WO2022074023A1 - Adaptives optisches element für die mikrolithographie - Google Patents
Adaptives optisches element für die mikrolithographie Download PDFInfo
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- WO2022074023A1 WO2022074023A1 PCT/EP2021/077485 EP2021077485W WO2022074023A1 WO 2022074023 A1 WO2022074023 A1 WO 2022074023A1 EP 2021077485 W EP2021077485 W EP 2021077485W WO 2022074023 A1 WO2022074023 A1 WO 2022074023A1
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- optical element
- measuring electrode
- adaptive optical
- dielectric medium
- element according
- Prior art date
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Classifications
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- 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
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
- G03F7/70883—Environment aspects, e.g. pressure of beam-path gas, temperature of optical system
- G03F7/70891—Temperature
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
-
- 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
- G02B26/0825—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 flexible sheet or membrane, e.g. for varying the focus
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- 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
- G03F7/70008—Production of exposure light, i.e. light sources
- G03F7/70025—Production of exposure light, i.e. light sources by lasers
-
- 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
- G03F7/70008—Production of exposure light, i.e. light sources
- G03F7/70033—Production of exposure light, i.e. light sources by plasma extreme ultraviolet [EUV] sources
-
- 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
- G03F7/70216—Mask projection systems
- G03F7/70258—Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
- G03F7/70266—Adaptive optics, e.g. deformable optical elements for wavefront control, e.g. for aberration adjustment or correction
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- 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
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/7085—Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load
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- 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
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
- G03F7/70883—Environment aspects, e.g. pressure of beam-path gas, temperature of optical system
Definitions
- the invention relates to an adaptive optical element for microlithography with at least one manipulator for changing the shape of an optical surface of the optical element and a projection exposure system for microlithography with at least one such adaptive optical element.
- Projection lenses are therefore equipped with manipulators that make it possible to correct wavefront errors by changing the state of individual optical elements of the projection lens.
- a state change include: a change in position in one or more of the six rigid body degrees of freedom of the relevant optical element and a deformation of the optical element.
- the optical element is usually implemented in the form of the above-mentioned adaptive optical element. This can have piezoelectric or electrostrictive manipulators to actuate the optical surface.
- the functioning of such manipulators is based on the deformation of a dielectric medium through the application of an electric field.
- the aberration characteristic of the projection lens is regularly measured and, if necessary, changes in the aberration characteristic between the individual measurements determined by simulation. For example, lens heating effects can be taken into account in the calculation.
- an adaptive optical element for microlithography with at least one manipulator for changing the shape of an optical surface of the optical element, the manipulator comprising: a dielectric medium which can be deformed by means of an electric field, working electrodes for Generation of the electric field in the dielectric medium, as well as a measuring electrode used for temperature measurement, which is arranged in direct connection with the dielectric medium and has a temperature-dependent resistance.
- An arrangement of the measuring electrode in direct connection with the dielectric medium is to be understood as meaning that the measuring electrode and the dielectric medium directly adjoin one another. That is, between the measurement No further medium, such as an adhesive layer, is arranged between the electrode and the dielectric medium.
- the measuring electrode can be embedded in the dielectric medium so that it is completely surrounded by the dielectric medium.
- the measuring electrode can also be arranged on a surface of the dielectric medium.
- the measuring electrode can be configured in particular from a noble metal, e.g. as a platinum electrode.
- a noble metal e.g. as a platinum electrode.
- suitable platinum electrodes are PT100 and PT1000.
- the adaptive optical element includes an evaluation device for converting the resistance value measured at the measuring electrode into a temperature value.
- the arrangement of the measuring electrode in direct connection with the dielectric medium enables a very precise measurement of the temperature of the dielectric medium, at least at least the temperature in a region of the dielectric medium adjoining the measuring electrode. Such a precise temperature measurement is not possible in the case of an arrangement that does not take place in a direct connection, such as the measuring electrode being glued on.
- the result of the measurement of the temperature of the dielectric medium can be taken into account or used when controlling the manipulator in order to correct the temperature.
