Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
  • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
  • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
  • G02B26/0841—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting element being moved or deformed by electrostatic means
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/08—Mirrors
  • G02B5/09—Multifaceted or polygonal mirrors, e.g. polygonal scanning mirrors; Fresnel mirrors
• • 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

Definitions

• Single mirror for constructing a facet mirror in particular for use in a projection exposure apparatus for micro-lithography
• the invention relates to a single mirror for constructing a facet mirror, in particular for use as a bundle-guiding optical component in a projection exposure apparatus for micro-lithography.
• the boundary shape of the reflection surface can be adapted to the number of movement electrodes.
• the reflection surface of the individual mirror can be designed, for example, triangular. Preference is given to a boundary shape of the individual mirror, with which a seamless tiling of a total reflection surface of a facet mirror can be created with identical individual mirrors.
• An embodiment of the movement electrode according to claim 3 provides the ability to continuously increase the contact surface portion when applying a voltage between the moving electrode and the counter electrode, wherein the distance between the moving electrode and the counter electrode is reduced in the distance surface portion, so that there is a high electric field strength resulting in correspondingly large actuating force.
• a progressively increasing according to claim 6 electrode spacing in the distance-surface portion creates the possibility of each themselves amplifying power development with increasingly applied electrical voltage between the electrodes.
• a voltage specification according to claim 7 makes it possible to bring about a precisely defined positioning of the mirror body to the carrier body even in a neutral position.
• the neutral position is then not predetermined by the force-free state of the at least one solid-state joint.
• a further object of the invention is to provide a single mirror for constructing a facet mirror, which is reproducible and precisely adjustable and at the same time ensures sufficient heat removal, in particular generated by residual-absorbed useful radiation, which is reflected by the individual mirror, by dissipating the heat from the mirror body.
• the size ratio according to the invention of the joint length to the joint strength ensures, given a low stiffness, in particular to achieve an adjustment displacement, that sufficient heat removal from the mirror body to the carrier body is ensured via the solid body joint.
• the joint length which is large compared to joint strength, ensures a sufficiently large heat transfer cross section through the solid-body joint. Due to the low joint strength in relation to the joint length, a given angular deflection of the mirror body is possible with little effort for adjusting the individual mirror. This creates the opportunity to use an actuator for tilting the mirror body, which manages with low forces and therefore, for example, can be designed very compact. As actuators for tilting the mirror body in particular those may be used which are used in the construction of conventional micromirror arrays.
• micromirror arrangements are known to the person skilled in the art under the heading "MEMS" (microelectromechanical systems), for example from EP 1 289 273 A1 Compared to known torsion suspensions of micromirrors (compare Yeow et al., Sensors and Actuators A 117 (2005) , 331-340) with a much lower L / S ratio, the heat transfer when using the solid-state joints according to the invention is markedly improved, which is particularly advantageous when heat has to be dissipated from the mirror body due to significant residual absorption, as is the case for example with the use of
• the heat transfer between the mirror body and the carrier body can be improved, for example, by using microchannels in the carrier body, which enable active cooling with a particularly laminar coolant flowing through.
• Two tilting joints according to claim 9 allow a variable adjustment of a deflection angle for incident on the mirror body useful radiation.
• a functional separation of the individual mirror body involved according to claim 10 allows a structurally simple interpretation of this.
• An embodiment with two solid-state joints according to claim 1 1 allows a good heat transfer over both solid joints.
• a good heat transfer is possible from the mirror body via the intermediate body to the carrier body.
• Separate solid-body joint sections according to claim 12 lead to a reduction of the flexural rigidity of the solid-body joint.
• a particularly capacitive electrode actuator according to claim 13 can be produced compactly and with micromachining techniques. For a given heat transfer can be realized on the inventive ratio of joint length and joint strength such a rigid little solid joint that typical forces that can be generated by such an electrode actuator and, for example, in the mN range are sufficient to produce necessary tilt angle.
• An actuator with an electrode stack according to claim 15 leads to the possibility of generating in total high adjusting forces given a given absolute voltage difference between adjacent electrodes.
• a reflection surface according to claim 17 has been found to be suitable for the design of the facet mirror according to the invention. If necessary, the mirror surface can also be made smaller and, for example, have a dimension spanning the mirror surface, which is in the range of a few tenths of a millimeter. Even larger mirror surfaces such as 1 mm 2 are possible.
• the reflection surface can have a rectangular, a hexagonal or even a triangular boundary shape. Other, polygonal boundary formations, for example pentagonal, are also possible.
