Mirror for projection exposure device

Abstract

The invention relates to a mirror for a projection exposure device, comprising a spectral filter, which is designed as a grating structure (30) and is used for the light reflected by the mirror. The grating structure (30) has at least two grating layers and thus specifies at least two optical path lengths of the reflected light. An integral side portion (35) of the grating structure (30) is arranged in each case between grating layer structural portions (33, 34) of the grating structure (30), each grating layer structural portion (33, 34) specifying an adjacent grating layer. The lower limit space wavelength on the defect-free partial side surface portion of the overall side surface portion (35) is within the range of 0.01 [mu] m to 1 [mu] m but excluding 0.01 [mu] m and 1 [mu] m, and the defect-free partial side surface portion of the overall side surface portion (35) constitutes at least 90% of the overall side surface portion (35). An upper limit spatial wavelength on the defect-free partial side surface portion of the overall side surface portion (35) is in a range between 0.1 [mu] m and 100 [mu] m but excluding 0.1 [mu] m and 100 [mu] m. The effective roughness of the defect-free local side surface portion is less than 10 nm in a range of not less than the lower limit spatial wavelength but not more than the upper limit spatial wavelength. A protective layer is arranged on the grating structure (30). Therefore, the service life of the reflector is prolonged.

Description

[0001] This patent application claims the priority of German patent application DE 10 2022 207 052.6, the content of which is hereby incorporated by reference. Technical Field

[0002] The invention relates to a reflector for a projection exposure device. In addition, the invention relates to an illumination optical unit having such a reflector, an optical system having such an illumination optical unit, an illumination system having such an illumination optical unit, a projection exposure device having such an optical system, a method for producing a microstructured or nanostructured component and a component produced by such a method. Background Art

[0003] Mirrors of the type mentioned at the outset are known from DE 10 2018 220 629 A1, WO 2017 / 207 401 A1 and DE 10 2012 010 093 A1. DE 10 2018 202 629 A1 discloses a mirror for an illumination optical device of a projection exposure apparatus, which has a spectral filter implemented as a grating structure. DE 10 2010 030 913 A1 discloses a method for producing a substrate for an EUV mirror, which substrate has a known surface shape at the use temperature. Summary of the invention

[0004] It is an object of the present invention to develop a reflector of the type mentioned at the outset in such a way that its service life is increased.

[0005] According to the invention, this object is achieved by a reflector having the features of claim 1 .

[0006] According to the invention, it is understood that the effective roughness of the flank portions of a grating structure for spectral filtering purposes on a reflector can influence the durability of a protective layer on the grating structure. Care must be taken that the flank portions have a small effective roughness, in particular above a spatial wavelength in the range between 0.01 μm and 1 μm but not including 0.01 μm and 1 μm, thereby ensuring an improved durability of the protective layer. It has been found that the smoothness of the defect-free local flank portions and the corresponding smoothness of the protective layer that can subsequently be applied thereto can have a positive influence on the durability of the protective layer and therefore on the service life of the reflector. In this case, structural effects and greater roughness can be tolerated within a certain range of the overall flank portion, as long as the roughness specification is ensured within the defect-free local flank portions. Depending on the embodiment of the grating structure, the lower limit spatial wavelength range above which the roughness specification should be met can be between 0.01 μm and 0.2 μm but not including 0.01 μm and 0.2 μm. The upper spatial wavelength (below which the roughness specification should be met) may range from 0.1 μm to 10 μm but not including (exclusive)

[0007] 0.1μm and 10μm.

[0008] For the definition of the parameters “ultimate spatial wavelength” and “effective roughness”, see WO 2017 / 207 401 A1.

[0009] This mirror may be a EUV collector.

[0010] The reflector may be a component of a source collector module, may be a component of an illumination optical unit, or may also be a component of a projection optical unit of an illumination device.

[0011] The more stringent roughness requirement according to claim 2 further increases the service life of the reflector. Above the lower spatial wavelength, the effective roughness may be less than 1 nm and may also be less than 0.3 nm.