- the length extension of the manipulator can thus be controlled more precisely, as a result of which the surface shape of the adaptive optical element can in turn be corrected with improved accuracy.
- the measuring electrode is arranged directly connected to the dielectric medium over an area of at least 1 mm 2 , in particular at least 5 mm 2 or at least 10 mm 2 .
- the measuring electrode is printed on a surface of the dielectric medium.
- the measuring electrode is linear with a large number of bends.
- the measuring electrode can be designed in the form of a wire which has a large number of bends.
- the bends are formed in such a way that the measuring electrode has a meandering shape.
- the measuring electrode has a flat shape with a length-to-width ratio of at least 2:1, in particular at least 3:1, at least 5:1 or at least 10:1.
- the flat shape can be rectangular, oval or configured in some other way.
- the working electrodes are arranged in the form of a stack of at least three electrodes and the measuring electrode is arranged outside of the stack.
- the measuring electrode is arranged outside of an active volume of the dielectric medium, in which a length expansion occurs during manipulator operation.
- the measuring electrode is arranged between two working electrodes, i.e. inside the stack of working electrodes.
- the dielectric medium is formed in one piece.
- a one-piece dielectric medium is understood to mean a coherent and seamless monolithic dielectric medium, ie any connections that may be present between different volume sections of the dielectric medium are seamless.
- Under a seamless A bond is understood to mean, for example, a connection that was created by sintering, but not a connection created by gluing. This means that individual volume areas of the dielectric medium cannot be separated from one another without changing or destroying the material structure in the separation area.
- the adaptive optical element also includes an electrical circuit, with which the electrical resistance of the measuring electrode can be measured.
- An electrical circuit is understood to mean the combination of electrical or electromechanical individual elements, such as a power source, resistors and measuring devices, etc. However, not all of the named individual elements have to be contained in the electrical circuit, in particular other individual electrical elements can also be used.
- the electrical circuit can comprise a two-wire circuit or a four-wire circuit for measuring the resistance at the measuring electrode.
- the electrical circuit is further configured to measure an impedance between the measuring electrode and one of the working electrodes.
- the impedance is measured between the measuring electrode and a grounded working electrode. This is preferably the working electrode closest to the measuring electrode.
- at least a capacitive resistance between the measuring electrode and said working electrode is measured by means of the impedance measurement.
- the capacitance corresponds to the imaginary part of the impedance.
- the electrical circuit includes at least one switch for switching between the resistance measurement and the impedance measurement.
- the electrical circuit comprises a frequency-controllable AC voltage source, which is connected to the fact that the resistance measurement can be carried out by means of a low AC voltage frequency and the impedance measurement can be carried out by means of a high AC voltage frequency.
- an evaluation device is provided which is used to determine a strain condition of the dielectric medium arranged in the area of the measuring electrode from a dependence of the impedance on the amplitude of an AC voltage applied to the measuring electrode for impedance measurement.
- the state of expansion is determined from the capacitive resistance determined by means of the impedance measurement.
- the adaptive optical element comprises a plurality of manipulators of the type mentioned, each with a measuring electrode, the measuring electrodes being connected in series to a direct current source.
- a voltmeter is connected to each of the measuring electrodes to measure the voltage drop across them. In this way, the number of wirings or cables required for measuring the resistance at the measuring electrodes can be reduced.
- the optical surface is configured to reflect EUV radiation. According to a further embodiment, the optical surface is configured to reflect DUV radiation, for example a wavelength of about 365 nm, about 248 nm, or about 193 nm.
