DE102018214437A1 - Imaging optics for imaging an object field in an image field and projection exposure apparatus with such an imaging optics - Google Patents

Abstract

An imaging optical system (7) is used to image an object field (4) in which an object to be imaged can be arranged in an image field (8) in which a substrate can be arranged by guiding imaging light (3) along an imaging light beam path. A last mirror (M4) and a penultimate mirror (M3) in the imaging light beam path in front of the image field (8) each have a passage opening (17) for the passage of the imaging light (3). The imaging optics (7) has at least two further mirrors (M1, M2) with imaging effect in the imaging light beam path between the object field (4) and the penultimate mirror (M3). These further mirrors (M1, M2) have a reflection-free used reflection surface. The image field (8) is the first field of the imaging optics (7) in the imaging light beam path after the object field (4). The result is an imaging optics with compared to the prior art in terms of a combination of good imaging properties and practical usability within a projection exposure system optimized properties.

Description

The invention relates to an imaging optics or projection optics for imaging an object field in an image field. Furthermore, the invention relates to an optical system and an illumination system with such a projection optics, a projection exposure apparatus with such an illumination system, a method for producing a micro- or nanostructured component with such a projection exposure system and a micro-extraction nanostructured component produced by this method.

Imaging optics of the type mentioned are known from the US 8,018,650 B2 , of the WO 2018/043 433 A1 and the US 5,291,340 ,

It is an object of the present invention to further optimize an imaging optic of the type mentioned in comparison with the prior art with regard to a combination of good imaging properties and practical usability within the projection exposure apparatus.

This object is achieved by an imaging optics with the features mentioned in claim 1.

According to the invention, it has been recognized that a design of an imaging optics with two last mirrors with passage opening and at least two further mirrors without passage opening for the imaging light offers the possibility for compact designs, in which small angles of incidence of the imaging light can be realized especially at the two last mirrors where the mirror can be made without passage opening with a comparatively small mirror surface. Such imaging optics have no intermediate image between the object field and the image field. Such imaging optics may find application in the field of metrology and / or in the field of projection lithography, in particular in conjunction with imaging light in the range of EUV wavelengths.

An imaging optics according to claim 2 has proven itself in practice.

An imaging optics according to claim 3 enables easy positioning of an aperture diaphragm and / or obscuration diaphragm. Such diaphragms can be realized, for example, as absorbing and / or reflective coatings on the mirrors arranged in the region of the pupil plane.

An imaging optics according to claim 4 enables a good correction of aberrations for a given number of mirrors. The imaging optics can have at most four mirrors and can in particular have exactly four mirrors.

Deviations of the free-form surfaces from best-adapted surfaces according to claims 5 to 7 simplify production of the free-form surface mirrors.

Imaging optics according to claim 8 have advantages discussed in the prior art for anamorphic imaging optics. An anamorphic projection optics is known from the US 2013/0 128 251 A1 , from the DE 10 2014 208 770 A1 and from the US 2016/0 327 868 A1 ,

A pupil obscuration according to claim 9 allows imaging with good throughput and a sufficiently high range of illumination angles. An obscuration value of this pupil obscuration is also called radii obscuration or radial obscuration. A radial pupil obscuration of less than 0.3 means that an obscured area is less than 9% of a total effective area of the mirror, or less than 9% of a total area of the pupil at the location of the pupil obscuration.

The advantages of an optical system according to claim 10, an illumination system according to claim 11, a projection exposure apparatus according to claim 12, a manufacturing method for a micro- or nanostructured component according to claim 13 and a microstructured or nanostructured component produced thereby correspond to those described above Reference to the erfmdungsgemäße imaging optics have already been explained. In particular, a semiconductor component, for example a memory chip, can be produced using the projection exposure apparatus.

The imaging optics can also be used as part of a metrology system. Such a metrology system can work with an optical system or with an illumination system, which was mentioned above in connection with claims 10 and 11.

• 1 schematisch eine Projektionsbelichtungsanlage für die EUV-Mikrolithographie;
• 2 in einem Meridionalschnitt eine Ausführung einer abbildenden Optik, die als Projektionsobjektiv in der Projektionsbelichtungsanlage nach 1 einsetzbar ist, wobei ein Abbildungsstrahlengang für Hauptstrahlen und für einen oberen und einen unteren Komastrahl dreier ausgewählter Feldpunkte dargestellt ist;
• 3 bis 5 in jeweils zu 2 ähnlichen Darstellungen weitere Ausführungen einer abbildenden Optik, jeweils einsetzbar als Projektionsobjektiv in der Projektionsbelichtungsanlage nach 1.

Embodiments of the invention will be explained in more detail with reference to the drawing. In this show:

• 1 schematically a projection exposure system for EUV microlithography;
• 2 in a meridional section, an embodiment of an imaging optic, which follows as a projection objective in the projection exposure apparatus 1 is usable, wherein an imaging beam path for main beams and for an upper and a lower Komastrahl three selected field points is shown;
• 3 to 5 in each case too 2 Similar representations of further embodiments of an imaging optics, each used as a projection lens in the projection exposure system according to 1 ,

A projection exposure machine 1 for microlithography has a light source 2 for illumination light or imaging light 3 , At the light source 2 it is an EUV light source that generates light in a wavelength range, for example between 5 nm and 30 nm, in particular between 5 nm and 15 nm. At the light source 2 it can be a plasma-based light source (laser-produced plasma (LPP), gas-discharge produced plasma (GDP) or even a synchrotron-based light source, for example a free-electron laser (FEL). At the light source 2 it may in particular 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 possible. In general, even arbitrary wavelengths, for example visible wavelengths or also other wavelengths which can be used in microlithography (for example DUV, deep ultraviolet) and for the suitable laser light sources and / or LED light sources are available (for example 365 nm, 248 nm) nm, 193 nm, 157 nm, 129 nm, 109 nm) for the in the projection exposure apparatus 1 led lighting light 3 possible. A beam path of the illumination light 3 is in the 1 shown very schematically.

For guiding the illumination light 3 from the light source 2 towards an object field 4 in an object plane 5 serves a lighting optics 6 , With a projection optics or imaging optics 7 becomes the object field 4 in a picture field 8th in an image plane 9 mapped with a given reduction scale.

To facilitate the description of the projection exposure apparatus 1 as well as the different versions of the projection optics 7 in the drawing, a Cartesian xyz coordinate system is given, from which the respective positional relationship of the components shown in the figures results. In the 1 the x-direction is perpendicular to the plane of the drawing. The y-direction runs in the 1 to the left and the z-direction to the top.

In the embodiment described in detail below with reference to the optical design data 2 is the image field 8th square and has an extension of 0.2 mm in the x direction and 0.2 mm in the y direction.

The projection optics 7 In addition to an application in projection lithography, it can also be used in metrology or for measuring reticle structures and / or for identifying and / or measuring defect structures or defects on a lithographic mask and / or on an exposed or unexposed substrate.

The object field 4 and the picture box 8th may alternatively have an xy aspect ratio that is greater than 1. The object field 4 then has a longer object field dimension in the x direction and a shorter object field dimension in the y direction. These object field dimensions run along the field coordinates x and y.

The object field 4 is accordingly spanned by the first Cartesian object field coordinate x along the first, larger (longer) object field dimension and the second Cartesian object field coordinate y along the second, smaller (shorter) object field dimension. The third Cartesian coordinate z, which is perpendicular to these two object field coordinates x and y, is also referred to as the object field normal coordinate.

The picture plane 9 is in the projection optics 7 in the execution after 2 parallel to the object plane 5 arranged.

The first object field coordinate x and the normal coordinate z span a first imaging light plane xz, which is also referred to as a sagittal plane. The second object field coordinate y and the normal coordinate z span a second imaging light plane yz, which is also referred to as the meridional plane.

The object field 4 and the picture box 8th can at the projection optics 7 bent or curved and in particular be designed part-ring. Alternatively it is possible to use the object field 4 and the picture box 8th square or rectangular.

For the projection optics 7 can one of the in Figs. 2ff. illustrated embodiments are used. The projection optics 7 to 2 reduced in both imaging light levels xz, yz by a factor 8th , Also, other reduction scales in the two imaging light planes xz, yz are possible, for example 3x, 4x, 5x, 6x, 7x, or even reduction scales larger than 8x.

Shown is the projection optics 7 one with the object field 4 coincident section of a reflection mask 10 , which is also called reticle. The reticle 10 is from a reticle holder 10a carried. The reticle holder 10a is powered by a reticle displacement drive 10b relocated.

