Illumination system for microlithography

0001The present invention relates to an illumination system for microlithography for illuminating an illumination field of view using illumination light. Further, the present invention presents a raster array for use in this type of illumination system, a microlithography projection exposure apparatus including this type of illumination system, a microlithography manufacturing method for microstructured components or nanostructured components. , And components manufactured according to this type of method.

0002The types of lighting systems listed at the beginning are known from WO 2007/093 433 A1.

<p num="0003"><patcit num="1"><text>WO 2007/093 433 A1</text></patcit></p>

<p num="0004"> An object of the present invention is such that it is possible to influence a particular lighting parameter of illumination in the illumination field or object field of view in such a way as to avoid undesired effects on other illumination parameters to the maximum extent possible. It is to develop the type of lighting system mentioned at the beginning in various ways.</p>

<p num="0005"> According to the first aspect of the present invention, this object is achieved by an illumination system having the characteristics shown in claim 1.</p><p num="0006"> According to the present invention, the distance type assignment between the raster elements of the raster array of the lighting system is a different focusing effect acting on the partial luminous flux assigned by the first raster element of a different type of the first raster array. Has been found to be able to partially or wholly compensate. In such cases, the difference in other effects between the individual raster element types that affect the partial luminous flux of the illumination light, especially the higher-order effects, is often the unavoidable first raster of a different type. It can be used to the extent that the light flux effect of different elements can be ignored. When refracted raster elements are used, for example, it is possible to compensate for the undesired effects exerted by raster elements with different lens radii, and thus other shape contributions, such as when using aspheric lens shapes, eg. Higher-order shape contributions can be used to compensate for specific lighting parameters. The lighting system according to the present invention makes it possible to make corrections or pre-compensations for specific lighting parameters. For example, if different types of raster elements are used in at least one of the raster arrays, ellipticity correction can be performed to avoid unwanted effects on the intensity distribution due to different illumination directions. Reflective raster elements can be used as well. In such cases, the differences between different types of raster elements are not due to the different refraction effects of the raster elements, but to the different reflection effects of the raster elements. Tilt lenses are also suitable for use as raster elements. The raster elements can be monolithic, i.e., they can be formed alone such that the raster arrangement is manufactured from a monolithic lens or substrate block. Alternatively, it can be considered to use raster elements composed of multiple parts, one of which can be a group of raster elements, or even individual raster elements. Changes in the individual distance between one particular type of raster element in the raster array and the assigned raster element in the other raster array The motion can have a graph shape of a strictly monotonous function representing the distance variation over the luminous flux induced cross section of the raster array. Alternatively, this function can have a maximum or minimum value within the luminous flux induction cross section. In other words, distance variation across cross sections can in particular have an irregular curved graph shape with at least one vertex. Generally speaking, each of the two raster arrays may be provided with only one type of raster element, and the distance variation across the luminous flux guided cross section of the raster array may be the function described above or below. It can be carried out in a stepwise manner. The lighting system can be equipped with a primary light source, but this is not required. It can also be considered to prepare an illumination system for the use of a laser having a primary light source different from the illumination system. The free distance between the raster elements of the two raster arrays is formed by voids, in other words, intermediate spaces that do not contain any solids. The two raster arrays can be separate components from each other. A raster array containing at least two types of raster elements with different luminous flux effect effects can be a first raster array, a second raster array, or both raster arrays. In other words, it is formed by an intermediate space that does not contain any solids. The two raster arrays can be separate components from each other. A raster array containing at least two types of raster elements with different luminous flux effect effects can be a first raster array, a second raster array, or both raster arrays. In other words, it is formed by an intermediate space that does not contain any solids. The two raster arrays can be separate components from each other. A raster array containing at least two types of raster elements with different luminous flux effect effects can be a first raster array, a second raster array, or both raster arrays.</p><p num="0007"> At least one distance step according to claim 2 is a separate practice of distance allocation according to the present invention. This type of distance step can be provided in the semi-finished products used to manufacture the raster array.</p><p num="0008"> The assignment of raster element types to the raster area of claim 3 ensures reproducible manufacturing and reproducible design of the lighting system. Raster areas can contain the same type of raster elements in each case.</p><p num="0009"> The design of the raster array including at least one distance step according to claims 4 and 5 provides a corresponding compensatory effect depending on the assignment of the type of raster element to the center and edge.</p><p num="0010"> The advantage of distance allocation is particularly apparent in the design of the raster elements of claim 6 and 7. The desired effect on a particular lighting parameter can be obtained using some conical constants of various types of first raster elements. Alternatively or additionally, the luminous flux affected surfaces of different types of raster elements can have different radii of curvature that can be compensated to the desired degree using distance type assignments. In other words, it is possible to consider spherical designs of raster elements with different types with different radii of curvature. The different conical constants allow controlled intensity changes to be applied over the illumination field of view for correction, compensation, or precompensation purposes. Alternatively or additionally, with different radii, or more generally, with the individually designed non-rotational symmetric free-form surfaces of the various types of first raster elements, for specific lighting parameters. The desired effect can be obtained.</p><p num="0011"> In the second aspect of the present invention, the object mentioned at the beginning is achieved by the present invention by a lighting system having the characteristics provided in claim 8.</p><p num="0012"> The displacement device according to the present invention is at least one of the first raster arrays relative to the second raster array essentially along the beam direction of the illumination light and / or essentially transverse to the beam direction of the illumination light. It can be configured for displacement of the segment and / or for pivoting one of the raster arrays with respect to the other raster array. If the two raster arrays are displaced relative to each other, the first raster array can be displaced, the second raster array can be displaced, or both raster arrays can be displaced. The segment that can be displaced using a displacement device is exactly one of the raster elements, some raster elements, in particular the raster rows, raster columns, or groups of predetermined raster areas, or the number of raster elements. The group can be included, or all raster elements, in other words the entire raster array, can be included. The illumination system according to the first aspect including the displacement device can be combined with the illumination system according to the second aspect including at least two types of raster elements having different luminous flux induction effects. In other words, all the features of the invention described above can be combined with each other.</p><p num="0013"> The displacement device of claim 9 can be used to take advantage of the averaging effect of a given lighting parameter.</p><p num="0014"> The design of the lighting system according to claim 10 makes it possible to perform the operation of the displacement device depending on the feedback, in other words, the measurement result of the measuring device. This type of feedback is also called an online feedback loop. The measuring device can detect the illumination intensity distribution in the visual field plane of the illumination field or a plane conjugate to it, and / or in the pupil plane of the illumination system or a plane conjugate to it. Similarly, it can be considered to detect the illumination intensity distribution in the plane arranged between the visual field plane and the pupil plane of the illumination system. In this regard, the pupil plane is a plane in which the intensity distribution of the illumination light is a measure of the illumination angle distribution of the illumination in the illumination field.</p><p num="0015"> The advantages of the raster array according to claims 11 and 12, the advantages of the projection exposure apparatus according to claim 13, the advantages of the manufacturing method according to claim 14, and the microstructured components according to claim 15. Alternatively, the advantages of the nanostructured components correspond to those described above with reference to the illumination system according to the invention.</p><p num="0016"> Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.</p>

