DE102012212753A1 - Projection optics for forming object field of optics plane in projection exposure system for microlithography, has blinding unit presetting outer boundary of optics with respect to diaphragm direction that is set parallel to planes - Google Patents

Abstract

The optics (7) has a set of beam-guiding optical elements guiding an illuminating radiation (3) along an optical path. A set of pupil-shells defined by the path and includes sectional planes that run perpendicular to each other. First and second blinding units are attached to one of the pupil-shells, where the second blinding unit presets an outer boundary of the optics with respect to a diaphragm direction. The blinding units are arranged in a direction of the path, and the diaphragm direction is set parallel to the sectional planes. An independent claim is also included for a method for manufacturing micro or nano-structured component.

Description

The invention relates to a projection optics for imaging an object field in an image field. The invention further relates to a projection exposure apparatus for microlithography with such a projection optics. Moreover, the invention relates to a method for producing a micro- or nanostructured device.

Katoptrische projection optics for lithography systems are from the US 6,396,067 B1 , of the JP 2004/246343 and the JP 2005/86148 known.

There is a continuing need to develop such projection optics.

The invention has for its object to provide a projection optics with improved imaging properties.

This object is solved by the features of claim 1. The essence of the invention is to divide an aperture stop to limit the system aperture into two separate aperture devices. This makes it possible to take into account the fact that the imaging of the entrance pupil of the projection optics by the optical elements of the projection optics is astigmatic. As a result, an essentially homocentric entrance pupil is usually imaged onto an astigmatic aberrated real aperture diaphragm located in the system. According to the invention, it has been recognized that the imaging properties of the projection optics can be improved if the diaphragm devices are respectively arranged in the vicinity of a pupil shell, in particular in the region of the same. In this case, the pupil shell refers to the surface on which a structural direction of the entrance pupil is imaged with minimal aberrations. In particular, one speaks of the X-pupil shell, in the vertical structures of the entrance pupil, ie structures in the y-direction in the sense of to be mapped with minimal aberrations. In other words, the X pupil shell is where the subapertures of the entrance pupil lie one above the other in the x direction and fanned out in the y direction. In the Y pupil shell, horizontal structures of the entrance pupil, ie structures in the x direction in the sense of , pictured with minimal aberrations. In other words, the Y pupil shell is where the subapertures of the entrance pupil lie one above the other in the y direction and fanned out in the x direction. The x-direction and y-direction are in particular perpendicular to one another and span a plane parallel to the object plane, in particular parallel to the plane of the entrance pupil of the projection optics. Here, the y-direction is also referred to as vertical and the x-direction as horizontal. The y direction corresponds to the scan direction. In particular, it lies in a plane which is defined by a principal ray of a central object field point and an axis which is perpendicular to the object field and extends through the central object field point. In particular, the right and left edges of the entrance pupil are imaged in the X-pupil shell without defocus, while the upper and lower edges of the entrance pupil are aberrated, ie primarily defocused. In the Y pupil shell, the upper and lower edges of the entrance pupil are imaged without defocus, while the left and right edges of the entrance pupil are aberrated, ie, predominantly defocused. In this case, the aperture device arranged in the vicinity, in particular in the region of the Y pupil shell, serves to predetermine outer limits of the pupil in the horizontal (or X) direction, while those arranged in the vicinity, in particular in the region of the X pupil shell Aperture means for specifying outer boundaries of the pupil with respect to the vertical (or Y) direction.

The pupil shells are generally spaced apart in the direction of the beam path by a distance d. This is also called astigmatic pupillary difference.

In general, the distance d of the pupil shells in the direction of the beam path is position-dependent. He usually takes to the edge. In the following, the distance of the pupil shells is given as the geometric distance of the surfaces, measured along the main ray of the central field point. This value is also referred to for simplicity's sake as distance d of the pupil shells.

The diaphragm devices are in particular in the direction of the beam path on spatially separated, d. H. spaced surfaces arranged. In particular, they comprise two separate, spatially separated diaphragm elements. In principle, however, it is also possible to design the two diaphragm devices constructively as a single, continuous diaphragm system.

The inventive design and arrangement of the diaphragm devices, in particular, the telecentricity of the image can be improved by the projection optics. In particular, the sum of the telecentricity errors with respect to the two main directions of the projection optics can be reduced.

In the projection optics is in particular a reflective optics. It can include a plurality of mirrors. In particular, it may comprise at least four, in particular at least six, in particular at least eight, mirrors.

It is in particular a projection optics for EUV lithography. The mirrors of the projection optics can therefore have, in particular, a coating which is reflective for EUV radiation, in particular a multilayer coating.

The projection optics is especially smaller. For example, it has a reduction factor of at least 2: 1, in particular at least 4: 1, in particular at least 6: 1, in particular at least 8: 1, as a magnification.

According to one aspect of the invention, the two directions, with respect to which the diaphragm devices predetermine outer boundaries of the pupil, run in the direction of the beam path in the image plane parallel to the scanning direction or perpendicularly thereto in the direction of the beam path. In the case of a rotationally symmetrical design of the projection optics, these directions correspond exactly to the Y or X direction. These directions are particularly relevant in the application of projection optics. Usually, the structures to be imaged are also aligned primarily parallel to these directions. The best possible telecentricity of the image with regard to these directions is therefore particularly relevant for the practical applications of projection optics.

According to one aspect of the invention, at least one of the diaphragm devices, in particular also both of the diaphragm devices, can be arranged directly on one of the optical elements, in particular directly on one of the mirrors of the projection optics. This allows a particularly simple design and arrangement of the aperture device. The corresponding diaphragm device can be applied to the corresponding optical element, for example, as a radiation-absorbing coating.

According to a further aspect of the invention, one of the diaphragm devices can be arranged on the last beam-guiding element in the beam path, in particular the last mirror of the projection optics. If the mirrors are numbered consecutively starting from the object field in the direction of the beam path with M1, M2, etc., the diaphragm device can be arranged in particular on the mirror M4, in particular the mirror M6, in particular the mirror M8. According to the invention, it was recognized that the last mirror in the beam path of the projection optics, i. H. the wafer nearest mirror may be disposed near a surface conjugate to the Y pupil shell. Due to the relatively small extent of the image field on the wafer in the scanning direction and the comparatively large distance from the last mirror to the image field, the half field extent in the y-direction of the image field on the wafer from the apex of the last mirror is less than 10 mrad, in particular less than 5 mrad, in particular less than 2 mrad. It varies in a good approximation linearly with the y-field coordinate. The arrangement of a Y-aperture on the last mirror therefore leads to a correspondingly small, linearly varying telecentricity error in the scanning direction.

In this case, the X-diaphragm can be arranged in particular in the region of the mirror M2, in particular on the mirror M2.

According to a further aspect of the invention, the diaphragm devices are arranged on beam-guiding elements which follow one another in the beam path, in particular on successive mirrors, in particular on the mirrors M2 and M3. In this case, the mirrors M2 and M3 are preferably arranged close to each other. Their spacing is in particular less than twice the astigmatic pupil difference of the projection optics. It corresponds in particular to the astigmatic pupil difference d.

According to a further aspect of the invention, at least one of the diaphragm devices is arranged between two optical elements which follow one another in the direction of projection, in particular between two successive mirrors, spaced from these. In particular, it is possible to arrange one of the diaphragm devices between the mirrors M2 and M3 and / or one of the diaphragm devices between the mirrors M5 and M6. In general, one of the diaphragm devices between the mirrors M2 and M3 and / or one of the diaphragm devices can be arranged between the last two beam-guiding mirrors M _n-1 and M _n , n indicating the total number of mirrors. The following applies: n ≥ 4, in particular n ≥ 6, in particular n ≥ 8.

An arrangement of the diaphragm device between two mirrors has the advantage that the mirrors do not have to be influenced by the arrangement of the diaphragms. In addition, such panels are also retrofitted. Another advantage is that such panels can be designed to be interchangeable.

Preferably, the diaphragms are arranged in an area in the beam path, in which the beam path is freely accessible on the circumference. These are in particular areas understood in which the beam path without overlapping with itself, d. H. is overlapping with other sections of the beam path, is.

An arrangement in such areas allows a vignette-free design and arrangement of the aperture.

According to one aspect of the invention, at least one of the diaphragm devices is arranged in the beam path in such a way that its passage region is traversed by the beam path exactly once. Preferably, both diaphragm devices are arranged in the beam path such that their transmission range from the beam path is traversed exactly once in each case.

This improves the targeted adaptation of the diaphragm devices to the shape of the pupils.

According to a further aspect of the invention, the diaphragm devices are arranged at positions in the projection direction such that one diaphragm device is arranged closer to the object field along the beam path and the other diaphragm device is arranged closer to the image field along the beam path.

