Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70058—Mask illumination systems
  • G03F7/70091—Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70058—Mask illumination systems
  • G03F7/70075—Homogenization of illumination intensity in the mask plane by using an integrator, e.g. fly's eye lens, facet mirror or glass rod, by using a diffusing optical element or by beam deflection
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70058—Mask illumination systems
  • G03F7/70083—Non-homogeneous intensity distribution in the mask plane
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70058—Mask illumination systems
  • G03F7/70091—Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
  • G03F7/70116—Off-axis setting using a programmable means, e.g. liquid crystal display [LCD], digital micromirror device [DMD] or pupil facets

Definitions

• Illumination optical system for microlithography and projection exposure system with an illumination optical system of this type is provided.
• German patent application DE 10 2010 030 089.6 and US- Provisional patent application US 61/354 772 is incorporated by reference.
• the invention relates to an illumination optical system for
• microlithography for guiding illumination light from a primary light source to an object field.
• the invention further relates to an optical system with an illumination optical system of this type and a projection optical system for imaging the object field in an image field.
• the invention relates to a microlithography projection exposure system with an optical system of this type and a primary light source, a microlithographic production method for microstructured or nanostructured components and a component produced by a method of this type.
• Illumination optical systems of the type mentioned at the outset are known from WO 2007/093433 Al and EP 1 262 836 Al .
• An object of the present invention is to develop an illumination optical system of the type mentioned at the outset in such a way that the illumination intensity over the object field can be influenced in a targeted or desired manner with respect to the total illumination intensity and/or with regard to the intensity amounts from different illumination directions.
• an illumination system having the features disclosed in claim 1.
• the invention makes use of the knowledge that, in practice, a dependency is generally present of an emergent angle of the illumination light part bundles leaving the raster module on the angles of incidence of the illumination light part bundles which enter the raster module.
• the raster module depending on the respective actual angle of incidence on the raster element, produces a different intensity course of an illumination from an illumination angle, which corresponds to this raster element, over the object field.
• This dependency was hitherto only evaluated as a disruptive effect.
• This dependency is now used in a targeted manner to provide additional degrees of freedom in a design of a desired course of
• illumination angle intensity distributions over the object field in other words, in particular, a field-dependent optical effect of the illumination optical system on the illumination angles produced.
• This predetermined desired course generally varies over the position of the object field.
• the specification or predetermined allocation of an actual tilting angle for each individual mirror by the controller depending on the intended desired intensity course in the pupil plane of the illumination system and depending on the predetermined desired course of illumination angle intensity distributions over the field leads to the fact that both a
• the controller may be configured in such a way that a first illumination setting, in other words a first illumination angle characteristic results, for example at one of the edges of the object field perpendicular to a displacement direction of an object to be illuminated, in other words, for example, perpendicular to a scanning direction of a projection exposure system, in which the illumination optical system can be used, and, at the opposing edge of the object field, a second illumination setting, which is different therefrom, results.
• a first illumination setting in other words a first illumination angle characteristic results, for example at one of the edges of the object field perpendicular to a displacement direction of an object to be illuminated, in other words, for example, perpendicular to a scanning direction of a projection exposure system, in which the illumination optical system can be used, and, at the opposing edge of the object field, a second illumination setting, which is different therefrom, results.
• Objects to be imaged arranged in the object field can then be imaged with illumination angles between these field edges of different design of the structures to be imaged with high precision and adapted to the respective structural design.
• An illumination setting can be achieved by impingement of the raster module by means of the mirror array with a specific local intensity distribution.
• one and the same intensity distribution of the impingement of the raster module can then be produced with different entry angle distributions of the illumination light part bundles on the raster module, in other words with different predetermined distributions of actual tilting angles of the individual mirrors or different allocations of the actual tilting angles to the individual mirrors, as a change in the allocation of the individual illumination light part bundles to the raster elements of the raster module can be ensured by means of a corresponding tilting of the individual mirrors.
• the illumination optical system according to the invention can make use of the aberrations of spherical surfaces of light-guiding raster elements of the raster arrangements of the raster module. A desired variation of the illumination angle characteristic over the object field can therefore be produced by the respectively selected entry angle distribution of the illumination light part bundles on the raster module by
• the predetermined distribution or desired distribution of actual tilting angles of the individual mirrors which are allocated by the controller to the predetermined desired course of the illumination angle intensity distributions, is a distribution of tilting angles to the individual mirrors. The result of this desired
• the raster module according to claim 2 increases a dependency of the emergent angles of the illumination light part bundles, proceeding from the raster module, on the respective angles of incidence of the illumination light part bundles toward the raster module.