[0012] Insofar as the defect-free partial side surface portion comprises more than 95% of the overall side surface portion according to claim 3, there is a correspondingly improved substrate adhesion and in this way the service life of the reflector can be further improved. The overall side surface portion can fully meet the specified roughness requirements so that the defect-free partial side surface portion coincides with the overall side surface portion.

[0013] The slope variation specification according to claim 4 leads to a further roughness characteristic, with which a design for extending the service life of the side portions of the grating structure is obtained. The maximum slope variation may not exceed 150° per μm, may not exceed 100° per μm, may not exceed 50° per μm or may not exceed 25° per μm, for example 20° per μm.

[0014] Further roughness specifications can be generated by specifying limiting values ​​of the second derivative of the defect structure with respect to at least one spatial coordinate.

[0015] According to the method for producing a defect-free local side portion according to claim 5, the local side portion is effectively smoothed and thus meets the roughness specification. Chemical and / or physical processes, local and / or global laser ablation, polishing methods or additional methods (especially coating-based additional methods) can be used as smoothing methods.

[0016] The advantages of the illumination optical unit according to claim 6, the optical system according to claim 7, the illumination system according to claim 8, the projection exposure apparatus according to claim 9, the production method according to claim 10 and the microstructured or nanostructured component according to claim 11 correspond to the advantages already discussed above for the reflector.

[0017] In particular, semiconductor components, such as memory chips, can be produced using projection exposure apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further advantages, features and details of the present invention can be seen from the description of several exemplary embodiments with reference to the drawings, wherein:

[0019] Figure 1 schematically shows a meridian section through a projection exposure apparatus for EUV projection lithography;

[0020] Figure 2 A schematic diagram showing a mirror having a spectral filter in the form of a coated grating structure;

[0021] Figure 3 schematically shows a cross-sectional view of a coated grating structure in a side region of another embodiment of a coated grating structure;

[0022] Figure 4 A cross-sectional view showing in perspective a grating structure before coating with two grating level structure portions and an interposed integral side portion, corresponding approximately to Figure 3 ;

[0023] Figure 5 Show Figure 4 A magnified excerpt of detail V in Figure 1 is used to illustrate the micro-roughness of the overall side face;

[0024] Figure 6 Show according to Figure 4 Cross-section of an uncoated grating structure used to illustrate the subtractive smoothing method.

[0025] Figure 7Shown through the Figure 4 Cross-section of an uncoated grating structure used to illustrate the additive smoothing method.

[0026] Figure 8 Shown for illustration purposes Figure 4 A schematic diagram of roughness parameters of a defect-free overall side surface of a grating structure;

[0027] Fig. 9 Similar to Figure 8 , schematically showing the corresponding diagram of roughness parameters for an example of a "rounded grain on the overall side" defect;

[0028] Fig.10 Similar to Figure 8 , schematically showing a corresponding diagram of roughness parameters for an example of an "edge profile grain on the integral side portion" defect;

[0029] Fig.11 Similar to Figure 8 , schematically showing a corresponding diagram of roughness parameters for an example of a "nick with edge profile in the overall side portion" defect;

[0030] Fig.12 Similar to Figure 8 , a corresponding graphical representation of roughness parameters schematically showing an example of a "rounded depression in the overall side portion" defect; and

[0031] Fig.13 Similar to Figure 8 , schematically showing corresponding graphs of roughness parameters for an example of a “statistical roughness on the overall side surface” defect. DETAILED DESCRIPTION

[0032] Firstly, the general structure of a microlithography projection exposure apparatus 1 will be described.

[0033] Figure 1 A meridional section through a microlithography projection exposure apparatus 1 is schematically shown. In addition to a radiation source 3 or light source 3, an illumination system 2 of the projection exposure apparatus 1 has an illumination optical unit 4 for exposing an object field 5 in an object plane 6. In this case, a reticle (not shown in the figure) arranged in the object field 5 and supported by a reticle holder (likewise not shown) is exposed. A projection optical unit 7 serves to image the object field 5 into an image field 8 in an image plane 9. The structures on the reticle are imaged onto a photosensitive layer (likewise not shown in the figure) of a wafer which is arranged in the image plane 9 in the region of the image field 8 and supported by a wafer holder (likewise not shown).