• a Kippachsenverlauf according to claim 18 allows a precise adjustment of the useful radiation. If the tilting axis lies in the plane of the mirror surface, a tilting of the individual mirror leads to no offset of the failing useful radiation or at most to a very small offset.
• a lateral arrangement of the tilting joint according to claim 19 allows a compact construction in terms of depth.
• a tilting joint arrangement according to claim 20 avoids dead surfaces on the plane of the reflection surface of the mirror body. Reflection surfaces of adjacent individual mirrors can then be arranged close to each other and virtually without a gap.
• An arrangement of the electrodes according to claim 23 simplifies the activation effort for an electrode actuator system of the individual mirror for specifying, for example, linearly targeted changes of a deflection of the incident useful radiation by the individual mirror.
• the advantages of a facet mirror according to claim 24 correspond to those which have already been explained above in connection with the individual mirror according to the invention.
• the facet mirror can have exactly one individual mirror according to the invention.
• the facet mirror may have a plurality of individual mirrors according to the invention.
• the facet mirror can have more than 50, more than 100, more than 200, more than 500 or even more than 1000 individual mirrors according to the invention.
• the individual controllability of the individual mirrors ensures that a large number of different illuminations of the object field become possible without losing light due to shadowing.
• an illumination optical system within which the facet mirror can be used to optical parameters of a radiation source for example to a beam divergence or to an intensity distribution over the beam cross section.
• the facet mirror can be designed so that several individual mirror groups each illuminate the entire object field.
• a single-mirror illumination channel is that part of the beam path of a beam guided by the facet mirror of the illumination radiation, which is guided by exactly one of the individual mirrors of the facet mirror. According to the invention, at least two such individual mirror illumination channels are required for illuminating the entire object field.
• the individual mirror illumination channels respectively illuminate object field sections whose size corresponds to the object field.
• both a field facet mirror subdivided according to the invention into individual mirrors and a pupil facet mirror subdivided into individual mirrors according to the invention are used. It is then possible to realize a specific illumination angle distribution, that is to say an illumination setting, by practically grouping the individual mirror groups on the field facet mirror and the pupil facet mirrors with virtually no loss of light.
• a specular reflector in the manner of that which is described, for example, in US 2006/0132747 A1 can also be subdivided into individual mirrors. Since both the intensity and the illumination angle distribution in the object field are set with the specular reflector, the additional variability due to the division into individual mirrors is particularly useful here.
• an illumination optical system can combine the advantages of a field facet mirror constructed from individual mirrors with those of a pupil facet mirror constructed from individual mirrors. It is possible to set different lighting settings with virtually no loss of light.
• the pupil facet mirror may have a larger number of individual mirrors than the upstream field facet mirror. With the upstream field facet mirror it is then possible to realize different illumination forms of the pupil facet mirror and thus different illumination settings of the illumination optics, as far as the facets can be displaced correspondingly actuatorally, in particular tilted, for the changeover.
• a projection exposure apparatus enables a high structural resolution.
• FIG. 1 schematically shows a meridional section through a projection exposure apparatus for EUV projection lithography
• FIG. 2 schematically shows a plan view of a field facet mirror constructed from individual mirrors for use in the projection illumination system according to FIG. 1;
• FIG. 1 schematically shows a meridional section through a projection exposure apparatus for EUV projection lithography
• FIG. 3 shows a plan view of a single mirror for constructing the field facet mirror according to FIG. 2;
• FIG. 4 shows a view of the individual mirror from the viewing direction IV in FIG. 3, wherein a reflection surface of the individual mirror is shown in an untilted neutral position;
• Fig. 5 is a partial enlargement of Fig. 4;
• FIG. 6 shows a view of the individual mirror from the viewing direction VI in FIG.
• FIG. 7 shows, in a representation similar to FIG. 4, the individual mirror in an actuatorically tilted tilted position
• FIG. 8 in a similar to Figure 4 representation of a further embodiment of an individual mirror.
• FIG. 9 shows a view similar to FIG. 6 of the individual mirror according to FIG. 8;
• FIG. 10 shows a perspective view of the embodiment of the individual mirror according to FIG. 10 in a tilted position, in which a mirror plate is tilted relative to a carrier substrate about one of two actuator-controllable tilting axes;
• FIG. 12 shows the individual mirror according to FIGS. 10 and 11 in a representation similar to FIG. 11, wherein the surface is shown tilted relative to the carrier substrate about both tilt axes;
• FIG. 13 shows a section of a tilting joint, designed as a solid-body joint, of the single mirror of one of the embodiments according to FIGS. 3 to 12;
• FIG. 14 shows, in a representation similar to FIG. 3, a further embodiment of an individual mirror for constructing the facet mirror according to FIG. 2;
• FIGS. 3 to 14 schematically shows an embodiment of an electrostatic capacitive wedge actuator for the controlled tilting of a mirror body of the individual mirrors according to FIGS. 3 to 14, wherein no voltage is applied between two electrodes of the actuator;
• FIG. 16 shows the actuator according to FIG. 15, wherein a voltage is applied between its electrodes