• the first raster arrangement of a raster module according to claim 3 may have raster elements, which are imaged overlapping one another in the object field.
• the second raster arrangement may produce an emergent angle distribution of the illumination light part bundles, which is directly correlated to a location distribution on the object field.
• a size ratio of a diameter of the illumination light part bundle to the total entry or impingement face of the raster element of the second raster arrangement according to claim 4 leads to correspondingly large freedoms during a different bundle influencing of the illumination light part bundles impinging on this raster element at various locations.
• a size ratio of this type provides the possibility of a strong field-dependent optical effect of the illumination optical system on the illumination angles produced.
• a configuration according to claim 5 can be designed to keep constant, in particular those emergent angles defining field edges of the object field.
• Configurations according to claims 6 and 7 allow a specification of field dependencies of illumination intensities from specific illumination angles.
• the predetermined desired course of illumination angle intensity distributions is extended to the two dimensions of the object field. This can be used, in particular, when the total object field is imaged simultaneously, in other words not by a scanning method.
• Production methods according to claims 10 and 1 1 allow a utilisation adapted to the respective boundary conditions of the possible dependencies between the angles of incidence and the impingement locations, on the one hand, and the emergent angles, on the other hand.
• Fig. 1 schematically shows a meridional section through an illumination system according to the invention within a microlithography projection exposure system with an illumination optical system with a mirror array with tilting actuators activated by a controller and a raster module with a two-stage raster arrangement;
• Fig. 2 shows a detail of the illumination optical system
• Fig. 3 and 4 show two variants of an illumination of the raster
• Fig. 5 in each case schematically shows the field dependency of an illumination light intensity from four excellent illumination directions, shown by intensity spots in the pupil plane; shows, in an enlarged manner, a raster element of the first raster arrangement of the raster module and an associated raster element of the second raster arrangement of the raster module and a bundle course of the illumination light part bundle guided by these two raster elements at a first angle of incidence of the illumination light part bundle on the first raster element; show views similar to Fig. 6 of the two raster elements and the illumination light part bundle at further angles of incidence of the illumination light part bundle on the first raster element; shows, in a graph, isolines for those pairs of
• Fig. 9 shows a graph similar to Fig. 9, which additionally shows an isoline for the pair of parameters (angle of incidence; impingement location) for a third emergent angle defining the field centre;
• Fig. 1 1 and 12 show graphs similar to Fig. 10, which show different courses of the isoline for the pair of parameters of the emergent angle defining the field centre;
• Fig. 13 shows an example of a curvature course of an entry face of a raster element of the second raster
• Fig. 14 to 16 show dependencies of an intensity distribution in an object plane of the illumination optical system on a given illumination of the raster module with
• the raster module having a second raster arrangement with raster elements with entry faces formed according to Fig. 13;
• Fig. 17 shows in a view similar to Fig. 2 a detail of the
• Fig. 18 to 20 in views similar to Fig. 3 and 4, show three variants of an illumination of the raster module with illumination light part bundles which are deflected by individual mirrors of the mirror array and in each case lead to the same illumination light intensity distribution in the illumination plane of the raster module, which may coincide with the pupil plane of the illumination optical system, a refractive effect of the Fourier lens arrangement in turn being shown.
• Fig. 1 schematically shows a microlithography projection exposure system 1 , which is designed as a wafer scanner and is used in the production of semiconductor assembly parts and other finely structured components.
• the projection exposure system 1 works to achieve resolutions to fractions of micrometres with light, in particular from the deep ultraviolet range (DUV or VUV).
• DUV deep ultraviolet range
• a Cartesian xyz coordinate system is reproduced in the drawing.
• the x-direction runs upwardly in Fig. 1.
• the y-direction runs perpendicular to the plane of the drawing in Fig. 1 and out of it.
• the z-direction runs to the right in Fig. 1.
• a scanning direction of the projection exposure system 1 runs in the y- direction, in other words perpendicular to the plane of the drawing in Fig. 1.
• the plurality of optical components of the projection exposure system 1 is arranged in a row along an optical axis 2 running in the z-direction. It is obvious that convolutions of the optical axis 2 other than shown in Fig. 1 are possible, in particular in order to make the projection exposure system 1 compact.
• An illumination system designated as a whole by 5 of the projection exposure system 1 is used for the defined illumination of an object or illumination field 3 in an object or reticle plane 4, in which a structure to be transferred in the form of a reticle, not shown in more detail, is arranged.
• the illumination system 5 comprises a primary light source 6 and an illumination optical system 7 with the optical components for guiding illumination or imaging light 8 to the object field 3.