0017<figref num="1">FIG. 5 is a schematic meridional cross-sectional view through an illumination system according to the present invention in a microlithography projection exposure apparatus including a raster module having a two-stage raster array according to the present invention.</figref><figref num="2">FIG. 5 is a diagram of an embodiment of the illumination system raster module according to the invention according to FIG. 1, comprising a first raster array without steps and a second raster array with steps provided between individual elements.</figref><figref num="3">FIG. 2 is a plan view of the first raster array according to FIG. 2, which schematically shows five raster areas provided with one of three different types of raster elements in total in each case.</figref><figref num="4">The sum of the first raster arrays of the raster modules shown in Figure 3 is the distance uncompensated intensity distribution I (x) over the illumination field illuminated by the illumination system for two of the three raster element types. It is the schematic of the graph which shows.</figref><figref num="5">FIG. 5 is a diagram of yet another embodiment of a raster module containing a raster array with steps between individual elements or areas.</figref><figref num="6">FIG. 5 is a diagram of yet another embodiment of a raster module containing a raster array with steps between individual elements or areas.</figref><figref num="7">FIG. 5 is a diagram of yet another embodiment of a raster module containing a raster array with steps between individual elements or areas.</figref><figref num="8">FIG. 5 is a diagram of yet another embodiment of a raster module containing a raster array with steps between individual elements or areas.</figref><figref num="9">FIG. 5 is a diagram of yet another embodiment of a raster module containing a raster array with steps between individual elements or areas.</figref><figref num="10">FIG. 5 is a diagram of yet another embodiment of a raster module containing a raster array with steps between individual elements or areas.</figref><figref num="11">FIG. 3 is a meridional cross section through a raster module containing two reflective raster arrays in which the distance between the raster elements of the two raster arrays assigned to each other is individual for each type.</figref><figref num="12">It is a schematic diagram of a raster module containing two raster arrays that illustrates the degrees of freedom when the two raster arrays are displaced relative to each other.</figref><figref num="13">It is a diagram similar to FIG. 12 of a raster module containing two raster arrays that illustrates two additional degrees of freedom when the two raster arrays are displaced relative to each other.</figref><figref num="14">FIG. 12 is a diagram similar to FIG. 12 of a raster module containing two raster arrays in which one raster element of the two raster arrays is individually displaced relative to the other raster array.</figref><figref num="15">It is a diagram similar to FIG. 12 of a raster module containing two raster arrays in which one raster element of the two raster arrays is also displaced separately with respect to the other raster array.</figref><figref num="16">It is a diagram similar to FIG. 3 of the embodiment of the raster array including three raster areas displaceable with respect to each other including a plurality of raster sequences composed of raster elements in each case.</figref><figref num="17">It is a figure similar to FIG. 4 of the effect on the intensity distribution over the illumination field of view when the raster area of the raster array shown in FIG. 16 is displaced.</figref><figref num="18">It is a figure of the change of the telecentricity curve over the illumination field of view brought about by changing the intensity distribution shown in FIG.</figref><figref num="19">FIG. 16 is a diagram similar to FIG. 16 of another embodiment of a raster array containing three raster areas that can be displaced relative to each other.</figref><figref num="20">It is a diagram similar to FIG. 17 of the effect on the intensity distribution over the illumination field of view when the raster areas of the raster arrangement shown in FIG. 19 are displaced with respect to each other.</figref><figref num="21">It is a figure of the effect on the ellipticity curve over the illumination field of view brought about by changing the intensity distribution shown in FIG.</figref>

0018FIG. 1 is a schematic diagram of a microlithography projection exposure apparatus 1 which is a wafer scanner and is used for manufacturing semiconductor components and other microstructured components. In order to obtain resolutions up to a fraction of the micrometer, the projection exposure apparatus 1 specifically uses deep ultraviolet (VUV).

0019To facilitate the explanation of the positional relationship, the Cartesian xyz coordinate system is used in the following description. In FIG. 1, the x-axis extends upward. The y-axis is perpendicular to the drawing in Figure 1 and extends towards the viewer. In Figure 1, the z direction extends to the right. The scanning direction of the projection exposure apparatus 1 coincides with the y direction. Within the meridional cross section shown in FIG. 1, all the optical components of the projection exposure apparatus 1 are arranged in a row along the optical axis 2. Of course, the optical axis 2 can be folded back irregularly, especially to obtain a projection exposure apparatus 1 with a small design.

0020The illumination system of the projection exposure apparatus 1 represented by the reference number 5 as a whole is an object field of view in the reticle plane 4 in which the structure in the form of a reticle, which is a structure transmitted by projection exposure (not shown in detail), is arranged. Alternatively, it functions to obtain a predetermined illumination of the illumination field of view 3. The object field of view 3 and the illumination field of view can coincide with each other. Usually, the object field of view 3 is arranged in the illuminated field of view. An F2 laser with an operating wavelength of 157 nm functions as a primary light source 6 with an illumination beam coaxial with the optical axis 2. ArF excimer lasers with an operating wavelength of 193 nm, KrF excimer lasers with an operating wavelength of 248 nm, and other primary sources with longer or shorter working wavelengths can be considered.

0021For ease of explanation, the components of the illumination optical system of the illumination system 5 are represented as refraction optical components. Alternatively or additionally, these components can be replaced or supplemented with reflective components, in other words mirrors. Therefore, it can be considered to use a reflection refraction system or a reflection system instead of the basic refraction imaging system of FIG. The reflection design of the illumination system 5 can be used especially when the primary light source 6 is an EUV light source that produces useful light with a wavelength between 5 nm and 30 nm, especially around 13.5 nm.