• FIG. 17 in a similar to Fig. 8 representation, a further embodiment of an individual mirror for the construction of the facet mirror 2, shown in a neutral position, wherein actuators are used according to FIGS. 15 and 16;
• FIG. 18 shows the individual mirror according to FIG. 17, shown in a first tilted position about a first of its two tilt axes;
• FIG. 19 shows the individual mirror according to FIG. 17, shown in a second tilted position opposite to FIG. 18, tilted about the same tilting axis as in the illustration according to FIG. 18;
• FIG. 20 shows a variant of the electrode arrangement of tilt actuators of the embodiment of the individual mirror according to FIG. 17;
• FIG. 21 is an exploded view, similar to FIG. 10, of the individual mirror with the electrode arrangement according to FIG. 20; FIG.
• FIG. 22 shows a side view of the individual mirror with the electrode arrangement according to FIG. 20;
• Fig. 23 is a perspective view of the single mirror with the
• FIG. 24 shows a variant of the electrode arrangement of tilt actuators of the embodiment of the individual mirror according to FIG. 17;
• FIG. 25 is an exploded view, similar to FIG. 10, of the individual mirror with the electrode arrangement according to FIG. 24;
• FIG. FIG. 26 shows a side view of the individual mirror with the electrode arrangement according to FIG. 24;
• FIG. 27 shows a perspective view of the individual mirror with the electrode arrangement according to FIG. 24;
• FIG. 28 shows schematically in a representation similar to FIG. 18 a further embodiment of an individual mirror for constructing the facet mirror according to FIG. 2 with a further embodiment of a tilt actuator with an electrode stack;
• FIG. 29 shows, in a representation similar to FIG. 17, a further embodiment of an individual mirror for constructing the facet mirror according to FIG. 2 with a design corresponding to FIG. 28 of tilt actuators;
• Fig. 30 is a similar to Fig. 18 representation of the individual mirror according to
• FIG. 31 is a perspective view of another embodiment of an individual tiltable actuator
• FIG. 32 shows a plan view of the individual mirror according to FIG. 31;
• FIG. 33 is a side view of the single mirror of FIG. 31; FIG. and
• FIG. 34 shows an exploded view of the individual mirror according to FIG. 31.
• FIG. 1 shows schematically in a meridional section a projection exposure apparatus 1 for micro-lithography.
• An illumination system 2 of the projection exposure apparatus 1 has, in addition to a radiation source 3, an illumination optical unit 4 for exposing an object field 5 in an object plane 6.
• a reticle arranged in the object field 5 and not shown in the drawing is exposed, which is held by a reticle holder (also not shown) is.
• a projection optical system 7 is used to image the object field 5 into an image field 8 in an image plane 9.
• a structure on the reticle is shown on a photosensitive layer of a wafer arranged in the region of the image field 8 in the image plane 9, which likewise is not shown in the drawing and is held by a wafer holder, also not shown.
• the radiation source 3 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.
• a radiation source based on a synchrotron can also be used for the radiation source 3. 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 10 emanating from the radiation source 3 is bundled by a collector 11. A corresponding collector is known from EP 1 225 481 A.
• the EUV radiation 10 After the collector 11, the EUV radiation 10 propagates through an intermediate focus plane 12 before it encounters a field facet mirror 13.
• the field facet mirror 13 is arranged in a plane of the illumination optics 4 which is optically conjugate to the object plane 6.
• the EUV radiation 10 is hereinafter also referred to as illumination light or as imaging light.
• the EUV radiation 10 is reflected by a pupil facet mirror 14.
• the pupil facet mirror 14 is arranged in a pupil plane of the illumination optics 4, which is optically conjugate to a pupil plane of the projection optics 7.
• individual field facets 19, which are also described in greater detail below, are also referred to as subfields or as individual mirror groups be imaged, the field facet mirror 13 in the object field 5.
• the last mirror 18 of the transfer optics 15 is a grazing incidence mirror.
• Fig. 2 shows details of the structure of the field facet mirror 13 in a highly schematic representation.
• An entire reflection surface 20 of the field facet mirror 13 is divided into rows and columns into a grid of individual mirrors 21.
• the individual reflection surfaces of the individual individual mirrors 21 are planar.
• An individual mirror row 22 has a plurality of individual mirrors 21 located directly next to one another. In a single-mirror row 22, several tens to several hundred of the individual mirrors 21 may be provided. In the example of FIG. 2, the individual mirrors 21 are square. Other forms of individual mirrors, which allow the most complete possible occupancy of the reflection surface 20 may be used. Such alternative single mirror shapes are known from the mathematical theory of tiling.
• the field facet mirror 13 may, for example, be designed as described in DE 10 2006 036 064 A1.
• FIG. 2 a Cartesian xyz coordinate system is shown in FIG. 2 as a local coordinate system of the field facet mirror 13.
• Corresponding local xyz coordinate systems can also be found in the following figures, which show facet mirrors or a section thereof in plan view.
• the x axis runs horizontally to the right parallel to the individual mirror lines 22.
• the y axis runs in FIG. 2 upwards parallel to the individual mirror columns 23.
• the z axis is perpendicular to the plane of the drawing Fig. 2 and runs out of this.
• the reticle holder and the wafer holder are scanned synchronously with one another in the y direction. Also, a small angle between the scanning direction and the y-direction is possible, as will be explained.
• the reflection surface 20 of the field facet mirror 13 has an extension of X 0 .
• the reflection surface 20 of the field facet mirror 13 has an extension of y 0 .