• the primary light source 6 is an ArF laser with a working wavelength of 193 nm, the illumination light beam of which is oriented coaxially with respect to the optical axis 2.
• Other UV light sources for example an F 2 excimer laser with a 157 nm working wavelength, a KrF excimer laser with a 248 nm working wavelength and primary light sources with larger or smaller working wavelengths are also possible.
• the beam widening optical system 9 may contain elements which reduce undesired effects of the coherence of the illumination light 8.
• the illumination light 8 substantially parallelised by the beam widening optical system 7 then impinges on a micro mirror array (Multi Mirror Array, MMA) 10 to produce an illumination light angle distribution.
• the micro mirror array 10 has a large number of rectangular individual mirrors 1 1 arranged in an xy- raster. Each of the individual mirrors 1 1 is connected to an associated tilting actuator 12.
• Each of the tilting actuators 12 is connected by a control line 13 to a controller 14 to activate the actuators 12.
• the actuators 12 can be actuated independently of one another by the controller 14.
• Each of the actuators 12 can adjust a predetermined x-tilting angle (tilting in the xz- plane) and, independently thereof, a y-tilting angle (tilting in the yz-plane) of the individual mirror 1 1 , so that an angle of reflection AS X of an illumination light part bundle 15 reflected by the associated individual mirror 1 1 can be predetermined in the xz-plane and, accordingly, an angle of reflection AS y , not shown in the drawing, can be predetermined in the yz-plane.
• the angle distribution produced by the MMA 10 of angles of reflection AS of the illumination light part bundles 15 is transformed when passing through a Fourier lens arrangement or a capacitor 16, which is positioned at the spacing of its focal length from the MMA 10, into a two-dimensional, location-dependent illumination light intensity thus distribution
• the intensity distribution thus produced is therefore present in a first illumination plane 17 of the illumination system 5.
• the MMA 10 is thus a light distribution device to produce a two-dimensional illumination light intensity distribution.
• a first raster arrangement 18 of a raster module 19 Arranged in the region of the first illumination plane 17 is a first raster arrangement 18 of a raster module 19, which is also called a honeycomb capacitor.
• Angles of incidence E X in the xz-plane (cf Fig. 1) and ER y in the yz-plane (not shown in the drawing) of the illumination light 8 on the raster module 19 are correlated to the angles of reflection AS X (cf Fig. 1), AS y (not shown in the drawing) of the illumination light part bundles 15 from the MMA 10 and/or the location, from which the respective illumination light part bundle 15 is emitted from the MMA 10, in other words the respective individual mirror 1 1.
• AS X cf Fig. 1
• AS y not shown in the drawing
• the impingement locations of the illumination light part bundles 15 on the first raster arrangement 18 are directly correlated to the angles of reflection AS X , AS y of the illumination light part bundles 15 from the MMA 10, as on the raster arrangement 18, the angles of reflection are AS X and AS y , as the Fourier lens arrangement 16 approximately leads to a conversion of angles into location coordinates.
• the angles of incidence ER X , ER y of the illumination light part bundles 15 on the raster module 19 are directly correlated with the positions of the illumination light part bundles 15 on the MMA 10, in other words with the individual mirror 1 1, from which the respective illumination light part bundle 15 is emitted, as both the use of a Fourier lens arrangement 16 and the use of a capacitor 16 leads to a conversion of location coordinates into angles.
• the raster module 19 is used to produce a spatially distributed arrangement of secondary light sources, in other words of images of the primary light source 6 and therefore to the production of a defined illumination angle distribution of the illumination light leaving the raster module 19.
• a second raster arrangement 21 is arranged in a further illumination plane 20.
• the illumination plane 17 is in or close to a front focal plane of individual elements of the second raster arrangement 21.
• the two raster arrangements 18, 21 are a honeycomb capacitor of the illumination optical system 7.
• the further illumination plane 20 is a pupil plane of the illumination system 5 or is adjacent to a pupil plane of the illumination system 5.
• the raster module 19 is therefore also designated the field- defining element (FDE).
• illumination light part bundle 15 impinges on the object field 3.
• a further capacitor 22 Arranged downstream of the raster module 19 is a further capacitor 22, which is also called a field lens. Together with the second raster arrangement 21 , the capacitor 22 images the first illumination plane 17 in a field intermediate plane 23 of the illumination system 5.
• a reticle marking system (EMA) 24 which is used as an adjustable shading mask to produce a sharp edge of the illumination light intensity distribution, may be arranged in the field intermediate plane 23.
• a following lens system 25 images the field intermediate plane 23 on the reticle, in other words, the lithography master, which is located in the reticle plane 4.