0022The first component that is incident after the light beam 6 with a small rectangular cross section is emitted by the light source 6 is beam magnifying optics that produces an output beam 8 with essentially parallel light and a larger rectangular cross section. System 7 The illumination light beam 8 has an x / y aspect ratio that can be around 1, and even an x / y aspect ratio that can be greater than 1. The beam magnifying optical system 7 can include an element for reducing the interference of the illumination light 8. When essentially parallelized by the beam-magnifying optical system 7, the illumination light 8 then incidents onto a diffractive optical element (DOE), which is a computer-generated hologram (CGH) for generating the illumination light angle distribution. .. The Fourier lens array, in other words, is shown in a very schematic diagram, the angle of the illumination light 8 generated by the DOE 9 as it passes through the condenser 10 located at a position corresponding to its focal width with respect to the DOE 9. The distribution is transformed into a two-dimensional illumination light intensity distribution, in other words, an illumination light intensity distribution that is position-dependent in the direction perpendicular to the optical axis 2. Therefore, the intensity distribution generated as described above exists in the first illumination plane 11 of the illumination system 5. Therefore, DOE9, together with the condenser 10, forms a light distribution device for generating a two-dimensional illumination light intensity distribution. This light distribution device is also called a pupil definition element (PDE).

0023Within the region of the first illumination plane 11, the first raster array 12 of the raster module 13 which is also called a honeycomb capacitor is arranged. The raster module 13 is also called the field of view definition element (FDE). The raster module 13 functions to generate a predetermined intensity distribution and illumination angle distribution of the illumination light 8. In FIG. 1, the raster module 13 is shown only in a schematic diagram in order to explain the basic functional principle of the raster module 13. 2 and 5 and subsequent figures show other embodiments of the raster module 13 according to the present invention.

0024The second raster module 15 is arranged in another illumination plane 14 downstream of the first illumination plane 11. The two raster arrays 12 and 15 form the honeycomb capacitor 13 of the illumination system 5. The pupil plane 16 of the illumination system 5 is arranged downstream of the other illumination plane 14.

0025Another capacitor 17, also called a field lens, is arranged downstream of the raster module 13. The condenser 17, together with the second raster array 15, approximates the first illumination plane 11 to the intermediate visual field plane 18 of the illumination system 5. Within the midfield plane 18, a reticle masking system (REMA) 19 can be placed, which is an adjustable light-blocking diaphragm for producing sharp edges in the illumination light intensity distribution. The downstream objective system 20, which is also called a relay objective system, forms an image of the intermediate visual field plane 18 on a reticle, in other words, a lithography template. The projection objective system 21 is used to image the object field of view 3 on a wafer (not shown in FIG. 1) arranged in the field of view 22 in the image plane 23, with the wafers along the y direction. Displace intermittently or continuously. In FIG. 1, the pupil plane of the projection objective system 21 is shown in 23a. When the projection exposure device 1 is operated so that the reticle and the wafer are displaced intermittently, the projection exposure device 1 is also referred to as a stepper. When the projection exposure apparatus 1 is operated so that the reticle and the wafer are continuously displaced, the projection exposure apparatus 1 is also referred to as a scanner.

0026The first raster array 12 has separate first raster elements 24 arranged in columns and rows. The first raster element 24 has, for example, a rectangular opening having an x / y aspect ratio of 2/1. Another particularly large aspect ratio of the first raster element 24 can be considered. For ease of explanation, in FIGS. 8 to 10 below, the first raster element 24 is shown as having a 1/1 x / y aspect ratio.

0027Alternatively, the raster arrays 12 and 15 can consist of cylindrical lenses arranged in crossing directions and adjacent to each other in each case. Each of the raster arrays 12 and 15 can be designed in this case as a monolithic lens block. In this case, one of the two optical surfaces of the lens block contains a cylindrical lens surface oriented in the first direction, whereas the opposite of the two optical surfaces is relative to the first direction. Includes a cylindrical lens surface oriented in the vertical direction.

0028The meridional cross section shown in FIG. 1 extends along the x-raster sequence. The first raster element 24 is a microlens having a positive refractive power. In the figure shown in FIG. 1, these microlenses are shown as plano-convex ones. In the schematic diagram shown in FIG. 1, the planes of the two raster arrays 12 and 15 face each other. As will be described below with reference to FIGS. 2 and 5, and subsequent figures, the convex surfaces of the two raster arrays 12 and 15 can be similarly arranged to face each other. You can also think of a biconvex design. The rectangular shape of the first raster element 24 corresponds to the rectangular shape of the illumination field of view 3. The first raster element 24 is arranged so as to be in direct contact with each other in the state of the raster corresponding to the rectangular shape of the first raster element 24, in other words, the first raster element 24 is basically the entire surface. Fill up. The first raster element 24 is also called the first honeycomb.

0029The luminous flux forming effect of the first raster element 24 of the first raster array 12 is such that the illumination light 8 has a number of partial luminous flux 25 (see, for example, FIG. 2) that matches the number of the first raster elements 24 to be illuminated. These partial luminous fluxes 25 are also referred to as optical channels or illumination channels, as they are initially provided separately from each other through the raster module 13 with the result that they are divided into two parts. The raster module 13 may be provided with hundreds of such optical channels offset from each other by the raster size of each x or y in each case in the direction of x or y. These optical channels are superposed within the object field of view 3.

0030In order to transmit each partial luminous flux 25, the first raster element 24 of the first raster array 12 is assigned the second raster element 26 of the second raster array 15. The second raster element 26 is also a microlens having a positive refractive power.

0031Figure 1 shows five optical channels of this type arranged next to each other in the x direction. In the embodiment of the raster module 13 according to the present invention, a total of seven raster elements 24, 26 for generating seven adjacent partial luminous fluxes or optical channels 25 arranged next to each other in the x direction are shown in FIG. 2 and FIG. It is shown in Fig. 5 and the subsequent figures.

0032The distance of the second raster array 15 from the first raster array 12 corresponds approximately to the focal width of the raster element 24. On the other hand, the distance of the pupil plane 16 from the second raster array 15 corresponds to the focal width of the second raster element 26.

0033Raster elements 24 and 26 are aspherical lenses. The sagittal height h of each of the lens surfaces of the raster elements 24 and 26 can be expressed by the following aspherical expression.<img id="000002" he="22" wi="95" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />In this formula, h (x) represents the sagittal height as a function of the x coordinate (field coordinate or lens coordinate). R is the radius of the microlens plane at the apex C is a conical constant, An is the coefficient of expansion of the aspherical surface.

0034The first raster array 12 has different types of first raster elements 24, in other words different types of aspheric microlenses. The first raster element 24 of these types has a different luminous flux effect, in other words a refraction effect.