• the individual mirrors 21 have x / y extensions in the range, for example, of 600 ⁇ m x 600 ⁇ m to, for example, 2 mm x 2 mm.
• the entire field facet mirror 13 has a xo / yo extension which, depending on the design, is for example 300 mm ⁇ 300 mm or 600 mm ⁇ 600 mm.
• the field single facets 19 have typical x / y dimensions of 25mm x 4mm or 104mm x 8mm.
• each of the individual field facets 19 has a corresponding number of individual mirrors 21.
• Each of the individual mirrors 21 is connected to an actuator or actuator 24 for individual deflection of incident illumination light 10, as indicated in dashed lines in FIG. 2 with reference to two individual mirrors 21 arranged in a corner at the bottom left of the reflection surface 20 and closer in FIG FIG. 3 is illustrated on the basis of a detail of a single facet line 22.
• the actuators 24 are arranged on the side of each of the individual mirrors 21 facing away from a reflective side of the individual mirrors 21.
• the actuators 24 may be designed, for example, as piezo actuators. Embodiments of such actuators are known from the construction of micromirror arrays.
• the actuators 24 of a single-mirror line 22 are each connected via signal lines to a row signal bus 26.
• a row signal bus 26 In each case one of the row signal buses 26 is assigned to a single-mirror row 22.
• the row signal busses 26 of the individual mirror rows 22 are in turn connected to a main signal bus 27.
• the latter is connected to a control device 28 of the field facet mirror 13 in signal connection.
• the control device 28 is in particular the rows, so line or column by column, common control of the individual mirror 21 executed.
• Each of the individual mirrors 21 is individually tiltable about two mutually perpendicular tilt axes, with a first of these tilt 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 21.
• the individual mirrors 21 can be realized, for example, in the manner of a micromirror array (MMA array) in which the individual mirrors are movably mounted by means of laterally mounted spring joints and can be electrostatically actuated.
• MMA array micromirror array
• MEMS microelectromechanical systems
• the individual mirrors 21 provide illumination channels for superimposing the EUV radiation 10, that is to say the illumination radiation, in the object field 5 of the projection exposure apparatus 1.
• the individual mirrors 21 have mirror surfaces with such an extent that these individual mirror illumination channels in the object field 5 illuminate object sections which are smaller than the object field 5.
• the individual mirrors 21 can have a multilayer coating with individual layers of molybdenum and silicon, so that the reflectivity of the individual mirrors 21 is optimized for the EUV wavelength used.
• An embodiment of an individual mirror for example one of the individual mirrors 21 for constructing the field facet mirror 13 according to FIG. 2, will be explained in more detail below with reference to FIGS. 3 to 7. Components which correspond to those which have already been explained above with reference to FIGS. 1 to 2 bear the same reference numerals and will not be discussed again in detail.
• the individual mirror 21 according to FIGS. 3 to 7 has a mirror body 79 designed as a mirror plate.
• the mirror body 79 is made of silicon.
• the mirror body 79 has a rectangular and in the embodiment of FIGS. 3 to 7 approximately square reflection surface 80 for reflection of the EUV radiation 10.
• the reflection surface 80 may be a multi-layer reflection coating to optimize the reflectivity of the single mirror 21 for the EUV radiation 10th exhibit.
• the mirror body 79 of the individual mirror 21 can be tilted about two tilt axes relative to a rigid carrier body 81 made of silicon. These two tilt axes are designated in FIGS. 3 to 7 with W 1 and W 2 .
• Each of these two tilt axes W 1 , W 2 belongs to a tilting joint 82, 83, which is in each case designed as a solid-body joint.
• the two tilt axes W 1 , W 2 are perpendicular to each other.
• the tilting axis W 1 runs parallel to the x-axis and the tilting axis W 2 runs parallel to the y-axis.
• the mirror body 79 and the carrier body 81 may also be formed of FiO 2 or Fi 3 N 4 .
• the tilting axis W 2 extends in the plane of extension of the mirror body 79.
• the two tilt axes W 1 , W 2 both run parallel to the plane of the reflection surface 80.
• the tilting joints 82, 83 it is also possible for the tilting joints 82, 83 to be arranged in this way. are arranged, that at least one of the two tilt axes W 1 , W 2 extends in the plane of the reflection surface 80.
• EUV and high-vacuum compatible materials which are suitable for constructing the individual mirror 21 are CVD (Chemical Vapor Deposition) diamond, SiC (silicon carbide), SiO 2 (silicon oxide), Al 2 O 3 , copper , Nickel, aluminum alloys and molybdenum.
• CVD Chemical Vapor Deposition
• SiC silicon carbide
• SiO 2 silicon oxide
• Al 2 O 3 copper
• Nickel nickel
• molybdenum molybdenum
• Fig. 5 shows the tilting axis W 1 associated tilting joint 82 in an enlarged view.
• the tilting joint 83 is formed accordingly.
• the tilting joint 82 has a joint thickness S perpendicular to the tilt axis W 1 , that is to say in the z direction in FIG. 5. Along the tilt axis W 1 , that is to say in the x direction in FIG. 5, the tilting joint 82 has a joint length L (see Fig. 6). The joint length L is comparable in size with a transverse extent of the mirror body 79.
• the joint length L in the individual mirror 21 according to FIGS. 3 to 7 is approximately 1 mm.
• the joint strength S, which is shown exaggerated in the drawing, is 1 micron.
• the quotient L / S is therefore approximately 1000 in the individual mirror 21 according to FIGS. 30 to 34.
• a material taper which leads to the joint strength S of the solid-state tilting joint 82 and is shown by way of example as a V-shaped notch in FIG. 5, can be produced, for example, by anisotropic AOH etching. Alternatively, it is possible to bring a material arm of the tilting joint 82 overall, for example, by an etching process to a strength corresponding to the joint strength S.