[0034] The radiation source 3 is an EUV radiation source, which emits the radiation used in the range between 5 nm and 30 nm. This can be a plasma source, such as a GDPP (gas discharge produced plasma) source or an LPP (laser produced plasma) source. For example, tin can be excited to form a plasma by a carbon dioxide laser operating at a wavelength of 10.6 μm (that is to say in the infrared range). A synchrotron-based radiation source can also be used as the radiation source 3. A person skilled in the art can find information about such a radiation source, for example, in US 6,859,515 B2. A concentrator 11 focuses the EUV radiation 10 emitted by the radiation source 3. A corresponding concentrator is known from EP 1 225 481 A. Downstream of the concentrator 11, the EUV radiation 10 propagates through an intermediate focal plane 12 before being incident on a field facet mirror 13 having a plurality of field facets 13a. The field facet mirror 13 is arranged in a plane of the illumination optical unit 4 that is optically conjugate to the object plane 6.

[0035] EUV radiation 10 is also referred to below as illumination light or imaging light.

[0036] Downstream of the field facet mirror 13, a pupil facet mirror 14 with a plurality of pupil facets 14a reflects the EUV radiation 10. The pupil facet mirror 14 is arranged in a pupil plane of the illumination optical unit 4, which is optically conjugate to a pupil plane of the projection optical unit 7. With the pupil facet mirror 14 and an imaging optical assembly in the form of a transmission optical unit 15, which has mirrors 16, 17 and 18 assigned in the order of the beam path, the individual facets 13a of the field facet mirror 13, which are also referred to as subfields or individual mirror groups, are imaged into the object field 5 (described in more detail below). The last mirror 18 of the transmission optical unit 15 is a grazing incidence mirror.

[0037] Figure 2 By way of example, a portion of a reflective surface of a mirror 29 is schematically shown with a spectral filter in the form of a grating structure 30. The mirror 29 can be a condenser, a mirror of the illumination optical unit 4 and / or a mirror of the projection optical unit 7.

[0038] The grating structure 30 acts as a spectral filter for shielding radiation having a wavelength in a predetermined range, in particular for shielding wavelengths in the infrared range, by diffraction. Shielded radiation of wavelengths other than the wavelength of the used light reflected by the reflector 29 is also referred to as stray light.

[0039] The grating structure 30 has two grating layers, namely a lower grating layer 31 and an upper grating layer 32. EThe grating structure 30 uses the two grating levels 31 and 32 to provide the corresponding reflected illumination or imaging light 10. R Two optical path lengths are specified. Depending on the embodiment of the grating structure 30, the latter can also have more than two grating layers, as a result of which in particular also the corresponding reflected illumination or imaging light 10 R Specify more than two different optical path lengths.

[0040] The lower grating layer 31 is specified by a lower grating layer structure portion 33 of the grating 30 which is flush therewith. The upper grating layer 32 is specified by an upper grating layer structure portion 34 of the grating structure 30.

[0041] An integral side surface portion 35 of the grating structure 30 is arranged in each case between grating level structure portions 33, 34 or 34, 33, each grating level structure portion 33, 34 or 34, 33 respectively designating an adjacent grating layer 31, 32 or 32, 31. There is a minimum side surface angle b between the integral side surface portion 35 and the lower grating layer 31, which is less than 90° and is typically between 5° and 80°, and ranges for example between 10° and 70° but not including 10° and 70°, or between 30° and 60° but not including 30° and 60°.

[0042] Figure 3 A variation of the grating structure 30 is shown, with Figure 2 Compared to the case of the embodiment of FIG. 1 , this variant has a smaller side angle b relative to the overall side portion 35 of the lower grating layer 31 .

[0043] Since the side angle b is not equal to 90°, the grating structure 30 has in each case a particularly trapezoidal cross section. This cross section can correspond to an isosceles trapezoid. It is particularly non-rectangular.

