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
  • G03F7/702—Reflective illumination, i.e. reflective optical elements other than folding mirrors, e.g. extreme ultraviolet [EUV] illumination systems
• • 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
  • G03F7/70091—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

• German Patent Application 10 2013 218 749.1 is incorporated herein by reference.
• the invention relates to an illumination optics for EUV projection lithography for guiding illumination light toward an object field in which a lithography mask can be arranged. Furthermore, the invention relates to an illumination system, in particular with such an illumination optical system, to a projection exposure apparatus with such an illumination system, to a method for producing a microstructured or nanostructured component, in particular a semiconductor chip, with the aid of such a projection exposure apparatus and one with this method manufactured micro- or nano-structured component.
• An illumination optical system of the type mentioned in the introduction is known from WO 2010/937453 A1, WO 2010/104163 A, WO 2008/149178 A1, US 201 1/0001947 A1, US 2009/0041 182 A1 and DE 10 2006 036 064 AI.
• the aim of the illumination is to superimpose the illumination light, which is guided via different illumination channels of the illumination optics, into the illumination field as loss-free as possible within predetermined tolerance ranges while maintaining predetermined illumination parameters.
• the invention is based on the concept that individual mirror groups are imaged into the object field such that the images of these individual mirror groups completely cover the object field in each case.
• Single-mirror groups whose images completely cover the object field are also referred to below as complete single-mirror groups.
• the abandonment of said boundary condition creates new degrees of freedom in the assignment of the individual mirrors of the field facet mirror to individual mirror groups, which are imaged into the object field via in turn assigned pupil facets.
• single-mirror groups are now also permitted which lead to an image not completely covering the object field.
• Such individual mirror groups whose images do not completely cover the object field are also referred to below as fractional individual-mirror groups.
• the result is the possibility to adapt an outer contour of a field facet mirror very well to an actual course of the far field of the EUV light source in which the field facet mirror is to be arranged. For example, it is no longer necessary to use the individual-mirror groups to parquet such a far-field region with groups of the same size and shape, so that the losses which are unavoidable in such a tiling can now be avoided in peripheral regions of the far field.
• An edge delimiting the far-field surface is defined as an outer boundary of the far field, which is exposed to an intensity fraction k r of a maximum far-field illumination light intensity.
• the fraction k r may be, for example, the value 0.1, 0.05, or an even smaller value.
• k r can also have the value 1 / e or 1 / e 2 .
• the newly created flexibility in the assignment of the individual mirror to individual mirror groups also makes it possible to use this assignment for the correction or compensation of illumination parameters or image effects. Examples of this are provided by the illumination optics according to claims 1 and 8. With a given number of individual mirrors on the field facet mirror, a larger number of individual mirror groups can then be formed and correspondingly a larger number of pupil facets can be exposed to illumination light simultaneously. This results in a higher flexibility in the specification of illumination angle distributions, ie lighting settings for object field illumination.
• the pupil facets may in turn be constructed as groups of individual pupil facet mirrors.
• illumination optics in which the number of simultaneously operable pupil facets multiplied by a nominal number of Einzelspie- gel per single mirror group results in a greater number than the actual number of individual mirrors on the field facet mirror, in the reverse direction, ie from the object field or so far If the object field is imaged into a field of view by means of projection optics, illuminated from the field of view, a pattern of illuminated field results on the field facet mirror. th sections which are acted upon by a first intensity with light and other illuminated sections, which are applied with a second, higher and in particular twice as high intensity.
• individual mirrors of the facet mirror are arranged, which can optionally be assigned to different pupil facets, which can be acted on simultaneously with illumination light.
• the higher intensity illuminated field facet sections regularly have a number of individual mirrors that is smaller than the nominal number of individual mirrors.
• the individual mirror groups can be divided in such a way that group forms are used which have a smaller scan-integrated extent in field height areas in which a higher illumination intensity is inherently present, for example due to a corresponding far-field distribution , is present.
• an image tilting correction or compensation is possible which does not presuppose that individual mirror groups adjoin one another via wedge-shaped area regions that can not be used for reflection.
• At least one changing section allows a flexible grouping of the individual mirrors to the respective desired, adjacent to the changing section other single-mirror group.