0035FIG. 3 shows the division of the first raster array 12 of raster module 13 into a total of five raster areas 27 to 31. Each of the raster areas 27-31 extends in the y direction in the form of a row. Seen in the x direction, each of the raster areas 27-31 can contain exactly one raster element 24 or multiple raster elements 24. Typically, each of the raster areas 27-31 has a plurality of raster elements 24. Each of the raster zones 27-31 is composed of exactly one type of raster element 24, in other words, these raster zones have exactly one refraction effect.

0036In the following description, the schematic divisions described in FIG. 2 containing a total of seven raster elements 24 arranged next to each other in the x direction are as follows. The top raster element 24 described in FIG. 2 is part of raster area 27, and the two raster elements 24 closest to this part are part of raster area 28, of FIG. The central raster element 24 is part of the raster area 29, and the two raster elements 24 closest to this part are part of the raster area 30 and are the bottom raster elements of FIG. 24 is part of raster area 31.

0037The raster element 24 in the central raster region 29 belongs to a type I raster element having a conical constant C of around 0.2 and a minimum lens radius R, in other words, these raster elements have the highest refractive effect. The raster elements 24 in the raster regions 28 and 30 are of type II having a conical constant C around 0.05 and a lower refraction effect than that of the raster elements 24 in the raster regions 29, in other words these raster elements It has a slightly larger lens radius R. The raster elements 24 within the raster areas 27 and 31 are of type III with a conical constant C around -0.1 and the lowest refraction effect, in other words the maximum lens radius R. Therefore, the cone constant C differs between type I and type III by 0.3. The type I, II, and III cone constants C can provide other values from the value range of the cone constants C between -0.3 and +0.3, and the type with the highest refraction effect is the largest cone. The type with the constant C and the lowest refraction effect for it has the smallest conical constant C. In another embodiment, the conical constant C is around 0.05 for Type II, around 0.1 for Type I, and around 0.0 for Type III. The type I conical constant C can vary, for example, in the range between 0.09 and 0.25. Type II conical constants can vary in the range between -0.09 and +0.09. The type III conical constant C can vary in the range between -0.25 and -0.09.

0038FIG. 4 shows the effect of type I and III raster elements 24 that are not distance compensated for different refractive power reasons, in other words the raster elements are not according to the invention. This figure shows the intensity I over the field coordinates x within the region of the object field of view 3. The high refraction effect of the type I raster element 24 causes the assigned partial luminous flux 25 to shrink severely on the assigned incident plane of the assigned second raster element 26, thereby causing an intensity curve 32 over the field coordinate x. Is similarly contracted. The conical constant C of the type I raster element 24 results in a "concave" intensity curve 32 over the object field of view 3, in other words the intensity curve 32 curves to open upwards.

0039Due to the low power of the type III raster elements 24, the luminous flux induction effect of these raster elements 24 causes the partial luminous flux to shrink only slightly on the second raster element 26, thereby causing the field coordinates x. A wide intensity curve 33 is provided across. The conical constant C of the type III raster element 24 results in a "convex" intensity curve 33 over the object field of view 3, in other words the intensity curve 33 opens downwards.

0040In the absence of any distance compensation as described below, the contraction effect of the type I raster element 24, which has a higher refraction effect than the type III raster element 24, is the intensity curve 32 over the object field of view 3 in FIG. As is clear when comparing the intensity levels of 33, the result is that the intensity contribution of type I is higher than that of type III when integrated over the object field of view 3.

0041According to the present invention, this intensity difference of curves 32, 33 over the object field of view 3 is compensated for by changing the distance Δ between the raster elements 24, 26 assigned to each other through the partial luminous flux 25. This will be described below with reference to FIG. As mentioned above, the type I raster element 24 has a higher refraction effect than the type III raster element. Therefore, the partial luminous flux 25I formed by the type I raster element 24 has an edge ray that converges higher than that of the partial luminous flux 25III produced by the type III raster element 24. On the other hand, the distance ΔI between the raster elements 24 and 26 in the raster area 29 is smaller than the distance ΔIII between the raster elements 24 and 26 in the raster areas 27 and 31. Therefore, the partial luminous flux 25 incident on the assigned raster element 26, whether of type I or III, is also subject to the higher refraction effect of the type I raster element 24 compared to type III. Nevertheless, they have the same spread x0 in x dimension. Similarly, a large distance ΔIII results in the partial luminous flux 25III being focused along the same x-dimension x0 as the partial luminous flux 25I, so a type III raster element with a low refraction effect is high over the object field of view 3. Has a strength effect. Therefore, within the region of the object field of view 3, the intensity curve 33 generated by type III increases to the intensity curve 34 illustrated by the alternate long and short dash line. When integrated over the object field of view 3, the two types I and III differ only with respect to concave or convex curves due to the different conical constants of types I and III, despite these different refraction effects. Gives the same strength contribution. Therefore, the different refraction effects of types I and III make it possible to perform intensity offset correction over the object field of view 3 used, which is shown in FIG. Shown by.

0042The refraction effect of the type II raster element 24 within the raster areas 28, 30 lies between the type I refraction effect and the type III refraction effect, so that type II has a corresponding intensity adjusting effect. The schematic of raster module 13 shown in FIG. 2 shows two different distances Δ between the assigned raster elements 24, 26 within raster areas 28, 30, resulting in a second raster array 15 Distance variation is obtained between the individual elements of. Alternatively, the second raster element 26 of the second raster array 15 is a uniform distance from the assigned raster element 24 of the first raster array 12, as shown by the dashed line 35 in FIG. It can be placed at the position of Δ, so in this case a uniform distance ΔII is provided.

0043The distance variation due to the different distances ΔI, ΔII, and ΔIII is obtained by the thickness change of the second raster array 15 extending in the x direction by the ridge method. The second raster array 15 has the highest raster thickness SI in the center, in other words raster area 29, and the lowest thickness SIII in the edges, in other words raster areas 27, 31. Looking at the second raster array 15 represented by the solid line, the thickness S measured in the z direction decreases element by element by the distance step 36.

0044In FIGS. 2 and 5, and subsequent figures, the distance Δ between the raster arrays 12 and 15 is greatly exaggerated when compared to the x dimensions of the raster elements 24 and 26, respectively.

0045The table below shows an example of the absolute distance variation or void variation required if the conical constant C or radius of curvature of each first raster element 24 is changed. In the first table, the change in the conical constant C is described as ΔC.