[0044] The area percentage of the overall reflective surface area of ​​the reflector 29, in particular the overall area percentage of the grating structure 30 formed by the integral side portions 35, in plan view, in particular in vertical projection, is no more than 10%, in particular no more than 5%, in particular no more than 3%, in particular no more than 2%, in particular no more than 1%, in particular no more than 0.5%, in particular no more than 0.3%. These area relationships apply in particular to the projection along the normal to the overall reflective surface of the reflector 29.

[0045] As an alternative to a trapezoidal cross section, the grating structure 30 may also generally have a cross section with a trapezoidal minimum envelope. The upper and lower grating layer structure parts 34, 33 do not need to extend parallel to each other.

[0046] The level difference d between the lower grating layer 31 and the upper grating layer 32 may be of the order of a quarter wavelength in the infrared range. The level difference d is particularly in the range of 1 micrometer to 10 micrometers. Other values ​​are also possible.

[0047] The level difference d is also referred to as the groove depth of the grating structure 30. For more details, reference should be made to DE 10 2012 010 093 A1.

[0048] The grating structure 30 carries a protective layer 36. A side angle b of less than 90° ensures that the protective layer 36 covers the substrate 37 completely and without gaps. This also ensures an optimally prolonged service life and in particular good and permanent adhesion of the protective layer 36 to the grating structure 30, in particular in the region of the integral side portion 35.

[0049] according to Figure 4 The perspective view of FIG. 3 again shows the structure of the uncoated grating structure 30 with the lower grating layer structure part 33, the upper grating layer structure part 34 and the inserted integral side part 35. Figure 5 of Figure 4 The enlarged excerpt V shows the microscopic roughness 37 of the overall side surface portion 35 .

[0050] Figure 4 and Figure 5 An uncoated grating structure 30 is shown, ie, a grating structure 30 before a protective layer 36 is applied.

[0051] The microscopic roughness 37 can be described as a surface structure distribution that depends on the spatial wavelength P. Due to appropriate surface treatment, in particular smoothing or polishing, the spatial wavelength is below the limiting spatial wavelength P. G The surface structure is significantly reduced, resulting in the following for wavelengths below the limiting space P G The effective roughness rms of the spatial wavelength P G =(4πrms G cos(θ) / λ) 2 <0.1.

[0052] Here, λ is the EUV wavelength used. Here, θ is the incident angle of the EUV light 3 used at the mirror surface of the mirror 29 .

[0053] In addition to the incident angle θ, the effective roughness rms G The relationship depends only on the wavelength of light used, λ. For λ = 13.5 nm and θ = 0, the following conditions apply: rms G ≤0.35nm.

[0054] The effective roughness rms is presented as the integral of the range between two different limiting spatial wavelengths. Effective roughness rms of the mirror surface GG’ Above the lower limit spatial wavelength P G and optionally below the upper spatial wavelength P G’ , that is, between the lower limit space wavelength and the upper limit space wavelength, the ratio is lower than the lower limit space wavelength P G At least 1.5 times larger, but no more than 6 times larger.

[0055] Effective roughness rms of the order of 0.5nm GG’ Can exist in the lower limit space wavelength P G In the surrounding area, 0.5nm represents the lower limit of the effective roughness. The effective roughness rms is on the order of 2nm GG’ , can exist in the upper limit space wavelength P G’ In the surrounding area, 2 nm represents the upper limit of the effective roughness.

[0056] Below the limit space wavelength P G The polishing of the mirror surface for spatial wavelengths can be such that these spatial wavelengths effectively have no contribution to the spectral power density (PSD).

[0057] The spectral power density PSD is specified in [nm 4 ] as units. For details on the definition of spectral power density, see the textbook "Optical Scattering: Measurement and Analysis", author: John C. Stover, SPIE, 2nd edition 1995 and 3rd edition 2012, and the article "Power Spectral Density (PSD)" on the web page www.nanophys.kth.se, retrieved on January 22, 2016.