• the at least one changeover section can also have an extent perpendicular to the object displacement direction which is smaller than half of a extent of the object field perpendicular to the object displacement direction, and which is, for example, 40%, 35%, 30% or even less of an extension of the object field perpendicular to the object displacement direction amounts.
• the at least one transition section may have an extension that is between 5% and 80% of the extent of a complete single mirror group.
• Image position differences according to claims 3 and 4 lead to corresponding degrees of freedom in the intensity or image influencing in the overlapping illumination of the object field on the individual mirror groups.
• the arrangement of the individual mirrors in the interchangeable section according to claim 7 is neutral with respect to a scan-integrated illumination intensity dependence over the field height.
• a design of the interchangeable portion according to claim 9 has been found to be particularly suitable for Ab Strukturs tilage correction or compensation.
• the increase of the extent of the change section along the object displacement direction in the dimension perpendicular to the object displacement direction can be strictly monotonous. tone and in particular can be linear. In this strictly monotonous and, in particular, linear increase, a quantization of the extent of the interchangeable portion due to the finite extent of the individual mirrors is therefore disregarded.
• a lighting system according to claim 10 an optical system according to claim 13, a projection exposure apparatus according to claim 14 and a manufacturing method according to claim 15 correspond to those already explained above with reference to the illumination system and the illumination optics.
• a micro- or nano-structured component can be produced.
• Such a component can be produced with high structural resolution. In this way, for example, a semiconductor chip with high integration or storage density can be produced.
• FIG. 1 is a schematic plan view of a detail of a field facet mirror of an illumination optical system constructed from individual mirrors for illuminating an object field, suitable for use in the projection exposure apparatus according to FIG. 1;
• 2 schematically shows a plan view of a section of the field facet mirror composed of individual mirrors in the region of two individual mirror groups, each of which can be assigned to exactly one pupil facet of the illumination optics, whereby individual mirrors of both individual mirror groups not individually arranged are arranged in a common change section of the field facet mirror and thus two individual mirror elements.
• Groups are assignable; in a diagram, a dependence of an illumination intensity over a field height of an object field of the projection exposure apparatus, wherein the illumination intensity is generated by reflection at the individual mirrors of the two individual mirror groups with the group assignment of FIG. 3; schematically a plan view of the object field, wherein individual object field points representing images of a specific individual mirror within the alternating section of the field facet mirror of Figure 3 are highlighted.
• Fig. 6 in a similar to Fig. 3 representation of the neck of the
• a plan view of the entire field facet mirror is greatly reduced; 14 shows an enlarged detail in the area XIV of FIG. 14 with an exemplary assignment of the individual mirrors to individual hatch groups shown with different hatchings, which respectively reflect light onto a pupil facet of the illumination optics, and in a diagram two examples of a dependency of the total illumination intensity on the field height for two Different assignment configurations of the individual mirrors to the individual mirror groups, whereby in each case within nierter changing sections between two adjacent individual mirror groups there is a change existing there individual mirror from a single mirror group to the other single-mirror group.
• FIG. 1 shows schematically in a meridional section a projection exposure apparatus 1 for micro-lithography.
• a lighting or radiation source 2 belongs to the projection exposure apparatus 1.
• An illumination system 3 of the projection exposure apparatus 1 has an illumination optics 4 for exposing an illumination field coinciding with an object field 5 in an object plane 6.
• An object in the form of an object field 5 is exposed in this case arranged Retikels 7, which is held by an object or reticle holder 8.
• the reticle 7 is also called a lithography mask.
• the object holder 8 can be displaced via an object displacement drive 9 along a displacement direction.
• a projection optical system 10 is used to image the object field 5 into an image field 1 1 in an image plane 12.
• a structure is depicted on the reticle 7 on a photosensitive layer of a wafer 13 arranged in the region of the image field 11 in the image plane 12.
• the wafer 13 becomes held by a wafer holder 14, also not shown.
• the wafer holder 14 can also be displaced along the direction of displacement via a wafer displacement drive 15 synchronized with the object holder 8.
