source 2.

[0031] The light source 2 is an LPP (laser produced plasma) source. For the purposes of producing plasma, tin droplets 15 are produced as a continuous droplet sequence by a tin droplet generator 16. A trajectory of the tin droplets 15 runs transversely to a principal ray direction 17 of the EUV used light 3. Here, the tin droplets 15 drop freely between the tin droplet generator 16 and a tin capturing device 18, with said droplets passing through a plasma source region 19. The EUV used light 3 is emitted by the plasma source region 19. When the tin droplet 15 arrives in the plasma source region 19, pump light 20 from a pump light source 21 impinges on said tin droplet. The pump light source 21 can be an infrared laser source in the form of, e.g., a CO2 laser. A different IR laser source is also possible, in particular a solid-state laser, for example an Nd: YAG laser.

[0032] The pump light 20 is transferred into the plasma source region 19 by way of a mirror 22, which can be a mirror that is tiltable in a controlled fashion, and by way of a focusing lens element 23. A plasma emitting the EUV used light 3 is produced by the pump light impingement from the tin droplet 15 arriving in the plasma source region 19. A beam path of the EUV used light 3 is illustrated in Figure 2 between the plasma source region 19 and the field facet mirror FF, to the extent that the EUV used light is reflected by a collector mirror 24, which is also referred to as EUV collector 24 below. The EUV collector 24 comprises a central passage opening 25 for the pump light 20 focused towards the plasma source region 19 by way of the focusing lens element 23. The collector 24 is embodied as an ellipsoid mirror and transfers the EUV used light 3 emitted by the plasma source region 19, which is arranged at one ellipsoid focus, to an intermediate focus 26 of the EUV used light 3, which is arranged at the other ellipsoid focus of the collector 24.

[0033] The field facet mirror FF is arranged downstream of the intermediate focus 26 in the beam path of the EUV used light 3, in the region of a far field of the EUV used light 3.

[0034] The EUV collector 24 and further components of the light source 2, which can be the tin droplet generator 16, the tin capturing device 18 and the focusing lens element 23, are arranged in a vacuum housing 27. The vacuum housing 27 has a passage opening 28 in the region of the intermediate focus 26. In the region of an entrance of the pump light 20 into the vacuum housing 27, the latter comprises a pump light entrance window 29. Figure 3 shows a beam path of the pump light 20 between the focusing lens element 23 and the passage opening 28 in the vacuum housing 27, which is only partly depicted in Figure 3. In comparison with Figures 1 and 2, in Figure 3 an xyz-coordinate system is tilted about the x-axis, which is perpendicular to the plane of the drawing, such that the z-axis runs along the principal ray direction 17. An arrangement plane of the EUV collector 24 runs parallel to the xy-plane with respect to this coordinate system.

[0035] The pump light 20 focussed by the focusing lens element 23 is partly reflected in the plasma source region 19 in the form of a pump light component 31 by the tin droplet 15 entering into this plasma source region 19 and, possibly, by already created plasma. This tin droplet 15 is present in a form which does not reflect the pump light component 31 reflected by the tin droplet back on itself. The reflected pump light component 31 leaves the tin droplet with an angle of reflection which can lie in the range of between 5° and 35° and which is approximately 20° in the exemplary embodiment depicted in Figure 3. The pump light component 31 reflected by the tin droplet 15 is incident on the EUV collector 24 in a pump light incidence zone 32 which is decentred in relation to the pump light passage opening 25.

[0036] The EUV collector 24 is embodied such that it guides the illumination light 3, i.e. the EUV used light, from the source region 19 of the EUV light source 2 by means of a reflective used surface 33 of the EUV collector 24 to the illumination optical unit 6 of the projection exposure apparatus 1 and additionally suppresses extraneous light, specifically the pump light 20 which impinges on the used surface 33 of the EUV collector 24 in particular in the pump light incidence zone 32. In order to provide this suppression effect, an optical diffraction grating 34 for the pump light 20 is applied on the used surface 33, said diffraction grating not being depicted in detail in the drawing.

[0037] Figure 4 shows the EUV collector 24 in a plan view. Said EUV collector has a collector mount 35 with a total of four mount cantilevers 36, 37, 38 and 39. The four mount cantilevers 36 to 39 are fixed to the EUV collector 24 in a circumferential direction around a main body 40 of said EUV collector, said main body bearing the used surface 33. By way of the mount cantilevers 36 to 39, the EUV collector 24 is secured to corresponding mating mounts of a carrying frame 41, which can be part of the vacuum or reduced-pressure housing 27 (cf. Figure 2).