[0058] The measurement methods of the spectral power density PSD and the effective roughness rms can be obtained from the article "Surface Characterization Techniques for Determining the Root Mean Square Roughness and Power Spectral Density of Optical Components" by Duparré et al. in Applied Optics, Vol. 41, No. 1, January 1, 2002. The various measuring devices are discussed in the "3. Instruments" section of the article. The "4. Power Spectral Density Function and Calculation of RMS Roughness" section of the article details: first, the spectral power density PSD and second, the calculation of the effective roughness rms (here referred to as σ) based on the obtained measurement data. rms ).

[0059] The respective rms value of the effective roughness is obtained from the PSD according to the following relationship:

[0060]

[0061] For example, at the lower limit spatial wavelength P G In the region, by selecting the integration limit f1 = 1 / P G and f2 = 1 / λ EUV From this relationship the effective roughness rms is obtained G Here, λ EUV It is the wavelength used by EUV.

[0062] For further details in the case of effective roughness, reference is made to WO 2017 / 207 401 A1.

[0063] In the case of the grating structure 30, the lower limit spatial wavelength P on the defect-free local side surface portion constituting at least 90% of the entire side surface portion 35 between the adjacent grating layer structure portions 33 and 34 is G The range of is between 0.01 μm and 1 μm, but not including 0.01 μm and 1 μm. Therefore, in particular, a higher lower limit spatial wavelength can be tolerated in a region extending over 10% of the overall side surface portion 35 .

[0064] The effective roughness rms of the defect-free local side surface of the overall side surface 35 G In short, the effective roughness can be understood as the deviation from the ideal structure of the two grating layers 31 , 32 between the linearly connected grating layer structure parts 33 , 34 .

[0065] Subtractive smoothing and / or additive smoothing can be used to generate defect-free local side portions of the overall side portion 35, as described below based on Figure 6 and Figure 7 Explained.

[0066] The exposed or protruding defects on the integral side portion 35 are exposed to a stronger chemical or physical reaction during the ablation process, such as chemical and / or physical processes or local or global laser ablation, assuming that the etching rate acts at least substantially isotropically. Therefore, more etching components, i.e., chemical molecules or ions, act on the defect A (see Figure 6 ),like Figure 6 As shown by the etching action arrow 38 in the figure. Therefore, the etching component acting on the comparison position B is less. Therefore, the reflector substrate of the grating structure 30 has more material ablated at the defect A than around it, resulting in the exposed defect A being smoothed. Corresponding statements apply to the polishing method as an example of a subtractive smoothing method for the overall side portion 35. The exposed defect A experiences stronger wear during the polishing process than the comparison position B. In this case, the polishing device can be used as a distributed polishing component.

[0067] In the additive method, the recessed defect C (see Figure 7) is smoothed by coating. Depending on the available energy of the coating particles used, these particles can migrate on the surface of the integral side portion 35 and preferably accumulate in the structure of the recessed defect according to the defect C. Then, during the additive smoothing method, the structure of such a recessed defect can be filled faster using the coating particles compared to the coating of the remaining surface of the integral side portion 35 (see comparison D in this case).

[0068] use Figures 8 to 13 Various defect examples on the integral side surface portion 35 are discussed based on the roughness parameters of the integral side surface portion 35 . Figures 8 to 13 Each of is subdivided into four graphs which are plotted on top of each other as a function of the spatial coordinate x. The top graph represents the defect level y D (x). The figure directly below shows the structural coordinate y of the grating structure E (x), that is to say in particular the profile of the integral side portion 35. The figure directly below shows the first derivative y of the grating structure profile E '(x). Figures 8 to 13 The bottom figure shows the second-order derivative y of the grating structure profile. E ” (x).

[0069] Figure 8 The ideal case of a defect-free integral side portion 35 is shown. The latter extends between the x-coordinates -3 and +3, specified in arbitrary units. The first derivative y' varies between 0 at the grating layer structures 33 and 34 and -1 in the region of the integral side portion 35. This corresponds to a side angle b of 45°.