The picture through the projection optics 7 takes place on the surface of a substrate 11 in the form of a wafer made by a substrate holder 12 will be carried. The substrate holder 12 is from a wafer or substrate displacement drive 12a relocated.

In the 1 is schematically between the reticle 10 and the projection optics 7 an incoming into this bundle of rays 13 of the illumination light 3 and between the projection optics 7 and the substrate 11 one from the projection optics 7 leaking radiation beam 14 of the illumination light 3 shown. An image field-side numerical aperture (NA) of the projection optics 7 is in the 1 not reproduced to scale.

The projection exposure machine 1 is the scanner type. Both the reticle 10 as well as the substrate 11 be during operation of the projection exposure system 1 scanned in the y direction. Also a stepper type of the projection exposure system 1 in which between individual exposures of the substrate 11 a stepwise displacement of the reticle 10 and the substrate 11 in the y-direction is possible. These displacements are synchronized with each other by appropriate control of the displacement drives 10b and 12a ,

The 2 shows the projection optics 7 in a meridional section, ie the beam path of the imaging light 3 in the yz plane.

Shown in the 2 the beam path in each case three individual beams 15 , of three in the 2 go out to each other in the y-direction spaced object field points. Shown are main rays 16 , so individual rays 15 passing through the center of a pupil in a pupil plane of the projection optics 7 run, and in each case an upper and a lower coma beam of these three object field points. Starting from the object field 4 close the main beams 16 with the normal to the object plane 5 an angle CRA of 5.5 °. Due to this main beam angle CRA is an interpretation of the projection optics 7 for the reflective reticle 10 given. It is thus ensured that an optical path of the reticle 10 incident illumination light 3 with a beam path of the reticle 10 failing illumination or imaging light 3 does not bother.

The projection optics 7 has a picture-side numerical aperture of 0.65.

The projection optics 7 to 2 has a total of four mirrors, which are in the order of the beam path of the individual beams 15 , starting from the object field 4 , with M1 to M4 numbered.

Shown in the 2 to 4 Portions of the calculated reflection surfaces of the mirrors M1 to M4. An actually used area of the reflection surfaces is present plus a projection at the real mirrors M1 to M4. These useful reflection surfaces are supported in a known manner by mirror bodies, which in the 2 are indicated in part.

In the projection optics 7 to 2 all mirrors M1 to M4 are designed as mirrors for vertical or normal incidence, ie as mirrors onto which the imaging light is incident 3 with an angle of incidence that hits less than 45 °. These vertical incidence mirrors are also referred to as NI (Normal Incidence) levels.

The mirrors M1 to M4 carry the reflectivity of the mirrors M1 to M4 for the imaging light 3 optimizing coating. This may be a ruthenium coating, a molybdenum coating or a molybdenum coating having a topmost layer of ruthenium. These highly reflective layers can be designed as multilayer layers, wherein successive layers can be made of different materials. Alternate layers of material can also be used. A typical multi-layer layer may comprise fifty bilayers each of one layer of molybdenum and one layer of silicon.

To calculate a total reflectivity of the projection optics 7 a system transmission is calculated as follows: A mirror reflectivity is determined as a function of the angle of incidence of a guide beam, ie a main beam of a central object field point, on each mirror surface and combined in a multiplicative manner to the system transmission.

Details on the reflectivity calculation are explained in the WO 2015/014753 A1 , Further information on the reflectivity of NI mirrors (normal incidence mirrors) can be found in the DE 101 55 711 A ,

The mirrors M3 and M4, ie the penultimate in the imaging beam path and the last in the imaging beam path mirror, each have a passage opening 17 , Through the passage opening 17 the mirror M3 enters picture light 3 , from the last mirror M4 to the image field 8th to be led. Through the passage opening 17 the mirror M4 enters picture light 3 which is reflected from the third last mirror M2 to the next to last mirror M3. The mirrors M3 and M4 are around their passages 17 around used reflectively. The other mirrors M1 and M2 have no passage opening and are used in a coherently coherent area reflective. The mirrors M1 and M2 thus have a reflection-free used reflection surface.

In the projection optics 7 is the image field 8th the first field in the imaging beam path after the object field 4 , The projection optics 7 So has no intermediate image plane.

22% of a radius of a respective mirror surface of the mirrors M3 and M4 are due to the respective passage openings 17 obscured, so do not stand for a reflection of the imaging light 3 to disposal.

A radius of an obscuration surface on the mirrors M3 and / or M4 may vary in relation to the mirror radius used, depending on the design of the projection optics 7 less than 0.3. Accordingly, the obscured reflection surface may be smaller than 9% of a total useful reflection area on the respective mirror M3 and / or M4.

A z-space between the object field and the image field 8th (Length) is 1390 mm. A y-distance between a central field point of the object field 4 and a central field point of the object field 8th (Object-image offset) is 190 mm. In the xz-plane is an entrance pupil of the projection optics 7 2243 mm in the imaging beam path after the object field 4 , In the yz plane, the entrance pupil lies 844 mm in the imaging beam path in front of the object field 4 ,

The projection optics 7 is telecentric on the image side.

A minimal distance between the wafer 11 and the wafer next mirror M3, which is also referred to as the working distance, is 35.0 mm.

The mirror M3 has a diameter of 473 mm. The mirror M4 has a diameter of 1083 mm. A mean wavefront error RMS of the projection optics 7 is 8.7 mλ at a use wavelength of the imaging light 3 of 13.5 nm.

The mirrors M1 to M4 are designed as freeform surfaces which can not be described by a rotationally symmetrical function. There are also other versions of the projection optics 7 possible in which at least one of the mirrors M1 to M4 is designed as a rotationally symmetric asphere. All mirrors M1 to M4 can also be designed as such aspheres.

A free-form surface can be described by the following free-form surface equation (Equation 1): $$\begin{array}{l}Z=\frac{c_x{x}^2+{\mathrm{<figure-callout\; id="2"\; label="c\; y\; y"\; filenames="DE102018214437A1\_0006.png"\; state="\{\{state\}\}">c\; </figure-callout>}}_y{y}^{}{}^2}{1+\sqrt{1-\left(1+k_x\right){\left(c_{x}x\right)}^2-\left(1+k_y\right){\left(c_{y}y\right)}^2}}\\ +C_{1}x+C_{2}y\\ +{\text{C}}_3{\text{x}}^2+{\text{<figure-callout id="4" label="C" filenames="DE102018214437A1\_0006.png,DE102018214437A1\_0007.png" state="{{state}}">C</figure-callout>}}_4\text{xy}+{\text{C}}_5{\text{<figure-callout id="2" label="y" filenames="DE102018214437A1\_0006.png" state="{{state}}">y</figure-callout>}}^2\\ +{\text{C}}_6{\text{x}}^3+...+{\text{C}}_9{\text{<figure-callout id="3" label="y" filenames="DE102018214437A1\_0006.png,DE102018214437A1\_0007.png" state="{{state}}">y</figure-callout>}}^3\\ +{\text{C}}_{10}{\text{x}}^4+...+{\text{C}}_{12}{\text{x}}^2{\text{<figure-callout id="2" label="y" filenames="DE102018214437A1\_0006.png" state="{{state}}">y</figure-callout>}}^2+{\text{C}}_{14}{\text{<figure-callout id="4" label="y" filenames="DE102018214437A1\_0006.png,DE102018214437A1\_0007.png" state="{{state}}">y</figure-callout>}}^4\\ +{\text{C}}_{15}{\text{x}}^5+...+{\text{C}}_{20}{\text{<figure-callout id="5" label="y" filenames="DE102018214437A1\_0007.png,DE102018214437A1\_0008.png" state="{{state}}">y</figure-callout>}}^5\\ +{\text{C}}_{21}{\text{x}}^6+...+{\text{C}}_{24}{\text{x}}^3{\text{<figure-callout id="3" label="y" filenames="DE102018214437A1\_0006.png,DE102018214437A1\_0007.png" state="{{state}}">y</figure-callout>}}^3+...+{\text{C}}_{27}{\text{<figure-callout id="6" label="y" filenames="DE102018214437A1\_0006.png" state="{{state}}">y</figure-callout>}}^6\\ +...\end{array}$$

For the parameters of this equation (1):

Z is the arrow height of the freeform surface at point x, y, where x ² + y ² = r ² . Here r is the distance to the reference axis of the free-form surface equation $$\left(\text{x}=0;\text{y}=0\right),$$

In the free-form surface equation (1), C ₁ , C ₂ , C ₃ ... designate the coefficients of the free-form surface series expansion in the powers of x and y.