[0038] The mount cantilevers 36 to 39 are arranged in a maimer distributed uniformly in a circumferential direction around a centre Z of the used surface 33 or of the main body 40, i.e. have an angular separation of 90 degrees with respect to one another in the circumferential direction around the centre Z.

[0039] Overall, the collector mount 35 is embodied such that it is possible to install the EUV collector 24 into an arrangement position of the used surface 33 in a total of four orientations of the used surface 33 relative to an installation target surface 42 in the beam path of the illumination light 3, i.e. in the used light beam path at the location of the arrangement position.

[0040] In the installation state, for example according to Figures 2 and 3, the used surface 33 coincides with the installation target surface 42. Figure 4 shows the EUV collector 24 in one out of a total of four installation orientations possible on account of the fourfold symmetry of the collector mount 35.

[0041] Figure 4 additionally illustrates an extraneous light suppression efficiency of the diffraction grating 34 over the used surface 33. Approximately in the “8 o’clock” position, a weak-suppression used surface portion 43 is present between the centre Z and an edge of the used surface 33. In this weak-suppression used surface portion 43, a diffraction efficiency of the diffraction grating 34 for the pump light 20 is reduced in comparison with the diffraction efficiency over the rest of the used surface 33. This diffraction efficiency, in the weak-suppression used surface portion 43, is in particular less than 90% of a mean extraneous light diffraction or suppression efficiency of the diffraction grating 34 and thus of the EUV collector 24. Depending on the embodiment of the EUV collector 24, the extraneous light suppression efficiency in the weak-suppression used surface portion 43 can also be less than 90% of the mean extraneous light suppression efficiency and can be for example less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20% or even less than 10% of the mean extraneous light suppression efficiency. In the extreme case, it is also possible for no pump light diffraction at all to take place in the weak-suppression used surface portion 43.

[0042] Figure 5 shows an extraneous light impingement intensity, i.e. an impingement intensity of the pump light 20, over the installation target surface 42 in the used light beam path at the location of the arrangement position of the used surface 33 of the EUV collector 24 to be installed. This extraneous light impingement intensity is highest in the pump light incidence zone 32. Outside the pump light incidence zone 32, the extraneous light impingement intensity decreases continuously, as illustrated in Figure 5.

[0043] The pump light incidence zone 32 constitutes a strong-impingement target surface portion of the installation target surface 42, in which the extraneous light impingement intensity is greater than 150% of a mean extraneous light impingement intensity over the installation target surface 42. Depending on the embodiment of the EUV light source 2, in the strong-impingement target surface portion 32 the extraneous light impingement intensity can also be greater than 175%, greater than 200%, greater than 250%, greater than 300%, greater than 400%, greater than 500% or greater than the mean extraneous light impingement intensity by an even greater factor.

[0044] Figure 5 additionally illustrates a relative pose of the strong-impingement target surface portion 32 with respect to the weak-suppression used surface portion 43 in the case of an installation orientation of the used surface 33 of the EUV collector 24 according to Figure 4 relative to the installation target surface 42. In the case of such an installation orientation, the strong-impingement target surface portion 32, firstly, and the weak-suppression used surface portion 43, secondly, overlap so that a comparatively weak diffraction efficiency, i.e. a weak extraneous light suppression efficiency, is present precisely where a large amount of pump light 20 is incident on the used surface 33.

[0045] Figure 6 shows a further installation orientation of the EUV collector 24, in the case of which the latter is rotated by 180 degrees about an axis which runs through the centre Z and which is parallel to the z-axis. The weak-suppression used surface portion 43 is now in the “2 o’clock” position. On account of the fourfold symmetry of the collector mount 35, in this installation orientation according to Figure 6, too, it is possible for the mount cantilevers 36 to 39 to be secured to the mating mounts of the carrying frame 41.

[0046] Figure 5 shows the relative pose of the weak-suppression used surface portion 43opt with respect to the pose of the strong-impingement target surface portion 32 of the installation target surface 42. In the case of the optimized installation orientation according to Figure 6, the weak-suppression used surface portion 43optand the strong-impingement target surface portion 32 do not overlap, with the result that a reduced diffraction efficiency of the diffraction grating 34 of the EUV collector 24 is not present at the location of high impingement intensity of the pump light 20.

[0047] In the case of the installation orientation according to Figure 6, the pump light 20 is thus suppressed more effectively than in the case of the installation orientation according to Figure 4.