In particular, it may be provided to arrange the aperture acting in the y-direction closer to the object field and the aperture acting in the x-direction closer to the image field. This can be advantageous in particular for an arrangement of the panels, in which they are not separated by an intermediate image.

In the case of an arrangement of the diaphragms in which there is an intermediate image in the beam path between the two diaphragms, the boundary acting in the y direction can preferably be arranged closer to the image field and the boundary acting in the x direction preferably closer to the object field.

According to a further aspect of the invention, at least one of the diaphragm devices has a section-wise borderless passband. The passband is in other words circumferentially not completely bounded. The rimless passband is preferably formed in an angular range about a direction perpendicular to the diaphragm direction. The diaphragm can be borderless, in particular in an angular range of up to 45 °, in particular up to 60 °, in particular up to 90 °, about the directions perpendicular to the diaphragm direction. In this way it can be achieved that the pupil aperture in this direction is not limited by the diaphragm. This avoids unwanted vignetting. Such a design of the diaphragm is particularly advantageous if the diaphragm is arranged in a region along the beam path in which the beam path overlaps itself.

According to another aspect of the invention, at least one of the aperture devices comprises an obscuration element. The obscuration element serves in particular for the obscuration of a central diaphragm area in the corresponding diaphragm direction. It can also be provided to provide both aperture devices with obscuration elements. In other words, the aperture devices can form combined aperture obscuration diaphragms.

According to an advantageous aspect of the invention, the projection optics have a catoptric design. In other words, it comprises only reflective beam-guiding optical elements.

According to a further aspect of the invention, at least one of the optical elements, in particular one of the mirrors, has a free-form surface. This is understood to mean a surface for which no axis of rotational symmetry can be specified. For details, for example, on the WO 2007/03127 A1 directed.

Another object of the invention is to improve a projection exposure apparatus for microlithography. This object is solved by the features of claim 13. The advantages correspond to those described for the projection optics.

Another object of the invention is to improve a method of manufacturing a micro- or nanostructured device. This object is solved by the features of claim 14. With the aid of the projection optics according to the invention, the structures of the reticle can be imaged more precisely on the wafer. In particular, a representation of finer structures is made possible. As a result, for example, an increased integration density can be achieved.

Further advantages, details and features of the invention will become apparent from the description of embodiments with reference to the drawings. Show it:

1 a schematic representation of the components of a projection exposure apparatus,

2 schematically the beam path in the projection optics according to a first embodiment,

3a to 3c schematically a selection of field points with a representation of the associated Subaperturen at different positions in the beam path, wherein in 3c Section enlargements of the beam path in the region of the X and Y pupil shells are shown to illustrate the respective numerical apertures of the pupil image,

4a to 4c schematic representations of the beam path of a projection optical system according to a further embodiment with the images of the subapertures according to 3b at different points in the beam path,

5a and 5b a further representation of a beam path of a projection optical system with the images of the subapertures of different object field points,

6a to 6c Representations according to the 4a to 4c according to a further embodiment of the projection optics,

7a to 7c Representations according to the 4a to 4c according to a further embodiment of the projection optics,

8a to 8e a further illustration of the beam path of a projection optical system according to the invention with images of subapertures at different locations in the beam path and a superimposition of these images.

A projection exposure machine 1 for microlithography has a light source or radiation source 2 for illumination radiation 3 , The illumination radiation 3 is also referred to as illumination light or imaging light. 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 radiation 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 principle, any wavelengths, z. As well as visible wavelengths or other wavelengths that can be used in microlithography, and for which suitable laser light sources and / or LED light sources are available, for example, 365 nm, 248 nm, 193 nm, 157 nm, 129 nm, 109 nm , for that in the projection exposure machine 1 guided illumination light possible. A beam path of the illumination radiation 3 is in the 1 shown very schematically.

For guiding the illumination radiation 3 from the radiation source 2 towards an object field 4 in an object plane 5 serves a lighting optics 6 , With a projection optics 7 , which is commonly referred to as imaging optics, becomes the object field 4 in a picture field 8th in an image plane 9 displayed.

The image field 8th has an extension of 26 mm in the x-direction and an extension of 2 mm in the y-direction. Other dimensions are also possible. The object field 4 and the picture box 8th are rectangular. They can also be curved. For the projection optics 7 can be used one of the embodiments described below.

The projection optics 7 has a predetermined reduction scale. In particular, it reduces by a factor of 4. Other reduction scales are possible, for. B. twice, five times, eight times or even reduction scales that are greater than eight times.

The picture plane 9 is in the projection optics 7 preferably parallel to the object plane 5 arranged. Here, one is shown 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 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.

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 For example, in one embodiment, 0.45. This is in the 1 not reproduced to scale.

To facilitate the description of the projection exposure apparatus 1 as well as the various embodiments of the projection optics 7 is in the 1 a Cartesian xyz coordinate system specified, 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 goes to the right and the z-direction to the bottom. The system is folded in the yz plane and has a mirror symmetry to it. However, it is basically possible to give up this mirror symmetry and to realize the system as a completely wind-skewed system. For details be on it DE 10 2011 083 888 directed.

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 gradual shift of the reticle 10 and the substrate 11 in the y-direction is possible.

2 shows the optical design of a first embodiment of the projection optics 7 , Shown in the 2 the beam path of two Einzelstrahltriplets 15 ₁ , 15 ₂ , by two edge object field points 16 ₁ , 16 _{2 go out} at the top and bottom of the object field. The drawing plane of the 2 represents a section in the yz plane. In the plane of the drawing 2 So lies the course of a main beam of a central object field point. A main beam plane is therefore parallel to the yz plane. The central object field point 16 is defined as the point that lies midway between the two edge object field points.

In the projection optics 7 according to 2 it is a catoptric projection optics 7 ie a purely reflective projection optics 7 , It comprises six projection mirrors M _i , which proceed from the object field 4 along the beam path with M ₁ to M _{6 are} numbered.

The projection optics according to 2 has a simply obscured mirror design. The last mirror M ₆ in the beam path in front of the wafer 11 has a passage opening 24 on. In the 2 is the location of a pupil plane 25 between the mirrors M ₅ and M ₆ shown. In general, this is not necessarily a flat surface but a curved pupil surface.

The projection mirrors M _i have free-form surfaces. In other words, its reflective surface can not be described by a rotationally symmetric function. For details of the training of the mirror M _i with freeform surfaces is on the WO 2007/031271 A1 directed. There are also versions of the projection optics 7 possible in which only a subset of the mirrors M _i , in particular at least one of the mirrors M _i or none of the mirrors M _i has such a free-form reflecting surface. An embodiment of one or more of the mirrors M _{i of} the projection optics 7 Free-form surfaces open up additional degrees of freedom in the design of the projection optics 7 , in particular for the compensation of aberrations.

wobei gilt:

The free-form surface can be described mathematically by the following equation sum of a biconic base surface and a free-form surface polynomial:

where:

Z is the arrow height of the freeform surface at point x, y, where x ² + y ² = r ² .

c _x , c _y are the vertex curvatures in the x and y directions, k _x , k _y , the associated conic constants. C _j are the coefficients of the monomials X ^m Y ⁿ . Typically, the values of c _x, c _y, k _x, k _y and C _j on the basis of the desired optical properties of the mirror within the projection optical system 7 certainly. The order of the monomial, m + n, can be varied as desired. A higher order monomial may result in a design of the projection optics with better image aberration correction, but is more expensive to compute. m + n can take values between 3 and more than 20.