• the radiation source 2 is an EUV radiation source with an emitted useful radiation in the range between 5 nm and 30 nm. It can be a plasma source, for example a GDPP source (plasma generation by gas discharge, gasdischarge-produced plasma) or to an LPP source (plasma generation by laser, laser-produced plasma) act. Also a radiation source that is based on a syn- chrotron or based on a free electron laser (FEL), can be used for the radiation source 2. Information about such a radiation source is found by the person skilled in the art, for example, from US Pat. No. 6,859,515 B2. EUV radiation 16 emanating from the radiation source 2 is bundled by a collector 17. A corresponding collector is known from EP 1 225 481 A.
• the field facet mirror 19 is a first facet mirror of the illumination optical unit 4.
• the field facet mirror 19 has a multiplicity of individual mirrors, which are not shown in FIG.
• the field facet mirror 19 is arranged in a plane of the illumination optical unit 4, which is optically conjugate to the object plane 6.
• the EUV radiation 16 is hereinafter also referred to as illumination light or as imaging light.
• the pupil facet mirror 20 is a second facet mirror of the illumination optics 4.
• the pupil facet mirror 20 is arranged in a pupil plane of the illumination optics 4 which is optically conjugate to the intermediate focus plane 18 and to a pupil plane of the projection optics 10 or coincides with this pupil plane.
• the pupil facet mirror 20 has a plurality of pupil facets 20a, of which two pupil facets 20a are shown schematically in FIG. With the help of the pupil facets of the pupil facet mirror 20 and a subsequent imaging optical assembly 21 in the order of the beam path designated mirrors 22, 23 and 24 will be described in more detail below individual mirror groups 25 (see, for example, Fig.
• a Cartesian xyz coordinate system as a global coordinate system for the description of the positional relationships of FIG Components of the projection exposure system 1 are drawn between the object plane 6 and the image plane 12.
• the x-axis runs perpendicular to the plane of the drawing in Figure 1.
• the y-axis in Figure 1 extends to the right and parallel to Displacement direction of the object holder 8 and the wafer holder 14.
• the z-axis extends in Fig. 1 downwards, ie perpendicular to the object plane 6 and the image plane 12.
• the x-dimension on the object field 5 and the image field 1 1 is also referred to as field height ,
• FIG. 2 shows details of the structure of a section of the field facet mirror 19 in a highly schematic representation.
• the detail of the field facet mirror 19 shown in FIG. 2 is, for example, exactly one of the individual mirror groups 25.
• An entire reflection surface 26 of the field facet mirror 19 is subdivided into a grid of individual mirrors 27 in rows and columns Thus, a single-mirror array.
• the individual reflection surfaces of the individual individual mirrors 27 are concave. In an alternative possible embodiment of the individual reflection surfaces of the individual individual mirror 27, these are flat and have no curvature.
• a single-mirror row 28 has a plurality of individual mirrors 27 directly adjacent to one another on.
• a single-mirror row 28 several tens to several hundred of the individual mirrors 27 may be provided.
• the individual mirrors 27 are square. Other forms of individual mirrors, which allow the most complete possible occupancy of the reflection surface 26 may be used. Such alternative single mirror shapes are known from the mathematical theory of tiling. In this connection, reference is made to the references given in WO 2009/100 856 A1.
• An individual mirror column 29, depending on the design of the field facet mirror 19, likewise has a plurality of individual mirrors 27. Per individual mirror column 29, for example, a few tens or a few hundred of the individual mirrors 27 are provided.
• FIG. 2 a Cartesian xyz coordinate system as a local coordinate system of the field facet mirror 19 is shown in FIG.
• Corresponding local xyz coordinate systems can also be found in the following figures, which show facet mirrors or a section thereof in a top view. 2, the x-axis runs horizontally to the right parallel to the individual mirror lines 28. The y-axis in FIG. 2 runs upwards parallel to the individual mirror columns 29. The z-axis is perpendicular to the plane of the drawing Fig. 2 and runs out of this. 1, ie the direction of displacement for the reticle 7 and the wafer 13, which is also referred to as scan direction, and the y direction of the local coordinate system according to FIG.
• a field-shaping effect by the mirror 24 may also lead locally to deviations between the y-direction of the local coordinate system and the y-direction of the global coordinate system.