0046If the conical constant C is changed by, for example, 0.05, a distance variation Δ of 13 μm is required for compensation.

0047The second table provides the radius change as a percentage.

0048(table)<img id="000003" he="31" wi="155" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />

0049(table)<img id="000004" he="31" wi="155" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />

0050FIG. 3 shows the first raster array 12, and thus the exemplary quadrupole illumination of the raster module 13 of the illumination system 5 of the projection exposure apparatus 1. The first raster array 12 is exposed to a total of four partial luminous fluxes incident on the first raster array 12 at the rhombic corners. In other words, the central raster area 29 is incident with two partial luminous fluxes 25 near the two edges of the raster area 29 in each case when viewed in the y direction. Within the raster areas 27 and 31, each one of the partial luminous flux 25 is incident on the first raster array 12 at the center when viewed in the y direction. In this quadrupole illumination, different types I and III raster elements 24 are provided by the other optical components of the projection exposure apparatus 1 and make it possible to compensate for the ellipticity change of the illumination in the object field of view 3. ..

0051Ellipticity is a measure for evaluating the lighting quality of the object field of view 3 in the object plane 4. By determining the ellipticity, it becomes possible to more reliably predict the distribution of energy or intensity over the entrance pupil of the projection objective system 21. For this purpose, the entrance pupil of the projection objective system 21 is divided into eight octets numbered O1 to O8 in the counter-timekeeping direction, similar to common practice in mathematics. In the following, the energy contribution or intensity contribution for illuminating the visual field point given by the octuple circles O1 to O8 will be referred to as energy contribution or intensity contribution I1 to I8.

0052The following quantities are called -45 ° / 45 ° ellipticity (Elly, E-45 ° / 45 °).<img id="000005" he="11" wi="48" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />On the other hand, the following quantities are called 0 ° / 90 ° ellipticity (Ellx, E0 ° / 90 °).<img id="000006" he="11" wi="46" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />

0053The aspherical shape of the first raster element 24 is generated in the multi-stage forming step. In this step, the raster array 12 is initially generated to have one raster element 24 with the same conical constant. After that, the desired modification of the conical constant is carried out, which results in different types I, II and III. This results in even more different lens radii, and thus different refraction effects of types I to III. Alternatively, the raster array 12 can be provided with different lens radii of types I-III in a single generation step.

0054FIG. 5 shows another embodiment of raster module 13 given distance variation between individual elements. The components and effects corresponding to those described above are represented by the same reference numbers with reference to FIGS. 1 to 4, and these will not be explained in detail again.

0055In the embodiment of the raster module 13 shown in FIG. 5, the ridge variation between the individual elements is given to the first raster array 12. As a result, there is a minimum distance ΔI between the assigned raster elements 24 and 26 in the central raster area 29, and a maximum distance ΔIII between the assigned raster elements 24 and 26. Similar to the above description of the embodiments described in FIG. 2, the different contraction effects of types I and III that act on the partial luminous flux 25I to 25III by the raster element 24 are also distance compensated and, as a result, again again. , The partial luminous flux 25I to 25III have the same x spread x 0 on the raster element 26 of the second raster array 15. From this, the same offset compensation with different intensity curves is obtained, as already described above with reference to FIG.

0056FIG. 6 shows another embodiment of the raster module 13. The components and effects corresponding to those described above with reference to FIGS. 1 and 5 are represented by the same reference numbers, and these will not be described in detail again.

0057The raster array 12 described in FIG. 6 is designed in an inverted ridge manner, in other words, has a minimum thickness S3 in the central region and a maximum thickness S1 at the edges. Similarly, the first raster elements 24 of types I to III in the first raster array embodiment shown in FIG. 6 are also dispersed over the x dimension of the first raster array 12 in an inverted manner.

0058Type III, which has the lowest refraction effect, is located in the center, in other words, raster area 29. The type I raster element 24, in other words the raster element 24 with the highest power, is located at the edge, in other words the raster areas 27, 31. Type II raster elements 24 are arranged in the meantime, in other words, in raster areas 28 and 30. The raster array 12 shown in FIG. 6 is also provided with a distance step 36 between the individual elements.

0059The larger distance ΔIII compared to the distance ΔI compensates for the lower Type III refraction effect than that of Type I, regardless of whether the raster element 26 is equipped with Type I, II, or III. However, the partial luminous fluxes 251 to 253 have the same x spread x 0 in the raster module 13 shown in FIG.

0060FIG. 7 shows another embodiment of the raster module 13. The components and effects corresponding to those described above are represented by the same reference numbers with reference to FIGS. 1 to 6, and these will not be explained in detail again.

0061In FIG. 7, in contrast to the raster module 13 described in FIG. 6, it is the first raster array 12 that has the minimum thickness SIII in the center and the maximum thickness SI at the edges. Not the second raster array 15. As a result, the distances ΔI to ΔIII have a corresponding compensatory effect on the partial luminous fluxes 251 to 253, as described above with reference to the raster module 13 shown in FIG.

0062FIG. 8 shows another embodiment of the raster module 13. The components and effects corresponding to those described above are represented by the same reference numbers with reference to FIGS. 1 to 7, and these will not be explained in detail again.

0063In the raster module 13 shown in FIG. 8, both raster arrays 12 and 15 are provided with ridge-like steps between the individual elements. The two ridges of raster arrays 12 and 15 face each other so that the shortest distance ΔI exists within the raster area 29, whereas the maximum distance ΔIII exists between the raster elements 24 and 26 at the edge. The arrangement of raster modules 13 shown in FIG. 8 is selected when types I and III have a greater difference in their refraction effect than that of the arrangements shown in FIGS. 2 and 5.

0064FIG. 9 shows another embodiment of the raster module 13. The components and effects corresponding to those described above are represented by the same reference numbers with reference to FIGS. 1 to 8, and these will not be explained in detail again.

0065Unlike the embodiments described in FIGS. 2 and 5-8 above, the embodiment described in FIG. 9 is provided with only three raster areas, i.e., raster areas 37, 38, and 39. In the schematic shown in FIG. 9, the first raster array 12 of the raster module 13 shown in FIG. 9 again has a total of seven first raster elements 24 when viewed in the x direction. The raster elements 24 in the raster areas 37 and 39 are of type I with high refractive power. The raster element 24 in the central raster area 28 of the first raster array 12 is of type III with low refractive power. Within raster areas 37 and 39, there are two type I raster elements in each case. Within the raster area 38, there are three type III raster elements 24 located next to each other.