• the reticle plane 4 is imaged on a wafer or image plane 27 on the wafer, not shown in Fig. 1 , which is intermittently or continuously displaced in the scanning direction (y).
• the first raster arrangement 18 has individual first raster elements 28, which are arranged column-wise and line -wise in the xy-plane.
• the first raster elements 28 have a rectangular aperture with an x/y aspect ratio of, for example, 1/1. Other, in particular greater x/y-aspect ratios of the first raster elements 28, for example 2/1, are possible.
• the meridional section according to Fig. 1 runs along a raster column.
• the first raster elements 28 are configured as microlenses, for example with a positive refractive power.
• the first raster elements 28 are arranged directly adjacent to one another in a raster corresponding to their rectangular shape, in other words, substantially filling the area.
• the first raster elements 28 are also called field honeycombs.
• the raster construction and the function of the raster module 19 basically correspond to that which is described in WO2007/093433 Al .
• Fig. 2 illustrates a course of two illumination light part bundles 15 1 and 15 2 from the MMA 10 to the second raster arrangement 21 of the raster module 19.
• a central angle of reflection, angle of incidence or emergent angle of the respective illumination light part bundle 15 is always shown.
• Angles of reflection AS X of two illumination light part bundles 15 from the MMA 10, an angle of incidence ER X of one of the two illumination light part bundles 15 on the second raster arrangement 21 (the corresponding central angle of incidence of the other illumination light part bundle is zero) and emergent angles AR X of the illumination light part bundles 15 from the raster module 19 are shown by way of example in Fig. 2.
• No refractive effect of the Fourier lens arrangement 16 is shown in a simplified manner in Fig. 2.
• a refractive effect of this type is present, such that an angle of reflection AS X of the illumination light part bundles 15 from the MMA 10 does not coincide with the respective angle of incidence ER X of the illumination light part bundles 15 on the first raster arrangement 18.
• the refractive effect of the Fourier lens arrangement 16 a correlation of the angle of reflection AS X of the respective illumination light part bundle 15 from the MMA 10 and of the location, from which the respective illumination light part bundle 15 is emitted from the MMA 10, to the angle of incidence ER X of the same illumination light part bundle 15 on the first raster arrangement 18 is provided.
• the illumination light part bundle 15 1 shown at the top in Fig. 2 is guided from the individual mirror 1 11 of the MMA 10 shown right at the top in Fig. 2 at an angle of reflection AS x i via the Fourier lens arrangement or the capacitor 16 to the first raster element 28, shown as second from the top, of the first raster arrangement 18 of the raster module 19.
• the illumination light part bundle 15 1 impinges at an angle of incidence on the first raster arrangement 18, which is only the same as the angle of reflection AS x i in the view of Fig. 2 disregarding the refractive effect of the Fourier lens arrangement 16.
• the illumination light part bundle 15 1 After passing through this first raster arrangement 28, the illumination light part bundle 15 1 impinges on a first location region 29 of a second raster element 30 of the second raster arrangement 21.
• This first location region 29 corresponds to the diameter of the illumination light part bundle 15 1 impinging on the second raster element 30 and predetermines a first impingement location for illumination light on the second raster element 30.
• the second raster elements 30 of the second raster arrangement 21, in each case allocated to the channels, are arranged in the light path behind the first raster elements 28 of the first raster arrangement 18.
• the second raster elements 30 are also configured as microlenses with, in particular, a positive refractive power.
• the second raster elements 30 are also called pupil honeycombs, which are arranged in the second illumination plane 20, in other words in a pupil plane of the illumination optical system 7.
• the second illumination plane 20 is conjugated to a pupil plane 31 of the projection lens system 26.
• the images of the first raster elements 28 are thus superimposed in the field intermediate plane 23.
• Fig. 1 shows the raster elements 28, 30 schematically as plano-convex lenses.
• the raster elements 28, 30 are also schematically shown as biconvex lenses.
• the second illumination light part bundle 15 2 shown in Fig. 2 is guided from the individual mirror 1 1 2 of the MMA 10, shown as the second from the bottom, to the same first raster element 28 as the first illumination light part bundle 15 1 shown in Fig. 2.
• An angle of reflection AS x2 of the illumination light part bundle 15 2 from the individual mirror 1 1 2 has the opposite sign to the angle of reflection AS x i of the illumination light part bundle 15 1 in the view according to Fig. 2 disregarding the refractive effect of the Fourier lens arrangement 16.