• the reflection surface 26 of the individual mirror group 25 In the x direction, the reflection surface 26 of the individual mirror group 25 has an extent of x 0 . In the y-direction, the reflection surface 26 of the individual mirror group 25 has an extension of y 0 .
• the individual mirrors have 27 x / y extensions in the range, for example, of 500 ⁇ m x 500 ⁇ m to, for example, 2 mm x 2 mm.
• the individual mirrors 27 may be shaped to have a converging effect on the illumination light 16. Such a bundling effect of the individual mirrors 27 is particularly advantageous when using a divergent illumination of the field facet mirror 19 with the illumination light 16.
• the entire field facet mirror 19 has an x / y extension, which, depending on the embodiment, for example
• the individual mirror groups 25 (see Fig. 7) have typical x 0 / yo extensions of 80 mm x 6 mm or 65 mm x 5 mm or 25 mm x 4 mm or 104 mm x 8 mm.
• the xo / yo aspect ratio of the individual mirror groups 25 can correspond to the x / y aspect ratio of the object field 5 insofar as the respective individual mirror group 25 is completely imaged into the object field 5.
• the aspect ratio of the individual mirror groups deviates from the aspect ratio of the object field and can be greater than the aspect ratio of the object field.
• FIG Each of the individual mirror groups 25 has a corresponding number of individual mirrors 27. Insofar as an individual mirror group contains so many individual mirrors 27 that the image of this individual mirror group completely covers the object field 5, this is also referred to below as a complete individual mirror group.
• Each of the individual mirrors 27 is each connected to an actuator or actuator 30 for individual deflection of incident illumination light 16, as indicated by dashed lines in FIG. 2 on the basis of two individual mirrors 27 arranged in a corner below the eflexion surface 26.
• the actuators 30 are arranged on the side of each of the individual mirrors 27 facing away from a reflective side of the individual mirrors 27.
• the actuators 30 can be embodied, for example, as piezoactuators. Embodiments of such actuators are known from the construction of micromirror arrays.
• the actuators 30 of a single-mirror row 28 are each connected via signal lines to a row signal bus 32.
• one of the row signal buses 32 is assigned a single-mirror row 28.
• the row signal busses 32 of the individual mirror rows 28 are in turn with a
• Main signal bus 33 connected.
• the latter is in signal communication with a control device 34 of the field facet mirror 19.
• the control device 34 is designed, in particular, for row-wise, ie line-wise or column-wise, common control of the individual mirrors 27. Even within the individual mirror rows 28 and the individual mirror columns 29, individual control of the individual mirrors 27 is possible.
• Each of the individual mirrors 27 is individually tiltable about two mutually perpendicular tilting axes, wherein a first of these individual tilting mirrors can be tilted. axes parallel to the x-axis and the second of these two tilt axes parallel to the y-axis. The two tilt axes lie in the individual reflection surfaces of the respective individual mirrors 27.
• the individual control of the actuators 30 via the control device 34 is a predetermined tilt grouping of the individual mirror 27 in the above-mentioned individual mirror groups 25 from at least two individual mirrors 27 adjustable.
• the individual mirror groups 25 are each assigned at least one separate pupil facet 20 a of the pupil facet mirror 20 for imaging the individual mirror group 25 into the object field 5 via at least one separate group mirror illumination channel for the illumination light 16. This assignment is made by predefining the respective tilting position or switching position of the individual mirrors 27 belonging to the individual mirror group 25 such that the partial bundle of the illumination light 16 which strikes the respective individual mirror 27 moves from this individual mirror 27 toward the associated pupil facet of the pupil facet mirror 20 and is reflected from there to the object field 5.
• the group-mirror illumination channel is the entirety of all individual-mirror illumination channels of the respective individual-mirror group 25, which complement each other on account of the image via the pupil facet 20 a for illuminating the illumination or object field 5.
• Each of the individual mirror groups 25 can therefore be regarded as a prototype image of at least one section of the illumination field 5.
• the prototype of the illumination field 5 is the structural form which is exactly imaged into the illumination field 5 taking into account the aberrations. This structural form is also called the actual archetype designated.
• the ideal prototype image of the illumination field 5 designates the structural form that is imaged exactly in the illumination field 5 without consideration of imaging aberrations.