In the case of a conical base, c _x , c _{y is} a constant that corresponds to the vertex curvature of a corresponding asphere. So c _x = 1 / RDX and c _y = 1 / RDY. k _x and k _y , also referred to as CCX and CCY, each correspond to a conical constant of a corresponding asphere. The equation (1) thus describes a biconical freeform surface.

An alternatively possible free-form surface can be generated from a rotationally symmetrical reference surface. Such free-form surfaces for reflecting surfaces of the mirrors of projection optics of projection exposure apparatuses for microlithography are known from US Pat US 2007-0058269 A1 ,

Alternatively, freeform surfaces can also be described using two-dimensional spline surfaces. Examples include Bezier curves or non-uniform rational base splines (NURBS). For example, two-dimensional spline surfaces may be described by a network of points in an xy plane and associated z-values or by these points and their associated slopes. Depending on the particular type of spline surface, the complete surface is obtained by interpolation between the mesh points using, for example, polynomials or functions that have certain continuity and differentiability properties. Examples of this are analytical functions.

A pupil-defining aperture stop AS is in the projection optics 7 on the mirror M4 and / or on the mirror M3 and / or in a position in the imaging beam path between the mirrors M3 and M4, which in the 2 is indicated, arranged. Realization possibilities for such an aperture stop are disclosed, for example, in US Pat WO 2016/188934 A1 , Instead of a single pupil-defining aperture diaphragm AS, its effect can also be taken over by a plurality of pupil-defining partial diaphragms which are at different locations in the projection optics 7 are arranged.

An arrangement plane of the aperture stop AS coincides with a pupil plane 17a the projection optics 7 together.

The optical design data of the reflection surfaces of the mirrors M1 to M4 of the projection optics 7 can be found in the following tables.

Table 1 gives coordinates of a surface origin of a respective mirror surface as well as a surface of the object field 4 based on an xyz coordinate system of the image field 8th at.

The first column gives the distance of the respective mirror or of the object field 8th from a coordinate origin in the center of the image field 4 in z-direction (first column) and in y-direction (column 2 ) at.

The third column of Table 1 is still a Verkippungswert the respective surface of the mirror M1 to M4 or the object field 4 with respect to the xy plane of the image field 8th at. In the execution after 2 are the object field 4 on the one hand and the mirrors M3 and M4 on the other hand so with respect to the image field 8th not tilted. This statement refers to the respective base area, with respect to the curved mirrors M3 and M4, from which the arrow height calculation of the curved mirror surface according to the above equation (1) in each case proceeds.

The second table separately tabulates for the mirrors M4 to M1 the parameters RDX, RDY, CCX, CCY and, sorted according to the powers in x and y, the values of the coefficients C1, C2, C3 ... of the free-form surface series development according to the above Equation (1). Table 1 to Fig. 2 z-distance [mm] y-distance [mm] Tilting about x-axis [Degree] M4 797.114367 0 0.0000 M3 50.587369 0 0.0000 M2 1187.962431 0 12.1777 M1 878.305658 140.176051 9.4133 object field 1389.879729 189.695360 0.0000 Table 2 to Fig. 2 M4 2 RDX -955.292778 RDY -991.490928 CCX 0.195640 CCY 0.163381 x ** i y ** j coefficient 2 1 6.792178E-09 0 3 -5.132081E-09 4 0 -1.285544E-11 2 2 3.454446E-12 0 4 4.586112E-12 4 1 -5.109120E-16 2 3 -1.900705E-15 0 5 -1.436546E-15 6 0 4.875178E-18 4 2 1.013369E-17 2 4 6.543131E-18 0 6 -7.066915E-19 6 1 1.113239E-20 4 3 7.538844E-21 2 5 1.652656E-21 0 7 -3.724025E-22 8th 0 -1.088614E-24 6 2 -3.946779E-24 4 4 -1.462326E-23 2 6 -1.928568E-23 0 8th 1.493475E-24 8th 1 -1.047656E-26 6 3 -1.113349E-26 4 5 -1.026264E-26 2 7 1.117119E-27 0 9 -1.991481E-27 10 0 -6.559550E-30 8th 2 -1.634135E-29 6 4 1.380024E-30 4 6 4.821144E-29 2 8th 4.542313E-29 0 10 2.988973E-30 10 1 1.673697E-32 8th 3 -1.401775E-33 6 5 -1.457554E-32 4 7 -1.552206E-32 2 9 -1.512618E-32 0 11 1.802961E-33 12 0 6.017480E-36 10 2 2.062152E-35 8th 4 -9.467724E-36 6 6 -9.457160E-35 4 8th -1.125858E-34 2 10 -3.818160E-35 0 12 -3.090341E-36 12 1 1.264123E-38 10 3 9.363503E-38 8th 5 2.283960E-37 6 7 2.857258E-37 4 9 1.452372E-37 2 11 1.907069E-38 0 13 -2.427780E-39 M3 2 RDX -1210.402728 RDY -1994.521816 CCX 0 CCY 0 x ** i y ** j coefficient 2 1 1.240642E-07 0 3 -6.923438E-08 4 0 -2.320957E-09 2 2 -1.958282E-09 0 4 -6.031571E-10 4 1 4.534733E-13 2 3 -2.544845E-13 0 5 7.559356E-15 6 0 -1.081468E-14 4 2 -1.002246E-14 2 4 -5.845165E-15 0 6 -1.495170E-15 6 1 7.030655E-18 4 3 2.324372E-18 2 5 2.214309E-18 0 7 1.428828E-19 8th 0 -4.734233E-20 6 2 -7.859519E-20 4 4 -9.096242E-20 2 6 -4.607712E-20 0 8th -1.181867E-21 8th 1 3.739715E-23 6 3 1.285892E-23 4 5 -2.299719E-23 2 7 -7.099442 E-24 0 9 2.699608E-24 10 0 -2.326219E-25 8th 2 -7.120118E-25 6 4 -8.140634E-25 4 6 -1.248081E-25 2 8th 1.788229E-25 0 10 7.062409E-27 10 1 -1.610790E-27 8th 3 -3.578991E-27 6 5 -2.436168E-27 4 7 -2.237443E-28 2 9 1.678910E-28 0 11 2.751998E-29 12 0 -4.357683E-30 10 2 -1.528661E-29 8th 4 -1.821360E-29 6 6 -1.045673E-29 4 8th -3.263954E-30 2 10 -8.002134E-31 0 12 -5.457799E-32 12 1 3.025944E-32 10 3 6.629237E-32 8th 5 1.040985E-31 6 7 7.084093E-32 4 9 1.825933E-32 2 11 8.152662E-34 0 13 -5.548182E-35 M2 2 RDX 2333.674205 RDY 272.442419 CCX 0 CCY 0 x ** i y ** j coefficient 2 1 9.645832E-07 0 3 -2.195674E-06 4 0 -1.540017E-08 2 2 -1.287713E-08 0 4 2.477099E-08 4 1 -7.677414E-11 2 3 -1.302951E-10 0 5 2.185498E-10 6 0 9.654103E-13 4 2 3.392311E-12 2 4 1.763941E-12 0 6 -5.178493E-12 6 1 1.293322E-14 4 3 6.545782E-14 2 5 1.558100E-13 0 7 2.274025E-14 8th 0 -8.253074E-17 6 2 -5.417253E-16 4 4 -7.433467E-16 2 6 3.722685E-15 0 8th 7.953878E-15 8th 1 -1.694577E-18 6 3 -2.082033E-17 4 5 -1.414736E-16 2 7 -1.814747E-16 0 9 7.946060E-17 10 0 7.862646E-21 8th 2 8.726735E-20 6 4 2.559805E-19 4 6 -8.250554E-19 2 8th -5.034308E-18 0 10 -2.525788E-18 10 1 8.928626E-23 8th 3 2.333398E-21 6 5 3.770507E-20 4 7 1.614375E-19 2 9 1.352834E-19 0 11 -7.000761E-20 12 0 -3.493967E-25 10 2 -5.451599E-24 8th 4 -2.110264E-23 6 6 7.436453E-23 4 8th 1.092554E-21 2 10 2.994668E-21 0 12 1.027011E-21 12 1 2.408231E-27 10 3 -3.731651E-26 8th 5 -2.723392E-24 6 7 -2.174568E-23 4 9 -5.954065E-23 2 11 -3.295184E-23 0 13 2.735053E-23 M1 2 RDX 4234.862804 RDY 711.414133 CCX 0 CCY 0 x ** i y ** j coefficient 2 1 2.609022E-07 0 3 -1.295251E-07 4 0 -1.532045E-08 2 2 -2.222746E-09 0 4 7.974257E-10 4 1 -3.492010E-11 2 3 -2.289228E-11 0 5 6.528042E-12 6 0 1.486219E-12 4 2 1.706300E-12 2 4 4.881876E-14 0 6 -1.410365E-13 6 1 1.278590E-14 4 3 3.153892E-14 2 5 1.568192E-14 0 7 -9.154165E-16 8th 0 -5.057845E-16 6 2 -9.532909E-16 4 4 -2.914418E-16 2 6 3.240234E-16 0 8th 9.200678E-17 8th 1 1.095657E-18 6 3 -2.207538E-17 4 5 -3.606090E-17 2 7 -8.354106E-18 0 9 1.118715E-18 10 0 1.646877E-19 8th 2 4.502289E-19 6 4 3.101783E-19 4 6 -1.211680E-19 2 8th -1.796495E-19 0 10 -1.771800E-20 10 1 -3.744372E-21 8th 3 3.734896E-21 6 5 2.246366E-20 4 7 1.814256E-20 2 9 2.279273E-21 0 11 -3.758422E-22 12 0 -1.687831E-23 10 2 -7.205247E-23 8th 4 -7.596828E-23 6 6 -3.104070E-24 4 8th 6.784973E-23 2 10 3.579117E-23 0 12 1.770229E-24 12 1 1.008740E-24 10 3 6.687271E-25 8th 5 -3.717455E-24 6 7 -6.137963E-24 4 9 -2.979028E-24 2 11 -1.806528E-25 0 13 5.067024E-26