• the angle of reflection AS x2 of the illumination light part bundle 15 2 from the individual mirror 1 1 2 may be approximately identical to the angle of reflection AS x i of the illumination light part bundle 15 1 if these impinge upon the same raster element 28 of the first raster arrangement 18. Because of the fact that the illumination light part bundles 15 l 5 15 2 are emitted from different locations from the MMA 10, in other words from different individual mirrors 1 1 , and therefore impinge at different locations on the Fourier lens arrangement 16, a difference is then nevertheless produced between the two angles of incidence of the illumination light part bundles 15i, 15 2 on the first raster arrangement 18. This situation, in which the same angles of incidence of various illumination light part bundles 15 l 5 15 2 are transferred to the Fourier lens arrangement 16 at different emergent angles, is not shown in Fig. 2, as already mentioned.
• the second illumination light part bundle 15 2 After passing through the first raster element 28, the second illumination light part bundle 15 2 impinges on a second location region 29' of the same second raster element 30 as the first illumination light part bundle 151.
• the second location region 29' specifies an impingement location of the second illumination light part bundle 15 2 on this second raster element 30.
• the two location regions 29 and 29', in which the two illumination light part bundles 15 l 5 15 2 impinge on the second raster element 30, are spatially separated from one another in the embodiment shown.
• Alternative embodiments are possible, in which the location regions 29 and 29', in which the two illumination light part bundles 15 l 5 15 2 impinge on the second raster element 30, partially overlap one another.
• Fig. 2 illustrates two alternatively possible effects of the second raster arrangement 21 and the second raster element 30: in a first bundle guidance shown by a continuous line in Fig. 2, the same emergent angles A xl , AR x2 results for the two illumination light part bundles 15 l 5 15 2 being emitted from the second raster element 30.
• the emergent angle AR X is independent of the impingement location 29 or 29' of the respective illumination light part bundle on the second raster element 30.
• the emergent angle AR x2 for the illumination light part bundle 15 2 is smaller than the emergent angle AR xl for the
• the angle of reflection AR X thus depends on the impingement location 29 on the second raster element 30.
• the emergent angle A X can also depend on an angle of incidence ER X of the respective illumination light part bundle 15 on the second raster element 30 of the second raster arrangement 21.
• This angle of incidence ER X is shown by way of example in Fig. 2 for the illumination light part bundle 1 1 2 .
• a corresponding dependency is present between the angle of incidence ER X of the respective illumination light part bundle 15 on the first raster element 28 of the first raster arrangement 18 and the emergent angle AR X .
• the second raster elements 30 are often configured in such a way that the emergent angle AR X depends on a combination of the angle of incidence ER X and the impingement location 29 on the second raster element 30.
• the impingement location or location region 29 (or 29', cf Fig. 2) will also be called AO below.
• the surface design of an entry face 33 and/or an exit face 34 of the second raster elements 30 of the second raster arrangement 21 of the raster module 19 can be designed in such a way that for specific emergent angles AR X , this emergent angle is identical for specific combinations of the
• the entry faces 33 and/or the exit faces 34 of the raster elements 30 may be spherical, aspherical and, in particular conical in design.
• the controller 14 is configured in such a way that a predetermined distribution of actual tilting angles of the individual mirrors 1 1 of the MMA 10 and, as a result, a predetermined distribution of actual angles of incidence E X , ER y of the illumination light part bundles 15 on the first raster elements 28 is allocated to a predetermined desired course of illumination angle intensity distributions, with which object field points over the object field 3 are impinged upon.
• the MMA 10 is shown there with individual mirrors 1 1 , which are arranged next to one another at an angle, which differs from the zero, with respect to the x-axis. Otherwise, the MMA 10 according to Figs. 3 and 4 corresponds to the MMA 10 according to Fig. 1. Components, which correspond to those, which were discussed above with reference to the figures already described, have the same reference numerals and will not be described again in detail.
• Fig. 3 shows a first distribution of actual tilting angles of the individual mirrors, which leads to a corresponding distribution of actual angles of incidence ER X of the illumination light part bundles 15 on the first raster elements 28 of the first raster arrangement 18 of the raster module 19.
• the actual tilting angle distribution according to Fig. 3 leads to minimal angles of incidence ER X , ER y of the illumination light part bundles 15 on the first raster elements 28 of the raster module 19 and as a result leads to the fact that everywhere in the object field 3, in other words independently of the field, the four illumination directions, which correspond to the intensity spots Ii to I 4 , are represented with the same intensity of the illumination light.
• Fig. 4 shows a variant of a distribution of actual tilting angles of the individual mirrors 1 1 of the MMA 10, which also leads to the quadrupole illumination setting with the four intensity spots (poles) Ii to I 4 according to Fig. 5, but with a different distribution of actual angles of incidence ER X ER y of the illumination light part bundles 15 on the first raster elements 28 of the raster module 19.