• the total illumination of the illumination or object field 5 then represents a superposition of these archetypes.
• one of the individual mirror groups 25 thus basically has the function of a facet of a field facet mirror, as disclosed, for example, in US Pat. No. 6,438,199 B1 or US Pat. No. 6,658,084 B2.
• FIG. 3 shows a section 35 of the field facet mirror 19 in a plan view.
• the individual mirrors (not shown individually) within the cutout 35 are assigned to two individual mirror groups 25a, 25b, which are imaged into the object field 5 via different pupil facets 20a.
• the two individual mirror groups 25a, 25b within the detail 35 are illustrated in FIG. 3 by different hatchings.
• the cutout 35 has in the x direction an extension of x t and the y direction an extension of y t .
• the x / y aspect ratio of the section 35 with the two individual mirror groups 25a, 25b is therefore greater by 50% than the x / y aspect ratio of the object field 5.
• the cutout 35 of the field facet mirror 19 is subdivided into three sections in the x direction perpendicular to the scanning direction y. Each of the sections represents a range between two field heights Xj and Xj, which is also described below as [xi; x j ].
• a section [0; xi / 3] all the individual mirrors of the section 35 are assigned to a first pupil facet 20a.
• these individual mirrors can also be assigned to another first pupil facet 20a from a defined group of first pupil facets 20a when changing a lighting setting. This assignment change always happens for all individual mirrors within the section [0; xi / 3] of the section 35 in common.
• a change section 36 of the section 35 of the FeldfacettenLites 19 lies in the range [1/3 xi; 2/3 x a change section 36 of the section 35 of the FeldfacettenLites 19.
• the change section 36 is on a dividing line 37 between the (x, y) coordinates (xi / 3, yi) and (2/3 x l5 0) in two changes Subsections 36a, 36b divided.
• This subdivision of the changeable section 36 into the alternating subsections 36a, 36b is effected by the tilting position of the individual mirrors 27 arranged there.
• the individual mirrors 27 are tilted in such a way that they are all individual mirrors 27, depending on their affiliation with the individual mirror groups 25a, 25b one of the two individual mirror groups 25a, 25b guide the illumination light 16 via a common pupil facet 20a.
• the switching section 36 has ichtung in the x, ie perpendicular to the object moving direction y, an extension x 3, that is, displayed in the object field 5, the extension x 0/2, multiplied by a magnification ß.
• the extent of the interchangeable portion 36 perpendicular to the object displacement direction y, that is, imaged in the object field 5, is half the extent x 0 of the object field 5 perpendicular to the object displacement direction y.
• FIG. 4 shows the effects of a subdivision of the section 35 into the two individual mirror groups 25a, 25b on an illumination intensity distribution I as a function of the field height x of the object field 5 in the field height range [-xo / 2; + Xo / 2]. Dashed is an intensity contribution 38 of the individual mirror group 25a and dash-dotted an intensity contribution 39 of the individual mirror group 25b shown. When drawn through, a total intensity contribution 40 is shown over the field height x. The intensity contributions 38 to 40 are shown integrated at the respective field height x via the scanning direction y. It is assumed here that the cutout 35 of the field facet mirror 19 is exposed to a constant illumination intensity I 0 .
• the intensity contribution 38 of the individual mirror group 25a runs in the range [-xo / 2; 0] initially constant at the value I 0 .
• the entire y-width of the cutout 35 contributes to the illumination of the object field.
• the intensity contribution 39 of the individual mirror group 25b is correspondingly mirror-inverted.
• the change subsection 36b contributes to the illumination of the object field, resulting in a linearly increasing intensity contribution.
• the total number of individual mirrors 27 in a single-mirror group 25 whose image covers the entire object field 5 will also be referred to below Nominal number of individual mirrors 27 per individual mirror group 25.
• Such a single mirror group which completely covers the object field 5 with its image is also referred to below as a complete single mirror group.
• the single-mirror group 25 according to FIG. 2 is therefore a complete single-mirror group.
• Single-mirror groups whose images cover only a fraction of the object field 5 are also referred to below as fractional-individual-mirror groups.
• the individual mirror groups 25a, 25b according to FIG. 3 are thus fractional individual-mirror groups.