The sums of the powers in x and y, whose coefficients Ci are greater than 0, are in the free-form surfaces of the mirrors M1 to M4 of the projection optics 7 not larger than 13. The free-form surfaces of the mirrors M1 to M4 can thus be described with xy polynomials up to the 13th order.

An optical path between the object field 4 and the mirror M3 is in the projection optics 7 greater than a distance between the mirrors M3 and M4, so that the object field 4 , As far as the optical path, from the passage opening 17 is clearly spaced in the mirror M4. In the execution after 2 For example, the optical path taken by the main beams from the object field 4 to the mirror M3 along the imaging beam path is more than twice as large as the optical path between the passage opening 17 in the mirror M4 and the mirror M3, which corresponds approximately to the distance between these mirrors M3 and M4. According to this ratio of the optical paths, a diameter of the entire imaging light beam is in the region of the passage opening 17 of the mirror M4, the diameter of this passage opening 17 in the mirror M4 pretends relatively large compared to the diameter of the mirror M3. The diameter of the passage opening 17 of the mirror M4 is about 50% of the diameter of the mirror M3.

Based on 3 Below is another embodiment of a projection optics 18 explains that instead of the projection optics 7 at the projection exposure machine 1 to 1 can be used. Components and functions similar to those described above in connection with 1 and 2 have already been explained, if necessary bear the same reference numbers and will not be discussed again in detail.

In the projection optics 18 is the diameter of the passage opening 17 in the mirror M4 about 80% of the diameter of the mirror M3.

The sums of the powers in x and y whose coefficients are greater than 0 are those of the free-form surfaces of the mirrors M1 to M4 of the projection optics 18 not larger than 12. The free-form surfaces of the mirrors M1 to M4 can thus be described with xy polynomials up to the 12th order.

The free-form surfaces of the mirrors M1 to M4 of the projection optics 18 have only slight deviations from a best fit toric surface and / or from a best fit spherical surface and / or a small deviation from a best fit conic.

• c_x = c_y, k_x = k_y = 0 (sphärische Fläche);
• k_x = k_y = 0 (torische Fläche);
• c_x = c_y, k_x = k_y (asphärische Fläche, allgemeiner Kegelschnitt).

A spherical, a toric and an aspherical surface result from the leading term of the freeform surface equation (1) above, when it is set:

• c _x = c _y , k _x = k _y = 0 (spherical surface);
• k _x = k _y = 0 (toric surface);
• c _x = c _y , k _x = k _y (aspherical surface, general conic section).

An example of a generalized aspheric equation with additional correction terms, given as even powers of the radius, can be found in the DE 10 2010 029 050 A1 ,

In the case of the mirror M1, a maximum deviation peak to valley (PV) to a best-matched toric surface is 4.5 μm and a maximum deviation peak to valley of a best-adapted spherical surface is 64.7 μm.

In the case of the mirror M2, a maximum deviation peak to valley to a best-matched toric surface is 14.1 μm, and a maximum deviation peak to valley of a best-adapted spherical surface is 127 μm.

For the mirror M3, a maximum deviation peak to valley to a best-matched toric surface is 39.5 μm and a maximum deviation peak to valley from a best-matched conic 47.2 μm.

For the M4 mirror, a maximum deviation peak to valley to a best-matched toric surface is 31.5 μm and a maximum deviation peak to valley from a best-matched conic 59.3 μm.

A deviation of the free-form surfaces of the mirrors M1 to M4 from a best-adapted spherical surface can, depending on the design of the projection optics 18 smaller than 150 μm.

A deviation of these free-form surfaces from a best-matched toric surface may vary depending on the design of the projection optics 18 smaller than 100 μm and smaller than 50 μm.

A deviation of the free-form surfaces from a best-adapted conic section surface can, depending on the design of the projection optics 18 smaller than 100 μm.

An obscuration radius of the openings 17 each of the mirrors M3 and M4 is 29% of the radius of the used mirror surface of the respective mirrors M3 and M4 of a projection optics 18 ,

The image field 8th has in the projection optics 18 an x-extension of 0.5 mm and a y-extension of 0.5 mm, so is also square.

An overall length of the projection optics 18 is 2269 mm. An object-image offset of the projection optics 18 is 294 mm.

The entrance pupil lies with the projection optics 18 in the xz-plane 2881 mm after the object field 4 , In the yz plane, the entrance pupil is 3024 mm after the object field 4 ,

A working distance of the mirror M3 to the wafer 11 is 45.0 mm. The mirror M4 has a diameter of 1368 mm. The mirror M3 has a diameter of 492 mm.

A mean wavefront error RMS is 7.5 mλ, again at a useful light wavelength of 13.5 nm.

A picture-side numerical aperture is in the projection optics 18 0.70.