• the actual tilting angel distribution according to Fig. 4 is such that, in comparison to Fig. 3, substantially greater angles of incidence ER X , ER y result.
• the raster elements 28, 30 impinged upon by the illumination light part bundle 15 in the illumination according to Figs.
• FIG. 3 and 4 are configured such that the increase in the angle of incidence in the actual angle of incidence distribution according to Fig. 4 can lead to a tilting of the illumination angle intensities I(x) from the direction of the four intensity spots Ii to I 4 over the object field 3.
• the effect on which this tilting is based is described in WO 2007/093433 Al, where this tilting was produced by means of an additional illumination angle variation device of the raster module, in other words not by means of an MMA.
• An actual course of illumination angle intensity distributions resulting on the basis of the actual angle of incidence distribution according to Fig. 4, with which object field points are impinged upon over the object field, is shown in Fig. 5 for the four illumination directions Ii to I 4 of the quadrupole illumination setting there.
• the I(x)- graph shown at the top in Fig. 5 shows the dependency of an intensity from the direction of the Ii-pole over the field coordinates x.
• the corresponding field dependency of the illumination intensity from the direction of the pole I 2 is shown on the left in Fig. 5.
• the I 2 -intensity increases linearly, proceeding from the left field edge to the right field edge.
• the I(x)-dependency for the I 3 -pole is shown at the bottom in Fig. 5.
• the intensity I (x) from the direction of the I 3 -pole is independent in relation to the field coordinates (x).
• the I x -dependency for the illumination intensity from the direction of the I 4 -pole is shown on the right in Fig. 5.
• the illumination intensity I 4 (x) from the direction of the I 4 -pole rises proceeding from the left field edge to the right field edge with a slope which is smaller in comparison to the slope of the dependency I 2 (x).
• a large bandwidth of other desired courses of illumination angle intensity distributions, with which object field points are impinged upon over the object field, can be predetermined.
• a desired distribution of angles of incidence E X , ER y of the illumination light part bundles 15 on the raster elements 28 of the raster module 19 is then firstly determined for the predetermined desired course, during the adjustment of the illumination optical system 7 to prepare the operation of the projection exposure system 1.
• a distribution of desired tilting angles of the individual mirrors 1 1 is then allocated to this determined desired angle of incidence distribution.
• a desired tilting angle is therefore predetermined for each individual mirror 1 1.
• the tilting actuators 12 of the individual mirrors 1 1 are activated in such a way that the actual tilting angles of the individual mirrors 1 1 coincide with the associated desired tilting angles.
• a degree of dependency of the desired course I(x) of the illumination angle intensity distributions, with which the object field points are impinged upon over the object field 3, on the distribution of actual angles of incidence ER X , ER y of the illumination light part bundles 15 on the first raster elements 28 or ER X , ER y on the second raster elements 30 can be influenced by the positional relationship of the two raster arrangements 18, 21 of the raster module 19 with respect to the at least one pupil plane of the illumination optical system 7. Depending on whether, for example, the second illumination plane 20 coincides with a pupil plane of the
• predetermined intensity distributions of the illumination light part bundles 15 on the raster module 19 and correspondingly predetermined intensity distributions in the pupil plane 31 may result.
• a further example to supplement the quadrupole intensity distribution described above in conjunction with Fig. 3 to 5 is a dipole intensity distribution, in which two pupil or intensity spots are illuminated in the pupil plane 31, the position of which may correspond to that of the intensity spots Ii and I 3 in the view according to Fig. 5.
• the ratios in the guidance of an illumination light part bundle 15 with the two raster elements 28, 30, allocated to a light channel, of the raster arrangements 18, 21 of the raster module 19 will be described in detail below with the aid of Figs. 6 to 8.
• the raster elements 28, 30 are in turn shown as plano-convex lenses in Figs. 6 to 8. These may just as well be biconvex lenses.
• Fig. 7 shows a variant of a guidance of the illumination light part bundle 15 at an angle of incidence ER X on the second raster element 30 in the order of magnitude of 15°.
• the impingement location 29 of the illumination light part bundle 15, in the bundle guidance according to Fig. 7, lies completely in a half-plane located above the z-axis, in other words an axis of symmetry of the raster elements 28, 30.
• Fig. 8 shows a further variant of a bundle guidance of the illumination light part bundle 15 at an angle of incidence ER X on the second raster element 30 with an opposite sign in comparison to the situation according to Fig. 7, but the same absolute size.
• the impingement locations 29 there in other words the diameters of the illumination part bundle 15, which impinges on the second raster element 30, are completely separate from one another.