- FIG. 1 shows an embodiment of a projection exposure system for microlithography with an adaptive optical element
- FIG. 2 shows a first embodiment of the adaptive optical element in an initial state and in a correction state
- FIG. 3 shows a further embodiment of the adaptive optical element in an initial state and in a correction state
- FIG. 4 shows a diagram which, for a manipulator of the adaptive optical element, illustrates a strain S as a function of an applied electric field E for different temperatures 0,
- 5 shows a diagram which illustrates a strain S as a function of the temperature 0 for the manipulator of the adaptive optical element
- 6 shows a first embodiment of a manipulator of the adaptive optical element according to FIG. 2 or 3 with a measuring electrode and an electrical circuit connected thereto,
- FIG. 7 shows a sectional view of the measuring electrode according to FIG. 6 along the line AA' in three different embodiments
- FIG. 8 shows a further embodiment of a manipulator of the adaptive optical element according to FIG. 2 or 3 with a measuring electrode and an electrical circuit connected thereto,
- FIG. 9 shows a further embodiment of a manipulator of the adaptive optical element according to FIG. 2 or 3 with a measuring electrode and an electrical circuit connected thereto,
- FIG. 10 shows a further embodiment of a manipulator of the adaptive optical element according to FIG. 2 or 3 with a measuring electrode and an electrical circuit connected thereto,
- FIG. 11 shows an embodiment of the adaptive optical optical element according to FIG. 2 or FIG. 3 with a plurality of manipulators arranged in series and an electrical circuit connected to the manipulators, and
- FIG. 1 a Cartesian xyz coordinate system is given in the drawing, from which the respective positional relationship of the components shown in the figures results.
- the y-direction runs perpendicular to the plane of the drawing into it, the x-direction to the right and the z-direction upwards.
- FIG. 1 shows an embodiment of a projection exposure system 10 for microlithography according to the invention.
- the present embodiment is designed for operation in the EUV wavelength range, i.e. with electromagnetic radiation having a wavelength of less than 100 nm, in particular a wavelength of approximately 13.5 nm or approximately 6.8 nm. Due to this operating wavelength, all optical elements are designed as mirrors.
- the invention is not limited to projection exposure systems in the EUV wavelength range. Further embodiments according to the invention are designed, for example, for operating wavelengths in the UV range, such as 365 nm, 248 nm or 193 nm. In this case, at least some of the optical elements are configured as conventional transmission lenses.
- a projection exposure system configured for operation in the DUV wavelength range is described below with reference to FIG.
- the projection exposure apparatus 10 includes an exposure radiation source 12 for generating exposure radiation 14.
- the exposure radiation source 12 is designed as an EUV source and can include a plasma radiation source, for example.
- the exposure radiation 14 first passes through an illumination optics 16 and is directed onto a photomask 18 by the latter.
- the photomask 18 has mask structures for imaging onto a substrate 24 and is movably mounted on a mask displacement stage 20 .
- the substrate 24 is slidably mounted on a substrate shifting platform 26 .
- the photomask 18 can be designed as a reflection mask or, alternatively, in particular for UV lithography, can also be configured as a transmission mask.
- FIG. 1 the photomask 18 can be designed as a reflection mask or, alternatively, in particular for UV lithography, can also be configured as a transmission mask.
- the exposure radiation 14 is reflected at the photomask 18 and then passes through a projection lens 22 which is configured to image the mask structures onto the substrate 24 .
- the substrate 24 is slidably mounted on a substrate shifting platform 26 .
- the projection exposure system 10 can be designed as a so-called scanner or as a so-called stepper.
- the exposure radiation 14 is guided within the illumination optics 16 and the projection objective 22 by means of a multiplicity of optical elements, presently in the form of mirrors.
- the illumination optics 16 comprise four optical elements 30-1, 30-2, 30-3 and 30-4 in the form of reflective optical elements or mirrors.
- the projection lens 22 also includes four optical elements 30-5, 30-6, 30-7 and 30-8, also in the form of reflective elements or mirrors.
- the optical elements 30 - 1 to 30 - 8 are arranged in an exposure beam path 28 of the projection exposure system 10 for guiding the exposure radiation 14 .
- the optical element 30-5 is configured as an adaptive optical element which has an active optical surface 32 in the form of its mirror surface, the shape of which can be actively changed to correct local shape errors.
- another one or more of the optical elements 30-1, 30-2, 30-3, 30-4, 30-5, 30-6, 30-7 and 30-8 can each be configured as an adaptive optical element .