The optical design data of the projection optics 18 can be taken from the following tables, which in their structure the tables for projection optics 7 to 2 correspond. Table 1 to Fig. 3rd z-distance [mm] y-distance [mm] Tilting about x-axis [Degree] M4 936.656947 0.000000 0.0000 M3 73.841094 0.000000 0.0000 M2 2038.775766 0.000000 13.6412 M1 1593.904541 229.442516 10.9160 object field 2268.776774 293.836209 0.0000 Table 2 to FIG. 3 M4 3 RDX -1113.715105 RDY -1113.720092 CCX 0.155064 CCY 0.155821 x ** i y ** j coefficient 2 1 6.998569E-11 0 3 -1.219334E-10 4 0 1.859915E-12 2 2 3.772005E-12 0 4 1.559240E-12 4 1 -2.168046E-16 2 3 3.537763E-16 0 5 4.865457E-16 6 0 2.299659E-18 4 2 5.953683E-18 2 4 6.490034E-18 0 6 2.850325E-18 6 1 1.300769E-21 4 3 2.209164E-21 2 5 6.757287E-22 0 7 -1.577442E-22 8th 0 -3.926427E-24 6 2 -1.287918E-23 4 4 -1.809551E-23 2 6 -1.339401E-23 0 8th -4.178562E-24 8th 1 -1.568142E-27 6 3 -5.016540E-27 4 5 -5.539817E-27 2 7 -2.747079E-27 0 9 -6.114262E-28 10 0 2.367795E-30 8th 2 9.074760E-30 6 4 1.467334E-29 4 6 1.393012E-29 2 8th 7.982691E-30 0 10 1.967840E-30 10 1 6.792414E-34 8th 3 3.310359E-33 6 5 6.341796E-33 4 7 6.211731E-33 2 9 3.346835E-33 0 11 8.137856E-34 12 0 3.228692E-37 10 2 2.377899E-36 8th 4 8.149450E-36 6 6 1.260486E-35 4 8th 1.025362E-35 2 10 4.401668E-36 0 12 8.171926E-37 M3 3 RDX -1184.127063 RDY -1185.001946 CCX 0 CCY 0 x ** i y ** j coefficient 2 1 3.720805E-09 0 3 -5.158645E-10 4 0 -6.775863E-10 2 2 -1.356137E-09 0 4 -6.989644E-10 4 1 -3.445519E-14 2 3 5.918730E-14 0 5 8.014771E-14 6 0 -1.353694E-15 4 2 -4.491591E-15 2 4 -4.292514E-15 0 6 -1.152377E-15 6 1 1.495354E-18 4 3 2.580213E-18 2 5 8.660846E-19 0 7 -1.187272E-19 8th 0 -2.037612E-20 6 2 -7.305357E-20 4 4 -1.056287E-19 2 6 -7.392035E-20 0 8th -2.069207E-20 8th 1 -1.177396E-23 6 3 -3.924222E-23 4 5 -4.597341E-23 2 7 -2.562596E-23 0 9 -6.772222E-24 10 0 3.044093E-27 8th 2 -3.647565E-26 6 4 -1.488559E-25 4 6 -1.805550E-25 2 8th -8.526963E-26 0 10 -1.523218E-26 10 1 2.417428E-29 8th 3 1.423920E-28 6 5 3.178845E-28 4 7 3.629090E-28 2 9 2.266107E-28 0 11 6.195984E-29 12 0 -4.144963E-32 10 2 -3.132205E-31 8th 4 -5.637557E-31 6 6 -4.935481E-31 4 8th -1.153608E-31 2 10 1.278958E-31 0 12 7.065895E-32 M2 3 RDX -5006.207030 RDY -5518.367079 CCX 0 CCY 0 x ** i y ** j coefficient 2 1 1.636128E-08 0 3 9.797508E-09 4 0 -3.629169E-11 2 2 -6.465349E-11 0 4 -7.683361E-11 4 1 -3.124101E-13 2 3 2.600879E-13 0 5 4.323842E-13 6 0 9.472184E-15 4 2 2.106001E-14 2 4 2.246156E-14 0 6 9.840769E-15 6 1 5.963885E-17 4 3 9.647936E-17 2 5 3.623178E-17 0 7 1.664285E-19 8th 0 -9.484923E-19 6 2 -2.938465E-18 4 4 -3.916766E-18 2 6 -2.604710E-18 0 8th -6.837371E-19 8th 1 -4.020607E-21 6 3 -1.224397E-20 4 5 -1.409860E-20 2 7 -7.663514E-21 0 9 -1.805973E-21 10 0 2.779717E-23 8th 2 1.024733E-22 6 4 1.661695E-22 4 6 1.420685E-22 2 8th 6.351628E-23 0 10 1.038026E-23 10 1 9.801167E-26 8th 3 4.155075E-25 6 5 7.250834E-25 4 7 6.596978E-25 2 9 3.218803E-25 0 11 6.856205E-26 12 0 -3.959101E-29 10 2 1.928871E-28 8th 4 1.184894E-27 6 6 2.306457E-27 4 8th 2.272179E-27 2 10 1.208856E-27 0 12 2.842663E-28 M1 3 RDX -5010.080640 RDY -6014.328024 CCX 0 CCY 0 x ** i y ** j coefficient 2 1 3.563448E-08 0 3 2.256595E-08 4 0 -1.076694E-10 2 2 -1.668334E-10 0 4 -1.866549E-10 4 1 -2.112467E-12 2 3 1.728980E-12 0 5 2.678600E-12 6 0 1.164993E-13 4 2 2.432929E-13 2 4 2.313527E-13 0 6 8.225805E-14 6 1 1.467279E-15 4 3 2.134897E-15 2 5 6.409773E-16 0 7 -4.893459E-17 8th 0 -4.496777E-17 6 2 -1.348255E-16 4 4 -1.695598E-16 2 6 -9.792036E-17 0 8th -1.941557E-17 8th 1 -3.612663E-19 6 3 -1.003931E-18 4 5 -1.064604E-18 2 7 -5.365503E-19 0 9 -1.226164E-19 10 0 5.074646E-21 8th 2 1.870056E-20 6 4 3.016123E-20 4 6 2.320352E-20 2 8th 7.770202E-21 0 10 3.645985E-22 10 1 3.230002E-23 8th 3 1.258082E-22 6 5 2.045058E-22 4 7 1.757773E-22 2 9 8.201832E-23 0 11 1.717709E-23 12 0 -4.395719E-26 10 2 -4.951629E-26 8th 4 1.587927E-25 6 6 7.121000E-25 4 8th 1.044049E-24 2 10 7.380244E-25 0 12 2.067152E-25

Based on 4 Below is another embodiment of a projection optics 19 explains that instead of the projection optics 7 at the projection exposure machine 1 to 1 can be used. Components and functions similar to those described above in connection with 1 to 3 have already been explained, if necessary bear the same reference numbers and will not be discussed again in detail.

In the projection optics 19 is the diameter of the passage opening 17 in the mirror M4 about 70% of the diameter of the mirror M3.

The projection optics 19 has a picture-side numerical aperture of 0.60.

The projection optics 19 is designed as anamorphic imaging optics and has a decreasing magnification β _x of 5.4 in the xz plane and a decreasing magnification β _y of 8.0 in the yz plane.

A radius obscuration at mirrors M3 and M4 is in the projection optics 19 each 23%. The image field 8th has an x-extension of 0.5 mm and a y-extension of likewise 0.5 mm.

An overall length of the projection optics 19 is 1823 mm. An object-image offset is 234 mm. A main beam angle CRA at the object field 4 is 5.3 °.

The entrance pupil lies with the projection optics 19 in the xz plane 2427 mm after the object field 4 and in the yz plane 1748 mm after the object field 4 , A working distance of the mirror M3 to the wafer 11 is 40.4 mm. The mirror M4 has a diameter of 1283 mm. The mirror M3 has a diameter of 475 mm. A mean wavefront error RMS is 7.0 mλ at a useful wavelength of 13.5 nm.

Also the mirrors M1 to M4 of the projection optics 19 have free-form reflecting surfaces. These free-form surfaces of the mirrors M1 to M4 of the projection optics 19 may be described by a surface equation which is explained in the technical article "Characterizing the shape of freeform optics" by GW Forbes, Optics Express, Vol. 20, No. 3, pages 2483 to 2499 , Free-form surfaces in such a surface description are also referred to as Forbes free-form surfaces.

The Forbes free-form surface equation is: $$\begin{array}{c}z\left(H.\theta \right)=\frac{\mathrm{<figure-callout\; id="2"\; label="\rho \; H"\; filenames="DE102018214437A1\_0006.png"\; state="\{\{state\}\}">\rho \; </figure-callout>}{H}^{}{}^2}{1+\sqrt{1-\left(1+\kappa \right){\rho }^2{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="DE102018214437A1\_0006.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}}+\frac{\sqrt{1-\kappa {\rho }^2{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="DE102018214437A1\_0006.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}}{\sqrt{1-\left(1+\kappa \right){\rho }^2{H}^2}}{u}^2\left(1-u^2\right){\displaystyle \underset{n=0}{\overset{N}{\Sigma }}{a}_n^0{Q}_n^0\left(u^2\right)}\\ +\frac{\sqrt{1-\kappa {\rho }^2{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="DE102018214437A1\_0006.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}}{\sqrt{1-\left(1+\kappa \right){\rho }^2{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="DE102018214437A1\_0006.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}}{\displaystyle \underset{m=1}{\overset{M}{\Sigma }}{u}^m{\displaystyle \underset{n=0}{\overset{N}{\Sigma }}\left[a_n^m\text{cos}\left(m\theta \right)+b_n^m\text{sin}\left(m\theta \right)\right]Q_n^m\left(u^2\right)}}\end{array}$$

• z ist die Pfeilhöhe der Freiformfläche am Punkt h, θ, wobei h die radiale Koordinate und θ die azimutale Koordinate dieses Punktes ist;
• u = h/NH ist eine normalisierte radiale Koordinate;
• p ist die Krümmung, ist also die Inverse des Krümmungsradius RD;
• κ ist die konische Konstante, entspricht also den Werten CC der obigen Tabellen;
• Q^m _n sind die orthogonalen Polynome auf dem Einheitskreis, die in dem oben erwähnten Fachartikel von Forbes beschrieben sind.