• the total number of individual mirrors 27 in the fractional-individual-mirror groups 25a, 25b is smaller than a total number of individual mirrors 27 in the complete individual-mirror group 25 according to FIG. 2, whose image covers the entire object field 5. This is because the fractional-single-mirror groups 25a, 25b do not respectively include the entire change section 36, but only one sub-section 36a, 36b of the alternate section 36. Thus, the images of the single-mirror groups 25a, 25b cover a fraction of the Object field 5 ab, in the illustrated embodiment, exactly 75% of the total area of the object field 5.
• an area requirement of the fractional-individual mirror groups corresponding to the individual mirror groups 25a, 25b, on the field facet mirror 19 is smaller than an area requirement of complete individual mirror Groups corresponding to the single mirror group 25 of FIG. 2, whose image covers the entire object field 5.
• an area requirement of the reflection surface 26 of the field facet mirror 19 as a whole or a given total number of individual mirrors 27 of the field facet mirror 19 as a whole it is possible with this like partial fractional mirror groups having a change subsection corresponding to the change subsections 36a, 36b apply a larger number of pupil facets 20a to the illumination light 16 than when subdivided into complete individual mirror groups 26 whose images respectively cover the entire object field 5 cover.
• the number of pupil facets 20a which can be acted upon simultaneously by the individual mirror groups 25 of the field facet mirror 19 with the illumination light 16 multiplied by the nominal number of a complete individual mirror group 25 results in a number of individual mirrors 27 which is greater than that actual number of individual mirrors 27 on the field facet mirror 19.
• N E sp the number of individual mirrors 27 of the entire field facet mirror 19.
• the dependence of the total intensity contribution 40 on the field height x and the corresponding assignment of the individual mirrors 27 to the fractional individual-mirror groups 25a, 25b can be used to correct a dependency an illumination light intensity integrated along the object displacement direction y can be used by the object field height x.
• FIG. 5 shows schematically a plan view of the object field 5.
• this has an extent of x 0 in the range [-xo / 2;
• FIG. 5 shows individual mirror images 41, 42 of a selected individual mirror 27i in the center of the interchangeable portion 36. Depending on whether the individual mirror 27i belongs to the interchangeable subgroup 36a or the interchangeable subgroup 36b, it is referred to either mirror image 41 or to the single-mirror image 42.
• the single-mirror images 41, 42 have the same y-coordinate, namely, yo / 2.
• a dividing line 37 extends linearly between the coordinates (xi / 3, 0) and (2 / 3xi, yi) at the subdivision of the exchangeable portion 36 of FIG. This in turn results in two triangular alternating subsections 36c, 36d.
• the alternating subsection 36c belongs to the individual mirror group 25a and the alternating subsection 36d to the individual mirror group 25b, as indicated in turn by the same hatching.
• the resulting individual mirror groups 25a, 25b each have the shape of a rectangle as well as a right-angled triangle connected herewith only over a point.
• FIG. 7 shows the effects of the shaping of the individual mirror groups 25a, 25b according to FIG. 6 on the illumination intensity, again integrated via the scanning direction y, depending on the field height x. Shown again dashed is an intensity contribution 43 of the individual mirror group 25a and dash-dotted an intensity contribution 44 of the individual mirror group 25b and solid a total intensity contribution 45, which results as an addition of both intensity contributions 43, 44.
• the interchangeable section 36 is subdivided into the intersection subsection 36e for y values in the range [0; y t / 2] and the change sub-section 36f in the y-range [yi / 2; y.
• FIGS. 10 and 11 show variants of an intensity dependence of an illumination intensity I over the field height x at subdivisions of the change section 36, similar to the subdivisions according to FIGS. 3 and 6, but in this case not with a linearly extending separation line 37 but with curved, for example parabolic dividing line 37.
• FIG. 12 and 13 A further subdivision of a section 49 of the field facet mirror 19 into individual mirror groups 25c, 25d and 25e is explained below with reference to FIGS. 12 and 13.
• the cutout 49 is subdivided into three individual mirror groups 25c to 25e. Insofar as these individual mirror groups are used as complete single-mirror groups, they have an x-extension of x 0 and a y-extension of y 0 .