The optical design data of the reflection surfaces of the mirrors M1 to M6 of the projection optics 7 can be found in the following tables. Each of these optical design data goes from the image plane 9 from, describe the respective projection optics so in the reverse direction of the imaging light 3 between the picture plane 9 and the object plane 5 , The first of these tables gives in each case the thickness (thickness) in mm to the optical surfaces of the optical components and to the aperture diaphragm, which corresponds to the z-spacing of adjacent elements in the beam path, starting from the object plane. The value radius indicates a mean radius of curvature of the respective mirror M _i . The second table gives in mm the vertex radii RDX = 1 / c _x and RDY = 1 / c _y the conical constants k _x and k _y , and the coefficients C _{j of} the monomials X ^m Y ⁿ in the free-form surface equation given above for the Mirror M1 to M6 on. According to the second table, the third table also indicates the amount along which the respective mirror is decentered (DCY) and tilted (TLA) in the y direction starting from a mirror reference design. This corresponds to a parallel shift and a tilt in the freeform surface design process. It is shifted in y-direction in mm and tilted about the x-axis. The twist angle is given in degrees. It is decentered first, then tilted. surface radius distance value operation mode Half diameter scene 268.422668 13.0 Pupil plane ( 25 ) * 470.000000 216.5 M6 -826.737305 -470.000000 REFL 344.8 Pupil plane ( 25 ) * -207.805145 216.5 M5 -721.773963 207.805145 REFL 88.5 Pupil plane ( 25 ) * 1599.928531 216.5 M4 -1,570.806961 -862.339186 REFL 252.7 M3 -1,196.858238 606.590912 REFL 122.8 M2 -7,164.774269 -370.238400 REFL 149.2 Cover ( 22 ) -600.000000 144.8 M1 2558.908199 1552.615796 REFL 199.9 object level 0.000000 52.2 Table 1 to Fig.2 * in the embodiment according to 8th : Cover ( 23 ) Coeff. M6 M5 M4 RDY -826.737305 -721.773963 -1,570.806961 KY 0 0 0 RDX -826.737305 -721.773963 -1,570.806961 KX 0 0 0 X0Y0 -7,806682E-02 -1,286266E + 00 1,584838E + 00 X0Y1 2,215108E-04 1,695373E-03 4,787135E-05 X2Y0 3,675772E-05 4,195983E-04 -4,741215E-06 X0Y2 -3,575074E-05 -5,941241E-04 8,810629E-07 X2Y1 9,388849E-09 1,164832E-07 -1,858078E-09 X0Y3 -3,271700E-09 5,617165E-07 -1,215290E-08 X4Y0 1,898639E-11 -6,536632E-10 -2,559750E-12 X2Y2 -2,740713E-11 -2,921283E-09 -6,635606E-12 X0Y4 -5,561899E-11 -7,941677E-09 -2,485663E-12 X4Y1 8,086352E-15 1,778925E-12 -2,762160E-16 X2Y3 9,411148E-15 6,151951E-12 -5,177502E-15 X0Y5 -2,942799E-15 3,399564E-12 -2,525470E-15 X6Y0 1,147164E-17 -2,668533E-15 -1,525103E-18 X4Y2 -3,078192E-17 -1,954749E-14 -4,763500E-18 X2Y4 -1,290602E-16 -7,481680E-14 1,126619E-18 X0Y6 -8,100203E-17 -1,691341E-13 7,505686E-18 X6Y1 6,982764E-21 7,345176E-18 -7,472085E-22 X4Y3 2,717231E-20 5,139040E-17 -9,258700E-21 X2Y5 1,386785E-20 3,031698E-16 1,542171E-20 X0Y7 -2,515168E-21 6,198123E-16 5,175107E-21 X8Y0 4,385054E-24 -1,047011E-20 -3,825892E-24 X6Y2 -5,243375E-23 -1,225615E-19 -2,140189E-23 X4Y4 -2,587042E-22 -4,405288E-19 -1,939811E-23 X2Y6 -3,065854E-22 1,295867E-19 -8,221875E-24 X0Y8 -1,120559E-22 1,843707E-18 8,278445E-23 X8Y1 2,731597E-28 8,870398E-23 -1,901606E-26 X6Y3 4,647830E-26 4,376308E-22 -1,178830E-25 X4Y5 5,413345E-26 9,827531E-23 7,170200E-27 X2Y7 2,574449E-26 9,466870E-21 -1,697588E-25 X0Y9 4,670798E-27 3,504341E-20 6,185946E-25 X10Y0 1,736594E-29 -1,843890E-25 1,148541E-29 X8Y2 -4,520462E-29 -1,393616E-24 -5,912674E-29 X6Y4 -3,308248E-28 -1,458822E-23 -3,084979E-28 X4Y6 -6,025522E-28 -8,487328E-23 -1,839191E-29 X2Y8 -4,792079E-28 -4,095463E-22 -3,680304E-28 X0Y10 -1,395542E-28 3,546941E-23 9,212164E-28 X10Y1 1,807493E-32 X8Y3 9,887541E-32 X6Y5 2,321557E-31 X4Y7 2,211098E-31 X2Y9 6,368942E-32 X0Y11 -1,817586E-32 X12Y0 -9,211138E-36 X10Y2 -2,592593E-34 X8Y4 -1,665406E-33 X6Y6 -3,807622E-33 X4Y8 -4,159422E-33 X2Y10 -2,189874E-33 X0Y12 -4,567134E-34 Coeff. M3 M2 M1 RDY -1,196.858238 -7,164.774269 2558.908199 KY 0 0 0 RDX -1,196.858238 -7,164.774269 2558.908199 KX 0 0 0 X0Y0 3,565942E + 00 4,275741E + 00 -3,563559E + 00 X0Y1 3,506474E-03 4,587909E-03 1,053276E-03 X2Y0 5,753469E-05 -9,220129E-05 -4,592065E-05 X0Y2 -7,363620E-05 7,040543E-05 4,284174E-05 X2Y1 -3,778219E-07 -1,675730E-07 1,137084E-08 X0Y3 -5,845520E-07 -3,305520E-07 1,799074E-08 X4Y0 2,724363E-11 3,202313E-11 -1,659137E-11 X2Y2 -2,375026E-10 -1,517503E-11 -6,909049E-11 X0Y4 -4,913915E-10 2,240929E-10 -7,944358E-12 X4Y1 -1,236632E-13 -2,232366E-13 3,390589E-14 X2Y3 -7,757640E-13 -1,934915E-13 4,597408E-14 X0Y5 -2,666871E-13 3,863113E-14 4,630437E-15 X6Y0 -1,406021E-16 -2,977192E-17 -1,265040E-17 X4Y2 -7,694761E-6 -5,785733E-16 -8,034988E-17 X2Y4 -5,825645E-16 2,927777E-16 -5,513885E-17 X0Y6 3,745886E-15 8,439578E-16 -1,590170E-17 X6Y1 -1,129552E-18 -9,171339E-19 -3,353471E-21 X4Y3 -9,368363E-18 -1,057478E-18 6,159050E-20 X2Y5 5,593215E-18 6,204459E-19 1,323807E-19 X0Y7 1,724618E-17 1,781541E-18 6,663224E-20 X8Y0 -1,394885E-21 2,307093E-22 -1,452014E-23 X6Y2 -2,022721E-20 -1,793365E-21 -6,595594E-23 X4Y4 -2,251234E-20 4,473412E-21 -1,724111E-22 X2Y6 6,679289E-20 -1,156415E-20 -3,398968E-22 X0Y8 1,470535E-19 -2,989863E-20 -9,379880E-24 X8Y1 -2,156912E-23 -6,467067E-24 -1,115772E-25 X6Y3 -1,224470E-22 -2,765830E-24 -1,626926E-25 X4Y5 4,129802E-22 1,953142E-23 -5,302682E-25 X2Y7 7,258395E-22 7,015663E-23 1,212696E-25 X0Y9 2,141106E-21 1,157678E-22 1,353179E-25 X10Y0 1,373644E-26 -6,217253E-27 8,292270E-29 X8Y2 -1,507049E-25 -2,139922E-20 -3,773883E-28 X6Y4 -2,305203E-25 2,099841E-26 -1,569737E-28 X4Y6 2,207134E-24 4,291041E-26 7,585857E-28 X2Y8 2,883301E-24 1,600003E-25 4,347604E-27 X0Y10 7,388556E-24 -1,036374E-25 -3,158670E-27 X10Y1 X8Y3 X6Y5 X4Y7 X2Y9 X0Y11 X12Y0 X10Y2 X8Y4 X6Y6 X4Y8 X2Y10 X0Y12 Table 2 to Fig.2 decentration decentration decentration surface DCX DCY DCZ M6 0.000000 0.000000 0.000000 Pupil plane ( 25 ) * 0.000000 0.000000 0.000000 M5 0.000000 97.529051 0.000000 Pupil plane ( 25 ) * 0.000000 0.000000 0.000000 M4 0.000000 -57.749771 0.000000 M3 0.000000 380.839995 0.000000 M2 0.000000 388.672514 0.000000 Aperture 9 ( 22 ) 0.000000 544.747335 0.000000 M1 0.000000 790.185064 0.000000 object level 0.000000 978.749222 0.000000 * in the embodiment according to 8th : Cover ( 23 ) tilt tilt tilt surface TLA [deg] TLB [deg] TLC [deg] M6 -4.079135 0.000000 0.000000 Pupil plane ( 25 ) * 0.000000 0.000000 0.000000 M5 -6.452680 0.000000 0.000000 Pupil plane ( 25 ) * 0.000000 0.000000 0.000000 M4 -15.953083 0.000000 0.000000 M3 -12.737716 0.000000 0.000000 M2 -10.264675 0.000000 0.000000 Aperture 9 ( 22 ) -22.168263 0.000000 0.000000 M1 -7.577787 0.000000 0.000000 object level 0.000000 0.000000 0.000000 Table 3 to Fig.2 * in the embodiment according to 8th : Cover ( 23 )

The numerical aperture (NA) is 0.45, the object field height is 13.04 mm, the wavelength of the illumination radiation is 13.5 nm.