- one or more of the optical elements 30-1, 30-2, 30-3, 30-4, 30-5, 30-6, 30-7 and 30-8 of the projection exposure system 10 can be movable be stored.
- each of the movably mounted optical elements is assigned a respective rigid-body manipulator.
- the rigid-body manipulators allow, for example, tilting and/or displacement of the assigned optical elements essentially parallel to the plane in which the respective reflecting surface of the optical elements lies. The position of one or more of the optical elements for correcting aberrations of the projection exposure system 10 can thus be changed.
- the projection exposure system 10 includes a control device 40 for generating control signals 42 for the manipulation units provided, such as the aforementioned rigid-body manipulators, one or more adaptive optical elements and/or possibly further manipulators.
- 1 shows the transmission of a control signal 42 to the adaptive optical element 30-5 by way of example.
- the control device 40 determines the control signals 42 on the basis of wavefront deviations 46 of the projection lens 22 measured by a wavefront measuring device 44 using a feedforward control algorithm.
- the adaptive optical element 30-5 is illustrated in a first embodiment in FIG.
- the representation in the upper section of FIG. 2 shows the adaptive optical element 30-5 in an initial state, in which the shape of the optical surface 32 has an initial shape, here a planar shape.
- the illustration in the lower section of FIG. 2 shows the adaptive optical element 30-5 in a correction state, in which the shape of the optical surface 32 has a changed shape, here a convex shape.
- the adaptive optical element 30-5 comprises a support element 34 in the form of a back plate and a mirror element 38, the upper side of which forms the active optical surface 32 and is used to reflect the exposure radiation 14.
- a large number of manipulators 36 also referred to as actuators, are arranged along the underside of the mirror element 38. These are preferably both in x-direction and in the y-direction, ie positioned in a two-dimensional arrangement along the underside of the mirror element 38 .
- the manipulators 36 only some of which are provided with a reference number in FIG. 2 for reasons of legibility, connect the support element 34 to the mirror element 38.
- the manipulators 36 are configured to change their extent when actuated along their longitudinal direction. In the embodiment according to FIG. 2, the manipulators 36 can be actuated transversely or perpendicularly to the optical surface 32. The manipulators are each controlled individually and can therefore be actuated independently of one another.
- centrally arranged manipulators 36 are increased in length by being actuated, so that the convexly curved shape for the optical surface 32 results.
- FIG. 3 A further embodiment of the adaptive optical element 30-5 is illustrated in FIG. 3 .
- the illustration in the upper section of FIG. 3 shows the adaptive optical element 30-5 in an initial state, in which the shape of the optical surface 32 has a flat shape as the initial shape.
- the representation in the lower section of FIG. 3 shows the adaptive optical element 30-5 in a correction state, in which the shape of the optical surface 32 has a convex curvature and thus a changed shape.
- the adaptive optical element 30-5 according to FIG. 3 differs from the embodiment according to FIG a rigid support member arranged parallel to the mirror member 38. This means that the manipulators 36 cannot be deformed transversely to the optical surface 32, as in FIG. 2, but rather parallel to the optical surface 32. These manipulators 36 are therefore also referred to as transverse manipulators.
- the manipulators 36 configured as transverse manipulators are embedded in one or more monolithic tiles.
- the manipulators 36 of the adaptive optical element 30-5 each comprise a dielectric medium 48 (see e.g. Fig. 6) which is deformable by application of an electric field.
- This can be a piezoelectric material or an electrostrictive material.
- piezoelectric material With piezoelectric material, the deformation is based on the piezoelectric effect, with electrostrictive material on the electrostrictive effect.
- the electrostrictive effect is understood to be the proportion of a deformation of a dielectric medium as a function of an applied electric field, in which the deformation is independent of the direction of the applied field and in particular is proportional to the square of the electric field.
- the linear response of the deformation to the electric field is called the piezoelectric effect.