For the parameters of this equation (2):

• z is the height of the free-form surface at point h, θ, where h is the radial coordinate and θ is the azimuthal coordinate of that point;
• u = h / NH is a normalized radial coordinate;
• p is the curvature, that is, the inverse of the radius of curvature RD;
• κ is the conic constant, ie it corresponds to the values CC of the tables above;
• Q ^m _n are the orthogonal polynomials on the unit circle described in the above-mentioned paper by Forbes.

der obigen Gleichung (2). Die Koeffzienten $b_n^m$

sind Null. Tabelle 1 zu Fig. 4 z-Abstand [mm] y-Abstand [mm] Verkippung um x-Achse [Grad] M4 1034.961878 0.000000 0.0000 M3 60.000000 0.000000 0.0000 M2 1572.379541 0.000000 16.2854 M1 1284.716398 183.762228 13.6536 Objektfeld 1822.823108 234.419336 0.0000 Tabelle 2 zu Fig. 4 M4 4 RD -1221.194121 Beschreibung mit Forbes-Q-Polynomen CC 0.053820 NH 650.000000 u = r/NH m (azimutal) n (radial) Koeffizient 0 0 1.264771E+00 0 1 -9.457430E-02 0 2 7.127344E-03 0 3 -6.479681E-04 0 4 3.901025E-05 0 5 -5.981646E-06 2 0 4.154391E+00 1 1 -2.209327E-01 3 0 3.118048E-02 2 1 -8.075943E-02 1 2 1.160536E-02 4 0 2.239639E-02 3 1 -6.261170E-04 2 2 -1.689044E-03 1 3 -9.116191E-04 5 0 9.155504E-06 4 1 4.029138E-03 3 2 1.417198E-04 2 3 -1.197859E-03 1 4 4.192597E-05 6 0 -6.012364E-04 5 1 2.020561E-04 4 2 8.932884E-05 3 3 5.251141E-06 2 4 1.086587E-04 1 5 6.720980E-07 7 0 -8.830022E-05 6 1 -4.076927E-05 5 2 -5.834243E-06 4 3 4.034868E-06 3 4 -9.170366E-07 2 5 -1.431768E-05 1 6 1.966264E-07 M3 4 RD -1206.371031 Beschreibung mit Forbes-Q-Polynomen CC -0.926109 NH 240.000000 u = r / NH m (azimutal) n (radial) Koeffizient 0 0 2.799899E+00 0 1 -1.306028E-01 0 2 1.014386E-02 0 3 -7.953716E-04 0 4 1.112310E-05 0 5 -2.762207E-06 2 0 4.387050E+00 1 1 -4.075168E-01 3 0 7.089429E-03 2 1 -4.005788E-01 1 2 4.102002E-02 4 0 1.428729E-02 3 1 4.163604E-03 2 2 2.740704E-02 1 3 -4.793377E-03 5 0 -9.066844E-04 4 1 4.771013E-03 3 2 -1.894499E-04 2 3 -3.690278E-03 1 4 3.618638E-04 6 0 1.802031E-04 5 1 4.472662E-04 4 2 -4.550850E-04 3 3 3.199290E-05 2 4 3.318992E-04 1 5 -5.104291E-06 7 0 2.753001E-06 6 1 -7.404236E-05 5 2 -3.194143E-05 4 3 6.474910E-05 3 4 3.595769E-06 2 5 -2.146419E-05 1 6 -3.483509E-06 M2 2 RD -6786.782879 Beschreibung mit Forbes-Q-Polynomen CC 0.000000 NH 110.000000 u=r/NH m (azimutal) n (radial) Koeffizient 0 0 1.386600E-02 0 1 2.262806E-03 0 2 -1.250799E-03 0 3 2.368242E-04 0 4 -4.531302E-05 0 5 -4.524278E-06 2 0 -1.006494E+00 1 1 -1.540809E-01 3 0 -2.524765E-02 2 1 2.358412E-02 1 2 3.545538E-03 4 0 1.945680E-02 3 1 3.178784E-03 2 2 -6.336456E-03 1 3 -7.346120E-04 5 0 1.209436E-03 4 1 -1.960984E-03 3 2 -4.031479E-04 2 3 8.238578E-04 1 4 1.124398E-04 6 0 -3.892968E-04 5 1 2.414961E-05 4 2 2.990597E-04 3 3 3.335064E-05 2 4 -2.298712E-04 1 5 -3.679875E-05 7 0 4.628592E-05 6 1 2.698940E-05 5 2 -6.368547E-06 4 3 -3.858661E-05 3 4 -5.047423E-06 2 5 7.756947E-06 1 6 4.243186E-06 M1 4 RD -4552.923789 Beschreibung mit Forbes-Q-Polynomen CC 0.000000 NH 62.000000 u = r/NH m (azimutal) n (radial) Koeffizient 0 0 5.307863E-03 0 1 4.389738E-04 0 2 -3.606911E-04 0 3 7.192783E-05 0 4 -1.523737E-05 0 5 -2.763495E-06 2 0 -7.600088E-02 1 1 -3.942214E-02 3 0 -4.488311E-03 2 1 6.136153E-03 1 2 5.890356E-04 4 0 4.233995E-03 3 1 3.905039E-04 2 2 -1.668451E-03 1 3 -9.079959E-05 5 0 8.461219E-05 4 1 -2.816198E-04 3 2 -3.201170E-05 2 3 2.137057E-04 1 4 1.375842E-05 6 0 -6.558436E-05 5 1 4.099844E-05 4 2 7.368117E-05 3 3 3.660614E-06 2 4 -7.137888E-05 1 5 -1.130603E-05 7 0 1.725110E-05 6 1 -1.030078E-05 5 2 -5.539323E-06 4 3 -5.415167E-06 3 4 -2.582303E-07 2 5 -3.223469E-06 1 6 1.335091E-06 The optical design data of the projection optics 19 can be found in the following tables. The coefficients in Table 2 below are the coefficients $a_n^m$

the above equation (2). The coefficients $b_n^m$

are zero. Table 1 to Fig. 4 z-distance [mm] y-distance [mm] Tilting about x-axis [Degree] M4 1034.961878 0.000000 0.0000 M3 60.000000 0.000000 0.0000 M2 1572.379541 0.000000 16.2854 M1 1284.716398 183.762228 13.6536 object field 1822.823108 234.419336 0.0000 Table 2 to Fig. 4 M4 4 RD -1221.194121 Description with Forbes Q polynomials CC 0.053820 NH 650.000000 u = r / NH m (azimuthal) n (radial) coefficient 0 0 1.264771E + 00 0 1 -9.457430E-02 0 2 7.127344E-03 0 3 -6.479681E-04 0 4 3.901025E-05 0 5 -5.981646E-06 2 0 4.154391E + 00 1 1 -2.209327E-01 3 0 3.118048E-02 2 1 -8.075943E-02 1 2 1.160536E-02 4 0 2.239639E-02 3 1 -6.261170E-04 2 2 -1.689044E-03 1 3 -9.116191E-04 5 0 9.155504E-06 4 1 4.029138E-03 3 2 1.417198E-04 2 3 -1.197859E-03 1 4 4.192597E-05 6 0 -6.012364E-04 5 1 2.020561E-04 4 2 8.932884E-05 3 3 5.251141E-06 2 4 1.086587E-04 1 5 6.720980E-07 7 0 -8.830022E-05 6 1 -4.076927E-05 5 2 -5.834243E-06 4 3 4.034868E-06 3 4 -9.170366E-07 2 5 -1.431768E-05 1 6 1.966264E-07 M3 4 RD -1206.371031 Description with Forbes Q polynomials CC -0.926109 NH 240.000000 u = r / NH m (azimuthal) n (radial) coefficient 0 0 2.799899E + 00 0 1 -1.306028E-01 0 2 1.014386E-02 0 3 -7.953716E-04 0 4 1.112310E-05 0 5 -2.762207E-06 2 0 4.387050E + 00 1 1 -4.075168E-01 3 0 7.089429E-03 2 1 -4.005788E-01 1 2 4.102002E-02 4 0 1.428729E-02 3 1 4.163604E-03 2 2 2.740704E-02 1 3 -4.793377E-03 5 0 -9.066844E-04 4 1 4.771013E-03 3 2 -1.894499E-04 2 3 -3.690278E-03 1 4 3.618638E-04 6 0 1.802031E-04 5 1 4.472662E-04 4 2 -4.550850E-04 3 3 3.199290E-05 2 4 3.318992E-04 1 5 -5.104291E-06 7 0 2.753001E-06 6 1 -7.404236E-05 5 2 -3.194143E-05 4 3 6.474910E-05 3 4 3.595769E-06 2 5 -2.146419E-05 1 6 -3.483509E-06 M2 2 RD -6786.782879 Description with Forbes Q polynomials CC 0.000000 NH 110.000000 u = r / NH m (azimuthal) n (radial) coefficient 0 0 1.386600E-02 0 1 2.262806E-03 0 2 -1.250799E-03 0 3 2.368242E-04 0 4 -4.531302E-05 0 5 -4.524278E-06 2 0 -1.006494E + 00 1 1 -1.540809E-01 3 0 -2.524765E-02 2 1 2.358412E-02 1 2 3.545538E-03 4 0 1.945680E-02 3 1 3.178784E-03 2 2 -6.336456E-03 1 3 -7.346120E-04 5 0 1.209436E-03 4 1 -1.960984E-03 3 2 -4.031479E-04 2 3 8.238578E-04 1 4 1.124398E-04 6 0 -3.892968E-04 5 1 2.414961E-05 4 2 2.990597E-04 3 3 3.335064E-05 2 4 -2.298712E-04 1 5 -3.679875E-05 7 0 4.628592E-05 6 1 2.698940E-05 5 2 -6.368547E-06 4 3 -3.858661E-05 3 4 -5.047423E-06 2 5 7.756947E-06 1 6 4.243186E-06 M1 4 RD -4552.923789 Description with Forbes Q polynomials CC 0.000000 NH 62.000000 u = r / NH m (azimuthal) n (radial) coefficient 0 0 5.307863E-03 0 1 4.389738E-04 0 2 -3.606911E-04 0 3 7.192783E-05 0 4 -1.523737E-05 0 5 -2.763495E-06 2 0 -7.600088E-02 1 1 -3.942214E-02 3 0 -4.488311E-03 2 1 6.136153E-03 1 2 5.890356E-04 4 0 4.233995E-03 3 1 3.905039E-04 2 2 -1.668451E-03 1 3 -9.079959E-05 5 0 8.461219E-05 4 1 -2.816198E-04 3 2 -3.201170E-05 2 3 2.137057E-04 1 4 1.375842E-05 6 0 -6.558436E-05 5 1 4.099844E-05 4 2 7.368117E-05 3 3 3.660614E-06 2 4 -7.137888E-05 1 5 -1.130603E-05 7 0 1.725110E-05 6 1 -1.030078E-05 5 2 -5.539323E-06 4 3 -5.415167E-06 3 4 -2.582303E-07 2 5 -3.223469E-06 1 6 1.335091E-06