Like from the 2 can be seen, the projection optics 7 a folded in the yz plane beam path.

Furthermore, in the 2 the location of a Y-pupil plane 17 and an X-pupil plane 18 shown. At the in 2 illustrated optical design of the mirror M _{2 is} in the range of the X-Pupillenebene 18 , The x-pupil level 18 is from the Y-pupil level 17 spaced in the direction of the beam path by a distance d. The distance d between the x-pupil plane 18 and the Y-pupil plane 17 is commonly referred to as astigmatic pupillary difference.

In general, the X-pupil level 18 and the Y-pupil plane 17 not necessarily aligned parallel to each other. The distance d thus varies for different areas within the aperture of the beam path of the projection optics 7 , In the following, the smallest distance within the aperture is referred to as d _min . Accordingly, the largest distance is referred to as d _max . Unless stated otherwise, the distance d is the distance along the main ray of the central field point 16 designated.

In general, the pixels of a section through a pupil plane defined by the entrance pupil do not lie in a plane, but on a curved surface. The surface which corresponds to a section in the y-direction is also referred to as the X-pupil shell. The surface which corresponds to a section in the x-direction is called a Y-pupil shell. In this case, be below the Y-pupil level 17 understood a plane which the Y-pupil shell in the region of the beam path, ie in the region of the aperture of the projection optics 7 cuts. Below the Y-pupil level 17 Let us understand in particular the plane which intersects the Y pupil shell in the region of the marginal rays at x = 0. Accordingly, be below the X-pupil level 18 understood a plane which the X-pupil in the region of the beam path of the projection optics 7 , in particular in the region of the aperture of the beam path, cuts. The x-pupil level 18 runs in particular by the marginal rays at y = 0 of the beam path of the projection optics 7 ,

At the in 2 The optical design shown is the Y-pupil plane 17 in the beam path between M ₁ and M ₂ . The mirror M ₂ is located just in the area of the X-pupil shell.

At your in 2 illustrated design of the projection optics 7 the mirror M _{1 is} tilted. It has a spherical basic shape with a predominantly astigmatic free-form deformation.

Due to the tilting of the mirror M ₁ , both the object and the entrance pupil of the system are imaged astigmatically in the image space of the M ₁ . In principle, it is possible to design the mirror M ₁ such that its free-form deformation at least partially, in particular largely, in particular completely compensates for the astigmatism in the diaphragm image.

The fact that the entrance and exit pupils are respectively imaged astigmatically is equivalent to the statement that the x-direction of the pupil, in particular a left and right edge of the entrance pupil, are best focused in another plane than the y-direction the pupil, in particular an upper and lower edge of the entrance pupil.

In 3b are pictures of subapertures 19 _i , from different object field points 20 _i (see 3a ), at different locations in the beam path between the Y-pupil plane 17 and the X-pupil level 18 shown. The pictures of the subapertures 19 _i are also called footprints. Like from the 3b As an example, the footprints come 19 _i in the area of the X-diaphragm plane 18 in the x-direction well superimposed, while in the X-aperture plane 18 Fan in y direction. The footprints fan accordingly 19 _i in the area of the Y-diaphragm plane 17 in the x direction while falling in the y direction. In other words, it comes in each of the two image levels 17 . 18 to a good superposition of the images of the entrance pupil in the associated direction, while the images diverge in the direction perpendicular thereto.

Also, in the 3b the footprints, ie the envelope of the images of the subapertures of all object field points, in an area between the y-iris plane 17 and the X-aperture plane, which is the area of least confusion 21 is designated, shown.

In the are the rays of the pupil image from the 3b shown enlarged again. The numerical apertures of the pupil image are drawn in the x and y directions NA _x ^P , NA _y ^P. Since the aperture of the pupil image by the shape of the elongated object field 4 is given (cf. 3a ), the numerical apertures NA _x ^P and NA _y ^{P have} different values, and accordingly fan the subapertures 19 _i in the respective levels 17 . 18 different degrees. We have NA _x ^P > NA _y ^P.

According to the invention, it has been recognized that an undesired vignetting of the pupil of the projection optics 7 can be avoided if two separate apertures 22 . 23 be used to limit the aperture with respect to the y- or the x-direction or generally with respect to two mutually perpendicular diaphragm directions. This makes it possible to improve the telecentricity in the x and y direction or generally in the two mutually perpendicular diaphragm directions. The diaphragm direction is preferably parallel to the sectional plane associated with the associated pupil shell. The two aperture devices are preferably at the primary orientations of the structures on the reticle 10 customized. At the in 2 illustrated embodiment is the aperture 22 arranged in the region between the mirrors M ₁ and M ₂ . The aperture 23 is arranged on the mirror M ₂ . It may be formed in particular as a radiation-absorbing coating on the mirror M ₂ . It can also be given by the outer dimension of the mirror M ₂ , ie by its contour.

It can also be formed by a mechanical shading at a small distance in front of the sealing surface in the form of a diaphragm.

In general: Is one of the apertures 22 . 23 arranged on one of the mirrors M _i , so the corresponding aperture surface does not have to be flat. It may be formed as a radiation-absorbing coating on a curved mirror surface or follow the contour of the mirror in the edge region.

If a diaphragm plane lies between two mirrors, then the diaphragm arranged in this region can be designed flat. In particular, it may be on the main ray of the middle field point 16 are essentially vertical. But it is also conceivable that it is inclined relative to this vertical, especially in the yz-section of the representation.

The irises 22 . 23 are preferably designed such that they have the respective footprints, ie the images of the subapertures 19 _i completely rewrite all field points.

The irises 22 . 23 For this purpose, they are preferably in an area along the beam path of the projection optics 7 arranged, which is peripherally freely accessible. A corresponding arrangement is exemplary in example 4a shown. The pictures of the subapertures 19 _i in the area of the pupil planes 17 and 18 are in the 4b and 4c shown.