- the expansion S of the manipulators 36 or actuators as a function of the electric field E applied is very temperature-dependent. This effect is illustrated in FIG. 4 using a schematic SE diagram of a manipulator 36 made with electrostrictive material for different temperatures 0 (%>O2>O1). Furthermore, as illustrated in FIG. 5, the dielectric medium expands significantly as the temperature 0 changes from the nominal temperature Oo due to its coefficient of thermal expansion, also known as CTE.
- the working electrodes 50 are arranged in combination with the one-piece dielectric medium 48 .
- the working electrodes 50 are contained in the dielectric medium 48 in the form of an electrode stack 51 .
- the electrode stack 51 contains eight plate-shaped working electrodes 50 arranged one above the other.
- the active volume 48a is shown as a white area in FIG.
- the area of the dielectric medium 48 which is arranged outside of the electrode stack is cross-hatched in FIG. 6 and is correspondingly referred to as the inactive volume 48b.
- the inactive volume 48b completely encloses the active volume 48a.
- the wiring 56 of the working electrodes 50 alternately connects them to an electrical ground 60 and to one pole of the adjustable voltage source 58 , the other pole of the voltage source also being connected to ground 60 .
- the electric field generated between each two adjacent working electrodes 50 thus also alternates. Since the dielectric medium 48 is an electrostrictive material in the present case, the expansion of the dielectric medium 48 caused by the electric field is independent of the direction of the electric field, ie the change in the expansion in the z-direction of the layers of the dielectric arranged between the electrodes 50 Medium 48 is rectified. When a control voltage U generated by the voltage source 58 is applied, the linear extension Az of the active volume 48a of the dielectric medium 48 changes in the z-direction. The magnitude of the change in elongation depends on the control voltage generated by the voltage source 58, according to one embodiment this value is proportional to the value of the control voltage.
- the measuring electrode 52 is used for temperature measurement and is made of platinum, in particular PT100 or PT1000, so that the measuring electrode 52 has an electrical resistance that is highly temperature-dependent.
- the measuring electrode 52 is arranged in the dielectric medium 48 and embedded in the inactive volume 48b, specifically between the mirror element 38 and the uppermost working electrode 50, in the dielectric medium 48, so that this is at least from above and below, ie from two sides, in the present Case even completely surrounded by the dielectric medium 48.
- the measuring electrode can be arranged in the middle of the inactive volume 48b.
- the measuring electrode 52 is thus arranged in direct connection with the dielectric medium 48 . This means that the measuring electrode 52 and the dielectric medium 48 directly adjoin one another.
- the shape is a rectangle with a length-to-width ratio of about 4:1, and in the embodiment 52-3 shown on the right, it is an oval with a length-to-width ratio of about 2 ,5:1 .
- the measuring electrode is formed in a line shape of a wire having a multiplicity of bends.
- the measuring electrode 52-2 thus has a meandering shape. Due to the wire-like design, the measuring electrode 52-2 has a comparatively high resistance, so that the current intensity required for resistance measurement can be kept as low as possible.
- the measuring electrodes 52-1, 52-2 and 52-3 each have an area of 1 mm 2 in the xy plane, so they are arranged in direct connection with the dielectric medium 48 over at least this area.
- the electrical circuit 54 to which the measuring electrode 52 is connected, comprises in the embodiment according to FIG Measuring electrode 52 are connected.
- This wiring 62 is used to carry out a four-wire measurement of the electrical resistance R of the measuring electrode 52.
- the measuring electrode 52 is acted upon by the direct current source 66 with a known electric current intensity.
- the voltage dropping at the measuring electrode 52 is tapped at high resistance and measured with the voltmeter 68 . In this arrangement, falsification of the measurement due to line and connection resistances is avoided.
- the resistance value 70 determined by the resistance measuring device 64 is converted by an evaluation device 72 into a current temperature value 74, also referred to as the actual temperature Ti.
- the actual temperature Ti is then forwarded to a control unit 76 for controlling the voltage source 58 connected to the working electrodes 60 .
- the control unit 76 is configured to specify the current voltage value U (reference number 78) to be generated by the adjustable voltage source 58 .