Based on 5 Below is another embodiment of a projection optics 20 explains that instead of the projection optics 7 at the projection exposure machine 1 to 1 can be used. Components and functions similar to those described above in connection with 1 to 4 have already been explained, if necessary bear the same reference numbers and will not be discussed again in detail.

In the projection optics 20 is the diameter of the passage opening 17 in mirror M4 about 65% of the diameter of the mirror M3.

The projection optics 20 has a decreasing magnification of 8x.

A radial obscuration contributes to the mirrors M3 and M4 respectively 23%.

The image field 8th has an x-extension of 6.5 mm and a y-extension of 0.5 mm.

An overall length of the projection optics 20 is 2217 mm. An object image offset is 258 mm. A main beam angle CRA on the reticle 10 carries 5.5 °. The entrance pupil lies with the projection optics 20 in the xz plane 2919 mm after the object field 4 and in the yz plane 3759 mm after the object field 4 ,

A working distance of the mirror M3 to the wafer 11 is 48.0 mm.

The mirror M4 has a diameter of 1028 mm. The mirror has a diameter of 358 mm. The projection optics 20 has a mean wavefront error RMS of 9.7 mλ at a useful wavelength of 13.5 nm.

The projection optics 20 has a picture-side numerical aperture of 0.40.

The reflection surfaces of the mirrors M1 to M4 are in turn designed as free-form surfaces, which can be described by means of the free-form surface equation (1) mentioned in the introduction.

The optical design data of the projection optics 20 can be taken from the following tables, which in their structure the tables for projection optics 7 to 2 correspond. Table 1 to Fig. 5 z-distance [mm] y-distance [mm] Tilting about x-axis [degrees] M4 1262.197076 0.000000 0.3529 M3 59.462864 13.669342 0.6626 M2 2016.191803 -8.871532 11.9571 M1 1559.136371 189.365142 8.9767 object field 2217.312161 257.773789 0.0000 Table 2 to Fig. 5 M4 5 RDX -1495.874993 RDY -1495.874993 CCX 0.136651 CCY 0.136651 x ** i y ** j coefficient 2 0 -2.200221E-07 2 1 1.698003E-09 0 3 1.396838E-09 4 0 8.396018E-13 2 2 1.678479E-12 0 4 -7.798379E-15 4 1 5.379941E-16 2 3 8.976778E-16 0 5 2.413604E-15 6 0 1.370014E-19 4 2 4.076776E-19 2 4 -2.411110E-20 0 6 4.992923E-18 6 1 3.927142E-22 4 3 6.826147E-22 2 5 3.464347E-21 0 7 -8.258855E-21 8th 0 9.841369E-26 6 2 2.718924E-25 4 4 2.398692E-25 2 6 3.099015E-24 0 8th -2.042886E-23 8th 1 -1.703719E-27 6 3 -7.861030E-28 4 5 1.373119E-27 2 7 -2.489612E-26 0 9 1.705321E-26 10 0 -4.414479E-31 8th 2 -1.607900E-30 6 4 -1.893528E-30 4 6 -1.556297E-31 2 8th -1.076712E-29 0 10 5.262579E-29 10 1 9.885555E-33 8th 3 1.118532E-32 6 5 -4.034599E-33 4 7 -8.340768E-33 2 9 1.092466E-31 0 11 1.766957E-33 12 0 1.203252E-36 10 2 5.716802E-36 8th 4 1.156202E-35 6 6 2.073578E-36 4 8th -4.820695E-36 2 10 1.217269E-35 0 12 -7.639600E-35 12 1 -2.733644E-38 10 3 -4.664982E-38 8th 5 3.325551E-39 6 7 5.184495E-38 4 9 3.369836E-38 2 11 -1.912844E-37 0 13 -3.629431E-38 14 0 -1.318110E-42 12 2 -7.675401E-42 10 4 -2.170443E-41 8th 6 -2.192926E-41 6 8th 1.432779E-41 4 10 1.316482E-41 2 12 7.380873E-42 0 14 4.873456E-41 14 1 2.996969E-44 12 3 7.660400E-44 10 5 3.095444E-45 8th 7 -4.942182E-44 6 9 -1.397868E-43 4 11 -4.811435 E-44 2 13 6.251726E-44 0 15 3.486406E-45 M3 5 RDX -1627.464186 RDY -1627.464186 CCX 0 CCY 0 x ** i y ** j coefficient 2 0 -4.112159E-06 2 1 4.118008E-08 0 3 3.279619E-08 4 0 -3.200185E-10 2 2 -6.466630E-10 0 4 -3.932964E-10 4 1 8.478134E-14 2 3 1.430091E-13 0 5 5.101140E-13 6 0 -5.841240E-16 4 2 -1.773063E-15 2 4 -2.113310E-15 0 6 2.553270E-15 6 1 5.366358E-19 4 3 9.412297E-19 2 5 5.826661E-18 0 7 -1.574216E-17 8th 0 -9.560211E-22 6 2 -4.525855E-21 4 4 -8.353011E-21 2 6 1.396992E-20 0 8th -1.080152E-19 8th 1 -2.229493E-23 6 3 -8.204730E-24 4 5 6.095019E-24 2 7 -4.140168E-22 0 9 2.578164E-22 10 0 -2.334168E-26 8th 2 -9.369744E-26 6 4 -1.107193E-25 4 6 3.718842E-26 2 8th -4.693023E-25 0 10 2.233573E-24 10 1 1.095245E-27 8th 3 9.998944E-28 6 5 -6.892011E-28 4 7 -2.786207E-28 2 9 1.597395E-26 0 11 1.133283E-27 12 0 4.486528E-31 10 2 2.292765E-30 8th 4 4.035512E-30 6 6 -4.415009E-31 4 8th -6.419522E-30 2 10 -4.715217E-30 0 12 -2.963299E-29 12 1 -2.619982E-32 10 3 -3.816968E-32 8th 5 1.482940E-32 6 7 5.731804E-32 4 9 1.534829E-32 2 11 -2.373627E-31 0 13 -5.854095E-32 14 0 -4.307542E-36 12 2 -2.814501E-35 10 4 -6.935405E-35 8th 6 -6.485798E-35 6 8th 8.019362E-35 4 10 1.241392E-34 2 12 2.268795E-34 0 14 2.093818E-34 14 1 2.479777E-37 12 3 5.734631E-37 10 5 -1.278263E-37 8th 7 -5.912491E-37 6 9 -1.341681E-36 4 11 -2.981989E-37 2 13 4.901717E-37 0 15 9.642036E-38 M2 5 RDX 5998.982993 RDY 5998.982993 CCX 0 CCY 0 x ** i y ** j coefficient 2 0 -3.728903E-05 2 1 1.823375E-07 0 3 1.753220E-07 4 0 3.088567E-11 2 2 7.322840E-11 0 4 -8.566605E-10 4 1 8.290626E-14 2 3 -1.402142E-13 0 5 -2.027512E-13 6 0 -3.460657E-16 4 2 -2.714092E-15 2 4 -3.959332E-14 0 6 4.131188E-13 6 1 3.377393E-17 4 3 6.449959E-17 2 5 7.682479E-16 0 7 2.094198E-15 8th 0 1.819878E-19 6 2 5.707703E-19 4 4 7.484654E-18 2 6 5.424249E-17 0 8th -1.039928E-16 8th 1 -2.097478E-20 6 3 -2.834480E-20 4 5 -1.473078E-19 2 7 -9.188082E-19 0 9 -1.562740E-18 10 0 -5.619819E-23 8th 2 -1.353175E-22 6 4 -7.130674E-22 4 6 -8.366702E-21 2 8th -3.349994E-20 0 10 5.612893E-21 10 1 6.990361E-24 8th 3 9.497817E-24 6 5 2.892384E-23 4 7 1.603700E-22 2 9 5.329720E-22 0 11 5.966265E-22 12 0 8.775121E-27 10 2 3.049542E-26 8th 4 -4.177209E-26 6 6 7.203695E-25 4 8th 3.795034E-24 2 10 9.494684E-24 0 12 2.306271E-24 12 1 -1.167608E-27 10 3 -2.336124E-27 8th 5 1.528806E-28 6 7 -2.442798E-26 4 9 -6.860664E-26 2 11 -1.452779E-25 0 13 -1.124688E-25 14 0 -5.384985E-31 12 2 -3.443977E-30 10 4 1.433070E-29 8th 6 -1.831304E-29 6 8th -1.728803E-28 4 10 -5.832245E-28 2 12 -9.932488E-28 0 14 -3.024419E-28 14 1 7.566846E-32 12 3 2.569465E-31 10 5 -4.256771E-31 8th 7 9.616159E-31 6 9 5.004947E-30 4 11 9.999921E-30 2 13 1.483076E-29 0 15 8.075824E-30 M1 5 RDX 8923.929747 RDY 8923.929747 CCX 0 CCY 0 x ** i y ** j coefficient 2 0 -4.758899E-05 2 1 1.859328E-07 0 3 1.669352E-07 4 0 3.457817E-11 2 2 -1.976191E-11 0 4 -1.061383E-09 4 1 -1.006325E-14 2 3 2.218251E-12 0 5 -1.491828E-11 6 0 -6.837221E-16 4 2 -6.601904E-15 2 4 -1.296826E-13 0 6 9.994116E-13 6 1 4.153457E-16 4 3 -2.836871E-16 2 5 -6.996930E-15 0 7 1.975888E-14 8th 0 9.446409E-19 6 2 3.958379E-19 4 4 6.124941E-17 2 6 5.620331E-16 0 8th -3.124072E-16 8th 1 -4.648572E-19 6 3 -5.828730E-19 4 5 1.819073E-18 2 7 9.615139E-18 0 9 -1.724027E-17 10 0 -7.109459E-22 8th 2 -6.127335E-22 6 4 -7.629513E-21 4 6 -2.340513E-19 2 8th -1.074666E-18 0 10 -4.343022E-19 10 1 2.651925E-22 8th 3 5.850868E-22 6 5 2.120418E-22 4 7 -7.751214E-22 2 9 -8.768765E-22 0 11 1.486381E-20 12 0 2.505179E-25 10 2 7.770641E-25 8th 4 -3.054181E-24 6 6 4.673774E-23 4 8th 3.242195E-22 2 10 9.201963E-22 0 12 4.010394E-22 12 1 -7.663200E-26 10 3 -2.324044E-25 8th 5 -1.746366E-25 6 7 -8.616006E-25 4 9 -2.768028E-24 2 11 -7.301342E-24 0 13 -8.503607E-24 14 0 -3.309399E-29 12 2 -2.239884E-28 10 4 1.294138E-27 8th 6 -3.395097E-27 6 8th -3.536527E-26 4 10 -1.442802E-25 2 12 -2.886844E-25 0 14 -8.370351E-26 14 1 8.881649E-30 12 3 3.479934E-29 10 5 1.022043E-29 8th 7 1.554064E-28 6 9 7.411200E-28 4 11 2.119358E-27 2 13 3.829199E-27 0 15 1.655980E-27