• the mirror body 79 is integrally connected to an intermediate carrier body 84.
• the intermediate carrier body 84 is also made of silicon.
• the intermediate carrier body 84 is L-shaped in the cross-section of FIG.
• Kippgelenks 83 is located between the mirror body 79 and the hinge portion 85 of the intermediate carrier body 84 before a distance B (see Fig. 6) before, which is also referred to as the width of the tilting joint 83.
• the plate portion 86 of the intermediate carrier body 84 is integrally connected via the tilting joint 82 with a hinge portion 87 of the support body 81.
• the hinge portion 87 is fixed to a plate portion 88 of the support body 81.
• the plate section 88 of the carrier body 81 is arranged below the plate section 86 of the intermediate carrier body 84. In the neutral position shown in FIGS. 4 and 6, the mirror body 79, the plate portion 86 of the intermediate carrier body 84 and the plate portion 88 of the carrier body 81 extend parallel to each other.
• the electrode actuator 89 is associated with the tilting joint 82, so that it is also referred to as w r actuator 90.
• the electrode actuator 90 is assigned to the tilting joint 83, so that it is also referred to as w 2 actuator. is drawing.
• the w 2 actuator has as the first electrode the mirror body 79 itself, which is designed to be electrically conductive.
• a counter-electrode 91 of the w 2 -actuator 90 is embodied as a conductive coating applied to the plate section 86 of the intermediate carrier body 84, which faces the mirror body 79. In the neutral position of the single mirror 21, the counter electrode 91 to the mirror body 79 has a distance of about 100 microns.
• the two electrodes 90, 91 of the W 2 actuator 90 are connected to a controllable voltage source 93.
• the voltage source 93 is connected to an actuator control device 95.
• the counter electrode 91 simultaneously serves as an electrode for the Wi actuator 89.
• a counter electrode 96 of the w r actuator 89 is designed as a conductive coating on the plate section 88 of the carrier body 81.
• the counter electrode 96 of the w ⁇ actuator 89 is arranged on the side of the plate section 88 of the carrier body 81 facing the plate section 86 of the intermediate carrier body 84. In the neutral position, ie in the force-free state, the distance of the counter electrode 96 of the WpAktuatros 89 to the plate portion 86 of the intermediate carrier body 84 is 100 microns.
• the electrodes 91, 96 are in electrical connection with a further voltage source 97.
• the voltage source 97 is connected via a further control line 98 to the actuator control device 95 in connection.
• the amount of the tilt angle about the respective tilt axis Wi, W 2 depends, inter alia, on the dimensioning of the tilting joints 82, 83, of the surface of the electrodes 90, 91, 96, their distance from each other and of course the size of the applied voltages Vl, V2 from.
• About the applied voltages Vl, V2 is a stepless tilt angle specification about the two tilt axes W 1 , W 2 possible.
• FIG. 7 shows a tilted position in which, on application of the voltages V 1, V 2, a tilting of the plate section 86 of the intermediate carrier body 84 relative to the plate section 88 of the carrier body 81 relative to the tilting axis W 1 and on the other hand a tilting of the mirror body 79 to the plate portion 86 of the intermediate carrier body 84 and on this to the tilt axis W 2 is done.
• Incident EUV radiation 10 is deflected in a correspondingly defined manner by the reflection surface 80 of the mirror body 79, as indicated in FIG. 7.
• FIGS. 8 and 9 A further embodiment of an individual mirror 99 will now be described with reference to FIGS. 8 and 9, which may be used instead of the single mirror 21 according to FIGS. 3 to 7 for the construction of a facet mirror as explained above.
• Components which correspond to those which have already been explained above with reference to FIGS. 1 to 2 and in particular with reference to FIGS. 3 to 7 bear the same reference numerals and will not be discussed again in detail.
• the usable reflection surface 80 of the individual mirror 99 covers the entire surface of the mirror body 79 free of dead spots.
• a plate-shaped reflective surface support 100 is fixed to the connecting strip 101 at the edge along the y-direction with a hinge section 102 of the mirror body 79 connected.
• the hinge portion 102 is also plate-shaped and occupies approximately half the area of the reflection surface 80 of the individual mirror 99 a.
• the joint section 102 extends parallel to the reflection surface carrier 100 and behind the reflection surface 80.
• the joint section 102 of the mirror body 79 is connected to a w 2 hinge section 103 of an intermediate carrier body 104 of the individual mirror 99.
• the intermediate carrier body 104 corresponds in terms of its function to the intermediate carrier body 84 of the individual mirror 21 according to FIGS. 3 to 7.
• the tilting joint 83 of the individual mirror 99 also extends along the entire width of the reflection surface 80, ie along the joint length L corresponding to the embodiment according to FIGS. 3 to 7. This also applies to the tilting joint 82 of the individual mirror 99.
• a connecting strip 105 of the w 2 joint portion 103 is fixedly connected to a turn plate-shaped W 1 joint portion 106 of the intermediate carrier body 104.
• the hinge section 106 in turn occupies approximately half the area of the reflection surface 80 of the individual mirror 99.
• the rectangular shape of the joint portion 106 is oriented rotated by 90 ° to the rectangular shape of the joint portion 102 oriented.
• the W 1 hinge section 106 is integrally connected via the tilting joint 82 with a hinge portion 107 of the support body 81.
• the joint portions 102, 103 on the one hand and 106, 107 on the other hand extend over the entire joint length L of the tilting joints 83, 82.
• the w 2 -actuator of the tilting joint 83 includes in turn the mirror body 79 and furthermore two counterelectrodes 108, 109 which are arranged on the plate section 88 of the intermediate carrier body 104 as two electrically insulated from one another and from the hinge section 103 separate coatings.