0066Between raster areas 37 and 38 on the one hand and between raster areas 38 and 39 on the other hand, the first raster array 12 includes one distance step 40 in each case. The distance ΔI between the raster element 24 in the raster area 37 and the assigned raster element 26 in the second raster array 15 is the first raster element 24 in the raster area 38 and the assigned second raster element 26. The distance between ΔIII is less than. As a result, as described above with reference to the raster module 13 described in FIG. 6, the different distances ΔI and ΔIII compensate for the different refraction effects of the types I and III.

0067FIG. 10 shows another embodiment of the raster module 13. The components and effects corresponding to those described above with reference to FIGS. 1 to 8 and particularly with reference to FIG. 9 are represented by the same reference numbers, which will not be described in detail again.

0068In the raster module 13 shown in FIG. 10, the first raster array 12 is inverted with respect to the raster array 12 shown in FIG. The high refractive power type I raster element 24 is located in the central raster area 38, whereas the low refractive power type III raster element 24 is located in the edge raster areas 37 and 39. In this case, since the distance ΔIII at the edge exceeds the distance ΔI, the compensation effect as described above can be obtained with reference to the embodiment of the raster module 13 shown in FIG.

0069During the microlithography production of the microstructured component or the nanostructured component using the projection exposure apparatus 1, a substrate provided with at least a partially layer of the photosensitive material is prepared. Usually, the substrate is a wafer. Further, a reticle provided with a structure to be imaged is prepared. The projection exposure apparatus 1 is then used to project at least a portion of the reticle onto the area of the photosensitive layer on the substrate.

0070The following is a description of another embodiment of the raster module 13 described in FIG. The components and effects corresponding to those described above are represented by the same reference numbers with reference to FIGS. 1 to 10, and these will not be described in detail again.

0071In the raster module 13 shown in FIG. 11, the two raster arrays 12 and 15 are provided with a reflective first raster element 24 and a reflective second raster element 26. Due to the reflective power of these raster elements, the raster element 24 of the first raster array 12 in the embodiment shown in FIG. 11 has a different luminous flux effect instead of a different refraction effect. Therefore, the type III raster element 24III shown at the top of FIG. 11 can be designed to exert the lowest focusing effect on the partial luminous flux 25III, whereas it is shown at the bottom of FIG. The type I raster element 24I can be designed to have the highest focusing effect on the partial luminous flux 25I. The focusing effect shown between these on the partial luminous flux 25II by the raster element 24II is located between the two focusing effects of the raster elements 24I and 24III.

0072In the two raster arrays 12 and 15, the optical path length Δ between one of the first raster elements 24 and the second raster element 26 of the second raster array 15 assigned to the first raster element 24 is the following equation. They are spatially arranged relative to each other as if the relationships were applied. ΔI &lt;ΔII &lt;ΔIII

0073The individual allocation of the distances ΔI to ΔIII from the type I to III of the first raster element 24 provides the compensation effect described above with reference to, for example, the raster module 13 described in FIG.

0074The two raster arrays 12, 15 of the above-described embodiment can be arranged in the opposite order in the beam path of the illumination light 8.

0075FIG. 12 is a schematic representation of another embodiment of raster module 13 including raster arrays 12, 15 having raster elements 24, 26. The components and effects corresponding to those described above are represented by the same reference numbers with reference to FIGS. 1 to 11, and these will not be described in detail again.

0076In the raster module 13 shown in FIG. 12, the two raster arrays 12 and 15 are displaced in the z direction, in other words, along the displacement stroke ΔZ perpendicular to the xy plane stretched by the two raster arrays 12 and 15. Can be done. In the embodiment illustrated in FIG. 12, it is the second raster array 15 that is displaced in the z direction. For this purpose, the second raster array 15 is mechanically connected to the displacement device 41. The displacement device 41 can be a linear displacement unit or a micromechanical actuator suitable for the displacement of the optical components.

0077An output coupling mirror 42 that is partially transparent to the illumination light 8 is placed in the beam path downstream of the second raster array 15. The output coupling mirror 42 transmits the partial beam 43 of the illumination light 8 to a position-sensing detector 44 such as a CCD array. The detector 44 is signal-connected to the displacement device 41 by a central control device not shown in the drawing. The detector 44 can detect the illumination intensity distribution of the partial beam 43, thereby drawing conclusions about the illumination intensity distribution and / or the illumination angle distribution of the illumination light 8 in the object plane 4.

0078The ΔZ displacement of the raster array 15 with respect to the raster array 12 makes it possible to perform an intensity offset correction over the object field of view 3 used, as described above with reference to FIG. The greater the distance Z between the two raster arrays 12 and 15, the smaller the x-spread of the illumination field of view, resulting in a stronger focus of intensity within the object field of view 3.

0079In addition, the ΔZ displacement can be used to obtain an ellipticity offset, in other words, an offset of, for example, the quantity E-45 ° / 45 ° or E0 ° / 90 ° already described above. The ΔZ displacement also makes it possible to adjust the illumination uniformity of the object field of view 3. Homogeneity is defined as the x-value within the object field of view 3, in other words the normalized total energy SE (x) scan-integrated with respect to the field of view height. Uniformity U is SE (x)_max) Is the x value x with the highest total scan integral energy_maxWhen it is the total energy in, it becomes as follows. U (percentage) = 100 (SE (x)_max)-SE (x)_min)) / (SE (x)_max) + SE (x)_min)) On the other hand, SE (x)_min) Is the x value x with the lowest total scan integral energy_minIs the total energy in.

0080In addition, the ΔZ displacement can be used to perform telecentric offset correction.

0081Telecentricity is a measure of the energy or intensity of the illumination light incident on the object field of view 3 in the main illumination angular direction.

0082The main ray of the luminous flux assigned to the field of view is defined for each field of view of the illuminated object field of view. The main ray has an energy weighted direction of the luminous flux emitted by this field point. Ideally, the main ray at each viewing point is parallel to the main ray as determined by the illumination optics or projection objective system 21.

0083Main ray direction:<img id="000007" he="6" wi="14" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />Is known from the design data of the illumination optical system or the projection objective system 21. The main ray of the visual field point is defined by the connecting line between the visual field point and the center point of the entrance pupil of the projection objective system 21. The direction of the main ray at the field of view x, y in the field of view of the object in the object plane 3 is obtained by the following equation.<img id="000008" he="14" wi="67" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />

0084E (u, v, x, y) is the energy distribution as a function of the pupil coordinates u, v at the field points x, y, in other words, it depends on the illumination angle received by each field point x, y.<img id="000009" he="8" wi="48" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />Is the total energy incident on points x, y.