The optical design data of the projection optics 7 according to 4a are summarized in the following tables. The numerical aperture (NA), the object field height and the wavelength of the illumination radiation 3 are the same as the design according to the 2 , surface radius distance value operation mode Half diameter image plane 748.631075 13.0 M6 2133.731404 -662.527231 REFL 344.3 M5 7766.222192 1694.204082 REFL 74.8 M4 -2,736.425367 -1,079.986122 REFL 182.6 M3 -1,688.395773 330.034497 REFL 105.2 Cover ( 23 ) 604.359226 80.8 M2 -444.197266 -1,124.733189 REFL 129.3 M1 -797.765133 1678.693693 REFL 230.2 object level 0.000000 52.2 Table 1 to Fig. 4a SRF M6 M5 M4 RDY -797.765133 -444.197266 -1,688.395773 KY 0 0 0 RDX -797.765133 -444.197266 -1,688.395773 KX 0 0 0 X0Y0 -1,929066E + 00 -2,678549E + 00 2,787761E + 00 X0Y1 1,514836E-04 2,013869E-04 1,212917E-06 X2Y0 2,475257E-05 6,062249E-04 -8,675534E-06 X0Y2 -2,043488E-05 -5,344923E-04 2,072564E-05 X2Y1 -8,020071E-09 -1,301825E-06 -9,539218E-09 X0Y3 3,775517E-09 4,538511E-07 1,641895E-08 X4Y0 5,792966E-12 -8,463659E-10 -9,647065E-12 X2Y2 -3,336959E-11 -9,755078E-09 -6,072678E-13 X0Y4 -4,047370E-11 -1,824373E-08 -2,451088E-11 X4Y1 -8,689993E-15 -9,314648E-12 -6,795793E-15 X2Y3 -5,573572E-15 -2,771914E-11 2,442966E-15 X0Y5 1,464873E-15 4,315334E-12 2,707821E-14 X6Y0 -2,620422E-18 -1,167629E-14 -4,172520E-18 X4Y2 -6,034725E-17 -1,095731E-13 7,039706E-19 X2Y4 -1,219198E-16 -3,225720E-13 -9,553681E-17 X0Y6 -6,124030E-17 -4,234194E-13 -1,664906E-16 X6Y1 -1,287409E-20 -8,098108E-17 3,788373E-21 X4Y3 -2,266130E-20 -4,392072E-16 -5,424492E-20 X2Y5 -6,021267E-21 -4,527446E-16 -2,614720E-19 X0Y7 1,486119E-20 5,948592E-15 -6,802977E-20 X8Y0 -6,664104E-24 -4,192241E-20 1,474679E-23 X6Y2 -1,249118E-22 -1,517888E-18 -9,747440E-23 X4Y4 -3,209837E-22 -7,815247E-18 -9,743886E-22 X2Y6 -3,017227E-22 -1,628730E-18 1,443809E-20 X0Y8 -9,519859E-23 1,049114E-17 4,814078E-20 X8Y1 -4,453219E-27 -1,138909E-21 -5,158324E-26 X6Y3 -3,661247E-26 -1,868911E-20 4,793582E-25 X4Y5 -6,754537E-26 -4,134413E-20 3,754274E-24 X2Y7 -1,671955E-26 -3,997364E-20 2,465367E-23 X0Y9 -7,098374E-27 -3,403482E-19 -9,600550E-23 X10Y0 -2,136289E-29 -3,615488E-24 -1,075906E-28 X8Y2 -8,964625E-29 -3,038636E-23 5,689310E-28 X6Y4 -2,835765E-28 -9,618617E-23 1,593435E-26 X4Y6 -5,640031E-28 -3,206254E-22 1,492118E-26 X2Y8 -3,568034E-28 -1,769851E-21 -6,768563E-25 X0Y10 -1,344523E-28 -5,827177E-21 -3,071984E-24 X10Y1 -6,521186E-32 X8Y3 -2,967664E-31 X6Y5 -2,538559E-31 X4Y7 -1,415927E-32 X2Y9 5,001387E-32 X0Y11 -2,076988E-32 X12Y0 -7,282607E-35 X10Y2 -8,638502E-34 X8Y4 -3,403029E-33 X6Y6 -5,300960E-33 X4Y8 -4,712609E-33 X2Y10 -2,488502E-33 X0Y12 -4,450600E-34 SRF M3 M2 M1 RDY -2,736.425367 7766.222192 2133.731404 KY 0 0 0 RDX -2,736.425367 7766.222192 2133.731404 KX 0 0 0 X0Y0 -4,352848E + 00 4,480204E-01 -3,995579E + 00 X0Y1 -1,230680E-04 1,023562E-03 -6,159050E-04 X2Y0 3,179678E-05 4,566307E-06 -1,221636E-05 X0Y2 -3,399865E-06 2,265661E-05 3,673757E-06 X2Y1 -1,764267E-07 -2,961490E-07 -3,298116E-08 X0Y3 -4,991974E-08 -2,407741E-08 1,004381E-08 X4Y0 -3,596896E-10 2,368433E-10 6,758954E-12 X2Y2 -2,112082E-10 1,118420E-10 6,389502E-12 X0Y4 -4,314458E-10 6,387896E-11 7,876769E-12 X4Y1 -7,194006E-13 -4,543194E-13 -6,437071E-15 X2Y3 -4,478461E-13 1,142570E-13 -1,375378E-15 X0Y5 1,138804E-12 -6,022639E-14 -1,891046E-15 X6Y0 -1,28303E-15 2,858082E-16 2,228875E-18 X4Y2 2,442271E-16 4,112075E-16 3,778424E-18 X2Y4 1,716800E-15 2,211825E-15 7,769420E-18 X0Y6 2,541676E-16 -1,207319E-15 -4,170776E-18 X6Y1 -2,053124E-18 -1,521893E-18 -1,404687E-21 X4Y3 -4,285776E-18 -2,901432E-18 8,608287E-22 X2Y5 -7,194994E-18 -7,749856E-19 -2,167785E-21 X0Y7 -7,063491E-17 2,102735E-17 2,284904E-19 X8Y0 9,603618E-21 3,163459E-21 9,935851E-24 X6Y2 -1,750118E-20 2,367326E-21 2,777734E-24 X4Y4 -2,656909E-19 7,493162E-21 2,662434E-23 X2Y6 -3,507485E-19 -6,965078E-20 1,059265E-23 X0Y8 8,620342E-19 1,855049E-19 -1,109523E-22 X8Y1 -5,792688E-23 -1,370508E-23 -1,578812E-26 X6Y3 2,947075E-22 -8,172386E-24 7,869584E-27 X4Y5 1,807847E-21 2,254728E-23 -5,407399E-26 X2Y7 2,262648E-21 -1,251593E-22 -1,345021E-25 X0Y9 3,904436E-21 -3,698569E-22 -1,518706E-24 X10Y0 -3,278882E-25 -3,958171E-26 -5,353927E-29 X8Y2 1,535872E-25 1,971578E-26 -1,617273E-29 X6Y4 1,211072E-23 4,195583E-25 1,499145E-28 X4Y6 4,031669E-23 2,787547E-25 -1,004860E-28 X2Y8 3,959965E-23 2,283943E-24 -4,880794E-28 X0Y10 -9,139068E-23 -4,854296E-24 1,771578E-27 X10Y1 X8Y3 X6Y5 X4Y7 X2Y9 X0Y11 X12Y0 X10Y2 X8Y4 X6Y6 X4Y8 X2Y10 X0Y12 Table 2 to Fig. 4a decentration decentration decentration surface DCX DCY DCZ M6 0.000000 0.000000 0.000000 M5 0.000000 103.133127 0.000000 M4 0.000000 -75.203365 0.000000 M3 0.000000 474.965965 0.000000 Cover ( 23 ) 0.000000 486.510044 0.000000 M2 0.000000 518.846958 0.000000 M1 0.000000 967.515512 0.000000 object level 0.000000 1171.416856 0.000000 tilt tilt tilt surface TLA [deg] TLB [deg] TLC [deg] M6 -4.410445 0.000000 0.000000 M5 -7.414608 0.000000 0.000000 M4 -16.471381 0.000000 0.000000 M3 -12.157200 0.000000 0.000000 Cover ( 23 ) 0.000000 0.000000 0.000000 M2 -9.482077 0.000000 0.000000 M1 -7.437851 0.000000 0.000000 object level 0.000000 0.000000 0.000000 Table 3 to Fig. 4a

For the sake of simplicity, an iris acting in the x-direction is referred to below as an x-iris. Accordingly, a diaphragm acting in the y direction is referred to as a Y diaphragm. At the aperture 22 it may in particular be a Y-aperture. At the aperture 23 it may in particular be an X-aperture. Of course, these terms can also be reversed, for example, by an alternative definition of the x and y direction.

According to the in 5a illustrated optical design of the projection optics 7 , which, moreover, according to 2 corresponds, is the Y-aperture 22 in the region of the last mirror M ₆ in the beam path in front of the wafer 11 arranged. This preferably corresponds to a region which is at least approximately at the Y-pupil plane 17 is conjugated. Due to the small extent of the image field 8th on the wafer 11 and the large distance of the wafer-closest mirror M ₆ to the wafer 11 is half the extent of the image field 8th in the Y direction on the wafer 11 seen from the mirror apex of the mirror M ₆ less than 2 mrad. It varies in a good approximation linearly with the Y field coordinate. The main beam direction in the y-direction therefore varies to a good approximation linearly with the y-field coordinate by less than ± 2 mrad and therefore has, to a first approximation, the same angle as the telecentricity angle. The pictures of the subapertures 19 _{i of} the different pixels on M6 is an example of a wafer assumed to be telecentric in FIG 5b shown. For clarification are in the 5b the offset OFS in the X direction, the offset OFM in the Y direction, the diameter of the footprint in the Y direction DPM and the diameter of the footprint DPS in the X direction. For the telecentricity error T _{y of} the upper and lower field edge in the Y direction then applies to a first approximation

The same applies to the telecentricity error in the x direction

In the embodiment according to the 5a , ie when arranging the Y-aperture 22 on mirror M ₆ , is the telecentricity error in y-direction T _y by the size of the image field 8th on the wafer 11 and the distance of the mirror M ₆ to the wafer 11 given. He is neither influenced by the optical design, nor binds design degrees of freedom. On the other hand, the correction of the X-stop 23 on the mirror M _{2 associated} with the specific optical design.

In the 6a is another embodiment of the optical design of the projection optics 7 shown. In this embodiment, the Y-aperture is 22 arranged on the mirror M ₂ . The aperture 22 may be formed in particular as a radiation-absorbing coating on the mirror M ₂ . The Y-aperture is designed to match the in 6d exactly describes the footprint.