[0070] For example, a target criterion associated with the derivative y' that can be used to establish the defect freedom of the corresponding side portion can be that the maximum slope change of the defect structure measured along the overall side portion 35 (in units: ° / path profile °Delta x) is less than 200° / μm with reference to the actual defect structure size. Lower limit values ​​can also be specified, such as 150° / μm, 100° / μm, 75° / μm, 50° / μm, 30° / μm, 25° / μm or 20° / μm. These values ​​are related to the values ​​of spatial frequency or spatial wavelength specified above.

[0071] The second-order derivative y" has a negative or positive quasi-singular point in the edge transition region between the upper grating layer structure portion 34 and the overall side portion 35 on the one hand, and has a negative or positive quasi-singular point in the edge transition region between the overall side portion 35 and the lower grating layer structure portion 33 on the other hand, at x-coordinates -3 and 3, respectively.

[0072] The conditions specified above for the first-order derivative y′ and / or the second-order derivative y″ do not need to exist on the entire grating structure 30. For example, it is sufficient for a defect-free local integral side portion to have an extent of at least 90% of the integral side portion 35. This extent of defect-free local integral side portions can also be larger and can be, for example, 95% of the integral side portion 35.

[0073] Fig. 9 The following defect examples are depicted in a greatly exaggerated manner in the following figures.

[0074] In the case of the "rounded grain" defect example as an example of a raised defect, that is, the defect protrudes beyond the rest of the side portion, according to Fig. 9 , in each case, in terms of absolute value, there is a large first-order derivative at the x-coordinate delimiting the defective particle with an absolute value of the order of 10. With an upper limit value range of the absolute value of the first-order derivative between 3 and 5 but not including 3 and 5, for example, a target value for smoothing the "rounded particle" defect example can be specified, which target value must be achieved within the smoothing range so that the x-coordinate range occupied by the original particle defect also belongs to the defect-free local side surface.

[0075] In accordance with Fig. 9 In the defect example of FIG. 3 , there is a very large absolute value of the second-order derivative in the edge transition region, the maximum value of which reaches about 1500. In order to specify a target value for a successful smoothing method, an upper limit value can also be specified for the second-order derivative, for example, in the order of 500. In this case, it can be assumed that the absolute limit value of the concave defect structure is higher than the absolute limit value of the convex defect structure, because it can be assumed that the protective layer 36 adheres better to the concave defect structure than to the convex defect structure.

[0076] Therefore, for positive values ​​of the second-order derivative y", an upper limit of the order of 500 can also be tolerated, while for negative values, a lower limit of the order of 300 can be set.

[0077] Fig.10 The corresponding values ​​are shown for the example of a particle with a "particle having an edge profile." This type of defect results in a relatively small absolute value of the first-order derivative.

[0078] In accordance with Fig.10 In the example of the same convex "particle with edge shape profile" defect, the absolute value of the second-order derivative y" is also greater than that in the Fig. 9 For the target values ​​of the first-order derivative y' and the second-order derivative y" defined above, only Fig.10 The direct raised edge region of the defect example exceeds the specification, so with the help of relatively moderate smooth ablation in this edge region x=0, the defect freedom in this defect structure region can also be obtained.

[0079] Fig.11 An example of a "scratch" defect is shown, that is, a recessed defect representing a depression in the surrounding side face, according to Fig.11 In the example, the cross section has a nearly triangular shape. Fig. 9 and Fig.10 In the description of the defect examples and in particular with regard to Fig.10 The explanations given in the defect example of 1.1.1.1.1 apply here accordingly. Fig.11 In the case of recessed defects, higher tolerance limits can be set than those which exist there, especially in the range of the second derivative y", according to Fig.11 Defects are tolerable and optionally no smoothing is required.

[0080] according to Fig. 9 The derivative data corresponding to the absolute value of the defect example appears according to Fig.12 An example of a "channel" defect. Fig.12 In the edge area of ​​the defect, the derivatives y' and y" show large values, which must be eliminated by using an appropriate additive smoothing method. Fig.12 The defect becomes part of the defect-free local side face.