• a characteristic of a dependency of the emergent angle AR X of the illumination light part bundle 15 from the second raster element 30 on the angle of incidence ER X which is shown in Figs. 6 to 8, can therefore be influenced by a suitable design of the entry face 33 of the second raster element 30.
• Fig. 9 schematically shows a dependency of emergent angles AR X , proceeding from the raster module 19, on the one hand on the angle of incidence ER X on the respective second raster element 30 and, on the other hand, on the impingement location AO of the respective illumination light part bundle 15 on the second raster element 30.
• the edges of the first raster element 28 are imaged on the field edges of the object field 3. Isolines of two emergent angles AR ⁇ and AR ⁇ , which define the two opposing x- field edges of the object field 3, are therefore produced in Fig. 9.
• One field edge emergent angle AR ⁇ is produced in each case for a given parameter pair (ER X ; AO) and the other field edge emergent angle AR ⁇ is produced for another linear course of parameter pairs (ER X ; AO).
• This course of the parameter pairs is also called isolines 36, 37 for the field edge emergent angles AR ⁇ , AR ⁇ .
• the same emergent angle AR ⁇ always results, so the field edges of the object field 3 in the x-direction, in other words the left field edge in the x-direction and the right field edge in the x-direction of the object field 3, remain sharply defined.
• the parameter pair dependencies do not have to run linearly, as shown in Fig. 9, but may also have a different course.
• the linear course shown in Fig. 9 may lead to a homogenous illumination of the object field at the field edges.
• Fig. 10 shows a view corresponding to Fig.
• the isoline 38 extends equidistantly between the two isolines 36 and 37, which leads to a homogenous illumination of the object field 3 with the illumination light 8.
• Fig. 1 1 shows a variant of the course of the isoline 38 for the emergent angle AR xm defining the object field centre in the x-direction.
• the angles of incidence ER X for the isolines 37 and 38 are located close together. This means that, the angle of incidence ER xm , which leads to the emergent angle AR xm for the object field centre is already located, with regard to the impingement location on the respective second raster element 30 close to the angle of incidence ER X , which leads to the emergent angle AR ⁇ for, for example, the left edge of the object field 3 in the x-direction.
• Fig. 12 shows by way of example a further course possibility of the isoline 38 for the emergent angle AR xm defining the object field centre.
• the isoline 38 changes from a course adjacent to the isoline 37 to a course adjacent to the isoline 36.
• the transition between stronger illumination of the left object field half to a stronger illumination of the right object field half is accordingly more abrupt depending on the respectively used region of the impingement locations.
• the situation according to Fig. 12 is approximately a limit case, in other words an arrangement, in which the face region 29 on one half of the entry face 33 of the raster element 30 illuminates one half of the object or illumination field 3 and the face region 29 opposing this (cf. Figs. 6 and 7) on the other half of the entry face 33 of the raster element 30 illuminates the other half of the object or illumination field 3.
• Fig. 13 shows an example of the structuring of the entry face 33 of one of the second raster elements 30 in order to achieve the limit case mentioned above.
• a conical contribution 40 is superposed on a spherical basic course 39 of the entry face 33, or an aspherical one with regard to the dependency on the spacing from the optical axis, said basic course being shown by dashed lines in Fig. 13, so the entry face 33 is elevated centrally in the manner of a roof edge. The location of this elevation is illustrated in Fig. 13 by K.
• the elevation K may be absolutely selected such that owing to the raster element 30 having the elevation K, the incident illumination light part bundle 15 is deflected in the x-direction by half a width of the object field 3, as will be described below with the aid of Fig. 14 to 16.
• a raster module 19 with a second raster arrangement 21 with second raster elements 30, the entry faces 33 of which are formed according to the design according to Fig. 13, is illustrated with the aid of Figs. 14 to 16.
• Figs. 14 to 16 in turn show the raster elements 28, 30 as biconvex lenses.
• the MMA 10 is shown divided into two parts, which are separated from one another. Each of these parts may have a plurality of individual mirrors 1 1 which can be individually tilted with respect to one another. A subdivision of the MMA 10 into a larger number of parts each with a plurality of individual mirrors 1 1 is also possible. Components which correspond to those which were discussed above with reference to the figures already described, have the same reference numerals and will not be described again in detail.
• Fig. 14 shows an illumination of the raster module 19 in the xz-plane from incidence directions with first angles of incidence E xI .
• this illumination takes place obliquely from the top left.
• Fig. 15 shows the illumination of the same second raster element 30, but now with an angle of incidence ER xII with an opposite sign, in other words obliquely from the top right in the arrangement according to Fig. 15.