[0048] The two installation orientations according to Figures 4 and 6 thus differ by 180 degrees in the circumferential direction around the centre Z of the used surface 33. Installation orientations which differ by 45 degrees in the circumferential direction around the centre Z of the used surface 33 are possible on account of the fourfold symmetry of the collector mount 35.

[0049] Indicated by dashed lines in Figure 4 is a further variant of a collector mount 45, which in addition to the four mount cantilevers 36 to 39 has four further mount cantilevers 46 to 49 as well. Overall, the collector mount 45 thus has eight mount cantilevers 36 to 39 and 46 to 49 having an angular separation between adjacent mount cantilevers of 22.5 degrees in the circumferential direction around the centre Z. Accordingly, the collector mount 45 has an eightfold symmetry and a total of eight installation orientations of the used surface 33 of the EUV collector 24 relative to the installation target surface 42 are possible, each differing by 22.5 degrees in the circumferential direction around the centre Z.

[0050] In the course of the installation of the EUV collector 24 into the projection exposure apparatus 1, firstly an extraneous light suppression efficiency is measured over the used surface 33 of the EUV collector 24. For this purpose, the used surface 33 is impinged on by the pump light 20 and the diffraction efficiency, i.e. the extraneous light suppression efficiency, of a respective surface portion of the used surface 33 is measured with the aid of a detector which in particular is a spatially resolving detector and is sensitive in regard to the pump light 20. The measurement result that arises is a diagram according to Figure 4 or 6, respectively. The diffraction efficiency can be measured using a possibly adapted measurement technique described in the technical article Development of an EUVL collector with infrared radiation suppression (spiedigitallibrary.org), https : / / www.spied- igitallibrary.org / conference-proceedings-of-spie / 9048 / 90483C / Develop- ment-of-an-EUVL-collector-with-infrared-radiation- suppression / 10.1117 / 12.2049279.full?SSO=l,.

[0051] Afterwards, at least one weak- suppression used surface portion is identified according to the weak-suppression used surface portion 43 where the measured extraneous light suppression efficiency is less than a predefined extraneous light suppression efficiency. The predefined extraneous light suppression efficiency can be a mean extraneous light suppression efficiency over the used surface 33. The weak-suppression used surface portion can then be identified as that portion of the used surface 33 in which the measured extraneous light suppression efficiency is less than 90% of the mean extraneous light suppression efficiency. A corresponding tolerance upper limit can also be smaller and can be for example 85%, 80%, 75%, 70%, 60%, 50%, or can be even smaller still. This upper limit is regularly greater than 1%.

[0052] Furthermore, the installation method includes measuring an extraneous light impingement intensity over the installation target surface 42, i.e. an intensity of the pump light 20 over the installation target surface 42. This can in turn be effected using a spatially resolving detector which is sensitive in regard to the pump light 20. A result of this measurement of the extraneous light impingement intensity over the installation target surface 42 is illustrated in Figure 5. As an alternative to a measurement, a simulation of the extraneous light impingement intensity can also take place, this being based on a modelling of the light source 2.

[0053] Afterwards, a strong-impingement target surface portion of the installation target surface 42 is identified where the measured extraneous light impingement intensity is greater than a given extraneous light impingement intensity. In the case of Figure 5, the identified strong-impingement target surface portion is the pump light incidence zone 32.

[0054] The identification of the strong-impingement target surface portion 32 can involve determining a mean extraneous light infringement intensity over the installation target surface 42 and identifying that at least one strong-impingement target surface portion in which the measured extraneous light impingement intensity is greater than 150% of the mean extraneous light impingement intensity. The tolerance lower limit can be higher in this case and can be for example 200%, 250%, 300%, 400%, 500%, 1000%. This lower limit is regularly less than 1 x 106. After the identification of, firstly, the at least one weak-suppression used surface portion 43 and, secondly, the at least one strong-impingement target surface portion 32, the used surface 33 of the EUV collector 24 is oriented relative to the installation target surface 42 into an installation orientation in which the weak-suppression used surface portion 43 does not correspond to the strong-impingement target surface portion 32. Such an installation orientation is shown in Figure 5 with respect to the pump light incidence zone 32 and the weak-suppression used surface portion 43opt.

[0055] The EUV collector 24 is then installed in this installation orientation. In this case, the mount cantilevers 36 to 39 or 36 to 39, 46 to 49 corresponding to this orientation are connected to the corresponding mating mounts of the carrying frame 41.