• the two counterelectrodes 108, 109 each cover approximately one half of the plate section 88 of the intermediate carrier body 104.
• the reflection surface can be tilted about the tilt axis W 2 in FIG. 9 in the counterclockwise direction.
• a breakover voltage between the electrodes 79, 109 the mirror body 79 can be tilted in the clockwise direction in FIG. 9.
• Counter electrodes 110, 111 serve as counterelectrodes for the electrodes 108, 109 for the w r actuator.
• the counterelectrodes 110, 111 are comparable to the electrodes 108, 109 applied as coatings on the plate section 88 of the carrier body 81 and separated from each other by the hinge section 107 separated and thus electrically isolated.
• tilting of the intermediate carrier body 104 in FIG. 8 takes place about the tilting axis Wj in a clockwise direction.
• a voltage-controlled tilting of the reflection surface 80 of the individual mirror 99, starting from the neutral position shown in FIGS. 8 and 9, is possible around both tilt axes W 1 , W 2 in each of the two tilt directions.
• FIGS. 10 to 12 A further embodiment of an individual mirror 112 is explained below with reference to FIGS. 10 to 12. Components which correspond to those which have already been explained above with reference to FIGS. 1 to 2 and in particular with reference to FIGS. 3 to 9 bear the same reference numerals and will not be discussed again in detail.
• the reflection surface carrier 100 is connected to the connection strip 101, which at the same time represents the joint section 102.
• a spacer 112a is arranged on the side of the reflection surface carrier 100 opposite the reflection surface 80, which ensures that the reflection surface carrier 100 does not come into direct contact with underlying components at larger tilt angles.
• the spacer 112a is machined from the solid material of the reflective surface carrier 100 by Deep Reactive Ion Etching (DRIE).
• DRIE Deep Reactive Ion Etching
• Via a first W 2 - tilt joint 83 of the joint portion 102 is connected to the w 2 joint portion 103, which simultaneously represents a first, L-shaped intermediate carrier body of the individual mirror 112.
• the w 2 joint section 103 is connected to a first joint section 107 which is rigidly connected to the plate section of the carrier body 81 is.
• a leg of the L-shape of the w 2 joint section 103 simultaneously represents the Wi joint section 106.
• the individual mirror 112 has a total of two L-shaped assemblies with joint sections 102, 103, 106, 107 and, correspondingly, with tilting joints 82, 83, which are each housed in one leg of this L-type construction. These two L-shaped assemblies each have the same joint joint components. In the area of the corner of the respective L-type construction, which is formed by the adjoining L-legs, these two assemblies are fitted into one another such that a total of a cross-shaped structure results (see also the construction of identical construction in this connection to be described Fig. 21), wherein in each case the two W 1 -Kippgelenke 82 and the two W 2 - Kippgelenke 83 are aligned.
• the spacer 112a is connected to the connecting strips 101 of the two w 2 tilt joints 83, respectively. Since the two connection strips 101 are arranged offset to one another parallel to the plane of the reflection surface 80 and transversely to their longitudinal extent due to the cross structure of the two L-assemblies, the spacer 112 also has two spacer sections arranged offset from one another in the same direction.
• the mirror body 79 itself serves as the electrode of the w r actuator on the one hand for controlled tilting of the reflection surface 80 about the tilt axis W 1 and the w 2 actuator on the other hand for the controlled tilting of the reflection surface 80 about the tilt axis w 2.
• the individual mirror 112 has four counterelectrodes 114 , 115, 116, 117, which respectively cover quadrants of the plate section 88 of the carrier body 81 and are used as counterparts. insulated conductive layers are formed on the plate portion 88.
• a breakdown voltage V is applied, a corresponding tilting of the reflection surface 80 results relative to the carrier body 81.
• a voltage V between the mirror body 79 and the two counter electrodes 114, 117 is applied.
• the result is a corresponding tilting of the mirror body 79 about the tilting axis Wi of the tilting joint 82.
• FIG. 12 shows in a further tilting example the situation in which a voltage V is applied exclusively between the mirror body 79 and the counterelectrode 114. This results in a tilting on the one hand about the tilting axis W 1 of the tilting joint 82 and on the other hand a tilting about the tilting axis W 2 of the tilting joint 83.
• FIG. 13 shows, in an alternative representation to FIG. 5, the dimensional relationships in a further embodiment of the tilting joint 82.
• a joint strength S is approximately 1 ⁇ m
• a joint width B is approximately 20 ⁇ m
• a joint length L perpendicular to the plane of the drawing about 1 mm.
• FIG. 14 shows a variant of a tilting joint 82 or 83, in which a segmentation in solid-body joint segments 118 is present along the joint length L.
• the joint length L is divided in the embodiment of FIG. 14 in about twenty-five such solid segments 118. Adjacent ones of the solid-body articulated segments 118 have a spacing, albeit very small.
• the subdivision of the tilting joint 82 or se 83 into the solid-state articulated segments 118 may be by Deep Reactive Ion Etching (DRIE).
• DRIE Deep Reactive Ion Etching
• microchannels may also be provided in the mirror body 79 and / or in the carrier body 81. These microchannels can enable active cooling of the individual mirror with a cooling fluid, in particular a cooling fluid, flowing through in particular laminar.
• FIGS. 15 and 16 show a further embodiment of an actuator 119 for controlled tilting of the reflection surface 80, for example of the individual mirror 21, about the at least one tilt axis Wj, W 2 .
• actuator 119 for controlled tilting of the reflection surface 80, for example of the individual mirror 21, about the at least one tilt axis Wj, W 2 .