The optical design data of the projection optics 7 according to 6a are summarized in the following tables. The numerical aperture (NA), the object field height and the wavelength of the illumination radiation 3 are the same as the design according to the 2 , surface radius distance value operation mode Half diameter image plane 727.669955 13.0 M6 -814.130621 -669.554795 REFL 337.3 M5 -728.380731 1831.686066 REFL 88.5 M4 -1,559.927222 -884.934970 REFL 246.6 M3 -1,128.818508 400.116303 REFL 115.8 Cover ( 23 ) 493.808056 147.3 M2 -4,283.457265 -1,101.540655 REFL 173.3 M1 3306.575787 1402.767776 REFL 185.7 object level 0.000000 52.2 Table 1 to Fig. 6a Coeff. M6 M5 M4 RDY -814.130621 -728.380731 -1,559.927222 KY 0 0 0 RDX -814.130621 -728.380731 -1,559.927222 KX 0 0 0 X0Y0 -1,673113E-02 -4,272888E + 00 -2,000125E + 00 X0Y1 1,673113E-02 -2,393931E-03 6,667129E-04 X2Y0 3,681073E-05 4,481510E-04 -1,029364E-05 X0Y2 -3,209257E-05 -4,364770E-04 9,714116E-06 X2Y1 1,622805E-08 3,225401E-07 -8,001331E-09 X0Y3 5,901913E-10 1,914791E-06 -8,999112E-09 X4Y0 2,818707E-11 -5,125110E-10 -3,528481E-12 X2Y2 -2,687125E-1 -4,314332E-09 -3,998183E-12 X0Y4 -5,438518E-11 -1,750310E-10 -6,212469E-13 X4Y1 2,066080E-14 1,774660E-12 -3,221991E-15 X2Y3 3,066133E-14 1,874800E-11 -1,003169E-14 X0Y5 8,185261E-15 3,261737E-11 -1,190346E-15 X6Y0 1,424432E-17 -6,188484E-15 -2,092346E-18 X4Y2 -3,082709E-17 -2,038197E-14 -3,267871E-18 X2Y4 -1,155636E-16 -1,286108E-13 -1,612366E-17 X0Y6 -5,779209E-17 -6,229355E-14 -7,945613E-18 X6Y1 2,438403E-20 3,190541E-17 -1,786029E-21 X4Y3 7,407985E-20 5,500691E-17 -5,941258E-21 X2Y5 8,018527E-20 -6,744789E-17 -2,015597E-20 X0Y7 2,317347E-20 -2,638020E-15 4,178054E-20 X8Y0 2,212209E-25 2,232756E-20 -5,522385E-24 X6Y2 -5,316257E-23 -1,973432E-19 4,043549E-24 X4Y4 -2,329251E-22 -9,872451E-19 4,368680E-24 X2Y6 -2,427651E-22 -7,139562E-18 1,027670E-22 X0Y8 -1,356257E-22 -1,584545E-17 2,073633E-22 X8Y1 3,042160E-26 -2,141276E-22 -4,792776E-27 X6Y3 1,329756E-25 1,749098E-21 -1,810290E-27 X4Y5 1,814405E-25 1,343439E-20 5,608087E-26 X2Y7 7,310730E-26 7,113409E-20 4,859766E-25 X0Y9 -5,794201E-26 1,325964E-19 2,483280E-25 X10Y0 3,294181E-29 3,323160E-25 2,742055E-29 X8Y2 -1,932643E-29 -6,979067E-25 -3,126859E-29 X6Y4 -2,671118E-28 -1,024574E-23 -6,259933E-29 X4Y6 -7,495043E-28 -3,510045E-23 1,455146E-28 X2Y8 -6,043509E-28 6,388899E-22 6,357182E-28 X0Y10 -1,482420E-28 1,923850E-21 9,491052E-29 X10Y1 1,184298E-31 X8Y3 3,318655E-31 X6Y5 6,957835E-31 X4Y7 9,044659E-31 X2Y9 3,818890E-31 X0Y11 -6,545784E-32 X12Y0 8,47312E-35 X10Y2 -3,450061E-34 X8Y4 -2,414213E-33 X6Y6 -3,760643E-33 X4Y8 -2,433686E-33 X2Y10 -1,229971E-33 X0Y12 -3,567703E-34 Coeff. M3 M2 M1 RDY -1,128.818508 -4,283.457265 3306.575787 KY 0 0 0 RDX -1,128.818508 -4,283.457265 3306.575787 KX 0 0 0 X0Y0 -5,298413E + 00 -1,808890E ± 00 3,940692E + 00 X0Y1 4,657428E-03 1,576477E-03 -3,544141E-04 X2Y0 3,645700E-06 -5,992984E-05 -4,548502E-05 X0Y2 -5,462723E-05 3,912005E-05 4,174800E-05 X2Y1 -5,253480E-07 -1,128342E-07 -1,265470E-08 X0Y3 -4,244709E-07 -1,812507E-07 3,565664E-08 X4Y0 1,892324E-10 2,402586E-11 -8,373986E-12 X2Y2 -1,868924E-10 9,607260E-11 -1,100485E-11 X0Y4 -3,266643E-10 2,413307E-10 -3,821209E-11 X4Y1 -4,158307E-14 -1,059480E-13 -1,454366E-14 X2Y3 -1,675845E-12 -2,965619E-13 4,101708E-14 X0Y5 1,540167E-13 4,107891E-13 -8,422551E-16 X6Y0 -1,105055E-15 -8,766604E-17 -6,594290E-18 X4Y2 -1,389153E-15 1,187625E-16 -2,326885E-17 X2Y4 -5,161637E-15 -3,115539E-16 7,829564E-17 X0Y6 1,009327E-16 -2,748657E-15 -2,096379E-16 X6Y1 -1,847366E-18 -2,334647E-19 -2,617307E-20 X4Y3 -3,251473E-18 6,842739E-20 -6,537459E-20 X2Y5 -1,055915E-17 4,379469E-18 -1,369874E-19 X0Y7 5,805359E-17 2,524361E-18 -3,872376E-20 X8Y0 -9,798388E-21 1,279747E-22 -1,359479E-22 X6Y2 1,057207E-20 -1,053138E-22 -2,673529E-22 X4Y4 3,019790E-20 -2,789802E-21 -2,940176E-22 X2Y6 3,456115E-19 -3,684445E-21 1,016812E-21 X0Y8 5,050667E-19 4,380040E-20 1,285834E-21 X8Y1 -1,957796E-23 -1,514417E-26 -2,745896E-25 X6Y3 -5,606311E-23 5,063355E-25 1,115150E-25 X4Y5 5,075524E-22 2,227127E-24 3,702846E-25 X2Y7 3,072950E-21 -6,683744E-23 3,027456E-24 X0Y9 9,393104E-22 -1,362150E-22 -6,898276E-24 X10Y0 2,998921E-25 2,362676E-27 1,548766E-27 X8Y2 -2,183900E-25 2,230600E-27 1,825038E-27 X6Y4 -1,253595E-24 1,241245E-26 7,922050E-27 X4Y6 2,302918E-24 1,327427E-26 -4,233367E-27 X2Y8 8,149117E-24 1,127985E-25 -3,395609E-26 X0Y10 -5,893218E-25 -1,619457E-25 3,610140E-27 X10Y1 X8Y3 X6Y5 X4Y7 X2Y9 X0Y11 X12Y0 X10Y2 X8Y4 X6Y6 X4Y8 X2Y10 X0Y12 Table 2 to Fig. 6a decentration decentration decentration surface DCX DCY DCZ M6 0.000000 0.000000 0.000000 M5 0.000000 90.753373 0.000000 M4 0.000000 -50.213188 0.000000 M3 0.000000 399.285875 0.000000 ' Cover ( 23 ) 0.000000 390.966887 0.000000 M2 0.000000 365.831776 0.000000 M1 0.000000 793.611806 0.000000 object level 0.000000 962.203665 0.000000 tilt tilt tilt surface TLA [deg] TLB [deg] TLC [deg] M6 -3.875190 0.000000 0.000000 M5 -6.184949 0.000000 0.000000 M4 -15.600540 0.000000 0.000000 M3 -14.062223 0.000000 0.000000 Cover ( 23 ) 0.000000 0.000000 0.000000 M2 -11.334714 0.000000 0.000000 M1 -7.053358 0.000000 0.000000 object level 0.000000 0.000000 0.000000 Table 3 to Fig. 6a

The X-aperture 23 is disposed between the mirrors M ₂ and M ₃ . In this embodiment, the X-stop is 23 formed so that it acts exclusively on the edges of the beam of rays perpendicular to the plane (ie in the x direction) between M ₂ and M ₃ . This takes into account the fact that the beam path in this area is not fully accessible on the periphery. This is exemplary in the 6b representing the images of the subapertures 19 _i in a sectional plane along the line VI-VI in 6a reproduces. How to get the 6b can be removed, the beam path overlaps with itself several times. In the 6c is an excerpt from the 6b shown, which in particular the images of Subaperturen 19 _i in the region of the beam path between the mirrors M ₂ and M ₃ reproduces. Moreover, in the 6c a possible formation of the X-aperture 23 shown. It acts only on the edges of the ray bundle between the mirrors M ₂ and M ₃ in the x direction. In particular, it acts in each case in an azimuth range of about 60 ° about the x-direction and opposite shorter. In other words, the aperture indicates 23 in this embodiment, a partially borderless passage area. In other words, the footprints in this design are in the x-iris plane 18 not completely circumscribed. Jump points in the effective pupil vignetting as a combination of the aperture in the y and x direction 22 . 23 are accepted. The passage region is designed to be borderless, in particular in the direction perpendicular to the diaphragm direction. It is in particular in an angular range of at least 30 °, in particular at least 45 °, in particular at least 60 ° formed by a direction perpendicular to the aperture direction borderless.