[0081] Fig.13 An example of a "statistical micro-roughness" defect is shown. The derivatives y' and y" partially have excessive values, which must be eliminated using a corresponding smoothing method, and then the corresponding large part of the overall side surface is re-processed to a defect-free local side surface that reaches the smoothing target value.

[0082] After structuring and smoothing of the substrate, a closing protective layer 36 is provided on the grating structure 30. The protective layer 36 is applied to the mirror substrate and can in particular be deposited on the mirror substrate. The protective layer 36 can also be allowed to grow on the mirror substrate.

[0083] In particular, a molybdenum-silicon bilayer structure can be used as protective layer 36. The details of such layer stacks are known from the prior art.

[0084] With the aid of the projection exposure apparatus 1, at least a portion of the reticle in the object field 5 is imaged onto a photosensitive layer region on a wafer in the image field 8 for the lithographic production of microstructured or nanostructured components, in particular semiconductor components, such as microchips. Depending on the embodiment of the projection exposure apparatus 1 as a scanner or a stepper, the reticle and the wafer are moved in a time-synchronized manner, either continuously in scanner operation or stepwise in stepper operation.

Claims

1. A reflector (29) for a projection exposure device, A spectral filter is provided, which is implemented as a grating structure (30) for the light (10) reflected by the reflector (29) R ), in, The grating structure (30) specifies at least two grating layers (31, 32) and thus specifies the reflected light (10 R ), wherein the integral side portions (35) of the grating structure (30) are in each case arranged between grating layer structure portions (33, 34) of the grating structure (30), each grating layer structure portion (33, 34) designating an adjacent grating layer (31, 32), The lower limit spatial wavelength (P) on the defect-free local side surface of the overall side surface (35) is G ) is in the range between 0.01 μm and 1 μm, excluding 0.01 μm and 1 μm, wherein the defect-free local side portion of the overall side portion (35) constitutes at least 90% of the overall side portion (35) between adjacent grating layer structure portions (33, 34), The upper limit spatial wavelength (P) on the defect-free local side surface of the overall side surface (35) is G’ ) is in the range between 0.1 μm and 100 μm but excluding 0.1 μm and 100 μm, Among them, in the lower limit space wavelength (P G ) and above the upper spatial wavelength (P G’ ) or less, the effective roughness (rms) of the defect-free local side surface G ) is less than 10nm, A protective layer (36) is disposed on the grating structure (30).

2. The reflector according to claim 1, characterized in that Above the lower spatial wavelength, the effective roughness (rms G ) is less than 3nm.

3. The reflector according to claim 1 or 2, characterized in that: The range of the defect-free local side surface portion is greater than 95% of the overall side surface portion (35) between the adjacent grating layer structure portions (33, 34).

4. The reflector according to any one of claims 1 to 3, characterized in that The maximum slope variation measured at the structure of the defect-free local side portion does not exceed 200° / μm.

5. The reflector according to any one of claims 1 to 4, characterized in that The defect-free local side portion is manufactured using a subtractive method and / or an additive method.

6. An illumination optical unit (4) for guiding illumination light (10) to an object field (5) in an object plane (6), in which an object to be imaged can be arranged, the illumination optical unit (4) having a reflector according to any one of claims 1 to 5.

7. An optical system, having an illumination optical unit according to claim 6; and A projection optical unit (7) is provided for imaging the object field (5) into an image field (8), in which a substrate can be arranged.

8. An illumination system having an illumination optical unit according to claim 6 and having an EUV light source (3).

9. A projection exposure apparatus having an optical system according to claim 7 and having an EUV light source (3).

10. A method for manufacturing a microstructure or nanostructure component, comprising the following steps: providing a substrate on which a layer of photosensitive material is at least partially applied, providing a reticle having a plurality of structures to be imaged, A projection exposure apparatus (1) according to claim 9 is provided, A projection exposure device (1) is used to project at least a portion of the mask master onto a region of the photosensitive layer of the substrate.

11. A component manufactured by the method according to claim 10.

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