• the actuator 119 has a movement electrode 120 whose free end 121 in FIGS. 15 and 16 is designed for movable connection to a joint body, not shown in FIGS. 15 and 16, of a tilting joint assigned to the actuator 119.
• the movement electrode 120 is designed flat and shown in Figs. 15 and 16 in cross section. In the section of FIGS. 15 and 16, the movement electrode 120 is bent.
• the counter electrode 122 is designed for example as a coating on the plate portion 88 of the support body 81.
• a layer in the form of a dielectric 123 is arranged between the movement electrode 120 and the counterpart electrode 122.
• the dielectric 123 may, for example, be designed as a planar coating on the counterelectrode 122.
• the counter electrode 122 abuts directly on the dielectric 123.
• a distance surface portion 125 of the moving electrode 120 is spaced from the counter electrode 122 and the dielectric 123.
• the free end 121 of the movement electrode 120 is part of the spacer surface portion 125.
• FIGS. 15 and 16 show two positions of the movement electrode 120.
• FIG. 15 shows a neutral position in which no voltage is applied between the two electrodes 120, 122. The free end 121 of the movement electrode 120 is then lifted at most far from the plate portion 88.
• 16 shows the position in which a breakover voltage of, for example, 80 V is applied between the electrodes 120, 122.
• the movement electrode 120 additionally lays against the dielectric 123 via a region adjacent to the abutment surface section 124, so that the distance between the free end 121 and the plate section 88 of the carrier body 81 is correspondingly reduced.
• Such actuators 19 according to FIGS. 15 and 16 are also referred to as micro wedge drives (zipper actuators, zipping actuators).
• FIGS. 17 to 19 show the use of two actuators 119 according to FIGS. 15 and 16 in the case of a single mirror 126, which is designed with regard to the arrangement of the tilting joints 82, 83 corresponding to the individual mirror 99 according to FIGS. 8 and 9.
• the Wi-joint portion 106 is formed at the single mirror 126 as integrally formed on the hinge portion 107 rocker about the tilt axis W 1 .
• two luffing jibs 127, 128 of the Wp joint section 106 are connected to the free ends 121 of two actuators 119 arranged back to back relative to the contact surface sections 124.
• FIG. 17 shows a neutral position of the two actuators 119, in which the Wi-hinge section 106 is not tilted relative to the plate section 88 of the carrier body 81.
• this neutral position according to FIG. 17 can be achieved in that all the electrodes 120, 121 are disconnected from the voltage.
• An alternative voltage control for the actuator 119 which is not shown in the drawing, is configured such that in a neutral position of the Wi joint section 106, ie the rocker arm 127, 128 (see Fig. 17) between the movement electrodes 120 and the associated counterelectrodes 122 of OV different bias is applied.
• Such an electrical bias serves to generate a mechanical bias of the rocker arms 127, 128 about the tilt axis Wi. In this way, the neutral position, in which the mirror body 79 is aligned exactly parallel to the carrier body 81, defined to be adjusted.
• FIG. 18 shows the situation in which a tilting voltage is applied to the electrodes 120, 122 of the actuator 119 shown on the left in FIG. Accordingly, the mirror body 79 is tilted about the tilt axis Wi counterclockwise.
• FIG. 19 shows the situation where a breakover voltage is applied to the actuator 119 shown in FIG. 19 on the right. Accordingly, the mirror body 79 is tilted about the tilt axis Wi in FIG. 19 in the clockwise direction.
• FIGS. 20 to 23 on the one hand and FIGS. 24 to 27 on the other hand show two different design and arrangement variants of the movement electrodes 120. Components which correspond to those which have already been explained above with reference to FIGS. 1 to 19 carry the same Reference numbers and will not be discussed again in detail.
• the counter electrodes to the moving electrodes 120 of the arrangements according to FIGS. 20 to 27 are designed as quadrant electrodes 114 to 117 corresponding to the embodiment according to FIGS. 10 to 12.
• the actuator 119 there are four movement electrodes 120 arranged radially on the plate section 88 of the carrier body 81 in each case in one of the quadrants of the plate section 88.
• the free ends 121 of the movement electrodes 120 according to FIGS. 20 to 23 are each arranged near the four corners of the square plate portion 88 of the carrier body 81.
• These free ends 121 carry contact portions 129, via which the movement electrodes 120 are movably connected to the intermediate carrier body or the mirror body 79.
• the contact section 129 represents a connection region of the movement electrode 120, for example, to the W 1 joint section 106, ie to a joint body. Opposite the free end 121, each of the movement electrodes 120 in the embodiment according to FIGS.
• each of the moving electrodes 120 is in the form of a spiral sheet. Between a fixed end 130 of the movement electrode 120 according to FIGS. 24 to 27, where it is fixed to the plate portion 88, and the contact portion 129 at the free end 121, each of the movement electrodes 120 passes through about three spiral turns.
• four movement electrodes 120 are also arranged in the arrangement according to FIGS. 24 to 27, one of the four movement electrodes 120 being arranged in each of the four quadrants of the plate section 88.
• each movement electrode 120 is in the arrangement according to Figs. 24 to 27 near a corner of the respective quadrant of the plate portion 88.
• the contact portions 129 are in the arrangement according to FIGS. 24 to 27 in the region of the center respective quadrants of the plate section 88.
• the actuator 119 may also have an electromagnetic drive instead of an electrostatic drive.
• an electromagnetic reluctance actuator is provided instead of the counter electrode 122 and the dielectric 123.
• a thin, ferromagnetic metal plate is provided.