- a setpoint expansion value Az s (reference number 80) of the manipulator 36 in the z-direction is transmitted to the control unit 76 as part of the control signal 42 shown in FIG.
- the control unit 76 takes into account the influence of the measured actual temperature Ti on the expansion of the dielectric medium 48 in the z-direction when determining the voltage value 78 and adjusts the voltage value 78 forwarded to the voltage source 58 accordingly.
- the control unit 76 can alternatively or additionally be configured to generate a control signal for a heating or cooling device, with which the temperature in the dielectric medium 48 is adjusted or kept constant.
- FIG. 8 A further embodiment of a manipulator 36 according to one of FIGS. 2 and 3 is illustrated in FIG.
- the embodiment according to FIG. 8 differs from the embodiment according to FIG. 6 only in the configuration of the electrical circuit 54 connected to the measuring electrode 52.
- the electrical circuit 54 comprises a resistance measuring device, which is available in various embodiments, as the resistance measuring device 64 .
- This is connected directly to the measuring electrode 52, usually contains a direct current source and can, for example, also include a Wheatstone bridge.
- FIG. 9 differs from the embodiment of FIG. 6 in that the electrical circuit 54 in addition to measuring the resistance at the measuring electrode 52 also for measuring a complex impedance (reference number 82) between the measuring electrode 52 and the uppermost working electrode 50, ie the working electrode 50 immediately adjacent to the measuring electrode 52 is configured.
- the electrical circuit 54 in addition to measuring the resistance at the measuring electrode 52 also for measuring a complex impedance (reference number 82) between the measuring electrode 52 and the uppermost working electrode 50, ie the working electrode 50 immediately adjacent to the measuring electrode 52 is configured.
- the electrical circuit 54 has two switches S1 and S2 (reference number 84) for switching between the resistance measurement and the impedance measurement. If the switch S1 is closed and the switch S2 is open, the result is the wiring 62 of the measuring electrode 52 according to FIG. 6 for measuring the resistance. If, on the other hand, switch S1 is opened and switch S2 is closed, an impedance measuring device 86 is activated. In this switching state, the upper output of the impedance measuring device 86 is connected to the measuring electrode 52 . Like the uppermost working electrode 50, the lower output of the impedance measuring device 86 is connected to the electrical grounding 60.
- the impedance measuring device 86 comprises an AC voltage source 88 for applying an AC voltage to the measuring electrode 52, an ammeter 69 and other electrical components, such as an operational amplifier 90 and a resistor 92.
- the AC voltage source 88 is configured to measure the amplitude u (reference number 94) of the generated Alternating voltage to vary over time during the measurement process.
- the impedance measuring device 86 determines the impedance 82 for different amplitudes 94 on the basis of the current measured by the current measuring device 69 and forwards this to an evaluation device 96 .
- the evaluation device 96 determines a current strain state Di (reference number 98) of the dielectric medium 48 in the inactive volume 48b. In other words, the evaluation device 96 determines the Elongation state 98 from the dependence of the impedance 82 on the amplitude 94.
- the strain state 98 is forwarded to the control unit 76 in addition to the temperature value 74 determined by means of the resistance measuring device 64 .
- the control unit 76 also takes into account the strain state 98 in addition to the temperature value 74 already processed in the embodiment according to FIG to be determined with better accuracy, so that the setpoint expansion value 80 can be achieved with a high level of accuracy using the stress value 78 .
- FIG. 10 differs from the embodiment according to FIG. 9 in that the resistance measurement and the impedance measurement are carried out in a combined resistance/impedance measuring device 87, one end of the measuring electrode 52 being connected to the electrical ground 60 and the other end of the measuring electrode 52 is connected to the measuring device 87.
- the measuring device 86 according to FIG high frequency f2 can be operated.
- the AC voltage source 88 is operated at the low frequency fi, which has a value of approximately 0 Hz to 100 Hz, for example.
- the frequency fi is selected so low that the resistance 70 of the measuring electrode 52 can be measured by measuring the current intensity passing through the measuring electrode 52 using the current intensity measuring device 69 .