0085For example, the central field of view x0, y0 receives the radiation of a partial radiation bundle from the directions u, v determined by the position of each raster element 26 on the second raster array 15. In this illumination example, the different energies or intensities of the partial radiation bundles or illumination channels assigned to the raster element 26 are combined to create a principal ray parallel to the principal ray direction of the illumination light 8 integrated across all raster elements 26. The main ray s travels along the main ray only if it forms. This is only under ideal circumstances. In practical use, telecentricity error:<img id="000010" he="6" wi="12" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />Main ray direction called:<img id="000011" he="5" wi="12" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />And the main ray direction:<img id="000012" he="6" wi="14" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />There is a deviation between.<img id="000013" he="6" wi="45" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />

0086In the practical application of the projection exposure apparatus 1, it is not the local telecentricity error at a specific object field of view (x, y) that must be corrected, but the telecentricity error that is scan-integrated at x = x0. .. This telecentricity error is obtained by the following equation.<img id="000014" he="15" wi="49" file="JP5908028B2_D0001.tif" img-format="tif" img-content="drawing" />

0087In other words, the telecentricity error integrated by a point (x, eg, x0) on the reticle moving through the object field of view 3 in the object plane 4 during the scanning process is corrected, in this case x telecentricity error and y telecentricity. A distinction can be made between errors. x Telecentricity error Tx is defined as the deviation in the direction perpendicular to the scanning direction of the main ray from the main ray, in other words, over the height of the field of view. y Telecentricity error Ty is defined as the deviation of the main ray from the main ray in the scanning direction.

0088The illumination parameters can be controlled using the detector 44, the central control device, and the displacement device 41, thus adjusting the actual value of the illumination parameter to a predetermined desired value while the raster module 13 is in operation. Allows it to act as a compensating element that can be used in. To this end, the central control device is able to evaluate the illumination parameters of the partial beam 43 detected by the detector 44, thereby drawing conclusions about the illumination parameters of the illumination light 8. Based on the actual values of the illumination parameters thus determined, the second raster array 15 is then displaced by appropriately activating the displacement device 41 by the central control device.

0089FIG. 13 is a diagram similar to FIG. 12 of another embodiment of the raster module 13 having different degrees of freedom in the displacement between the two raster arrays 12 and 15. The components corresponding to those described above with reference to the embodiments described above, especially with reference to the embodiments described in FIG. 12, are represented by the same reference numbers, which will be described in detail again. do not.

0090In the raster module 13 shown in FIG. 13, the second raster array 15 can be displaced with respect to the first raster array 12 along the displacement strokes Δx and Δy in the x and y directions. To this end, again, the raster module 13 is equipped with a displacement device 41 that is mechanically coupled to the second raster module 15.

0091The Δx or Δy displacement of the second raster array 15 relative to the first raster array 12 makes it possible to determine the relative x or y position of the illumination field of view with respect to the object field of view 3. The telecentric tilt dependence over the field height x, the so-called telecentric tilt, and the tilt dependence of the ellipse over the field height x can also be adjusted by Δx displacement or Δy displacement.

0092Yet another Δz displacement that can be considered in the raster module 13 shown in FIG. 13 in combination with the Δx displacement or Δy displacement, corresponding to the description of the raster module 13 shown in FIG. 12, is the intensity of the illumination light 8. Allows the displacement to be adjusted over the object field of view 3.

0093If the raster module contains a raster array such as raster array 12 divided into raster zones with different luminous flux effects, such as raster zones 27-31 shown in FIG. 3, the Δx displacement or Δy displacement is , Brings a tilt change of ellipse over the object field of view 3. It can be used to adjust the slope of ellipticity over the field height x.

0094The parameter control by the detector and the central control device described above with respect to the raster module 13 shown in FIG. 12 can also be considered in the raster module 13 shown in FIG.

0095FIG. 14 is a diagram similar to FIG. 12 of another embodiment of the raster module 13 having different degrees of freedom in the displacement between the two raster arrays 12 and 15. The components corresponding to those described above with reference to the embodiments described above, especially with reference to the embodiments described in FIG. 12, are represented by the same reference numbers, which will be described in detail again. do not.

0096In the raster module 13 shown in FIG. 14, again, the second raster array 15 is displaceable along the z direction with respect to the first raster array 12. The individual raster elements 26 of the second raster array 15 can be individually displaced along the displacement strokes ΔZ1, ΔZ2, ..., ΔZN independently of each other. Each of the raster elements 26 is mechanically coupled to the assigned displacement device 41, as outlined in FIG. The displacement device 41 allows individual displacement of the raster element 26 in the z direction. The individual displacement device 41 can be assigned to each of the raster elements 26. The displacement of the raster element 26 by the displacement device 41 is controlled by a central control device (not shown) as before. The lighting parameter control by the detector and the central control device described above with respect to the raster module 13 shown in FIG. 12 can also be considered in the raster module 13 shown in FIG.

0097Based on the position of the z-displaced raster element 26, a locally different distance ΔZi allows the size of the illumination field segment belonging to the illumination channel to be adjusted in an adjustable manner, and the size of the illumination field segment is associated with this. Judgment by the lighting channel. As a result, the elliptical offset can be adjusted. The course of the ellipse over the object field of view 3 can be influenced, for example, by changing the distance ΔZi so that a predetermined distribution is obtained. This makes it possible to correct the ellipse. Similarly, the uniformity can be adjusted by changing the distance ΔZi.

0098In the raster module 13 described in FIGS. 12-14, the displacement device 41 described above is at least one segment of the first raster array 12, in other words at least one of the raster elements 24, a group of raster elements 24. Or at least one segment of the entire second raster array 15 of the raster array 12, in other words at least one raster element 26, at least a group of raster elements 26, or a periodic displacement of the entire raster array 15 with respect to the object. It can be designed to occur at a smaller cycle than the exposure time of the field or illumination field 3. The displacement device 41 capable of performing this kind of periodic displacement is also called a wobbler.

0099This type of wobbler displaces the raster array 15 or its segments with a time constant that displaces the illumination channel each time the primary light source 6 generates an optical pulse. During the time of exposure of a particular segment on the illuminated wafer using the projection exposure apparatus 1, this segment is subject to incidents from, for example, 30 light pulses of light source 6. A periodic displacement of the wobbler can be generated between these 30 optical pulses.