• FIGS. 28 to 30 A further embodiment of an actuator 131 for the controlled tilting of the mirror body 79 about a tilting axis will be explained below with reference to FIGS. 28 to 30.
• an electrically conductive coating 132 on the plate section 88 of the carrier body 81 serves once again as one of the electrodes of the actuator 131.
• a stack 133 of counter electrodes 134, 135, 136 is arranged above this electrode 132. Adjacent of the counterelectrodes can be tilted relative to each other by a solid-state joint 137 which is shown schematically in FIG. 28.
• Each of the solid-state hinges 137 extends along the entire width of a reflection surface on the mirror body 79 corresponding to the tilting joints 82, 83 described above.
• FIG. 28 shows in a solid state the situation in which an additional breakover voltage is applied between adjacent ones of the electrodes 132 and 134 to 136.
• adjacent ones of the electrodes 132 and 134 to 136 starting from the neutral inclination position, are further tilted toward one another by deflection about the solid-state hinges 137.
• the counterelectrode 136 shown at the top in FIG. 28 experiences an angle of inclination which corresponds to the sum of the relative inclinations of the electrode pairs arranged underneath.
• the mirror body 79 can in turn be connected to the counterelectrode 136 shown at the top in FIG. 28, which is then tilted in accordance with the actuator.
• a total tilt angle of the uppermost counterelectrode 136, ⁇ is the sum of the individual tilt angles ⁇ i, ⁇ 2 , ⁇ 3 of the counterelectrodes 134, 135 and 136.
• the actuators 131 with the counter-electrode stacks 133 are arranged between the plate section 88 of the carrier body 81 and the luffing arms 127, 128 of the Wi-joint section 106 of the intermediate carrier body 104.
• the solid-body joints 157 are arranged adjacent to the tilting axis Wi.
• Fig. 29 shows the neutral position.
• 30 shows the position in which a tilting voltage is applied to the electrodes 132 and 134, 135, 136 of the actuator 131 shown on the left in FIG. The result is a tilting of the Wi-joint portion 106 in FIG. 30 about the tilting axis Wi counterclockwise.
• L / S can be greater than 50, greater than 100, greater than 250 or greater than 500.
• a ratio of L / S greater than 1000 is also possible.
• FIGS. 31 to 34 A further embodiment of an individual mirror 139 with actuators in the manner of the actuators 119 for the controlled tilting of the mirror body 79 will be explained below with reference to FIGS. 31 to 34. Components corresponding to those discussed above with reference to Figs. 1 to 30 and more particularly to Figs. 3 to 30 bear the same reference numerals and will not be discussed again in detail.
• the mirror body 79 and also the reflection surface 80 have the shape of an equilateral triangle in the individual mirror 139.
• the side length of one of the three sides can be about 1 mm.
• one of the actuators 119 is arranged parallel to one of the three sides of this triangle.
• Each of the actuators 119 has a movement electrode 120 which is connected to the mirror body 79 via a contact section 129 and to the support body 81 via a contact surface section 124.
• An actuation of the three actuators 119 can be carried out independently of one another in accordance with what has been described above in connection with the explanation of the actuator 119 according to FIGS. 15 to 27. In this way, a tilting of the reflection surface 80 relative to the carrier body 81 by three independent tilting degrees of freedom is possible.
• the arrangement of the three actuators 119 is such that the contact sections 129 are each arranged above the contact surface section 124 of the actuator 119, which is adjacent to the individual mirror 139 in a counterclockwise direction.
• the individual mirror 139 has no joints of the type of tilting joints 82, 83.
• the above-explained actuators for tilting the mirror body 79 may have an integrated sensor system for measuring the respective tilt angle about the tilt axes W 1 , W 2 .
• This sensor can be used in particular for monitoring the set tilt angle.
• Such a sensor system can be formed, for example, by a capacitive measuring bridge, in particular in the form of a Wien bridge.
• a capacitive measuring bridge in particular in the form of a Wien bridge.
• a DC voltage which is used for the above-explained actuator of the mirror body 79, be superimposed by an AC component, which is applied between the above-described electrodes.
• An impedance change of the sought-after capacitance can then be measured by means of the integrated measuring bridge.
• a zero balance is made, in which a known variable capacitance or a known, variable resistance is used within the bridge circuit.
• the measuring bridge itself may be embedded in an integrated circuit which is located directly below or even inside the carrier body 81. This ensures that parasitic capacitances are minimized due to short signal line lengths.
• a signal amplification and an A / D conversion of the sensor as well as an actuator control can take place in a likewise integrated ASIC (Application Specific Integrated Circuit).
• the reticle and the wafer are moved synchronously in the y-direction continuously in scanner mode or stepwise in stepper mode.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Mounting And Adjusting Of Optical Elements (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
• Optical Elements Other Than Lenses (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Related Child Applications (1)

Publications (2)

Family

ID=42262714

Family Applications (1)

Country Status (5)

Cited By (7)

Families Citing this family (21)

Citations (7)

Family Cites Families (27)

• 2009
  • 2009-01-09 DE DE200910000099 patent/DE102009000099A1/de not_active Withdrawn
• 2010
  • 2010-01-08 WO PCT/EP2010/000044 patent/WO2010079133A2/de not_active Ceased
  • 2010-01-08 JP JP2011544842A patent/JP2012514863A/ja active Pending
  • 2010-01-08 CN CN2010800042108A patent/CN102272636A/zh active Pending
• 2011
  • 2011-06-29 US US13/172,448 patent/US9013676B2/en active Active

Patent Citations (7)

Non-Patent Citations (5)

Also Published As

Similar Documents

Legal Events