• first changing section 50 in the cutout 49 individual mirrors 27 are arranged, which can optionally be assigned to the individual mirror groups 25c or 25d.
• second changing section 51 in the cutout 49 individual mirrors 27 are arranged, which can optionally be assigned to the individual mirror groups 25d or 25e.
• the two change sections 50, 51 extend differently than the change section 36 of the embodiment according to FIGS. 3, 6 and 8, over the entire x extension of the cutout 49, that is over a length x 0 .
• the changing sections 36, 50, 51 may have an extent which is between 5% and 80% of the extent of a complete single mirror group.
• individual mirrors 27 are arranged, which can optionally be assigned to the individual mirror groups 25d or 25e.
• the individual mirror group 25d lying between the two individual mirror groups 25c and 25e fully utilizes the two changing sections 50, 51, insofar as all individual mirrors within these alternating subsections 50, 51 are assigned to the individual mirror group 25d, the individual mirror group has 25d as a complete single mirror group with Aspect ratio xo / yo a shape corresponding to a tilted by an angle ⁇ complete single mirror group.
• This tilted complete single mirror group 25d can then be imaged via a path of a group mirror illumination channel into the object field 5, which results in an image tilt which is just compensated by the tilted contour of the complete single mirror group 25d. This results in a compensation of an image tilt.
• FIG. 13 shows in the object field 5 images of two selected individual mirrors 27 j , 27 k in the change sections 50 and 51, depending on their individual mirror group assignment.
• An image 52 of the individual mirror 27 j when assigned to the individual mirror group 25 c arises in the object field 5 in the lower right quadrant.
• an image 53 of this field facet 27 j is formed in the upper right quadrant of the object field 5.
• a y-distance y j of these two images 52, 53 is greater than 40% along the scan direction y and is for example 0.7 y 0 .
• FIG. 14 shows, by way of example, a division of the entire field facet mirror 19 into individual mirror groups 25.
• Each individual mirror 27 of the field facet mirror 19 is assigned to exactly one individual mirror group 25.
• the individual mirror groups 25 are, on the one hand, complete single-mirror groups and, on the other hand, fractional single-mirror groups.
• the individual mirrors 27 of the field facet mirror 19 are arranged in a far field 56 (see also FIG. 1) of the light source 2 such that at least 80% of a surface of the far field 56 is covered by the individual mirrors 27 such that they reflect the illumination light 16 ,
• FIG. 15 shows by way of example two different, depending on a division of the field facet mirror 19 into complete single-mirror groups and
• changing section designs can be such that when individual mirrors are changed, depending on the individual mirror tilt position, these individual mirrors are projected onto different field heights of the object field. it becomes. This can generally be used to correct an intensity distribution over the object field height.
• a change section may be designed such that a change of an individual mirror arranged in the change section, depending on its tilt position between the individual mirror groups, does not lead to a change in a field height position of this individual mirror in the object field. This can be used for the correction of a mapping of the individual mirror groups into the object field which does not affect the field height dependence of the illumination intensity distribution.
• the explained correction or compensation mechanisms are lossless, since the correction can be made without loss of light, which is guided via individual mirror illumination channels.
• the illumination system 3 is initially set up, wherein the field facet mirror 19 is designed and arranged such that it covers at least 80% of a far field area to be used with the individual mirrors 27. Subsequently, a subdivision of the individual mirror array of the field facet mirror 19 into individual mirror groups, including defined alternating sections, is specified. A calibration measurement then takes place in which an x-dependence of a scan-integrated illumination intensity is measured for a given illumination setting, that is to say for a given illumination angle distribution. In this case, for example, an x-dependence corresponding to the intensity distribution 57 may result.
• At least part of the label 7 in the object field 5 is applied to a region of the photosensitive layer on the wafer 13 in the image field 11 for the lithographic production of a micro- or nano-structured component, in particular a semiconductor component.
• a micro- or nano-structured component in particular a semiconductor component.
• a microchip shown.
• the reticle 7 and the wafer 13 are moved synchronously in the y-direction continuously in scanner operation in synchronized time.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
• Microscoopes, Condenser (AREA)
• Lenses (AREA)

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• 2013
  • 2013-09-18 DE DE102013218749.1A patent/DE102013218749A1/de not_active Ceased
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