[0056] A main body of the EUV collector 24 can be manufactured from aluminium. Alternative materials for this main body are copper, alloys comprising the constituent copper and / or aluminium or alloys of copper and aluminium oxide produced by powder metallurgy.

[0057] In order to produce a microstructured or nanostructured component, the projection exposure apparatus 1 is used as follows: First, the reflection mask 10 or the reticle and the substrate or the wafer 11 are provided. Subsequently, a structure on the reticle 10 is projected onto a light-sensitive layer of the wafer 11 with the aid of the projection exposure apparatus 1. Then a micro structure or nanostructure on the wafer 11, and hence the microstructured component, is produced by developing the light-sensitive layer.

Claims

Patent Claims1. Method for installing an EUV collector (24), embodied for guiding EUV used light (3) from an EUV light source (2) of an EUV projection exposure apparatus (1) by means of a used surface (33) of the EUV collector (24) to an illumination optical unit (6) of the EUV projection exposure apparatus (1), and for suppressing extraneous light (20) which impinges on the used surface (33) of the EUV collector (24) proceeding from the EUV light source (2), into the EUV projection exposure apparatus (1) or an assembly therefor, comprising the following steps: measuring an extraneous light suppression efficiency over the used surface (33), identifying at least one weak-suppression used surface portion (43), in which the measured extraneous light suppression efficiency is less than a given extraneous light suppression efficiency, measuring an extraneous light impingement intensity over an installation target surface (42) in the used light beam path at the location of an arrangement position of the used surface (33) of the EUV collector (24) to be installed, identifying at least one strong-impingement target surface portion (32) of the installation target surface (42), in which the measured extraneous light impingement intensity is greater than a given extraneous light impingement intensity, orienting the used surface (33) relative to the installation target surface (42) into an installation orientation in which the weak-suppression used surface portion (43opt) does not correspond to the strong-impingement target surface portion (32),installing the EUV collector (24) in the installation orientation.

2. Method according to Claim 1, characterized in that the following steps are carried out for identifying the weak-suppression used surface portion (43): determining a mean extraneous light suppression efficiency over the used surface, identifying the weak-suppression used surface portion (43), in which the measured extraneous light suppression efficiency is less than 90% of the mean extraneous light suppression efficiency.

3. Method according to Claim 1 or 2, characterized in that the following steps are carried out for identifying the strong-impingement target surface portion (32): determining a mean extraneous light impingement intensity over the installation target surface (42), identifying a strong-impingement target surface portion (32) of the installation target surface (42), in which the measured extraneous light impingement intensity is greater than 150% of the mean extraneous light impingement intensity.

4. EUV collector (24) for carrying out a method according to any of Claims 1 to 3, embodied for guiding EUV used light (3) from an EUV light source (2) by means of a used surface (33) of the EUV collector (24) to an illumination optical unit (6) of an EUV projection exposure apparatus (1), andfor suppressing extraneous light (20) which impinges on the used surface (33) of the EUV collector (24) proceeding from the EUV light source (2), comprising a collector mount (35; 45) embodied such that it is possible to install the EUV collector (24) into an arrangement position of the used surface (33) in at least two orientations of the used surface (33) relative to an installation target surface (42) in the used light beam path at the location of the arrangement position.

5. EUV collector according to Claim 4, characterized in that two of the possible orientations of the used surface (33) relative to the installation target surface (42) differ by at least 45 degrees in a circumferential direction around a centre (Z) of the used surface (33).

6. Illumination system comprising an EUV collector (24) according to either of Claims 4 and 5 and comprising an illumination optical unit (6) for illuminating an object field (4), in which an object (10) to be imaged is arrangeable, with the EUV used light (3).

7. Optical system comprising an illumination system according to Claim 6 and comprising a projection optical unit (7) for imaging the object field (4) into an image field (8), in which a substrate (11) is arrangeable, onto which a portion of the object (10) to be imaged is to be imaged.

8. Projection exposure apparatus (1) comprising an optical system according to Claim 7 and comprising an EUV light source (2).

9. Method for producing a structured component comprising the following method steps: installing an EUV collector (24) into a projection exposure apparatus according to Claim 8 using the installation method according to any of Claims 1 to 3, providing a reticle (10) and a wafer (11), projecting a structure on the reticle (10) onto a light-sensitive layer of the wafer (11) with the aid of the projection exposure apparatus, creating a micro structure and / or nanostructure on the wafer (11).

10. Structured component, produced according to a method according to Claim 9.

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