0100FIG. 15 is a diagram similar to FIG. 12 of another embodiment of the raster module 13 having different degrees of freedom in the displacement between the two raster arrays 12 and 15. The components corresponding to those described above with reference to the embodiments described above, especially with reference to the embodiments described in FIG. 12, are represented by the same reference numbers, which will be described in detail again. do not.

0101The displacement device 41 for the raster element 26 of the second raster array 15 is an individual x, of the raster element 26 along each of the displacement strokes ΔX1, ΔX2, ..., ΔXN or ΔY1, ΔY2, ..., ΔYN. guarantees displacement. This x, y displacement results in a pupil-dependent displacement of the illuminated channel displaced within the object field of view 3. This pupil-dependent displacement can be used to optimize the superposition of illumination channels within the object field of view 3, and thus to optimize the intensity distribution over the object field of view 3. The displacements ΔXi, ΔYi of x or y result in a slope dependence of the intensity distribution of each illumination channel of the displaced raster element 26, and this dependence has a corresponding effect on uniformity. This makes it possible to correct the inclination dependence of telecentricity.

0102In the following, the effect of x-displacement of the raster area of the first raster array 12 will be described in more detail with reference to FIGS. 16 to 18. The components or functions corresponding to those already described above with reference to FIGS. 1 to 15 are represented by the same reference numbers, and these will not be described in detail again.

0103The first raster array 12 described in FIG. 16 has three raster areas 45, 46, 47 having different luminous flux effect effects, in other words, these raster areas are, for example, the first raster area shown in FIG. Includes raster elements 24 with different conical constants corresponding to the above description of raster areas 27-31 of raster array 12 of.

0104Starting from the reference position of the three raster areas 45 to 47 relative to each other, the raster area 45 on the left hand side of FIG. 16 is displaced to the left by stroke -ΔX with respect to the central raster area 46, whereas the right hand of FIG. The raster area 47 on the side is displaced to the right by stroke ΔX with respect to the fixed central raster area 46.

0105The two displacements-ΔX, ΔX result in a change in the intensity curve over the object field of view, as shown in FIG. Corresponding to FIG. 4, FIG. 17 shows an I (x) graph of the scan integral intensity over the field height x. When the raster area 45 was displaced by stroke-ΔX, it tilted with the highest intensity at the left-hand edge of the object field of view 3 shown in FIG. 17 and the lowest intensity at the right-hand edge of the object field of view 3 shown in FIG. An intensity curve 48 is provided. By displacing the raster area 47 by stroke ΔX, it has the opposite slope, in other words, the intensity curve with the lowest intensity at the left-hand visual field edge of FIG. 17 and the highest intensity at the right-hand visual field edge of FIG. 49 is brought.

0106The slanted intensity curves 48, 49 provide a telecentricity curve 50 over the object field of view 3, as shown in FIG. This is because at the left-hand edge of the object field of view 3 shown in FIG. 18, the most dominant is the intensity contribution from the raster area 47, whereas at the right-hand edge of the object field of view 3 shown in FIG. 18, the most dominant is the raster. Due to the strength contribution from area 45.

0107The effect of the relative displacements of the raster areas 45 and 47 on the fixed central raster area 46 of the second raster array 15 on the specific illumination parameters of the illumination of the object field of view 3 will be described with reference to FIGS. 19 to 21. The components corresponding to those described above with reference to FIGS. 1 to 18 and particularly with reference to FIGS. 16 to 18 are represented by the same reference numbers, and these will not be described in detail again.

0108In contrast to FIG. 16, which shows the first raster array 12, what is shown in FIG. 19 is the second raster array 15.

0109Starting from the reference position of the raster areas 45 to 47 with respect to each other, the displacement shown in FIG. 19 is that the raster area 45 is displaced to the right by the stroke ΔX with respect to the raster area 46 of FIG. 19, and at the same time, the raster area 47 is also fixed. It is also carried out so as to be displaced by the stroke ΔX with respect to the central raster area 46 of. Therefore, the two outer raster areas 45, 47 are both displaced in the same direction with respect to the central raster area 46, that is, in the positive x direction.

0110The central raster area 46 on the one hand and the two outer raster areas 45, 47 on the other are composed of raster elements having different luminous flux induction effects. The central raster area 46 includes, for example, a first luminous flux effect type I raster element with a first conical constant. The two outer raster areas 45, 47 include a second type II raster element 26 with a different luminous flux effect, in particular a conical constant different from that of type I.

0111The ΔX displacements of the two outermost raster areas 45, 47 with respect to the central raster area 46 result in a tilt of the Type II field-dependent intensity distribution such that the left field edge is incident with a higher intensity than the right field edge ( Compare with the intensity curve 51 in Figure 20). Since the central raster area 46 is not displaced, its intensity curve 52 remains unchanged over the object field of view 3.

0112The slope of the intensity curve 51 results in the corresponding slope of the ellipticity curve 53 shown in FIG. The ellipticity curve 53 shown in FIG. 21 can be an ellipticity E-45 ° / 45 ° curve or an E0 ° / 90 ° curve. The slope of the ellipticity curve 53 results in an ellipticity offset 54 on the right hand side of the object field of view 3 shown in FIG.

0113Starting from the reference position, the displacement strokes ΔX, ΔY in the group or area of raster sequences 12, 15, raster elements 24, 26, or individual raster elements 24, 26 shall be in the range between -10 μm and +10 μm. Can be done. Therefore, the absolute total displacement stroke can be 20 μm. The absolute ΔZ displacement stroke in raster arrays 12, 15, groups or regions of raster elements 24, 26, or individual raster elements 24, 26 can be 30 μm.

0114The displacement in the z direction is basically a displacement performed along the beam direction of the illumination light. The displacement of x or y is basically a displacement performed in the transverse direction with respect to the beam direction of the illumination light 8.

0115Alternatively, the displacement device 41 has a pivot axis in which one of the two raster arrays 12, 15 is parallel to, for example, the x-axis or the y-axis with respect to the other of the two raster arrays 15, 12. It can be designed to be pivotally rotatable around. In this case, the displacement device 41 is designed as a pivot device for at least one of the two raster arrays 12, 15.

0116Based on the raster module design, the above types of raster elements can be part of the first raster array 12 and / or part of the second raster array 15.

011712 First raster array 13 Raster module 15 Second raster array 24 First raster element 26 Second raster element 27, 28, 29, 30, 31 raster areas 36 distance steps