- the measured resistance, as in the 9 is converted into a current temperature value 74 by means of the evaluation device 72 and transmitted to the control unit 76.
- the AC voltage source 88 is operated at the high frequency f2, which has a value of approximately 100 Hz to 1 MHz, for example.
- the value of the frequency f2 is selected such that the complex impedance 82 between the measuring electrode 52 and the uppermost working electrode for different AC voltage amplitudes 94 can be measured analogously to the mode of operation of the impedance measuring device 86 according to FIG.
- the respective AC voltage amplitude 94 and the impedance 82 measured therewith is, as in the embodiment according to FIG.
- Fig. 11 illustrates an embodiment of the adaptive optical element 30-5 according to one of Figures 2 and 3 with a plurality of manipulators 36 arranged next to one another, i.e. in series optical element 30-5 shown.
- the electrical circuit 54 connects the measuring electrodes 52 of the manipulators in series and includes a direct current source 66 of the type shown in FIG 68 of the type shown in FIG. 6 for measuring the voltage drop across the measuring electrode 52 in question.
- FIG. 12 shows a schematic view of a projection exposure system 110 configured for operation in the DUV wavelength range, which includes illumination optics in the form of a beam shaping and illumination system 116 and a projection lens 122 .
- DUV stands for “deep ultraviolet” and designates a wavelength of the exposure radiation 114 used in the projection exposure system 110 between 100 nm and 250 nm.
- the beam shaping and illumination system 116 and the projection objective 122 can be arranged in a vacuum housing and/or surrounded by a machine room with corresponding drive devices.
- the DUV projection exposure system 1 10 has a DUV exposure radiation source 1 12 .
- a DUV exposure radiation source 1 12 for example, an ArF excimer laser can be provided, which emits exposure radiation 114 in the DUV range at, for example, approximately 193 nm.
- the beam shaping and illumination system 116 shown in FIG. 12 guides the exposure radiation 114 onto a photomask 118.
- the photomask 118 is designed as a transmissive optical element and can be arranged outside the systems 116 and 122.
- the photomask 118 has a structure which is imaged in reduced form on a substrate 124 in the form of a wafer or the like by means of the projection objective 122 .
- the substrate 124 is slidably mounted on a substrate shifting platform 126 .
- the projection objective 122 has a plurality of optical elements 130 in the form of lenses and/or mirrors for imaging the photomask 118 onto the substrate 124.
- the optical elements 130 include lenses 130-1, 130-4 and 130-5, the mirror 130-3 and the further mirror designed as an adaptive optical element 130-3.
- individual lenses and/or mirrors of the projection objective 122 can be arranged symmetrically to an optical axis 123 of the projection objective 122 .
- the number of lenses and mirrors of the DUV projection exposure system 110 is not limited to the number shown. More or fewer lenses and/or mirrors can also be provided.
- the mirrors are usually curved on their front side for beam shaping.
- An air gap between the last lens 130-5 and the substrate 124 can be replaced by a liquid medium 131 which has a refractive index>1.
- the liquid medium 131 can be, for example, ultrapure water.
- a Such a structure is also referred to as immersion lithography and has an increased photolithographic resolution.
- the medium 131 can also be referred to as an immersion liquid.
- the mirror configured as an adaptive optical element 130-2 is designed such that the shape of its mirror surface 132 can be actively changed to correct local shape errors.
- the mirror surface is therefore also referred to as an active optical mirror surface 132 .
- the adaptive optical element 130-2 is configured analogously to the adaptive optical element 30-5 described above with reference to FIGS. 1, 2, 3 and 11. All the statements made above with regard to the adaptive optical element 30-5 can thus be transferred to the adaptive optical element 130-2.
- actuator device Analogously to the projection exposure system 10 according to FIG. Without restricting the generality, only one actuator device is shown here in FIG. 12, but it goes without saying that a large number of actuator devices are preferably present, each of which can be controlled and/or regulated individually.