Generally, one of the apertures 22 . 23 directly on one of the mirrors M _i , in particular as a radiation-absorbing coating, be arranged on this. You can also go through the contour of one of the mirrors M _{i be} given. The irises 22 . 23 may also be each formed as a separate radiopaque, in particular radiation-absorbing elements. They can be arranged directly on one of the mirrors M _i . In particular, they can be mechanically connected to a substrate of one of the mirrors M _i . They can also be arranged as a separate element in the region between two adjacent mirrors M _i .

According to another, in the 7a illustrated embodiment of the projection optics 7 is the X-aperture 23 arranged on the mirror M ₃ . The Y-aperture 22 is arranged on the mirror M ₂ . The irises 22 . 23 are thus arranged on mirrors M _i adjacent to the beam path. This is possible if the astigmatism in the image of the entrance pupil is sufficiently large, or adjacent mirrors M _{i are} sufficiently close to one another.

The optical design data of the projection optics 7 according to 7a are summarized in the following tables. The numerical aperture (NA), the object field height and the wavelength of the illumination radiation 3 are the same as the design according to the 2 , surface radius distance value operation mode Half diameter image plane 743.766065 13.0 M6 -806.920085 -668.350267 REFL 347.1 M5 -577.279412 1724.444434 REFL 85.4 M4 -1,709.824357 -1,250.256739 REFL 148.1 M3 -1,159.607532 1003.321636 REFL 82.0 M2 -3,095.603883 -1,081.959918 REFL 232.9 M1 3784.972679 1653.204121 REFL 243.0 object level 0.000000 52.2 Table 1 to Fig. 7a Coeff. M6 M5 M4 RDY -806.920085 -577.279412 -1,709.824357 KY 0 0 0 RDX -806.920085 -577.279412 -1,709.824357 KX 0 0 0 X0Y0 4,084782E-05 -5,003033E-05 -1,206498E-05 X0Y1 -6,234607E-06 1,368931E-05 -2,910665E-05 X2Y0 7,191750E-06 1,902694E-04 -2,328265E-05 X0Y2 -1,711942E-06 -1,495379E-04 2,626027E-05 X2Y1 -1,006561E-08 -9,865848E-07 -7,850949E-09 X0Y3 4,741798E-09 -9,377605E-08 4,811461E-09 X4Y0 -9,009084E-12 -2,349454E-09 -1,008834E-11 X2Y2 -2,879845E-11 -8,215593E-09 -8,498137E-14 X0Y4 -2,122084E-11 -6,447272E-09 5,467140E-13 X4Y1 -1,393952E-14 -8,672047E-12 -6,299827E-15 X2Y3 -5,085691E-15 -1,188497E-11 -4,655946E-15 X0Y5 1,976480E-15 9,160524E-13 5,371864E-14 X6Y0 -1,895330E-17 -2,328367E-14 -4,240086E-18 X4Y2 -7,392086E-17 -9,448825E-14 -1,086551E-17 X2Y4 -9,567460E-17 -1,398817E-13 -9,773673E-17 X0Y6 -3,390607E-17 -6,866177E-14 -7,273479E-16 X6Y1 -2,314778E-20 -6,879790E-17 -7,072692E-21 X4Y3 -3,047116E-20 -2,728988E-16 -1,060288E-20 X2Y5 -6,983341E-21 -1,330413E-16 -4,893117E-19 X0Y7 7,730906E-21 2,573119E-16 -2,481600E-18 X8Y0 -3,896900E-23 -8,145168E-20 4,424314E-24 X6Y2 -1,616023E-22 -1,504286E-18 3,922959E-23 X4Y4 -2,871796E-22 -3,223023E-18 7,373005E-22 X2Y6 -2,062572E-22 -2,294023E-18 1,209179E-20 X0Y8 -6,097481E-23 -8,633330E-19 8,635429E-20 X8Y1 -1,822435E-26 -3,640522E-21 5,178012E-27 X6Y3 -5,906480E-26 -1,241683E-20 -4,014823E-25 X4Y5 -2,930996E-26 -9,414047E-21 1,978354E-24 X2Y7 6,582041E-27 -3,562625E-21 3,558543E-23 X0Y9 8,403446E-27 -7,439837E-21 -6,231819E-23 X10Y0 -3,615769E-29 -7,879185E-24 -3,772362E-29 X8Y2 -2,150817E-28 -3,775240E-23 -7,488879E-28 X6Y4 -4,457406E-28 -9,443693E-23 -1,263762E-26 X4Y6 5,188981E-28 -1,332391E-22 -2,844580E-26 X2Y8 -2,867467E-28 -1,084768E-22 -6,145893E-25 X0Y10 -8,103617E-29 -1,422544E-22 -3,312563E-24 X10Y1 -8,154012E-32 X8Y3 -2,790619E-31 X6Y5 -3,271652E-31 X4Y7 -1,551011E-31 X2Y9 8,389868E-33 X0Y11 -1,063616E-32 X12Y0 -1,555719E-34 X10Y2 -1,066287E-33 X8Y4 -3,102501E-33 X6Y6 -4,480920E-33 X4Y8 -3,478544E-33 X2Y10 -1,468010E-33 X0Y12 -2,533160E-34 Coeff. M3 M2 M1 RDY -1,159.607532 -3,095.603883 3784.972679 KY 0 0 0 RDX -1,159.607532 -3,095.603883 3784.972679 KX 0 0 0 X0Y0 -3,468089E-03 9,273329E-05 -8,782289E-05 X0Y1 2,036473E-03 -4,057654E-05 1,487482E-05 X2Y0 -1,380178E-04 -1,445189E-05 -3,069350E-07 X0Y2 1,222305E-04 1,922180E-05 1,242420E-05 X2Y1 -4,377699E-08 -7,064962E-08 -5,452762E-08 X0Y3 -1,657950E-07 -2,889281E-08 -7,383051E-09 X4Y0 -7,962108E-10 2,191198E-11 3,870952E-12 X2Y2 1,810764E-10 1,893253E-11 -1,159922E-11 X0Y4 -1,386637E-10 9,362683E-12 1,207732E-11 X4Y1 1,400876E-12 -4,028354E-14 -1,616909E-14 X2Y3 -7,345956E-13 -3,532403E-15 -7,438147E-16 X0Y5 5,235916E-13 -1,449675E-14 1,113430E-14 X6Y0 5,688239E-15 8,274526E-18 1,482541E-18 X4Y2 8,008347E-15 1,691057E-17 -3,283332E-18 X2Y4 -7,171436E-15 3,745135E-17 1,437792E-17 X0Y6 -2,194164E-15 -1,027908E-16 -4,890830E-17 X6Y1 1,309202E-16 -3,775309E-20 -1,236192E-20 X4Y3 5,826556E-17 -2,398979E-20 -4,704105E-22 X2Y5 1,575480E-17 4,774309E-20 2,968446E-21 X0Y7 -3,140698E-17 7,393155E-20 1,123002E-19 X8Y0 -6,692472E-19 2,940612E-23 1,213175E-23 X6Y2 2,195539E-19 -1,857890E-24 -2,730648E-23 X4Y4 7,254175E-20 7,004868E-23 4,308402E-23 X2Y6 5,013892E-19 -4,384569E-23 1,349001E-22 X0Y8 2,925552E-19 1,422081E-21 6,109805E-22 X8Y1 -2,447562E-21 8,666931E-26 3,880481E-26 X6Y3 -6,560365E-22 1,937245E-25 5,900414E-26 X4Y5 -3,611257E-21 -2,069965E-25 -1,500486E-25 X2Y7 -1,710920E-21 -1,325431E-24 6,629223E-26 X0Y9 2,080452E-22 -1,072282E-24 -1,098385E-24 X10Y0 1,706747E-23 -1,283092E-28 -6,358988E-29 X8Y2 8,889490E-25 -2,695754E-28 3,599661E-29 X6Y4 -1,176154E-23 -2,190951E-28 -7,491636E-30 X4Y6 -3,961270E-23 -8,200817E-28 -8,841395E-28 X2Y8 -2,598224E-23 7,217805E-28 -2,518854E-27 X0Y10 -1,026854E-23 -3,473657E-27 4,428111E-28 X10Y1 X8Y3 X6Y5 X4Y7 X2Y9 X0Y11 X12Y0 X10Y2 X8Y4 X6Y6 X4Y8 X2Y10 X0Y12 Table 2 to Fig. 7a decentration decentration decentration surface DCX DCY DCZ M6 0.000000 0.000000 0.000000 M5 0.000000 113.692018 0.000000 M4 0.000000 -79.722954 0.000000 M3 0.000000 541.181036 0.000000 M2 0.000000 510.747831 0.000000 M1 0.000000 917.341170 0.000000 object level 0.000000 1117.176867 0.000000 tilt tilt tilt surface TLA [deg] TLB [deg] TLC [deg] M6 -4.827633 0.000000 0.000000 M5 -8.027587 0.000000 0.000000 M4 -16.472945 0.000000 0.000000 M3 -14.233690 0.000000 0.000000 M2 -11.260893 0.000000 0.000000 M1 -6.850557 0.000000 0.000000 object level 0.000000 0.000000 0.000000 Table 3 to Fig. 7a