• a displacement results of the illumination light part bundle 15 thus guided in the object field 3 in the negative x-direction, as shown in the I(x)-graph of Fig. 15 at the bottom.
• Fig. 16 shows the combination of the illuminations according to Figs. 14 and 15.
• a desired dependency A (E , AO) of a course of resulting constant emergent angles AR X of the illumination light part bundles 15 from the second raster elements 30 depending on the impingement location AO of the illumination light part bundles 15 on these raster elements 30 and depending on the angles of incidence ER X of the illumination light part bundles 15 on these raster elements 30 can be predetermined.
• the entry faces 33 and optionally also the exit faces 34 of the second raster elements 30 are then structured in such a way that at a predetermined illumination of the raster module 19, an actual dependency of the emergent angle course is produced, which corresponds to the predetermined desired dependency.
• classes of desired dependencies AR(ER, AO) of a course of resulting constant emergent angles AR X of the illumination light part bundles 15 from the second raster elements 30 are determined depending on the impingement location AO of the illumination light part bundles 15 on these raster elements 30 of the second raster arrangement 21 and depending on the angle of incidence ER X of the illumination light part bundles 15 on these raster elements 30, which can be achieved with typical face designs of the entry faces 33 and/or the exit faces 34 of the second raster elements 30.
• These classes of desired dependencies A (E , AO) may have isoline courses of parameter pairs of angles of incidence ER X and of impingement locations AO, which lead to the same emergent angles AR X , as described above in conjunction with Figs. 9 to 12.
• a desired dependency AR(ER, AO) obtained in one of the classes determined is then predetermined and the entry faces 33 and/or the exit faces 34 of the raster elements 30 of the second raster arrangement 21 are structured in such a way that with a predetermined illumination of the raster module 19, an actual dependency of the course is produced, which corresponds to the predetermined desired dependency within predetermined tolerance limits.
• the effect of the raster module 19 on the illumination light part bundles 15 was described above primarily in the xz-plane. Corresponding effects and dependencies are also produced in the yz-plane.
• This can be used in order to define the y- field edges of the object field 3 and to also predetermine an intensity distribution from the illumination angles predetermined by an illumination setting over the object field 3 in the y-direction. This may, in particular, be used in the case of the configuration of the projection exposure system 1 as a stepper, in which the entire object field 3 is simultaneously, in other words, not by a scanning method, illuminated and imaged.
• the raster elements 28, 30 are dioptric, in other words refractive raster elements.
• the raster elements 28, 30 may also be designed as catoptric, in other words reflective raster elements. It was already stated above that no refractive effect of the Fourier lens arrangement 16 is shown in a simplified manner in Fig. 2.
• Fig. 17 shows an arrangement corresponding to Fig. 2, the refractive effect of the Fourier lens arrangement 16 being shown. Components which correspond to those which have already been discussed above with reference to the figures already described and, in particular, with reference to Fig. 2, have the same reference numerals and will not be described again in detail.
• the course of two illumination light part bundles 15 1 and 15 2 from the respective individual mirrors 1 11 and 1 1 2 of the micro mirror array 10 is in turn shown.
• the two part bundles 15 l 5 15 2 have angles of reflection AS xi and AS X 2 from the individual mirrors 1 11 and 1 1 2 .
• the refractive effect of the Fourier lens arrangement 16 leads to the conversion of these angles of reflection AS xi and AS x2 to angles of reflection AS ' xl and AS ' x2 after the Fourier lens arrangement 16.
• the angles of incidence E xl and ER x2 of the two illumination light part bundles 15 l 5 15 2 on the entry face 33 of the same raster element 30 of the second raster arrangement 21 are also shown. In the view according to Fig.
• Fig. 17 now shows the situation in which the same angles of incidence on the Fourier lens arrangement 16, in other words the angles AS xi and AS x2 are transferred into different angles of reflection AS ' xl and AS ' x2
• Fig. 17 in turn shows two alternatively possible effects of the second raster arrangement 21 and the raster element 30 acted upon by the two part bundles 15 l 5 15 2 .
• AR xl emergent angle
• Fig. 18 to 20 show alternative illuminations for the raster module 19, which, in the second illumination plane 20, in each case lead to the impingement of the same raster elements 30, but with different
• a substrate or a wafer in the wafer plane 27 is firstly provided for the microlithographic production of microstructured or nanostructured components with the projection exposure system 1. At least one layer of a light-sensitive material is applied to the wafer. A reticle having structures to be imaged is furthermore provided in the reticle plane 4. The part of the reticle arranged in the object field 3 is then projected, using the projection exposure system 1 , onto a region of the layer arranged in the image field.

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