- liquid medium 132 active optical mirror surface
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JP2023520338A JP7482323B2 (ja) | 2020-10-08 | 2021-10-06 | マイクロリソグラフィ用適応光学素子 |
US18/188,814 US20230229091A1 (en) | 2020-10-08 | 2023-03-23 | Adaptive optical element for microlithography |
Applications Claiming Priority (2)
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DE102020212743.3A DE102020212743A1 (de) | 2020-10-08 | 2020-10-08 | Adaptives optisches Element für die Mikrolithographie |
DE102020212743.3 | 2020-10-08 |
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US18/188,814 Continuation US20230229091A1 (en) | 2020-10-08 | 2023-03-23 | Adaptive optical element for microlithography |
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WO2022074023A1 true WO2022074023A1 (de) | 2022-04-14 |
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PCT/EP2021/077485 WO2022074023A1 (de) | 2020-10-08 | 2021-10-06 | Adaptives optisches element für die mikrolithographie |
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US (1) | US20230229091A1 (de) |
DE (1) | DE102020212743A1 (de) |
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DE102021205425A1 (de) * | 2021-05-27 | 2022-12-01 | Carl Zeiss Smt Gmbh | Optikvorrichtung, Verfahren zur Einstellung einer Soll-Deformation und Lithografiesystem |
DE102022210244A1 (de) * | 2022-09-28 | 2024-03-28 | Carl Zeiss Smt Gmbh | Spiegelvorrichtung, insbesondere für eine mikrolithographische Projektionsbelichtungsanlage, und Verfahren zum Messen der Temperatur eines Spiegels |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2001013297A (ja) * | 1999-06-30 | 2001-01-19 | Nikon Corp | 反射光学素子および露光装置 |
US20110235012A1 (en) * | 2008-09-30 | 2011-09-29 | Carl Zeiss Smt Gmbh | Projection exposure apparatus for microlithography for the production of semiconductor components |
DE102010030442A1 (de) * | 2010-06-23 | 2011-12-29 | Endress + Hauser Wetzer Gmbh + Co Kg | Widerstandstemperatursensor |
DE102015213275A1 (de) * | 2015-07-15 | 2017-01-19 | Carl Zeiss Smt Gmbh | Spiegelanordnung für eine Lithographiebelichtungsanlage und Spiegelanordnung umfassendes optisches System |
US20190310555A1 (en) * | 2010-07-30 | 2019-10-10 | Carl Zeiss Smt Gmbh | Euv exposure apparatus with reflective elements having reduced influence of temperature variation |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
LU100594B1 (en) | 2017-12-22 | 2019-06-28 | Luxembourg Inst Science & Tech List | Piezoelectric device with a sensor and method for measuring the behaviour of said peizoelectric device |
-
2020
- 2020-10-08 DE DE102020212743.3A patent/DE102020212743A1/de not_active Ceased
-
2021
- 2021-10-06 WO PCT/EP2021/077485 patent/WO2022074023A1/de active Application Filing
-
2023
- 2023-03-23 US US18/188,814 patent/US20230229091A1/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001013297A (ja) * | 1999-06-30 | 2001-01-19 | Nikon Corp | 反射光学素子および露光装置 |
US20110235012A1 (en) * | 2008-09-30 | 2011-09-29 | Carl Zeiss Smt Gmbh | Projection exposure apparatus for microlithography for the production of semiconductor components |
DE102010030442A1 (de) * | 2010-06-23 | 2011-12-29 | Endress + Hauser Wetzer Gmbh + Co Kg | Widerstandstemperatursensor |
US20190310555A1 (en) * | 2010-07-30 | 2019-10-10 | Carl Zeiss Smt Gmbh | Euv exposure apparatus with reflective elements having reduced influence of temperature variation |
DE102015213275A1 (de) * | 2015-07-15 | 2017-01-19 | Carl Zeiss Smt Gmbh | Spiegelanordnung für eine Lithographiebelichtungsanlage und Spiegelanordnung umfassendes optisches System |
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DE102020212743A1 (de) | 2022-04-14 |
JP2023544176A (ja) | 2023-10-20 |
US20230229091A1 (en) | 2023-07-20 |
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