Another, in the 8a option shown is the Y-aperture 22 on the mirror M ₂ and the X-aperture 23 at the pupil level 25 between the mirrors M ₅ and M ₆ to arrange. The pupil level 25 in this case forms an X-diaphragm plane 18 , It is also possible, the Y-aperture 22 to arrange on the mirror M ₃ . The relevant footprints of the optical design are in the 8b to 8d or superimposed in the 8e shown. In 8b is the footprint of the beam path between the wafer 11 and the mirror M ₆ shown. In the 8c that of the beam path between the mirrors M ₅ and M ₆ together with the diaphragm 23 , The aperture 23 includes the footprint in the peripherally accessible area as much as possible. It covers the footprint in an angular range of about 270 °. Generally, the apertures include 22 . 23 the respective footprints in their peripherally accessible area as far as possible. They comprise the footprints on the circumference in an angular range of at least 90 °, in particular at least 180 °, in particular at least 210 °, in particular at least 240 °, preferably at least 270 °. In 8d the beam path between the mirror M ₅ and a passage opening 24 in the mirror M ₆ .

The optical design data of the projection optics 7 correspond to those of the projection optics 7 according to 2 ,

Generally it is possible the irises 22 . 23 in the two different, halves of the beam path of the projection optics 7 to arrange. It is possible in other words, the one of the apertures 22 . 23 along the beam path closer to the object field 4 and the other of the panels 23 . 22 along the beam path closer to the image field 8th to arrange. In this case, it is provided in particular, the Y-aperture 22 in the direction of the beam path closer to the object field 4 and the X-aperture 23 in the direction of the beam path closer to the image field 8th to arrange, if in the beam path between the two diaphragm levels 17 . 18 no intermediate image is located. Is, however, between the two aperture levels 17 . 18 an intermediate image is provided, the Y-aperture 22 closer to the image field 8th and the X-aperture 23 closer to the object field 4 to arrange.

From the 8c it is immediately apparent that the footprint is in the immediate vicinity of an X-diaphragm plane. In other words, this is a suitable position for the arrangement of the X-stop 23 , From the 8e is also apparent that this X-aperture 23 in the air space between the wafer 11 and the mirror M ₆ can be realized mechanically in a simple manner. The arrangement of a corresponding Y-aperture 22 is not possible in this area for reasons of optical overlap.

Generally, at least one of the apertures 22 . 23 be arranged in the beam path so that its passage area is traversed by the beam path exactly once. It can also both screens 22 . 23 be arranged in the beam path so that their passage area from the beam path is traversed exactly once.

In all of the described embodiments, the apertures 22 . 23 also have obscuration to hide a central portion of the beam path. The obscuration elements are in this case preferably designed for defined obscuration of the beam path in the corresponding diaphragm direction.

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 11 or, the wafer provided. Subsequently, a structure on the reticle 10 on a photosensitive layer of the wafer 11 with the help of the projection exposure system 1 projected. By developing the photosensitive layer, a micro or nanostructure is then formed on the wafer 11 and thus the microstructured component, in particular a microchip produced.

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

• US 6396067 B1 [0002]
• JP 2004/246343 [0002]
• JP 2005/86148 [0002]
• WO 2007/03127 A1 [0030]
• DE 102011083888 [0049]
• WO 2007/031271 A1 [0054]

Claims (14)

Projection optics ( 7 ) for mapping an object field ( 4 ) in an object plane ( 5 ) in an image field ( 8th ) in an image plane ( 9 ) comprising a. a plurality of beam-guiding optical elements (M _i ) for guiding imaging radiation ( 3 ) along an optical path, wherein at least one pair of first and second pupil shells ( 17 . 18 ) of a pupil of the projection optics ( 7 ), i. each of the pupil shells ( 17 . 18 ) contains in each case all pixels of the rays of the pupil with one of two mutually perpendicular sectional planes, and ii. the pupil shells ( 17 . 18 ) of a pair in the direction of the beam path have a distance d, where 0 <d _min ≦ d ≦ d _max , b. a first aperture device ( 22 ) for specifying outer boundaries of a pupil of the projection optics ( 7 ) with respect to a first diaphragm direction, i. wherein the first aperture device ( 22 ) one of the first pupil shells ( 17 ) and is arranged in the direction of the beam path at a distance of at most d _min / 2 thereto, and c. a second aperture device ( 23 ) for specifying outer boundaries of a pupil of the projection optics ( 7 ) with respect to a second diaphragm direction, i. wherein the second aperture device ( 23 ) one of the second pupil shells ( 18 ) and is arranged in the direction of the beam path at a distance of at most d _min / 2 to this, d. wherein the diaphragm direction in each case parallel to that of the associated pupil shells ( 17 . 18 ) is part of the cutting plane. Projection optics ( 7 ) according to claim 1, characterized in that the two directions with respect to which the diaphragm devices ( 22 . 23 ) Specify outer boundaries of a pupil, in a projection in the direction of the beam path in the image plane ( 9 ) parallel to a scanning direction or perpendicular thereto. Projection optics ( 7 ) according to one of the preceding claims, characterized in that at least one of the diaphragm devices ( 22 . 23 ) is arranged directly on one of the optical elements (M _i ). Projection optics ( 7 ) according to one of the preceding claims, characterized in that one of the diaphragm devices ( 22 . 23 ) is arranged on the last beam guiding element (M ₆ ) in the beam path. Projection optics ( 7 ) according to one of the preceding claims, characterized in that the diaphragm devices ( 22 . 23 ) are arranged on in the beam path successive beam-guiding elements (M _i , M _{i + 1} ). Projection optics ( 7 ) according to one of claims 1 to 4, characterized in that at least one of the diaphragm devices ( 22 . 23 ) is arranged between two successive in the projection direction optical elements (M _i , M _{i + 1} ), spaced therefrom. Projection optics ( 7 ) according to claim 6, characterized in that at least one of the shutter devices ( 22 . 23 ) is arranged in the beam path such that its passage area is traversed by the beam path exactly once. Projection optics ( 7 ) according to one of the preceding claims, characterized in that the diaphragm devices ( 22 . 23 ) are arranged at positions in the projection direction such that the one diaphragm device ( 22 . 23 ) along the beam path closer to the object field ( 4 ) and the other aperture device ( 23 . 22 ) along the beam path closer to the image field ( 8th ) is arranged. Projection optics ( 7 ) according to one of the preceding claims, characterized in that at least one of the diaphragm devices ( 22 . 23 ) has a sectionless borderless passband. Projection optics ( 7 ) according to one of the preceding claims, characterized in that at least one of the diaphragm devices ( 22 . 23 ) comprises an obscuration element. Projection optics ( 7 ) according to one of the preceding claims, characterized by a catoptric design. Projection optics ( 7 ) according to one of the preceding claims, characterized in that at least one of the optical elements (M _i ) has a free-form surface. Projection exposure apparatus ( 1 ) for microlithography with projection optics ( 7 ) according to one of the preceding claims. Method for producing a microstructured or nanostructured component comprising the following steps: - providing a projection exposure apparatus ( 1 ) according to claim 13, - providing a reticle ( 10 ) and a wafer ( 11 ), - projecting a structure on the reticle ( 10 ) on a photosensitive layer of the wafer ( 11 ) using the projection exposure apparatus ( 1 ).

Images