The projection exposure apparatus is used to produce a microstructured or nanostructured component 1 used as follows: First, the reflection mask 10 or the reticle and the substrate or the wafer 11 provided. Subsequently, a structure on the reticle 10 on a photosensitive layer of the wafer 11 using the projection exposure system 1 projected. By developing the photosensitive layer, a micro or nanostructure is then formed on the wafer 11 and thus produces the microstructured component.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US8018650 B2 [0002]
• WO 2018/043433 A1 [0002]
• US 5291340 [0002]
• US 2013/0128251 A1 [0010]
• DE 102014208770 A1 [0010]
• US 2016/0327868 A1 [0010]
• WO 2015/014753 A1 [0038]
• DE 10155711 A [0038]
• US 20070058269 A1 [0053]
• WO 2016/188934 A1 [0055]
• DE 102010029050 A1 [0069]

Cited non-patent literature

• "Characterizing the shape of freeform optics" by GW Forbes, Optics Express, Vol. 20, No. 3, pages 2483 to 2499 [0092]

Claims (14)

Imaging optics (7; 18; 19; 20) for imaging an object field (4), in which an object (10) to be imaged can be arranged, in an image field (8), in which a substrate (11) can be arranged, by guiding Imaging light (3) along an imaging light beam path, - With a last mirror (M4) in the imaging light beam path in front of the image field (8) having a passage opening (17) for the passage of the imaging light (3), - With a penultimate mirror (M3) in the imaging light beam path in front of the last mirror (M4), wherein the penultimate mirror (M3) has a passage opening (17) for the passage of the imaging light (3), with at least two further mirrors (M1, M2) with imaging effect in the imaging light beam path between the object field (4) and the penultimate mirror (M3), wherein the further mirrors (M1, M2) have a reflection-free used reflection surface, - wherein the image field (8) is the first field of the imaging optical system (7) in the imaging light beam path after the object field (4). Imaging optics after Claim 1 , characterized in that the imaging optical system (7; 18; 19; 20) is designed telecentrically on the image side. Imaging optics after Claim 1 or 2 , characterized by a pupil plane (17a) in the region of the last mirror (M4) and / or in the region of the penultimate mirror (M3). Imaging optics after one of the Claims 1 to 4 , characterized in that at least one of the reflection surfaces of the mirrors (M1 to M4) is designed as a free-form surface. Imaging optics after Claim 4 , characterized by a deviation of the free-form surface from a best-adapted spherical surface, which is smaller than 150 microns. Imaging optics after one of the Claims 4 or 5 , characterized by a deviation of the free-form surface from a best-matched toric surface, which is smaller than 100 microns. Imaging optics after one of the Claims 4 to 6 , characterized by a deviation of the free-form surface from a best-adapted conic surface, which is smaller than 100 microns. Imaging optics after one of the Claims 1 to 7 , characterized by different magnifications (β _x , β _y ) for two mutually perpendicular field coordinates (x, y). Imaging optics after one of the Claims 1 to 8th characterized by a pupil obscuration of the penultimate mirror (M3) and / or the last mirror (M4) whose radius is smaller than 0.3 in relation to the radius of the mirror surface used. Optical system - with an imaging optic according to one of the Claims 1 to 9 , - with an illumination optical system (6) for illuminating the object field (4) with illumination light (3) of a light source (2). Lighting system with an optical system after Claim 10 and with a light source (2). Projection exposure system with a lighting system after Claim 11 , A method of fabricating a patterned device comprising the steps of: providing a reticle (10) and a wafer (11), projecting a pattern on the reticle (10) onto a photosensitive layer of the wafer (11) using the projection exposure apparatus Claim 12 , - Generating a micro or nanostructure on the wafer (11). Structured component produced by a method according to Claim 13 ,

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